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Bilateral distal fibula stress fractures in late pregnancy: A case report

by C. Wek1, I. Pilkington1*, J. Compson1, R. Ahluwalia1

The Foot and Ankle Online Journal 13 (2): 9

In this case report we describe an unusual case of bilateral distal fibula stress fractures during late pregnancy. The predisposing and precipitating factors for development of stress fractures were examined, and an evaluation of the impact of pregnancy related factors were completed. Our patient presented at 32 weeks of her pregnancy when the stress fractures developed and was evaluated both in the Emergency Department and orthopaedic outpatient clinic. She was diagnosed with bilateral distal fibula stress fractures which were managed conservatively due to their stable nature and monitored until union.

Keywords: stress fractures, fibula stress fractures, pregnancy, bilateral

ISSN 1941-6806
doi: 10.3827/faoj.2020.1302.0009

1 – Trauma and Orthopaedic Surgery Department, Kings College Hospital, London, UK
* – Corresponding author:

Stress fractures are caused by repetitive cyclical loading of bone. They are often caused by a sudden increase in exercise, smoking, glucocorticoid intake, alcohol abuse, or by metabolic and hormonal imbalances. Stress fractures during pregnancy are rare. Studies have reported that pregnant females with macrosomic infants, an increase in activity, or a vaginal delivery may run a higher risk of stress fractures

Case Report

A 42-year old lady who was 1-month postpartum was referred by her general practitioner to the orthopedic outpatient clinic with bilateral ankle pain. She reported that a month before delivery (at 32 weeks), she developed severe pain in her left ankle. This was then followed by the same pain experienced in her right ankle. The pain was over her lateral malleolus and she attended her local Emergency Department. She underwent clinical and radiological assessment but no cause for the pain was visualized on x-rays. She did not have any co-morbidities and there was no history of smoking or excessive alcohol intake.

On examination she had bilateral pes planus with valgus heels. She had a full range of movement and there was no neurovascular deficit. The repeat x-rays obtained in the clinic at 8 weeks demonstrated stress fractures of the distal fibula at the level of the syndesmosis of both ankles. There was no suggestion of osteoporosis or osteopenia.

The fractures were nondisplaced and the patient was managed conservatively with bilateral “aircast” boots. At week 4, the fractures had healed clinically and radiologically (Figure 1) and she was able to remove the boots. She was given medial arch supports for her pes planus deformity.

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Figure 1 Right and left ankle fractures.


Stress fractures were first described by Aristotle in 200 BC and initially recorded in the literature as a syndrome of painful swollen feet in Prussian soldiers by Breithaupt in 1855, as described by Bucholz, et al. [1]. These are fractures that occur in normal bone when it is subjected to abnormal or uncommon stresses which are in the form of repetitive loading. In repetitive loading, there is an imbalance between bone resorption and formation which engenders a resorption-dominated accelerated remodeling process that reduces the strength of bone. Stress fractures can occur in any bone in the body and a study of 320 athletes by Matheson, et al., found that the most common bones affected were the tibia (49.1%) and the fibula (6.6%) with bilateral stress fractures in 16.6% of cases [2].

During pregnancy numerous hormonal, anatomical and physiological changes occur. As a result, neuromechanical adaptations to gait, postural parameters and sensory feedback gradually occur throughout. Weight gained during pregnancy may impact the ability to maintain balance which leads to an increase in stresses at the ankle. A biomechanical study by Ogamba, et al., evaluated the changes in gait with an anteriorly added mass [3]. In this study, a kinematic analysis was performed on healthy female volunteers with a pseudopregnancy sac with a gradual increase in weight. This study found that the volunteers modified their gait biomechanics and this resulted in kinematic changes in the lower limb which increased joint stresses and may contribute to musculoskeletal pain.

Metabolic and hormonal imbalances may also confer an increased risk to fracture and the entity of pregnancy-associated osteoporosis has been described in the literature. A review article by Kovacs, et al., suggested that genetics were a contributing factor such that deficiency of calcitonin or its receptor and elevated levels of parathyroid hormone-related protein enhance osteoclastic activation resulting in a local reduction of bone mineral density.

Our patient had a bilateral pes planus deformity which may also have contributed to the development of a stress fracture. A biomechanical study by Takebe, et al., found that with the ankle in a neutral position the fibula receives between 6.4 – 17.2% of the load applied to the lower extremity [4]. Cheng, et al., reported a stress fracture of the distal fibula occurring in a patient with pes planus deformity and suggested that this may be due to increased loading of the fibula due to lateralization of the load axis during weight bearing [5]. These factors combined with the biomechanical changes seen in pregnancy may account for the development of a stress fracture.

In 1948, Burrows divided stress fractures of the distal fibula into two groups: the first involving young male athletes with fractures 5-6cm proximal to the tip of the lateral malleolus and the second involving middle-aged females with fractures occurring 3-4cm proximal to the tip of the distal fibula [6]. This study also suggested that radiographic findings were often not evident until 3 weeks post injury. Tavakkolizadeh, et al., described bilateral distal fibula stress fractures in a 38-year old lady and suggested that these injuries were more likely to occur in cancellous bone in the second group of patients as previously described by Burrows [7]. The majority of stress fractures may be treated conservatively with splinting in the form of an aircast boot which provides support during ambulation. In this case arch supports were also utilized for the underlying pes planus deformity.


Stress fractures in pregnancy are very rare and to date there have been no reports of bilateral distal fibula fractures occurring in late pregnancy. The hormonal and physiological changes that occur during pregnancy may result in increased joint contact stresses, transient osteoporosis and ligamentous laxity. These changes may predispose individuals to stress fractures.

There is always a hesitancy to expose pregnant patients to radiation, however localized joint pain should be investigated as this may be attributed to a stress fracture. These injuries are inherently stable as the bone is under compression so they may be managed conservatively without any adverse effects.


  1. Bucholz RW, et al. Rockwood and Green’s Fractures in Adults. LWW; Seventh edition (December 29, 2009). ISBN-10: 1605476773
  2. Matheson GO, Clement DB, Mckenzie DC, et al. (1987). Stress fractures in athletes: A study of 320 cases. The American Journal of Sports Medicine, 15(1), 46–58.
  3. Ogamba MI, et al. Changes in Gait with Anteriorly Added Mass: A Pregnancy Simulation Study. J Appl Biomech. 2016 Mar 8
  4. Takebe K, Nakagawa A, Minami H, et al. Role of fibula in weight bearing. Clin Orthop 1984;184:289.
  5. Cheng Y, et al. Stress fracture of the distal fibula in flatfoot patients: case report. Int J Clin Exp Med. 2015 Apr 15;8(4):6303-7
  6. Burrows JH. Fatigue fractures of the fibula. J Bone Joint Surg 1948; 30B:266–79.
  7. Tavakkolizadeh A, Klinke M, Davies MS. Bilateral distal fibular stress fractures. Foot and Ankle Surgery 11 (2005) 171–173.


Surgical technique tip: Using reaming systems for joint surface preparation for first metatarsophalangeal joint arthrodesis

by Stephen A. Mariash, DPM1*, Sarah L. Hatton, CST2

The Foot and Ankle Online Journal 13 (2): 8

Various techniques have been described for joint preparation when performing a first metatarsophalangeal joint arthrodesis. These include power saw resection of the cartilage and subchondral bone, curettage, rongeur, osteotome, and power joint reamers. The reaming systems have the advantage of maintaining the convexity of the first metatarsal head and the concavity of the base of the proximal phalanx of the hallux. Unfortunately, these systems have been the target of criticism in that they can be quite aggressive leading to overzealous bone resection causing excessive shortening and possible fractures, especially in the presence of osteopenic bone. We present a technique tip which will offer the surgeon more control of the power instrumentation and subsequently less risk of intraoperative complications.

Keywords: first metatarsophalangeal joint, joint preparation, reaming, arthrodesis, fusion

ISSN 1941-6806
doi: 10.3827/faoj.2020.1302.0008

1 – St. Cloud Orthopedics, Sartell, MN, USA
2 – St. Cloud Hospital, St. Cloud MN, USA

* – Corresponding author:

Arthrodesis of the first metatarsophalangeal (MTP) joint is a procedure that is utilized successfully for the treatment of various pathologies involving the hallux. These include arthrosis of the first MTP joint, severe hallux valgus deformities, hallux rigidus, hallux varus, neuromuscular disorders, and as a salvage procedure for failed first MTP joint procedures [1,2]. As with any arthrodesis procedure, the success relies on proper joint preparation and satisfactory fixation in adequate alignment. Maintaining the convexity of the head of the first metatarsal and concavity of the base of the proximal phalanx of the hallux yields several advantages. Shortening of the first ray is minimized compared to power saw resection of the cartilage and subchondral bone. In addition, surface area of the opposing osseous surfaces is maximized. Moreover, the convex and concave surfaces of the first metatarsal head and base of the proximal phalanx respectively allow the surgeon to “dial-in” the alignment of the proposed arthrodesis in all three body planes prior to final fixation.

Surgical Technique

The first metatarsophalangeal joint is accessed in the usual fashion. Any loose bodies may be removed and osteophytic lipping over the doral, medial and lateral aspects of the first metatarsal head and base of the proximal phalanx of the hallux is resected with a rongeur.


Figure 1 The guide pin is inserted into the shaft of the first metatarsal.


Figure 2 The StrykerSystem 7 Rotary Drill. The instrument may be set in either the “drill” or “ream” mode.

A guide pin is inserted into the first metatarsal head and shaft with care taken to drive the pin down the center of the medullary canal of the first metatarsal (Figure 1). This may be verified with anterior-posterior and lateral views utilizing intraoperative fluoroscopy. The appropriate size reamer for the head of the first metatarsal is selected. The sizes vary depending upon the manufacturer, but usually range from 16 mm to 22 mm in 2 mm increments. The reamer is placed onto a rotary drill/reamer. We used a Stryker System 7 single-trigger rotary drill (Figure 2). Any system that has a separate setting for drill and ream will suffice. The device is placed in the ream position and the cartilage and subchondral bone at the head of the first metatarsal is removed (Figures 3).

image6.jpg image3.jpg

Figure 3 A-B, Cartilage and subchondral bone removed from the head of the first metatarsal.

The surgeon has more control of the power instrument in the ream setting versus the drill setting. With the ream setting, there is a lower speed and higher torque compared to the drill setting (Table 1).





DRILL 1200 41
REAM 270 157

Table 1 Specifications for the Stryker System 7 Rotary Drill.


Figure 4 Guide pin driven into the base of the proximal phalanx of the hallux.

image2.jpg image5.jpg

Figure 5 A-B, Cartilage and subchondral bone removed from the base of the proximal phalanx of the hallux.

A guidepin is then placed into the base of the proximal phalanx of the hallux (Figure 4). The pin is driven down the shaft of the medullary canal and satisfactory placement may be confirmed with anterior-posterior and lateral views utilizing intraoperative fluoroscopy.


Figure 6 The hallux is placed in the desired alignment and temporary fixation is placed using Kirschner wires.

The appropriate size reamer for the base of the proximal phalanx of the hallux is selected. This matches the size used for the head of the first metatarsal. Once again, the reamer is inserted into the rotary drill/reamer. The cartilage and subchondral bone at the base of the proximal phalanx is resected (Figure 5). The reader is encouraged to view the video demonstrating the difference between the ream and drill settings on the rotary power instrument (Video). A rongeur may be used to remove any remnants of subchondral bone.


The position of the proposed arthrodesis is finalized by placing the head of the first metatarsal and the base of the proximal phalanx of the hallux in the desired alignment [3]. This is easily achieved due to the convexity of the first metatarsal head and concavity of the base of the proximal phalanx of the hallux. It is generally agreed that the toe should be arthrodesed in approximately 10 to 15 degrees of valgus and should not touch the second toe. In addition, the toe should be in about 10 to 15 degrees of dorsiflexion relative to the weightbearing surface of the foot in the sagittal plane. Temporary fixation with Kirschner wires is performed (Figure 6) and the alignment is checked with fluoroscopy. Final fixation is achieved depending on surgeon preference [4–8].


The main advantages of the presented technique tip are intraoperative time saving, minimal resection of cartilage and subchondral bone, decreased shortening of the first ray, and the maintenance of the convexity at the head of the first metatarsal and the concavity at the base of the proximal phalanx of the hallux which allows for greater bone to bone contact area and the ability for the surgeon to “dial-in” the desired position of the proposed arthrodesis [9]. Moreover, placing the power rotary instrument in the “ream” setting, allows the surgeon to have more control of the device given the decreased speed and increased torque compared to the “drill” setting. One must still be cautious when addressing bone with cystic changes and osteopenia.


  1. Sage RA, Lam AT, Taylor DT. Retrospective analysis of first metatarsal phalangeal arthrodesis. J Foot Ankle Surg. 1997;36: 425–9; discussion 467.
  2. Donegan RJ, Blume PA. Functional Results and Patient Satisfaction of First Metatarsophalangeal Joint Arthrodesis Using Dual Crossed Screw Fixation. J Foot Ankle Surg. 2017;56: 291–297.
  3. Roukis TS. A simple technique for positioning the first metatarsophalangeal joint during arthrodesis. J Foot Ankle Surg. 2006;45: 56–57.
  4. Coughlin MJ, Abdo RV. Arthrodesis of the first metatarsophalangeal joint with Vitallium plate fixation. Foot Ankle Int. 1994;15: 18–28.
  5. Coughlin MJ. Arthrodesis of the first metatarsophalangeal joint with mini-fragment plate fixation. Orthopedics. 1990;13: 1037–1044.
  6. Goucher NR, Coughlin MJ. Hallux metatarsophalangeal joint arthrodesis using dome-shaped reamers and dorsal plate fixation: a prospective study. Foot Ankle Int. 2006;27: 869–876.
  7. Rongstad KM, Miller GJ, Vander Griend RA, Cowin D. A Biomechanical Comparison of Four Fixation Methods of First Metatarsophalangeal Joint Arthrodesis. Foot & Ankle International. 1994. Aug;15(8):415-419
  8. Herr MJ, Kile TA. First Metatarsophalangeal Joint Arthrodesis with Conical Reaming and Crossed Dual Compression Screw Fixation. Techniques in Foot and Ankle Surgery 2005; 4(2): 85-94.
  9. Kundert H-P. [Cup & cone reamers for arthrodesis of the first metatarsophalangeal joint]. Oper Orthop Traumatol. 2010;22: 431–439.


A case of stenosing peroneal tendinopathy in a fibro osseous tunnel due to a hypertrophied peroneal tubercle in the setting of a ball and socket ankle joint

by Zach T. Laidley1*, DPM, Daniel A. Lowinger2,4, DPM, FACFAS, Douglas S. Hale3, DPM, FACFAS

The Foot and Ankle Online Journal 13 (2): 7

Peroneal tendinopathy is a common pathology encountered by the foot and ankle surgeon. A hypertrophied or enlarged peroneal tubercle can be implicated in the etiology of tendinopathy. We present a case of stenosing peroneal tendinopathy due to an enlarged peroneal tubercle with concomitant ball and socket joint. Ball and socket ankle joint is a rare pathology that can present among different pathologic entities. The foot and ankle surgeon should consider the role of the peroneal tubercle in peroneal tendon disease especially in cases of complex rearfoot and ankle deformities.

Keywords: peroneal tendinopathy, ball and socket ankle joint, rearfoot coalition, lateral ankle instability, congenital foot deformity

ISSN 1941-6806
doi: 10.3827/faoj.2020.1302.0007

1 – Resident, Swedish Foot & Ankle Residency Program, Swedish Medical Center, Seattle, WA
2 – Attending Physician, Swedish Foot & Ankle Residency Program, Swedish Medical Center, Seattle, WA
3 – Residency Director, Swedish Foot & Ankle Residency Program, Swedish Medical Center, Seattle, WA
4 – The Polyclinic, Seattle, WA

* – Corresponding author:

Stenosing peroneal tendinopathies are relatively rare and can be associated with an enlarged peroneal tubercle [1,2]. The reported presence of a peroneal tubercle is varied but is present in 90% of specimens and enlarged in 20% [3,4]. It is located at the lateral aspect of the calcaneus and serves as a fulcrum to guide the peroneus longus underneath the cuboid [5]. It sits between the peroneus brevis and longus with the brevis superior and the longus inferior. It serves as an insertion point for the inferior peroneal retinaculum and separation point of the peroneal sheaths. With hypertrophied peroneal tubercles, the inferior peroneal retinaculum can be thickened, trapping the peroneal tendons in a dense fibrous tissue layer [1,2].

The peroneal tendons can be stenosed at the retromalleolar sulcus, at the peroneal tubercle, or inferior to the cuboid notch [1,2,6,7]. The exact etiology of an enlarged peroneal tubercle is unknown but has been theorized as either congenital or acquired. The hypertrophied peroneal tubercle has been associated with tenosynovitis and rupture of the peroneus longus tendon [8]. The enlarged tubercle can alter the stresses on the peroneal tendons, or tendons can be entrapped between the enlarged tubercle and the fibula leading to stenosing pathologies [8].

Figure 1 AP ankle radiograph, ball and socket ankle joint with enlarged peroneal tubercle.

Figure 2 (A) Coronal T2 MR image showing enlarged peroneal tubercle with peroneal tendons traveling in osseous tunnel, with surrounding tenosynovitis. (B) Coronal T1 showing enlarged peroneal tubercle.

Ball and socket ankle joint is a rare condition that can initially present as lateral ankle or peroneal tendon pathology [9]. The ball and socket ankle joint has a loss of concavity of the talar articular surface and rounding (increased concavity) of the tibial and fibular surfaces. The etiology of the deformity is controversial, with the most contested origins being embryologic malformation and adaptive deformation due to abnormal subtalar and midtarsal structural abnormalities [5,10-12]. Using arthrographic studies, Takura, et al., showed that ball and socket ankle deformity did not occur until after 5 years of age , supporting the theory that ball and socket ankle joint is an acquired deformity [13]. Others have supported the findings of Takura, stating that the ball and socket ankle joint occurs as a result of abnormal subtalar joint structure and function [5,12]. Several different orthopedic pathologies are associated with the ball and socket ankle joint, including fibular shortening or aplasia, limb length discrepancy, tarsal coalitions, and ligamentous laxity [10,11,13-15]. The nature of the deformity lends itself to increased frontal plane instability. As a result, these patients can present with chronic ankle instability or persistent lateral ankle pain [14,16].

The association between hypertrophied peroneal tubercle and peroneal tendinopathy has been extensively reported in the literature [1-3,6-8,17,18]. There are also cases of peroneal tendinopathy in the setting of ball and socket ankle joint [9]. However, to our knowledge, this is the only case report of stenosing peroneal tendinopathy due to a hypertrophied peroneal tubercle in the setting of a ball and socket ankle joint.

Case Report

A 35-year old female with past medical history significant for ligamentous laxity and chronic lower back pain presented with a 3-month history of lateral ankle pain. Symptoms initially started following an increase in activity during a vacation. She denied any recent or past inciting event or trauma to her ankle. The physical exam was most notable for significant tenderness along the course of peroneal tendons at the posterior aspect of the lateral malleolus and extending to the hindfoot. There was pain with eversion against resistance.

Figure 3 Coronal T2 (A) and sagittal T1 (B) MR images showing subtalar joint coalition.

Initial radiographs showed an osseous talocalcaneal coalition with a ball and socket ankle joint (Figure 1). There was evidence of an enlarged peroneal tubercle of the calcaneus. An MRI was subsequently obtained to assess the peroneal tendons and lateral ankle ligaments. The MRI showed an enlarged peroneal tubercle (Figure 2) and a solid osseous subtalar joint middle facet coalition extending into portions of the posterior facet with an associated hindfoot valgus (Figure 3). Severe common peroneal tendon sheath tenosynovitis with a high-grade partial thickness tear of the peroneus brevis with subluxation into the fibular calcaneal interval was noted (Figure 2 & 3). Moderate peroneus longus tendinosis was noted. The syndesmotic, anterior talofibular and calcaneofibular ligaments were intact.

Conservative treatment was attempted with an ankle brace and NSAIDs, but the patient was unable to tolerate the brace long-term. Surgical excision of hypertrophic peroneal tubercle with repair of peroneal tendons was planned.

Description of Procedure

The patient was placed in a lateral decubitus position with appropriate padding. The right foot and leg were prepped and draped, and the pneumatic tourniquet was placed. A linear longitudinal incision was made at the posterolateral aspect of the ankle over the peroneal tendon sheath extending in a curvilinear fashion distal to the peroneal tubercle. The peroneal tendon sheath was incised, exposing the peroneus longus tendon and inflamed synovial tissue.

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Figure 4 Intraoperative image of peroneal tendons retracted out of the way to show enlarged peroneal tubercle.

The peroneus brevis tendon was visualized impinged between a large prominence of bone at the lateral wall of the calcaneus and the lateral malleolus (Figure 4).

The prominent bone was resected using an osteotome and mallet and smoothed using a rasp. Bone wax was applied to exposed cancellous bone. The peroneus brevis was somewhat thinner than normal diameter distal to the excised bone, but with normal appearing texture of the tendon. At the level of the peroneal tubercle, the peroneus brevis tendon was thickened, and there was a full-thickness split tear at the level of the peroneal tubercle and distal portion of the lateral malleolus, measuring approximately 3cm length. Fibrous and scar tissue within the tendon was excised, and the defect was repaired. The peroneal tendon sheath was then reapproximated, followed by closure of subcutaneous tissues and skin.

Postoperatively, the patient was non-weight bearing in orthopedic cast boot for two weeks and then allowed to transition to weight-bearing as tolerated. At the six-month follow up, the patient was doing well and reported overall satisfied with the surgery. She had successfully transitioned out of the ankle brace for ambulation and was currently undergoing a course of physical therapy. Eversion strength was intact with no crepitus with range of motion of peroneal tendons and no evidence of effusion.


Hypertrophied peroneal tubercle resulting in stenosing peroneal tendon pathology is a rare condition. This case is also unique given the osseous subtalar joint coalition and concomitant ball and socket ankle joint. The etiology of the hypertrophied peroneal tubercle is largely unknown, but is commonly associated with peroneal tendon pathology. In this case the etiology of the hypertrophied peroneal tubercle is likely secondary to congenital abnormalities. A literature review by Kocadal, et al., investigated 22 studies, including 186 ball and socket ankle joints, no study reported on the occurrence of concomitant hypertrophied peroneal tubercle [9]. To our knowledge this is the only case in the literature describing hypertrophied peroneal tubercle resulting in stenosing peroneal tendon pathology predisposed by subtalar joint coalition and an associated ball and socket ankle joint.


  1. Burman M. Stenosing tendovaginitis of the foot and ankle: studies with special reference to the stenosing tendovaginitis of the peroneal tendons of the peroneal tubercle. AMA Arch Surg. 1953; 67:686–698.
  2. Burman M. Subcutaneous tear of the tendon of the peroneus longus: its relation to the giant peroneal tubercle. AMA Arch Surg. 1956; 73:216–219.
  3. Hyer C, J Dawson J, Philbin T, Berlet G, Lee T. The peroneal tubercle: Description, Classification, and relevance to peroneus longus tendon pathology. Foot Ankle Int. 2005; 26:947–950.
  4. Palmanovich E, Laver L, Brin YS, Kotz E, Hetsroni I, Mann G, Nyska N. Peroneus longus tear and its relation to the peroneal tubercle: a review of the literature. Muscles Ligaments Tendons J. 2011; 1:153–160.
  5. Ruiz SF, Picazo MC, Canadillas BL, Garcia BE. 2002. Ball-and socket ankle joint with hypoplastic sustentaculum tali. Eur Radiol. 2002;12:S48– S50.
  6. Bruce, WD, Christoferson MR, Phillips DL. Stenosing tenosynovitis and impingement of the peroneal tendons associated with hypertrophy of the peroneal tubercle. Foot Ankle Int. 1999; 20(7):464–467.
  7. Pierson JL, Inglis AE. Stenosing tenosynovitis of the peroneus longus tendon associated with hypertrophy of the peroneal tubercle and an os peroneum. J Bone Joint Surg. 1992; 74A:440–442.
  8. Taneja AK, Simeone FJ, Chang CY, Kumar V, Daley S, Bredella MA, Torriani M. Peroneal tendon abnormalities in subjects with an enlarged peroneal tubercle. Skeletal Radiol. 2013;42:1703–1709.
  9. Kocadal O, Ozsoy A, Ozsoy H. Lateral Ligament Reconstruction for Ball-and-Socket Ankle Accompanying Lateral Ankle Instability: A Case Report and Literature Review. J Foot Ankle Surg. 2017; 56(6):1339-1342.
  10. Channon GM, Brotherton BJ. The ball and socket ankle joint. J Bone Joint Surg Br. 1979; 61:85–89.
  11. Takakura Y, Tamai S, Masuhara K. Genesis of the ball-and-socket ankle. J Bone Joint Surg Br. 1986; 68(5):834-7.
  12. Stevens PM, Aoki S, Olson P. Ball-and-socket ankle. J Pediatr Orthop. 2006; 26:427–431.
  13. Takakura Y, Tanaka Y, Kumai T, Sugimoto K. Development of the ball-and-socket ankle as assessed by radiography and arthrography: a long-term follow-up report. J Bone Joint Surg Br. 1999; 81:1001–1004.
  14. Ellington JK, Myerson MS. Surgical correction of the ball and socket ankle joint in the adult associated with a talonavicular tarsal coalition. Foot Ankle Int. 2013; 34:1381– 1388.
  15. Scranton PE, McDermott JE. Pathologic anatomic variations in subtalar anatomy. Foot Ankle Int. 1997; 18:471–476.
  16. Colin F, Wagner P, Bolliger L, Hintermann B. Tibia dome-shaped osteotomy for a valgus deformity in a ball-and-socket ankle joint: a case report. Clin Res Foot Ankle. 2013; 1:116.
  17. Ford T. Peroneal tenosynovitis secondary to peroneal tubercle osteochondroma and calcaneal varus. J Am Podiatr Med Assoc. 1995; 85:214–217.
  18. Lohrer H. Distal Peroneus Longus Dislocation and Pseudohypertrophy of the Peroneal Tubercle: A Systematic Review. J Foot Ankle Surg. 2019 ;58(5):969-973.


Benign schwannoma of the medial dorsal cutaneous nerve of the foot: A case report

by Mark Capuzzi DPM1, Zachery Weyandt DPM1, Dawn Masternick DPM2

The Foot and Ankle Online Journal 13 (2): 6

Schwannomas are benign soft tissue tumors of Schwann cells in the peripheral nerve system that can occur in the foot and ankle with preference for the posterior tibial nerve. A 60-year old female with a histologically diagnosed schwannoma of the medial dorsal cutaneous nerve is described in a location that is atypical according to the literature. These soft tissue masses can easily be misdiagnosed, and MRI studies can be inconclusive in determining possible malignancy. Clinicians should be suspicious and include malignant peripheral nerve tumors in their differential diagnosis with excisional biopsy as a way of definitive diagnosis.

Keywords: schwannoma, foot and ankle tumor, soft tissue mass, medial dorsal cutaneous nerve

ISSN 1941-6806
doi: 10.3827/faoj.2020.1302.0006

1 – University of Louisville Podiatric Medicine and Surgery Residency/Fellowship, Louisville, Kentucky
2 – Tipton and Unroe Foot and Ankle Care, Kentucky

* – Corresponding author:

Neurilemoma was originally described histologically by Verocay in 1908, with the term schwannoma being coined by Abadie and Argaud some 20 years later [1]. Schwannomas are a variety of peripheral nerve sheath connective tissue masses that arise in the periphery usually of benign nature. This group also includes neurofibromas and malignant peripheral nerve sheath tumors (PNSTs) that are classified based on their histological appearance. Schwannomas are solitary encapsulated tumors histologically described by homogenous arrangement of palisading cells (Verocay bodies) and exhibit hypercellular and hypocellular areas of devoid spindle cells; otherwise known as Antoni A and Antoni B [2]. These lesions can have major clinical impact on the neurocutaneous diseases neurofibromatosis 1 and neurofibromatosis 2 or can be seen as isolated occurrences without systemic involvement [3].

In a retrospective single-center study by Toepher, et al., 25.2% of all foot and ankle tumors were reported to be benign soft tissue tumors, of which, 16 different variants exist. The most common of which are hemangiomas, pigmented villo-nodular synovitis, superficial fibromatosis, and schwannomas, respectively [4]. Neurinoma/schwannoma account for about 1-10% of all soft tissue tumors in the foot and ankle. It is estimated that 1% of cases have malignant potential [4].

Schwannomas are most frequently seen in the trunk, head, neck, retroperitoneum, brachial plexus, and posterior tibial nerve [5]. Multiple case studies have been published in recent years describing these tumors in the foot and ankle, usually in connection with the posterior tibial nerve, but less commonly also seen in areas of the digits and the forefoot [6,7,8,9].

In this detailed case report, we describe a 60-year old woman with a schwannoma of the medial dorsal cutaneous nerve. The palpable mass arises in the dorsal midfoot associated with the tarsometatarsal joint, an area that has only been reported once in the literature and extending distally over the 2nd metatarsal base. The report includes a thorough clinical history, physical examination, diagnostics, as well as a histopathological description.

Case Report

A 60-year old Caucasian female presented to the attending surgeon’s private clinic with a chief complaint of a painful right midfoot mass that began one year previous. She felt the lesion had been increasing in size over time and worsening in severity of pain. She recalls the pain began only in shoe wear, as a rubbing irritation, but upon presenting to the clinic was painful also while walking barefoot. The patient’s history revealed trauma to the area of the mass two years ago when a large sign was dropped on her foot that she did not seek medical care for, leaving her foot bruised. She denied any other source of pain and other cutaneous masses as well as any history of puncture wounds or foreign bodies. Her medical history includes tubular adenoma, hemorrhoids, osteopenia, and a non-descript heart murmur. She denied taking any prescription medications, using only calcium supplements daily for her osteopenia.

Clinical examination revealed an apparently healthy female in no acute distress. A family history was non-contributory for soft tissue masses and a review of systems was unremarkable. Vascular examination revealed palpable pedal pulses and a brisk capillary refill time to all digits. Neurological examination revealed normal sensory sensations to digits and foot without deficit. No Tinel’s or Valleix’s signs were noted. Biomechanical examination revealed pes planus foot type with normal range of motion of all joints and without structural deformities. Dermatological examination revealed an oval, mobile, semi-compressible, tender to palpation, subcutaneous mass beginning over the 2nd tarsometatarsal joint extending over the base of the 2nd metatarsal. The bulk of the mass was distal to the 2nd tarsometatarsal joint. The mass was non-adherent to underlying structures without signs of infection, drainage, or irritation. There was no open wound in the area or bony exostosis. The mass measured 1.0cm x 1.0cm. The mass did not transilluminate nor have a palpable pulse.

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Figure 1 T1 Sagittal and T2 Axial MRI.

Differential diagnoses discussed included: fibroma, neuroma, neurofibroma, lipoma, foreign body, and benign/malignant peripheral nerve sheath tumors. The patient was educated and was presented treatment options for a ganglion cyst during her first appointment. She agreed to receive a corticosteroid injection in the area of the mass. She returned one month later without improvement and received a second injection, with aspiration attempted, revealing no fluid collection. At the 3rd visit, the patient again demonstrated no signs of improvement and worsening pain. An MRI was ordered at this time as there was a lowered clinical suspicion for a ganglion cyst (Figure 1).

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Figure 2 Schwannoma immediately visible in superficial fascia after incision.

The impression of the MRI report read a 6mm x 6mm x 4mm subcutaneous nodular lesion, superficial tear contacting the second extensor tendon anterior to the second TMT joint.

The radiologist suggested statistically the mass was a synovial/ganglion cyst but could not confirm or deny a benign or malignant soft tissue mass on a non-contrast MRI. The patient was educated on the results of her MRI and the inconclusive results. Upon discussion of an additional attempted aspiration versus further work-up including a MRI with contrast, a MRI with contrast was ordered. The second MRI reported a fairly uniform enhancement of the previously noted well-circumscribed subcutaneous nodular lesion along the dorsal aspect of the midfoot. The enhancement aspect of the image favored a non-cystic benign or malignant soft tissue mass in which surgical excision was recommended. Surgical excision was proposed and agreed upon by the patient.

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Figure 3 Schwannoma after surgical dissection with distal nerve continuation.

She was taken to the operative room and monitored anesthesia care was exercised in addition to a V-block of local anesthetic just proximal to the soft tissue mass. An approximately 3cm longitudinal incision was made directly over the mass. Careful and meticulous dissection immediately revealed a yellow, firm, and oval mass in the subcutaneous tissue that was encapsulated (Figure 2). The mass was freed from its surrounding structures with ease. Upon further blunt dissection, nerve-like structures were found to be projecting from the mass in a proximal and distal direction with abnormal thickening. The nerve-like projections mimicked the course of the medial dorsal cutaneous nerve as it extends to the 2nd interspace (Figure 3). A measurement of 5mm proximal and distal to the mass was marked and the nerve was transected and removed from the body in its entirety. The specimen was placed in formalin and prepared for histopathological examination (Figure 4).

Figure 4 Pathological specimen of schwannoma without distal and proximal nerve projections.

Upon visual inspection, no further remnants of the mass or abnormal nerve remained and the area was irrigated. Deep structures were approximated with vicryl sutures and skin was closed with prolene. The patient was placed in a soft dressing to the operative foot.

The pathology report grossly described a soft tissue mass of the right foot received in formalin, as yellow-white soft and feathery tissue in multiple fragments. The pathologist described a low power photomicrograph showed a well-circumscribed and encapsulated nodule with no infiltrating borders and no identifiable necrosis. High power photomicrograph showed bland spindle cell proliferation with eosinophilic cytoplasm, indistinct cell borders, and tapered nuclei (Figures 5 and 6). Mitotic figures were inconspicuous. Immunohistochemical stain for S100 was strongly and diffusely positive in the neoplastic cells. Schwannoma was favored by palisading nuclei and encapsulation.

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Figure 5 H&E Histopathological image.

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Figure 6 S-100 stain positive.

Post-operative protocol for the patient included full weight-bearing as tolerated in a surgical shoe to the operative side. She was evaluated two weeks out from surgery, demonstrating a well healed surgical site without wound dehiscence, infection, or pain. Sutures were removed at this time and the patient returned to normal shoe gear. She was encouraged to complete range of motion exercises at this time. The patient’s follow up at 4 weeks again demonstrating a healed surgical wound in the absence of pain. The patient was satisfied with her surgical results. A phone call was conducted 6 months post-operatively, and the patient denied any pain, wound complications, no neurologic symptoms, and noted she was extremely satisfied with the result.


The diagnosis of a Schwannoma, can pose a challenge for a clinician in the office setting. As reported, our patient was originally thought to present with a ganglion cyst which was treated with steroid injections and attempted aspiration. For any benign soft tissue mass, multiple differential diagnosis should be thought of prior to intervention, such as, but not limited to, ganglion cyst, fibroma, neuroma, neurofibroma, lipoma, and benign/malignant peripheral nerve sheath tumors. Good practice dictates that if the mass is not responding to conservative measures, biopsy with histopathological examination is the standard of care. Excisional biopsy is the accepted technique in cases of the foot and ankle with small lesions (< 2cm) located in the subcutaneous tissue as was the case in our report [10].

Schwannomas’ have been reported in the foot and ankle literature, however, rarely in the dorsal midfoot. To the author’s knowledge only one other case has been reported in the location of the tarsometatarsal joint [11]. An area not uncommon to find ganglion cysts corresponding to an underlying joint. Knight, et al., retrospectively review 234 benign solitary schwannomas and describe their peripheral nerve distribution. Of 64 schwannomas involving the lower limb and pelvis, they reported the most commonly involved nerves included the sciatic nerve (n = 15), tibial nerve (n = 21), and common peroneal nerve (n = 15) [12]. Kransdorf, et al., described one of the largest retrospective review studies regarding benign soft tissue lesions. They looked at over 18,000 benign soft tissue lesions, and further categorized them via distribution of specific diagnosis by age, sex and location. Regarding total body distribution, schwannoma prevalence in the foot and ankle was 0.09% (81/895). No definitive predilection for male vs. female has been noted in the literature. There is a wide age range, with the majority of patients being between the ages of 50-70 years old [13].

Topfer, et al., as part of a retrospective study looked at the data of patients that were treated for foot and ankle tumors between June 1997 and December 2015. The primary aim of the study was to describe the prevalence, demography, and anatomical distribution of the tumors. This study presented an analysis of the second largest population of patients, with current literature. Out of 7487 musculoskeletal tumors, 413 cases (5.52%) of tumors of the foot and ankle were included. There were 147 soft tissue tumors (36%), of those 104 (71%) were benign and 43 (29%) were malignant. Benign soft tissue tumors, including all variants, were most commonly located in the ankle and midfoot. Malignant soft tissue tumors were most commonly at the midfoot. Schwannomas specifically were most common in the hindfoot and least common in the midfoot. Of the 104 benign soft tissue tumors, only 11 were found to be Schwannomas with zero being found in the midfoot and only one in the forefoot [4]. Malignancy should be suspected early in treatment, with regard to the aforementioned literature at hand.

Hao, et al., conducted a literature review of schwannomas that included 46 reported masses. Of the 46 schwannomas, 14/46 were on the ankle, 14/46 plantar aspect of foot, 9/46 heel, 3/46 interdigital spaces, 1/46 dorsal foot over 4th and 5th metatarsal, 5/46 unreported anatomical location. Again, none were found associated with the tarsometatarsal joint or located in the midfoot [7].


To our knowledge this is the first reported case of a schwannoma associated with the dorsal 2nd tarsometatarsal joint, and one of two reported cases overlying the tarsometatarsal joint complex. They can be difficult to diagnose clinically and become more challenging when mimicking a common ganglion cyst location. A detailed medical history is to be performed on all patients, with a high index of suspicion in patients with a familial history or active history of Neurofibromatosis Type 1 or Type 2. Recurrence and failed attempts of injections and/or aspirations should warrant the podiatric physician to have a detailed discussion regarding surgical intervention. MRI can be an effective diagnostic and surgical planning tool; however, surgical excision and histopathological examination is considered to be the gold standard. Particularly in cases where MRI cannot definitively diagnose a mass and is inconclusive in regard to a mass’s malignancy.  Schwannomas may resemble other soft tissue tumors of the foot and diagnosis is generally made via histopathological findings status-post excision, as was the case in this report.

Funding Declaration: N/A

Conflict of Interest Declaration: No Conflicts of Interest to Report

Acknowledgements: University of Louisville Department of Pathology


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Treatment of lesser metatarsophalangeal joint plantar plate tear via Extracorporeal Pulse Activation Technology (EPAT) with MRI Follow-up: A case report

by Ziad G. Labbad MD DPM Cped1, Ebony Love DPM DABPM1*, Deep N. Shah DPM2, Yusuke Kihira DPM2, Vsevolod Grinberg DPM2

The Foot and Ankle Online Journal 13 (2): 5

Predislocation syndrome has recently gained attention as a common cause of lesser metatarsophalangeal joint (MTPJ) instability, contributing to tenderness, edema, and forefoot pain. The efficacy and utilization of non-operative treatments of plantar plate tears remains controversial; no current studies have conclusively indicated a successful restoration of a plantar plate tear by conservative treatment modalities. Within seven weeks, five total EPAT treatments were administered. Each weekly treatment consisted of 3000 pulses at 2.8 bars, performed directly at MTPJ 2-4 of the affected left forefoot. The patient was monitored on a weekly basis and progress measured utilizing the pain analog scale (0-10), subsequent MRI scans, and a complete return to normal, pre-injury activity. In the final follow-up examination, two months after the first EPAT treatment, the patient reported pain-free ambulation and a complete return to full normal activity. Subsequent MRI scans revealed no evidence of defects with notable improvements in structural integrity to the previously torn plantar plate. The results of this case report demonstrate the potential viability of shockwave therapy for the treatment of plantar plate tears. Further investigation may help to challenge the current standard of care and to provide a better, modern solution to an age-old debate between operative and nonoperative treatments of plantar plate tears

Keywords: plantar plate, metatarsophalangeal stability, lesser metatarsophalangeal joints, Extracorporeal Pulse Activation Treatment

ISSN 1941-6806
doi: 10.3827/faoj.2020.1302.0005

1 – Faculty, Temple University School of Podiatric Medicine
2 – PGY-4 Temple University School of Podiatric Medicine
* – Corresponding author:

Pain and agony at the lesser metatarsophalangeal joint (MTPJ) are a typical objection, and a few causes have been depicted including injury, instability, synovitis, and other incendiary conditions [1,2]. Chronic inflammation of the fibrocartilaginous anatomy can lead to a tear and eventual luxation of the lesser metatarsophalangeal joints. If not treated appropriately, the plantar plate injury could further predispose the patient to a multitude of forefoot pathologies. The significance of the plantar plate as a static limitation to lesser MTP joint stabilization and separation has been very much recorded, and injury of the plantar plate assume a critical job in the advancement of sagittal plane MTPJ instability [3]. In this way, predislocation disorder has as of late picked up consideration as a common cause for lesser MTPJ instability, adding to tenderness, edema, and forefoot torment.

Historically, surgical repairs of plantar plate tears have resulted in poor outcomes [4]. Generally, the operative treatment of lesser MTPJ instability incorporated an assortment of methods including synovectomy, capsular delicate tissue releases with reefing, flexor to extensor ligament exchange, phalangeal and metatarsal osteotomies, and even digital amputation. Distal metatarsal osteotomies yielded great outcome for decompression and realignment of the included joint, at the same time, none of these surgical techniques tended addressed the main cause of MTPJ instability which is plantar plate rupture [5,6,7]. As a result, the efficacy and utilization of non-operative treatments of plantar plate tears remains controversial; no current studies have conclusively indicated a successful restoration of a plantar plate tear from conservative treatment modalities.

In addition, despite numerous indications, benefits, and its well documented efficacy, previous research regarding the use of EPAT in the lower extremity has been predominantly limited to plantar fasciitis [8,9]. and Achilles tendinopathy. Little has been published regarding the use of shockwave therapy for the treatment of a partially torn plantar plate. As such, conclusive evidence recommending EPAT for the treatment of plantar plate injuries is lacking. This case study details the rehabilitation of a partially torn plantar plate at the metatarsophalangeal joints 2-4 via shockwave therapy (EPAT) confirmed via serial MRI.

Case History

A 47-year-old female started experiencing pain at the metatarsophalangeal joint (MTPJ) 2-4 of her left foot as a result of extensive ambulation on cobblestone streets. Upon a forefoot evaluation, she reported a score of an 8 on the 0-10 numeric pain rating scale (NPRS), and complained of significant localized pain. Her initial clinical presentation consisted of pain on palpation at the plantar proximal phalangeal bases 2-4, and moderate swelling at the dorsal forefoot. Additionally, a gait evaluation revealed guarding, and limping on the affected limb.


Figure 1 Partial thickness tear at the distal insertion of plantar plate at (a) second, (b) third and (c) fourth into proximal phalanx as indicated by hyperintensity (red arrow) on sagittal STIR images. Reactive joint effusions present.


Figure 2 Custom orthoses.

A subsequent MRI scan, evaluated by an external radiologist, revealed partial-thickness tears of the plantar plates of her lesser MTP joints 2-4, with reactive joint effusions at MTP joints 1-5 (Figure 1).


Figure 3 Alignment evaluation of patient weight bearing on orthoses.

Electing to avoid invasive surgical interventions, the patient was recommended EPAT as a primary treatment modality (with the addition of a custom molded orthosis (CMO) with metatarsal sling pad, as adjunctive treatments) (Figures 2, 3), which she agreed to.

Each treatment consisted of 3000 pulses at 2.8 bars. After the initial EPAT treatment, a significant reduction in pain was reported by the patient (5/10 on NPRS), and she was advised to avoid using NSAIDs and limit weight bearing on the affected area. After a second EPAT treatment, she was still unable to walk with standard footwear, however she reported a further decrease in her pain level to a 4/10 NPRS. After three EPAT treatments, three weeks after her initial treatment, she reported a 1/10 NPRS pain at rest, and 5/10 NPRS on ambulation. The clinical evaluation revealed that the joint was gaining stability, and on deep palpation, was less painful when compared to the initial examination. She was advised to transition to weight bear as tolerated (WBAT) while wearing the custom molded orthotics with metatarsal pads which were obtained at that time.


Figure 4 Lack of hyper intensity at insertion of plantar plate into proximal phalanx of (a) second, (b) third, and (c) fourth toe. Plantar plate insertion (blue arrow) shows homogeneous hypo intensity on sagittal STIR images.

At her seventh week follow-up appointment, and after five EPAT treatments, mild pain upon palpation was noted only at the second proximal phalanx with a NPRS score of 2/10, and no pain was elicited on deep palpation and passive range of motion (PROM) of 3rd and 4th MTP joint. Otherwise, she expressed a 0/10 NPRS at rest and upon ambulation. Upon clinical examination, the MTP joints 2-4 were stable on a dorsal drawer test, with no swelling present.

In the final follow-up examination, approximately two months after the first EPAT treatment, the patient disclosed that she was able to return to the same level of activity that she had before her injury. Additionally, when compared to her contralateral foot, the patient stated that she experienced neither pain nor edema. Furthermore, her second through fourth MTP joints were stable, and were not tender on palpation, nor on ambulation. A final MRI scan, obtained five and half months after the last EPAT treatment, revealed evidence of repair of her previously torn plantar plate, and improvement in the structural integrity of the plantar plate of her second through fourth MTP joint with no evidence of predislocation phenomenon (Figure 4).


The patient was closely monitored on a weekly basis and progress was measured by a notable decrease in reported pain on the pain analog scale (0-10). Within seven weeks, the patient reported pain-free ambulation without stiffness and complete return to full normal activity. The pre-treatment sagittal Short TI Inversion Recovery (STIR) MRI images demonstrated increased intensity at the distal insertion sites of plantar plates into proximal phalanges at MTP joints 2-4 (Figure 1). Partial-thickness tearing of plantar plates 2-4 with reactive joint effusions of MTPJs 1-5 was determined by an independent radiologist. The post-treatment MRI revealed homogeneous hypointense signal at the distal insertions of plantar plates 2-4 into proximal phalanges (Figure 4). Per an independent radiologist, no plantar plate defects or evidence of partial tears were noted on the post-EPAT MRI scan.


This case report demonstrates the potential viability of shockwave therapy for the treatment of plantar plate tears and furthermore, advocates the need for medical providers to reevaluate the standard of care for such pathologies. By directly correlating a reduction in pain to the associated physiological process of healing, improvements could be evaluated. Thus, the course of healing of the previously torn plantar plate was determined using pain as a critical indicator. Subsequent MRI scans and the complete return to normal activity were objective findings that confirmed the full revitalization of the plantar plates. In our case study, therapeutic EPAT treatments facilitated the full recovery and rehabilitation of a previous plantar plate tear in just seven weeks (five treatments). The capacity of EPAT therapy to promote healing is evidenced by the significant reduction in total treatment time. The absence of additional or otherwise invasive operative procedures seems to substantiate the sole use of shockwave therapy for the treatment of plantar plate tears.

Despite notable findings presented in this case study, further investigation is required to fully appreciate the role of EPAT in the non-operative management of plantar plate injuries. Several notable factors likely influenced our results and must be addressed for the sake of future studies. As stated earlier, throughout this study, the physiological process of healing was monitored and determined by 3 main parameters: patient reported pain, pre- and post-treatment MRI scans, and the complete return to normal activity. However, these parameters are not without intrinsic flaws. Notably, the reduction in pain was monitored on a weekly basis by a patient reported score on a 10-point analog scale. However, not only is pain subjective, but the correlation between a reduction in pain and the physiological process of healing is widely debated. A reduction in pain may suggest healing but is not always a definitive diagnostic measure, as additional comorbidities may mask underlying pathologies. As such, to say that the plantar plate is healing because of a reduction in pain is very plausible, but still an assumption nonetheless. Conversely, an MRI would provide much more objective or definitive findings in regard to monitoring the healing process of the plantar plate. However, the timing and chronology in which the MRI scans were obtained in this study was less than ideal. The initial MRI revealed partial-thickness tears of the plantar plates of lesser MTP joints 2-4. A subsequent and final MRI, however, was not obtained until five and half months after seven weeks of EPAT treatment, which confirmed full resolution of the previously torn plantar plate. As such, the rehabilitation of the plantar plates and the healing process was almost exclusively monitored by clinical examination and the gradual reduction in reported pain. Ideally, MRI scans could have been obtained in shorter increments of two to three weeks to definitively confirm clinical findings (stability and reduction in pain). However, due to cost, MRI’s were not obtained in such a manner.

The third parameter in which the rehabilitation of the plantar plates was determined, was the patient’s complete return to normal activity. Again, this functional outcome measure, although appropriate, is patient reported, and therefore subjective: we cannot say with certainty that the patient had regained her pre-injury strength and mobility.

Another notable factor that must be addressed is the natural biological course of healing. Although less likely, we cannot rule out a “placebo effect” in which the patient reported a gradual decrease in pain scores which was attributed to EPAT therapy. The partial-thickness tears of the plantar plate may have followed a biological healing process, exclusive of the effects of EPAT therapy. This theory, however, is less likely due to numerous studies detailing the difficulty of treating plantar plate tears and their notable lack of resolution [4,10,11,12].

Despite such possible intrinsic shortcomings, this case report demonstrates the potential viability of shockwave therapy for the treatment of plantar plate injuries. Further studies must be performed to provide conclusive evidence recommending EPAT. In addition, guidelines such as the number of treatments, the number of pulses per treatment, and/or the frequency of each pulse must be established. This unique case study was conducted by utilizing recent advancements in technology in hopes of challenging the current standard of care. Our findings were consistent with our goals to provide a better, modern, solution to an age-old debate between operative and nonoperative treatments of plantar plate tears.


The results of this case report demonstrate the viability of shockwave therapy for the treatment of plantar plate tears. Although further studies must be performed to provide conclusive evidence, our findings were consistent with our goals to provide a better, modern solution to an age-old debate between operative and nonoperative treatments of plantar plate tears. This unique case study was conducted by utilizing recent advancements in technology in hopes of challenging the current standard of care.


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Heel spoke wheel injuries in a community hospital in Togo

by Gamal AYOUBA PhD1*, Komla Séna AMOUZOU PhD2, Batarabadja BAKRIGA PhD3, Kouami AMAKOUTOU PhD4, Noufanague Kanfitine KOMBATE PhD5, Anani ABALO PhD2

The Foot and Ankle Online Journal 13 (2): 4

Motorcycles are one of the commonly used vehicles in our setting. Injuries caused by the wheels of the spokes to the heel engage the functional outcome of the foot and ankle. We aim to report the patterns of these injuries and the results of the treatment of such injuries in our community hospital. This prospective observational study included all cases with spoke wheel injury to the heel presenting between June 2014 to October 2018 in a community hospital in Kpalime, a city located northwest to the capital of Togo. Demographic and clinical data were collected from each patient including age, sex, occupation, injured side, and characteristics of the wounds. The wounds were grouped into those with Achilles tendon injury and those without Achilles tendon injury. The soft tissue injuries were classified according to Tscherne and Gotzen classification and managed accordingly. The AOFAS hindfoot score was used to assess the clinical outcome. Twenty-six patients were included, 13 females and 13 males. The mean age was 16 years (range 4-56 years). Seventeen patients were children (aged under 16 years). The right foot was affected in 21 patients and the left foot in 5 patients. The injury was classified as grade 2 (n=15) and grade 3 (n=11) of Tscherne and Gotzen. Wounds with Achilles tendon involvement accounted for 17 and without Achilles tendon accounted for 9. The mean time from injury to surgery was 18.4 hours (range 3-72 hours). Healing was achieved in 12 patients without complications. Complications included wound dehiscence (n=2), cutaneous necrosis and local infection (n=10), superficial infection (n=2). Secondary procedures performed were wound debridement (n=3) followed by skin graft (n=3), sural pedicled flap (n=2). The mean follow-up was 16.7 months (range 4-20 months). The average AOFAS score was 86.8 (range 64 – 100). The heel injuries are one of particularity of road traffic trauma in our setting. The outcome depends upon the involvement of Achilles tendon, an associated calcaneal fracture, and a high grade Tscherne and Gotzen classification.

Keywords: heel, spoke wheel, wounds, Achilles tendon, motorcycle, Africa

ISSN 1941-6806
doi: 10.3827/faoj.2020.1302.0004

1 – Department of orthopaedic and traumatology. Community Hospital of Kegue. University of Lomé. Togo
2 – Department of plastic and reconstructive surgery. University Hospital of Sylvanus Olympio. University of Lomé. Togo
3 – Department of orthopaedic and traumatology. University Hospital of Sylvanus Olympio. University of Lomé. Togo
4 – Department of orthopaedic surgery. University hospitals Cleveland Medical Center, Cleveland, Ohio, USA.
5 – Department of orthopaedic and traumatology. Hospital of Saint-Jean de Dieu d’Afagnan, Togo
* – Corresponding author:

Motorcycles are one of the most popular means of transportation in developing countries including sub-Sahara African countries such as Togo. Accidents associated with motorcycles are common among road traffic accidents in urban and rural areas in developing countries [1]. In Togo, during the first semester of 2019, motorcycles were involved in more than 51.36% of road traffic accidents [2]. The incidence of motorcycle spoke injuries to the heel has shown some specific features among road traffic accidents ranging from a simple laceration to a total traumatic foot amputation. [1,3-5]. Children make up a large proportion of the victims of these accidents [2]. The involvement of the Achilles tendon makes it a challenge for the orthopedic surgeons. In these cases, the exposure of the bony part of the Achilles tendon required a vascularized soft tissue resurfacing.

The main objective was to report data related to heel injuries and the secondary objectives of this study was to report patterns of the injury to the heel caused by spoke wheel, the management of these injuries, and the functional outcome.

Materials and Methods

This prospective study was carried out between June 2014 and October 2018 and included patients treated for motorcycle spoke injuries to the heel in the Department of Surgery at the community hospital of Kpalime, a city located 120km northwest from the capital of Togo in West Africa. The following demographic and clinical data of patients were recorded: gender, age, type of occupation, affected side, injury of Achilles tendon, associated injuries, number of surgical procedures and the course of treatment. We identified two groups of patients according to the clinical presentation of the wound: wounds with Achilles tendon involvement and wounds without Achilles tendon involvement. Soft tissue injuries were classified according to Tscherne and Gotzen [6] classification. Anteroposterior and lateral X-rays of the ankle were obtained in the Emergency Department. The functional outcomes were assessed using the AOFAS score (The American Orthopedic Foot and Ankle Score).


Clinical and socio-demographic characteristics

The study included 26 patients, 13 males and 13 females. The average age of the patients was 16 years (range, 4-56 years). Children (under 16 years old) accounted for 17, while adults (patients above 16 year-old) accounted for 9. All the adult patients were on the back seat and were wearing sandals at the time of the accident. As a mechanism of injury, the spokes of the wheel caught the heel of the patient just after the wheels had slipped over a bump of the road. The children were seated between their mother on the back seat and the rider of the motorcycle. Their feet were dangling and caught by wheel spoke. The wound was located on the vertical bony aspect of the heel or in some cases extended from the medial to lateral aspect of the heel. The wound was located on the posterior bony surface and extended 2 to 6 cm proximally in nine cases (Figure 1A), on the posteromedial aspect in 5 cases and on posterolateral (Figure 1B) aspect in 2 patients.

Figure 1 A: Posterior wound with complete section of Achilles tendon, B: Postero-lateral wound laceration, Achilles tendon partially sectioned, C: Semicircular laceration with Achilles tendon tearing and calcaneus fracture.

In the group with Achilles tendons involvement (17 patients): 7 had tendon tearing, 8 had complete section and 2 had partial section of the Achilles tendon. The wound of the heel was semi-circular in 10 patients (Figure 1C).

In 10 patients there were some associated injuries such as calcaneus fracture (5, 19%), tibia fibula third distal fracture (4, 15%), a particular calcaneus enucleation and one toes extensors tendons section. The demographic characteristics of the patients and the clinical presentations are reported in Table 1.

Treatment protocol

All patients received upon arrival in the emergency department, IV antibiotic (amoxicillin acid clavulanic 1g) and tetanus prophylaxis. The wounds were treated with abundant irrigation, drainage, and debridement. All sectioned Achilles tendons were sutured using the Kessler suture technique using non-absorbable suture. In a case of osseous disinsertion, the tendon was fixed to the calcaneal tubercle using a non-absorbable suture. The ankle was kept in a plantar flexion with circular POP for 3 weeks in all patients with Tscherne and Gotzen grade 3. In patients presenting with grade 2, an anterior POP slab maintained the ankle in a moderate plantar flexion for 10 days. In all cases, there was a window for the wound’s daily assessment during the first week (Figure 2) and until the wound is totally healed. In 4 patients tibial and or distal fibula fractures were associated with heel injury.

Figure 2 Window in the plaster contention for the wound assessment.

Figure 3 A: healing after skin graft, B: healing after sural pedicled flap.

The treatment of these fractures was a non-operative management using a long leg slab which was kept until wound healing. Then, the POP slab was replaced by circular contention. In a particular patient with calcaneus enucleation, after wound debridement a bone cement was used to fill the space. All patients received postoperatively the IV amoxicillin and clavulanic acid as antibiotic prophylaxis for 3 days. Rehabilitation began after removal of the splint in all patients. All adult patients were sent to physiotherapy for 2 consecutive weeks. Self-physiotherapy was established and encouraged in children.

Therapeutic Results

The average waiting time for surgery was 18.4 hours (range, 3-72 hours). The outcome after surgery at 3-weeks follow-up is summarized in Table 2. The healing of the wound was obtained in 12 patients (48%) without any complication.

Revision procedures were required in 14 patients. For a patient who had an enucleation of the calcaneus, the bone cement, which was put in during the index procedure, was removed after two weeks and then the wound was closed. The calcaneus space was filled with soft tissue. The Achilles tendon was fixed to soft tissues in a neutral position of the ankle. Table 3 summarizes the different revision procedures in the Tscherne and Gotzen grades.

The average duration of immobilization was 3.3 weeks (range, 3-6 weeks). The average healing time was 25 days (range to 20-49 days). The average length of stay in hospital was 10.3 days (range, 2-24 days). Postoperative complications included cutaneous necrosis in 13 patients, and superficial infection in 2 patients, Achilles tendon necrosis in one case. The long-term complications included an obvious disturbance in walking patterns in four cases, ankle instability in four cases, hindfoot varus of 6° in two cases. The flexion/extension range of motion of the ankle was between 15° and 30° in four cases. There were unsightly and retractile scars in eight cases. The mean follow-up (Figure 3) was 16.7 months (range, 4-20 months). The average AOFAS score was 86.8 (range, 64 – 100). The AOFAS score in patients who had Achilles tendon injury was 86.1 versus 88.2 for patients without Achilles tendon injury (p = 0.67).


The incidence of motorcycle spoke injuries to the heel has been increasing in developing countries especially in Africa and Asia [3,5,7]. In Nigeria an incidence of 4.26% has been reported among all road traffic trauma in a 10 years retrospective analysis published in 2017 by Agu TC [1]. These specific injuries occurring in the road traffic trauma affected mostly children [1,3,5,7] as confirmed in the current study. The overload of the motorcycle, inadequate footwear and sometimes bumpy roads are the main contributing factors to spoke injuries to the heel [2,4].

Our study, as well as past several studies, showed that motorcycle spoke injury is always unilateral, mostly confined to the right foot [3,4, 8]. This could be explained by the fact that the left foot is often protected by the motorcycle chain guard cover shield and therefore rarely injured.

Items N %
Sex Male 13 50
Female 13 50
Age Adult [>16 y] 9 35
Children [≤16 y] 17 65
Occupation Students 21 81
Farmers 4 15
Craftworker 1 4
Affected side Right 21 81
Left 5 19
Tscherne and Gotzen classification Grade 1 0
Grade 2 15 58
Grade 3 11 42
Achilles tendon involvement Without Achilles tendon involvement 9 35
With Achilles tendon involvement 17 65
Associated injuries None 15 58
Toes Extensors tendon section 1 4
Calcaneus fracture 5 19
Calcaneus enucleation 1 4
Tibia / fibula distal fracture 4 15

Table 1 Demographic and clinical data of the patients.

Grade Tscherne and Gotzen Healing Dehiscence of the wound Cutaneous necrosis Superficial infection Total
Grade 2 8 2 4 1 15
Grade 3 4 0 6 1 11
Total 12 2 10 2 26

Table 2 Three weeks postoperatively follow-up in the Tscherne and Gotzen grades.

Grade of Tscherne and Gotzen Healing by secondary intention Debridement + healing by secondary intention Skin graft Sural reverse pedicled flap Total
Grade 2 3 2 1 1 7
Grade 3 3 1 2 1 6
Total 6 3 3 2 14

Table 3 Second procedures according to the stage of Tscherne and Gotzen.

The shoe wearing could reduce the severity of the injuries, but the study of Naumeri et al. did not confirm this precaution [3]. The injuries are less severe (grade 0 and 1) in case of involvement of bicycle thus to low velocity of them [9]. But in our study the injuries were severe (grade 2 and 3) with extensive wound, degloving of the heel pad, and multiple associated injuries (tibia /fibula fractures, extensor tendon injuries, and a rare case of calcaneus extirpation). The injury can extend to all aspects of the heel in a semi-circular shape. In case of rupture of the Achilles tendon, the location could vary between 1 and 8 cm according to the different authors [4,10,11]. The severity of the soft tissue damages associating multiples injuries have been described by several authors [2,5,11]. This is a high velocity trauma due to wheel spokes, especially when riding at high speed. No main vascular pedicle was injured in our study. This complication has not been reported in the literature. There is no unanimous classification to describe motorcycle spoke injuries of the heel. Most authors used the classification of Tscherne and Gotzen. In our study, the treatment as well as the prognosis were evaluated using this classification. However, this classification gives little details about the fracture of the calcaneus, the rupture of the Achilles tendon and the other associated injuries.

The Grade 2 injuries required debridement and suturing of the wound without tension. The monitoring of the wound is important especially over 48 hours postoperative because secondary necrosis and sepsis are common at this step [3]. In some cases, in this study, patients initially classified grade 2 were managed secondarily for a reverse sural flap due to cutaneous necrosis. All grade 3 injuries in our study had Achilles tendon injury which was a partial or a complete rupture. The repair technique was similar to the common technique used in the literature [2,9]. Two sural pedicled flaps were performed because of secondary skin necrosis. This is the most common flap for the management of skin loss of the heel [3], [12,13]. Postoperative complications are common in motorcycle spoke injuries of the heel because of the extent of the injury and the population that is mostly affected [4,7,11].

The healing time and the duration of the hospital have not been reported to the grade of Tscherne and Gotzen. These parameters had been influenced by the complications in many patients requiring a secondary procedure. Also, Agu TC [1] found that the average duration of hospital stay was more than 3 weeks, and this depended on the degree of the injury. The major injuries including heel pad avulsions and ankle fractures stayed beyond 3 weeks in the hospital [1]. Naumeri and al [3] found that healing time was markedly increased in grade III injuries. Nevertheless, the global outcome was excellent in all patients on the AOFAS grading. However, there has been a better outcome (p=0.67) in the group of patients without Achilles tendon involvement compared to the group with Achilles tendon injuries. Only two patients that were poor had calcaneus enucleation (AOFAS=64) and Achilles tendon necrosis (AOFAS=65). In the patient with Achilles tendon necrosis, the infection and delayed treatment have hindered the reconstruction of the necrosed Achilles tendon leading to the poor result. In the second patient the loss of calcaneus had led to lack of heeling support with disturbance in walking pattern and loss of hind foot alignment which was 11° of valgus.

This excellent outcome due to the early presentation of the patients, the appropriate and timely care given, and the young ages of patients involved.


The heel injuries caused by motorcycle spoke wheels are a one of particularity of road traffic trauma in our setting. The difficulty to manage such patients starts with the difficulty to clinically assess the wound as no classification exists for such injuries, and to obtain reliable skin coverage. The high rate of complications works against patients that are part of the population that needed to stand for its daily food. The outcome depends upon the involvement of Achilles tendon, and a high grade of Tscherne and Gotzen and associated injuries such as calcaneus fracture. We had a satisfactory final outcome in mostly all of our patients. A dedicated team of orthopedic and plastic surgery could contribute to minimize the complications and expedite care, thus resulting in a faster return to work.

Funding declaration.

No funding to declare

Conflict of interest.

Authors declare that they have no competing interest in relation with this manuscript


  1. Agu TC. Motorcycle spokes entrapment foot injuries: Prevalence, and pattern of presentation in a private orthopedic and trauma center, Southeast Nigeria – A 10-year retrospective analysis. Afr J Trauma 2017; 6:6-10.
  2. Annual road traffic report. Ministry of road traffic security in Togo.
  3. Naumeri F, Qayyum B, Cheema NI, Sohail M, Bashir MM. Motorcycle spoke wheel injuries in children: A preventable accident. Ulus Trauma Acil Cerrahi Derg 2019; 25:474-478.
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  6. Oestern HJ, Tscherne H. Pathophysiology and classification of soft tissue injuries associated with fractures. In: Tscherne H, editor. Fractures with soft tissues injuries. New York: Springer-Verlag; 1984:1–9.
  7. Zhu YL, Li J, Ma WQ, Mei LB, Xu YQ. Motorcycle spoke injuries of the heel. Injury 2011;42: 356–61
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  13. Farooq U, Ishtiaq R, Mehr S, Ayub S, Chaudhry UH, Ashraf A. Effectiveness of Reverse Sural Artery Flap in the Management of Wheel Spoke Injuries of the Heel. Cureus: 2017;9[6]: 1-6. e1331.


Repair of Achilles tendon tear by unique hybrid technique

by RCS Khandelwal1, Jagdish Dhake2, Abhinav Jogani3*, Kishore Kumar4

The Foot and Ankle Online Journal 13 (2): 3

Achilles tendon rupture is a debilitating injury with a protracted and sometimes incomplete recovery. The surgical method of Achilles tendon repair, like open repair with or without augmentation, has a higher complication rate like delayed tendon healing (since paratenon integrity is destroyed in open repair technique which delays or hampers the tendon healing). Wound healing problems like suture granuloma, deep infection, skin edge necrosis, superficial dehiscence, pressure ulcer, and blisters may occur. Here we developed a newer hybrid technique (open exposures of the tendon and percutaneous tenodesis through calcaneum) for Achilles tendon repair to minimize the complications and enhance the tendon healing. Excellent results were observed with this hybrid technique.

Keywords: Achilles tendon tear, Achilles rupture, watershed, tendon augmentation

ISSN 1941-6806
doi: 10.3827/faoj.2020.1302.0003

1 – Professor & Head of Unit, Department of Orthopaedics, Seth GS Medical College and KEM Hospital, Mumbai, India
2 – Senior Registrar, Department of Orthopaedics, Seth GS Medical College and KEM Hospital
3 – Assistant Professor, Department of Orthopaedics, Seth GS Medical College and KEM Hospital
4 – Senior Registrar, Department of Orthopedics, Seth GS Medical College and KEM Hospital

* – Corresponding author:

The Achilles tendon is the most frequently ruptured tendon in the human body [1]. The mean age of presentation is 35 years with a male:female ratio of 20:1 [2,3].

The commonest site of rupture is in a region 3 to 6 cm above the calcaneus which corresponds to a watershed region of poor vascularisation[4]. Perfusion in this region is further compromised during stretching and contraction [5,6]. With increasing age there is decreased collagen-cross linking and weakening of the tensile strength of the tendon. Maffulli, et al., [7] and Järvinen, et al., [8] histologically observed significant collagen degeneration in patients with Achilles tendon rupture. Ruptured Achilles tendons have histologically demonstrated collagen degeneration with a greater content of collagen III and less collagen I [8].

Both oral and intratendinous injection of steroids have been implicated in spontaneous tendon rupture [9]. Other risk factors for rupture of the Achilles tendon include steroid therapy, hypercholesterolemia, gout, rheumatoid arthritis, long-term dialysis, and renal transplantation [10-14].

Surgical treatment, like the open repair technique, is associated with an increased incidence of postoperative complications, such as skin-tendon adhesions, infection, delayed healing of the surgical wound, sural nerve lesion, and suture granulomas [15].

Percutaneous repair, first described by Ma and Griffith [16], seems to bridge the gap by combining the advantages of both methods [17,18]. It is associated with a lower complication rate compared to open operative repair [15] but it may be associated with a higher risk of re-rupture and sural nerve injury [19]. However, several researchers have reported the absence of re-ruptures and nerve lesions [20].

Material and methods

A consecutive series of Achilles tendon rupture in 12 patients, occurring between 2 to 4 cm proximal to the calcaneus tuberosity, were treated by a hybrid technique (open exposures of the tendon and percutaneous tenodesis through the calcaneus). In all cases, the diagnosis was based mainly on history and clinical examination (functional impairments, palpation of the gap, and the Thompson test) and confirmed by ultrasound examination and MRI.  All patients were evaluated on follow-up.


The patient typically presents with pain, inability to bear weight and a history of a clear popping sensation or sound after an episode of activity during which they sustain a forced dorsiflexion of the ankle. The injury can also be sustained during eccentric contraction. The patient frequently describes the sensation of being kicked, shot or even bitten on the back of the heel. Acute Achilles tendon rupture can readily be detected on physical examination. Plantar flexion of the foot is understandably weak [16]. The Achilles tendon is best examined with the patient kneeling and the feet hanging over the edge of the chair. In this position, soft tissues hang off the Achilles tendon like a tent ridge pole and defects can be readily visualized (Figure 1). There is frequently a visible defect in the Achilles tendon. This is accompanied by swelling due to peritendinous hematoma.

Operative technique

The patient was placed in a prone position under general, spinal or peripheral nerve block anesthesia with the knees slightly flexed and a pneumatic tourniquet placed around the proximal part of the thigh. Before starting the procedure, the rupture and the diastasis (gap) were localized. The procedure is illustrated and described in detail in Figures 2-18.

C:\Users\DELL\Pictures\Screenshots\Screenshot (60).png

Figure 1 (patient in prone position) The left TA is ruptured. The right Achilles tendon is well defined and soft tissues hang off it like a tent. The suspension of the soft tissues off the Achilles tendon is not visible on the left side as the tendon is ruptured.

C:\Users\DELL\Pictures\Screenshots\Screenshot (79).png

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Figure 2 Schematic diagram showing Kessler suture used in our Hybrid Technique.

E:\ \ta repair dr khandelwal sir\DSC_3367.JPG

Figure 3 Preoperative MRI showing Achilles tendon tear.

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Figure 4 Patient placed in prone position on table.


Figure 5 Tunnel made by insertion of K-wire through the calcaneum for passage of ethibond suture.

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Figure 6 Preoperative incision markings along Achilles tendon with level of Achilles tendon rupture.

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Figure 7 Skin incision over Achilles tendon in midline.

E:\ \ta repair dr khandelwal sir\DSC_3383.JPG

Figure 8 Ethibond suture passed through proximal tendon stump.


Figure 9 Ethibond passed vertically along the length of tendon from proximal to distal stump.


Figure 10 The Ethibond is then passed in a subcutaneous plane, taken out through the exit point of the tunnel.


Figure 11 The Ethibond is passed through a tunnel made by K-wire in calcaneus.


Figure 12 The Ethibond is passed in a subcutaneous plane, back into the incision site.


Figure 13 Ethibond passed along the length of the tendon from distal to proximal stump.


Figure 14 Final tightening of both ends of the Ethibond with foot in plantar flexion before making a knot.

C:\Users\DELL\Pictures\Screenshots\knot 2.png

Figure 15 Arrow pointed over a knot made and buried subcutaneously with vicryl.

C:\Users\DELL\Pictures\Screenshots\Screenshot (74).png

Figure 16 Staple wound closure.


Figure 17 Postoperative follow-up after staple removal.


Figure 18 Postoperative MRI after two weeks.


The choice of suture material has important implications in tendon repair. Here we demonstrated excellent tendon healing results. Adverse surgical outcomes can be avoided by selection of the suitable suture materials for appropriate indication. Risks of Achilles tendon repair with open technique with or without augmentation include:

  • Excess bleeding
  • Nerve damage
  • Deep Infection
  • Blood clot
  • Wound healing problems like suture granuloma, skin edge necrosis, superficial dehiscence, pressure ulcer, blister.
  • Calf weakness


Hybrid technique (open exposures of the tendon and percutaneous tenodesis through calcaneus) of Achilles tendon repair with single ethibond suture has obtained better results in terms of tendon width , muscle mass and strength recovery of plantar flexion and patient satisfaction. As single Ethibond suture is used for tendon repair it decreases chances of postoperative infection. significantly good results were found in terms of clinical outcomes. Better outcomes found with Achilles Tendon Rupture Score.


  1. Maffulli N, Waterston SW, Squair J, Reaper J, Douglas AS. Changing incidence of Achilles tendon rupture in Scotland: a 15-year study. Clin J Sport Med. 1999;9:157–160.
  2. Möller A, Astron M, Westlin N. Increasing incidence of Achilles tendon rupture.  Acta Orthop Scand.  1996;67:479–481.
  3. Leppilahti J, Puranen J, Orava S. Incidence of Achilles tendon rupture. Acta Orthop Scand. 1996;67:277–279.
  4. Beddy P, Dunne R, de Blacam C. Achilles wiiitis. AJR Am J Roentgenol. 2009;192:W79.
  5. Carr AJ, Norris SH. The blood supply of the calcaneal tendon. J Bone Joint Surg Br. 1989;71:100–101.
  6. Komi PV, Fukashiro S, Järvinen M. Biomechanical loading of Achilles tendon during normal locomotion. Clin Sports Med. 1992;11:521–531.
  7. Maffulli N, Ewen SW, Waterston SW, Reaper J, Barrass V. Tenocytes from ruptured and tendinopathic achilles tendons produce greater quantities of type III collagen than tenocytes from normal achilles tendons. An in vitro model of human tendon healing. Am J Sports Med. 2000;28:499–505.
  8. Järvinen M, Józsa L, Kannus P, Järvinen TL, Kvist M, Leadbetter W. Histopathological findings in chronic tendon disorders. Scand J Med Sci Sports. 1997;7:86–95.
  9. Newnham DM, Douglas JG, Legge JS, Friend JA. Achilles tendon rupture: an underrated complication of corticosteroid treatment. Thorax. 1991;46:853–854.
  10. Lee WT, Collins JF. Ciprofloxacin associated bilateral achilles tendon rupture. Aust N Z J Med. 1992;22:500.
  11. Poon CC, Sundaram NA. Spontaneous bilateral Achilles tendon rupture associated with ciprofloxacin. Med J Aust. 1997;166:665.
  12. McGarvey WC, Singh D, Trevino SG. Partial Achilles tendon ruptures associated with fluoroquinolone antibiotics: a case report and literature review. Foot Ankle Int. 1996;17:496–498.
  13. Donck JB, Segaert MF, Vanrenterghem YF. Fluoroquinolones and Achilles tendinopathy in renal transplant recipients. Transplantation. 1994;58:736–737.
  14. West MB, Gow P. Ciprofloxacin, bilateral Achilles tendonitis and unilateral tendon rupture–a case report. N Z Med J. 1998;111:18–19.
  15. Chiodo CP, Wilson MG. Current concepts review: acute ruptures of the achilles tendon. Foot ankle Int [Internet] 2016 Sep 27;27(4):305–313.
  16.  Ma GW, Griffith TG. Percutaneous repair of acute closed ruptured achilles tendon: a new technique. Clin Orthop Relat Res [Internet] 2016. Sep 27, pp. 247–255.
  17. Maffulli N, Longo UG, Oliva F, Ronga M, Denaro V. Minimally Invasive Surgery of the Achilles Tendon. Orthop Clin North Am [Internet] 2017 Jul 15;40(4):491–498. 2009.
  18. McClelland D, Maffulli N. Percutaneous repair of ruptured Achilles tendon. J R Coll Surg Edinb [Internet] 2017 Jul 15;47(4):613–618.
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Bosworth fracture with proximal fibula entrapped within posterior pilon variant: A case report

by Sara Stachura, DPM1*; Edward J. Chesnutis III, DPM, AACFAS2; Melinda A. Bowlby, DPM, AACFAS3

The Foot and Ankle Online Journal 13 (2): 2

A Bosworth fracture is a rare injury that can result in an irreducible dislocation of the ankle joint. This case study presents a rare form of a Bosworth fracture in which the proximal portion of the fibula was entrapped within the posterior tubercle fracture of a pilon variant. It is important for physicians to be aware of rare variants of ankle fractures in order to diagnose and treat appropriately.

Keywords: Bosworth fracture, posterior malleolar fracture, irreducible trimalleolar fracture

ISSN 1941-6806
doi: 10.3827/faoj.2020.1302.0002

1 – 3rd Year Resident, Swedish Medical Center, Seattle, WA.
2 – Attending Surgeon, Swedish Medical Center, Seattle, WA; Private Practice, The Polyclinic, Seattle, WA
3 – Attending Surgeon, Swedish Medical Center, Seattle, W; Private Practice, The Ankle and Foot Clinic of Everett, Everett, WA
* – Corresponding author:

The Bosworth fracture is described as an irreducible ankle fracture-dislocation in which the proximal portion of the fibula is dislocated posterior to the posterior tubercle of the tibia. Though it has been described in the literature previously, it has become known as a Bosworth fracture due to a paper published in 1947 by Dr. David Bosworth, in which he described 5 patients in a case series. There have been over 60 cases reported since the original article [1].

It is reported in the literature that urgent surgery is required due to the irreducible nature of the Bosworth fracture by closed reduction. This is due to compromise of the soft tissue envelope seen with skin tenting from bone protrusion, neurovascular compromise, and compressive damage to talar and tibial cartilage [2]. The irreducibility has been attributed to an intact interosseous membrane holding the fibula posterior to the posterior tubercle [3].

Repeated attempts at closed reduction has been implicated in poor outcomes as well, causing increased damage to the soft tissue and articular cartilage [4].

There are multiple reasons that a fracture may resist closed reduction, the most common being interposition of soft tissue including the neurovascular bundle as well as the flexor tendons [2]. Fracture fragments may also become interposed in the joint, inhibiting motion [2]. Several variants have been described in the literature, including Bosworth fractures with an intact fibula, medial malleolar fractures, posterior tibial tubercle fractures, and deltoid ligament ruptures [3].

This case report presents a rare case of an irreducible trimalleolar ankle fracture with a Bosworth fracture, in which the proximal portion of the fibula was entrapped within the posterior malleolar fracture.

Figure 1 Pre-reduction radiographs.

Figure 2 Post-reduction radiographs.

Case Report

A 37-year old female with past medical history significant for obesity presented to the emergency department with right leg pain extending from the knee to the ankle. She had fallen off of an electric bike when she swerved to avoid a car one hour prior to presentation. The patient reported 10/10 pain and inability to bear weight. On physical exam, her right lower extremity was neurovascularly intact. There was ecchymosis noted to the ankle and mild edema consistent with a closed fracture dislocation. The foot appeared to be externally rotated. Even under conscious sedation, it was noted to be a difficult ankle reduction. Post reduction radiographs demonstrated improved alignment with the talus relocated beneath the tibia (Figure 2). A Computed Tomography (CT) Scan was ordered and surgery was scheduled. CT imaging revealed that the proximal portion of the fibula was dislocated behind the posterior lip of the tibia within the posterior tubercle fracture, inhibiting full reduction.

Figure 3 Preoperative CT demonstrating fibular entrapment within the posterior tubercle fracture.

The posterior tubercle fracture was noted to extend through the medial malleolus, with multiple comminuted fragments (Figure 3). There was another fracture noted at the tip of the medial malleolus. The injury appeared to be a supination external rotation type fracture, with blunt trauma from the talus and fibula resulting in a posterior pilon variant fracture.

Surgery was performed in a supine position. A lateral incision was made over the distal fibula. A large bone hook was used to wrap around the mid-portion of the fibula, and the fibula was successfully reduced into the incisura. Due to the degree of comminution, no interfragmentary screw was placed. A locking plate was utilized after fibular length was successfully restored. The posterior malleolus had been successfully reduced at this point. An anterior-to- posterior cannulated screw was advanced across the distal tibia, perpendicular to the fracture line. Next, a medial incision was made. The distal medial malleolar fracture fragment was noted to be comminuted and angled distal medial to proximal lateral, precluding the use of a hook plate. Cerclage wire was used in order to fixate this fracture fragment. A Hook test revealed significant gapping at the syndesmosis. A pelvic reduction clamp was used to reduce the syndesmosis and a fully threaded trans-syndesmotic screw was placed from the fibula into the tibia.

Figure 4 Postoperative radiograph one week status post open reduction with internal fixation. Cerclage wire noted to be broken.

The incisions were closed and the patient was placed in a posterior splint. She was discharged home with instructions to remain non-weight bearing to her right lower extremity.

The patient was examined regularly post-operatively (Figure 4). In accordance with pre-operative planning, the patient was taken back to the operating room approximately 8 weeks later and the syndesmotic screw was removed and replaced with a non-absorbable suture button device. By 12 weeks postoperatively the patient was walking in a CAM walker with minimal pain and undergoing physical therapy.


Bosworth fractures are uncommon amongst ankle fractures, with one study reporting 51 out of 3,140 patients, or 1.62% [5]. This is the only prevalence study that has been performed due to the rarity of this fracture pattern.

Figure 5 Postoperative radiographs one week status post syndesmotic screw replacement with tightrope.

There are many variants, associated injuries, and complications reported with the Bosworth fracture, including dislocation with an intact fibula, rupture of the deltoid ligament, medial malleolar fracture, posterior tibial tubercle fracture, increased risk of compartment syndrome, avascular necrosis of the talus, osteoarthritis of the ankle, neurovascular injury, joint stiffness, osteochondral lesions, skin necrosis, and wound infection [3-5].

Radiographic signs of a Bosworth fracture include widening of the medial joint space, posterior displacement of the fibula on lateral radiographs, and overlap of the proximal fibular fracture fragment with the distal tibia on the anteroposterior view [4]. Unfortunately, these signs can all be interpreted as poor radiographic technique in terms of positioning [1]. It has been proposed that external oblique radiographs may be a useful tool to diagnose this injury by measuring the displacement of the fibular shaft [6]. The “axilla sign” has also been described, resulting from the internal rotation of the tibia when the fibula is posterior dislocated. It appears on the mortise view at the medial tibial plafond as a cortical radiodensity [7].

There has been conflicting data in the literature in regards to timing of surgery and outcome. One study of 15 patients with Bosworth fractures found that patients who underwent surgical open reduction and internal fixation within 24 hours had better functional outcomes. In addition, this study showed that intermediate-term clinical outcomes were comparable between Bosworth fractures and other ankle fracture dislocation types [4].

Aggressive attempts at closed reduction are not advised due to the possibility of increasing trauma to the fibula, cartilage, and surrounding soft tissues [5]. One study found poorer clinical outcomes associated with multiple attempts at closed reduction [4]. Due to the difficulty of diagnosis on radiographs, general belief that early surgical intervention leads to better outcomes, and poorer outcomes in regard to multiple closed reduction attempts, it is important for physicians to have a high index of suspicion for fracture dislocations resisting reduction and low threshold for CT imaging.

In terms of surgical approach, a lateral incision was made over the fibula in order to reduce the fracture. Although adequate, a posterolateral approach may have allowed more exposure of the deformity for evaluation and correction.

One cadaveric study reported a mechanism for the Bosworth fracture, noting that the mechanism is external rotation on a supinating foot. Stage one and two involve the fibula being posteriorly dislocated out of the fibular notch with rupture of the anterior and posterior tibiofibular ligaments, respectively. In stage three, the anterior medial ankle joint capsule ruptures. Stage four involved tearing of the interosseous membrane, followed by entrapment of the fibula posterior to the tibia in stage five. Finally, further rotation of the talus results in an oblique fracture of the fibula in stage six, and deltoid rupture or medial malleolus fracture in stage seven [8].

There is one other reported case of a Bosworth fracture with the proximal fibular fracture fragment dislocated within the posterior tubercle portion of a pilon fracture [9]. This has been predicted to be a rare form of injury due to the nature of pilon fractures. There is often comminution of the posterior tubercle which can include fracture of the posterior lip of the fibular groove, precluding the possibility of the proximal fibula becoming trapped behind the posterior lip and between large fracture fragments [1].


This case study presented a rare form of Bosworth fracture in which the proximal portion of the fibula was entrapped within the posterior tubercle of a trimalleolar ankle fracture dislocation. It is important for physicians to be aware of rare variants and have a high index of suspicion in ankle fractures that are difficult to reduce in order to diagnose and treat appropriately. Further imaging should be performed to evaluate the deformity, as this form of ankle fracture is easily identified with a CT scan. In these cases, surgery should be strongly considered due to the poor prognosis with conservative treatment.

Funding declaration: None

Conflict of interest declaration: None


  1. Peterson ND, Shah F, Narayan B. An unusual ankle injury: the Bosworth-Pilon fracture. J Foot Ankle Surg 2015 Jul-Aug;54(4):751-753.
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Lower extremity neurological complication following routine surgical intervention

by Dr. Christina Sigur Long1, Dr. Michael McCann1*

The Foot and Ankle Online Journal 13 (2): 1

Pneumatic tourniquets have been utilized for centuries to assist in hemostasis, resulting in faster operating times and better identification of anatomical structures. Mortality and morbidity are rare but can be associated with improper tourniquet use.  This case study reports on a lower extremity neuropathy that developed after seemingly proper pneumatic tourniquet use during ankle surgery. Nerve conduction velocity (NCV) testing suggested likely etiology was from a resolved compartment syndrome. 

Keywords: compartment syndrome, tourniquet, neurapraxia

ISSN 1941-6806
doi: 10.3827/faoj.2020.1302.0001

1 – Wake Forest Baptist Health, 1 Medical Center Blvd, Winston-Salem, NC 27157
* – Corresponding author:

The U.S. Food and Drug Administration recognizes the pneumatic tourniquet as a Class-I medical device indicating minimal harm to the patient with routine use [1]. When properly utilized, tourniquet application creates a bloodless surgical field enhancing the surgeon’s ability to identify anatomic structures and reduce intraoperative blood loss [1]. Its roots can be traced back to the Roman Empire (199 BCE – 500 CE), when bronze and leather devices were donned to injured extremities to reduce bleeding during war-time amputations [1]. In 1864, Joseph Lister was the first surgeon to apply a tourniquet in the operating room [1]. Harvey Cushing introduced the pneumatic tourniquet in 1904 allowing tourniquet pressure to be manually controlled which aided in decreasing associated injuries. It has been estimated that over 15,000 surgical procedures occur daily which require the use of a pneumatic tourniquet [1]. Routine tourniquet use is not without risk of morbidity or even mortality with potential complications including compression neurapraxia, compartment syndrome, wound infection, wound hematoma, delayed recovery of muscle power, arterial hypertension, cardiorespiratory decompensation, rhabdomyolysis, and cardiorespiratory decompensation [2]. The rate of nerve injury associated with tourniquet use ranges from 0.1% – 7.7% [3]. To assist in decreasing comorbidities and mortality related to tourniquet use, numerous studies have been conducted to determine appropriate tourniquet applications, tourniquet duration, tourniquet design, and patient selection when utilizing tourniquets [1]. This Case Study reports a patient developing a common fibular neuralgia after routine use of high calf tourniquet during routine ankle surgery.

Case Report

A 48 year-old healthy female presents to the clinic complaining of chronic right ankle pain and weakness after an ankle sprain one year prior. She underwent a two-year period of conservative treatment with no resolution of her symptoms.  MRI obtained showed tendinosis and possible tearing of her peroneal tendons. 

Surgical intervention was deemed necessary based on progression and chronicity of her symptoms with failure and exhaustion of conservative treatment.

The patient received a preoperative popliteal fossa and saphenous nerve block and was placed in the supine position with a pneumatic calf tourniquet set to 250 mmHg. A semi-linear incision was made along the course of the peroneal tendons.  Dissection carried down to the peroneal tendons with further evaluation, identifying an intrasubstance tear of the peroneus brevis tendon. The tendon was debrided and re-tubularized in the usual manner. The foot was then everted to re-approximate the superior retinaculum. The surgical incision was closed and dressed in the usual manner. The pneumatic tourniquet was deflated at 68 minutes. Proper hyperemic response was noted. A modified Jones compression posterior splint was applied with the foot slightly everted and ankle at 90 degrees. She was discharged from PACU with all vitals stable and vascular status intact to the right lower extremity.   Postoperative instructions were given to remain non-weight bearing to her right lower extremity. 

The first postoperative visit occurred ten days following her procedure without any notable complications. Pain level was tolerable and no complications involving falls were noted.  She was transferred into a removable CAM boot at this time, continuing non-weight bearing status to the right lower extremity.  At 3 weeks post-procedure, she complained of acute onset of pain, numbness, and paresthesia in her right lower extremity, from knee to foot, which worsened at night but was constant. Based upon clinical symptoms, a diagnosis of neuralgia was made.  Treatment began with oral Gabapentin 300 mg taken nightly.  Physical therapy was initiated 1 week later. At 6 weeks, the patient continued to have numbness and paresthesia to the entire right foot and up to her knee.  Patient denied any help from the Gabapentin medication.  Physical exam revealed decreased muscle strength and a hyper-sensitivity to light touch to her right foot and lower leg. Physical therapy helped with recovery of her tendon repair but no change to her neurological symptoms was noted.  Patient was sent to pain management and complex regional pain syndrome was ruled out.  She tried and failed Elavil oral medication. She was intolerant to Cymbalta oral medication.  Nerve conduction velocity and EMG studies were obtained approximately 14 weeks following surgery to assess for potential areas of nerve entrapment or injury. Results revealed a mild polyneuropathy affecting sensory and motor nerves without evidence of a localized neuropathy such as a tarsal tunnel syndrome or focal sensory neuropathy. The study suggested small nerve fibers may have been affected and a resolved compartment syndrome was deemed as a likely etiology of the polyneuropathy. At 5 months, the patient showed recovery from her peroneal tendon surgery but still with continued paresthesia and numbness to the right foot and ankle, up to the knee.  The pain at this point is tolerable with shoe and activity modifications.  


Complications arising after tourniquet use during lower extremity surgical procedures are rare but still occur. A questionnaire survey in Norway estimated neurological complications associated with lower extremity tourniquet use occurred in one per 3752 applications [4]. Our case study reports neurological complication occurring secondary to a possible compartment syndrome that occurred 3 weeks after the surgical procedure. Compartment syndrome is a potentially serious complication which can occur once interstitial pressure in a closed fascial compartment increases to a level which impedes vascular flow resulting in myoneuronal function impairment and soft tissue necrosis [5]. Normal compartment pressures allowing capillary perfusion are described ranging from 0 to 8 mmHg [6]. Once interstitial pressure increases above this range, blood flow is impaired leading to the associated complications [6]. Previous case studies have reported compartment syndrome occurring after tourniquet use [5,7,8]. but in our case study the clinical presentation of compartment syndrome was not present directly following surgery. Classic presentation of compartment syndrome has been described as pain out of proportion, pain on passive stretching of the affected compartment with associated clinical symptoms of pallor, pulselessness, and paresthesia of the affected extremity [5]. Compartment syndrome resulting after lower extremity tourniquet application has been reported to occur after prolonged ischemia time with reperfusion edema, direct muscle trauma secondary to repeated inflations of the tourniquet and improper positioning [9]. As described per the surgical report, the patient was appropriately positioned on the operating table, with proper application, location, and duration of a pneumatic tourniquet and without repeated inflations. This patient did obtain regional anesthesia via a popliteal fossa and saphenous nerve block which some suggest can delay the diagnosis of compartment syndrome [10].

Pain is a cardinal feature of compartment syndrome which theoretically can be altered by analgesia. Our patient did not begin to experience pain until approximately 3 weeks following her surgical procedure. Mar, et al., reported 32 of 35 patients who received epidural analgesia had “classic signs” of compartment syndrome which included pain out of proportion. Their conclusion stated there was no convincing evidence regional analgesia delays the diagnosis of compartment syndrome [10].  

Peripheral nerves are composed and organized into connective tissue structures forming a framework to provide protection and function to nerve fibers. These connective tissue structures include the endoneurium, perineurium, and epineurium. Individual nerve fibers are surrounded by the endoneurium. Fascicles, groups of endoneurium, are enveloped by the perineurium. Epineurium encases bundles of fascicles [11]. Vessels in the epineurium are more vulnerable to compression trauma resulting in permeability changes compared to endoneurium vessels. Vessel permeability changes occurring secondary to trauma lead to associated edema formation and accumulation.  Endoneurium edema is prevented from draining into adjacent areas due to a blood-nerve-barrier and a lack of lymphatic channels. Perineurium edema is prevented from draining into adjacent areas due to a selective diffusion barrier. Past studies have suggested edema accumulation inside nerve fascicles create a “miniature compartment syndrome” which could alter nerve function [12]. A miniature compartment syndrome may affect or impair nerve function through a sustained increase in fascicle pressure, altering endoneurium fluid electrolyte composition or reducing blood flow to nerve segments.

Ochoa, et al., demonstrated nerves directly beneath and near the tourniquet cuff edge were subjected to injury due to external compression. This direct pressure has been shown to cause displacement of Nodes of Ranvier and myelin sheath invagination which disrupts nerve conduction [13]. The resulting damage associated with displacement of Nodes of Ranvier and myelin sheath invagination is associated with partial or complete local conduction block which is usually reversible within weeks or months. Nodes of Ranvier are essential components of nerve function and are located along peripheral nerve axons to increase conduction velocities [14]. Compression from tourniquet application has been shown to displace Nodes of Ranvier up to 300 nanometers from their original site [13]. Tourniquet induced compression can affect larger nerve fibers responsible for motor function or smaller nerve fibers responsible for pain, temperature and autonomic function. 

Our case study reports a polyneuropathy affecting motor and sensory nerves with a likely etiology of a resolved compartment syndrome. Clinical presentation of classic compartment syndrome was not present during this patient’s immediate postoperative period. Nerve injury resulting in the polyneuropathy most likely was secondary to nerve injury sustained from external compression via a pneumatic tourniquet. As discussed, nerve function can be altered from an increase in fascicle pressure secondary to edema accumulation or displacement of essential nerve components required for normal nerve function. 

If the patient experiences nerve related injuries after surgery, proper evaluation and a thorough work-up is warranted to determine the severity of injury. To determine the severity of the lesion, a nerve conduction study can be utilized to confirm the lesion grade. Seddon, et al., classified nerve injuries into three grades, neuropraxia, axonotmesis, and neurotmesis based on the severity of lesion [16]. Sunderland later expanded this classification into five different nerve injury patterns.  Neurapraxia, Grade 1, is the mildest injury and produces a local nerve conduction block at the site of injury with normal nerve conduction proximal and distal to injury. There is no associated injury to the surrounding nerve tissues. Axonotmesis, Grade 2, is seen when demyelination occurs at the injured site leading to Wallerian degeneration distal to the demyelinated segment [17]. Nerve regeneration is possible due to the preserved endoneurium and perineurium.  If full functional recovery of the nerve occurs within 3 months after the injury it is classified as a neurapraxia but if recovery occurs at a rate of one inch per month the injury is classified as axonotmesis. Fibrillations and denervation potentials can be seen distal to the site 3 weeks following the injury. Recovery is spontaneous and complete with axonotmesis injuries but can take weeks to years [18]. Damage to the endoneurium without damage to the epineurium is seen in grade 3 injuries. Damage to the myelin, endoneurium, perineurium, and axon indicates a Grade 4 injury. Grade 5 injuries are seen with complete transection of the nerve [17].

Nerve-related injuries during surgery can create a complex postoperative course. If questionable nerve symptoms do occur, proper work up is warranted to determine diagnosis and severity of the damage. Treatments range from oral and topical medications to surgical neurolysis. This case study shows our patient developing polyneuropathy 3 weeks after seemingly proper surgical use of calf tourniquet, likely from a resolving compartment syndrome after surgical use of tourniquet.  If a patient displays the appropriate symptoms, a high suspicion for compartment syndrome is warranted.  

Funding declaration

Acknowledgment that the authors did not receive any funding from any sources

Conflict of interest declaration

The authors whose names are listed certify that they have no affiliations with or involvement in any organization or entity with any financial interest.


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The influence of great toe valgus on pronation and frontal plane knee motion during running

by Richard Stoneham PhD1, Gillian Barry PhD1, Lee Saxby BSc2, Mick Wilkinson PhD1*

The Foot and Ankle Online Journal 13 (1): 7

Injury rates in running range from 19.4‐79.3%, with injuries at the knee comprising 42.1%. Pronation and altered frontal plane knee joint range of motion have been linked to such injuries. The influence of foot structure on pronation and knee kinematics has not been examined in running. This study examined associations between great toe valgus angle, peak pronation angle and frontal plane range of movement at the knee joint during overground running while barefoot. Great toe valgus angle while standing, and peak pronation angle and frontal plane range of motion of the dominant leg during stance while running barefoot on an indoor track were recorded in fifteen recreational runners. There was a large, negative association between great toe valgus angle and peak pronation angle (r = -0.52, p = 0.04), and a strong positive association between great toe valgus angle and frontal plane range of motion at the knee joint (r = 0.67, p = 0.006). The results suggest that great toe position plays an important role in foot stability and upstream knee-joint motion. The role of forefoot structure as a factor for knee-joint injury has received little attention and could be a fruitful line of enquiry in the exploration of factors underpinning running-related knee injuries.

Keywords: great toe valgus, pronation, frontal plane knee range of motion, running

ISSN 1941-6806
doi: 10.3827/faoj.2018.1301.0007

1 – Department of Sport, Exercise and Rehabilitation, Northumbria University, UK
2 –, Suffolk House, Louth, Lincolnshire, UK
* – Corresponding author:

Injury incidence in running ranges from 19.4‐79.3% [1, 2]. The knee is the most injured site, comprising 42.1% of all running‐related injuries [2, 3]. Patellofemoral Pain Syndrome (PFPS) is the most common running‐related knee injury, followed closely by Iliotibial Band Syndrome (ITBS) [3].  Altered frontal plane hip and knee joint kinematics and pronation during the stance phase of running have been linked to these injury types, and differentiate injured from uninjured runners [4-6]. Knee abduction, femoral internal rotation, tibial external rotation, and foot pronation, have been theoretically linked to injury in a population of patients with PFPS [7]. As such, interventions to normalise altered frontal plane kinematics during running might be valuable for rehabilitation of this type of knee injury. Interventions have tended to focus on proximal areas linked to altered knee kinematics. However, training studies to increase hip abduction and external rotation strength have not decreased hip or knee frontal plane peak joint angles or joint excursions during the stance phase of running [8-10]. Moreover, associations between hip strength and frontal plane hip and knee peak angles and joint excursions while running and jumping are weak [9, 11]. These findings suggest that proximally-based interventions are not effective at altering lower extremity running mechanics and risk of running related injury. Studies exploring the distal end of the kinetic chain have utilised barefoot and minimal footwear, and hip and foot muscle strengthening interventions to reduce surrogate measures associated with injury at the knee and other sites [10, 12-14]. Injury rates, however, remain high [15]. The influence of foot structure on pronation and knee joint kinematics in running has, by contrast, received little attention.

Data comparing foot structure in habitually-barefoot and habitually-shod populations have reported consistent differences in the spread/abduction of the great toe from the other toes [16-19]. Based on Newtonian physics, larger areas of support provide greater stability. It has been suggested that an abducted great toe position might be important for controlling the direction of body weight during running, secondary to improved stability of the foot [20, 21]. Running is essentially a series of alternate single-leg jumps, where multiples of bodyweight must be supported and controlled using a spring-like action of the supporting foot and limb [22, 23]. Early research showed an active role of the toes, the great toe in particular, from midstance to toe off in running [24]. More recent data comparing habitually barefoot to habitually shod populations suggested that the abducted great toe position, characteristic of the barefoot group, reduced peak forefoot pressures during running by increasing the area of support [19]. Another comparative study from the same lab [25] found larger ankle eversion and internal rotation (which together comprise pronation) during the landing phase of jumping in habitually shod compared to habitually-barefoot participants, attributing differences to the abducted great toe position characteristic of the barefoot group. Together, these studies suggest a link between great toe position and foot and ankle stability in running, and dynamic tasks with similar demands to running. Given evidence of the link between pronation, altered frontal plane motion at the knee joint and risk of knee injury [7], there is a possible mechanistic link between great toe position, pronation and frontal plane knee joint kinematics.

Previous research suggests that the toes have a stabilising function, and that great toe position influences area of support in running, and the extent of pronation in the landing phase of jumping. The influence of great toe position on pronation and on kinematics at the knee joint has not been examined in running. The aim of this study was to examine associations between great toe valgus angle, peak pronation angle and frontal plane range of movement at the knee joint during overground running while barefoot, the latter being necessary to avoid toe position being constrained by shoes.



With institutional ethics approval, 15 volunteers (ten male, five female) participated. Mean and SD age, stature and mass of all participants were 26±7 yrs, 1.71±0.01 m and 69±10.9 kg respectively. Inclusion criteria were aged 18-45 years and participation in endurance running more than once per week as part of habitual-exercise regimes, with at least one run longer than 30 minutes. Participants were excluded if they had an injury to the lower limbs in the previous six months, or any condition that could affect their normal running gait.


An observational design assessed the relationship between great toe valgus angle relative to the first metatarsal, peak pronation angle and frontal plane range of movement at the knee joint of the dominant leg during stance, while running barefoot on an indoor runway. The barefoot condition was chosen as it was the only way to ensure that the toe angle recorded in standing was not altered by footwear while running. Data were collected in a single visit. Participants were provided with a short-sleeved compression top and shorts to improve skeletal representation in biomechanical modelling, and were instructed to be well rested before testing. Reflective markers were attached in ‘Plug-In gait’ and ‘Oxford-Foot Model’ formations to assess lower-limb kinematics of the dominant limb. Participants were habituated to running barefoot with a 30-minute, self-paced run. After habituation, participants ran over a 20-m runway where kinematic data were captured by 14 optoelectronic cameras. Electronic timing gates (Brower timing gates, Utah, USA) placed in the data capture area (2.7m apart) were used to record speed in each trial. The average running speed was 2.48±0.38 m·s-1.


Great toe valgus angle

Participants stood barefoot on top of a 0.35-m high platform covered in graph paper. The non-dominant foot was placed on the platform first, aligning the most posterior aspect with a horizontal reference line on the graph paper. The dominant foot was positioned next, shoulder width apart from the other foot, and with the most posterior aspect on the same horizontal reference line. The first metatarsal proximal-and distal-dorsal protrusions, and the central and dorsal point of the interphalangeal joint of the great toe were identified by palpation, and marked using a permanent pen. A digital camera (CX240, Sony, Japan) positioned 0.3m above the platform on a tripod was aligned with the first metatarsophalangeal joint, and the zoom was adjusted so that bony prominences defining great toe angle were visible. A still image was captured and saved for analysis of great toe valgus angle.


Prior to habituation, anthropometric measures were recorded for use in biomechanical modelling (stature (mm), mass (kg), bilateral-leg length (mm), and knee and ankle joint width (mm)). For assessment of lower-limb joint kinematics, participants had a series of markers (Ø=14mm) attached in ‘Plug-In gait’ and ‘Oxford-Foot Model’ formations. Anatomical locations of the ‘Plug-In gait’ and ‘Oxford-Foot Model’ were sacrum, bilateral anterior-and posterior-superior iliac spines, the bilateral distal-lateral thigh, bilateral femoral-lateral epicondyle, the bilateral distal-lateral lower-leg, the bilateral lateral malleoli, the left/right toe (dorsal aspect of the second metatarsal head) and the calcaneus of the non-dominant limb at the same height as the toe marker. The following markers were placed on the dominant limb only, lateral head of the fibula, tibial tuberosity, anterior aspect of the shin, the medial malleoli, the proximal aspect of the calcaneus, a ‘peg marker’ extending from the most posterior aspect of the calcaneus, the inferior aspect of the calcaneus, sustentaculum tali, proximal and dorsal aspect of the first metatarsal head, the medial and distal aspect of the first metatarsal head, the proximal-and distal-lateral aspects of the fifth metatarsal and the medial aspect of the first phalanx. Fourteen infrared-optoelectronic cameras (Vicon 10 xT20 and 2 x T40, Oxford, UK) captured kinematic trajectories at 200Hz. 

Data treatment

A trial was deemed successful when running speed was ± 5% of the predetermined running speed from the habituation run. Dominant limb data for peak pronation angle and frontal plane range of motion at the knee joint were exported to Microsoft Excel (Microsoft, USA). Foot structure images were loaded to Dartfish ClassroomPlus (version 7.0, Fribourg, Switzerland) where great toe valgus angle was measured using the angle tool. (Chicago, USA).

Statistical analysis

Statistical analysis was undertaken using JASP 0.10.2. Following verification of assumptions of linearity and uniformity of errors using Q-Q and residuals versus predicted value plots respectively, linear regression assessed associations between great toe valgus angle, peak pronation angle and frontal plane range of motion at the knee joint. Strength of associations were judged against Cohen’s effect size categories for Pearson’s  r i.e. small association 0.1-0.3; moderate association 0.3-0.5; large association 0.5-1.0 [26]   Significance was accepted at p < 0.05.


Mean and SD great toe valgus angle, peak pronation angle and frontal plane knee range of motion were 9.5±6.1°, -5.2±6.6° and 6.2±2.2° respectively.

Association between great toe valgus and peak pronation angle.

There was a large, negative association of great toe valgus angle and peak pronation angle during stance (r = -0.52, p = 0.04). As great toe valgus angle increased (more positive = more valgus), peak pronation angle decreased (more negative = increased pronation) (see Figure 1). The regression equation showed a 0.59° increase in peak pronation for every additional degree of great toe valgus (95% CI 0.01 to 1.12°).

Figure 1 Association between great toe valgus angle and peak pronation angle during overground barefoot running on an indoor track in 15 recreational runners.

Association between great toe valgus and frontal plane knee range of motion.

Great toe valgus angle was strongly and positively associated with frontal plane range of motion at the knee joint (r = 0.67, p = 0.006). As great toe valgus angle increased, frontal plane knee range of motion also increased (see Figure 2). The regression equation showed a 0.24° increase in frontal plane knee joint excursion for every one degree increase in great toe valgus angle (95% CI 0.01 to 0.40°).

Figure 2 Association between great toe valgus angle and frontal plane range of motion at the knee joint during overground barefoot running on an indoor track in 15 recreational runners.


The aim of this study was to examine associations between great toe valgus, peak pronation and frontal plane range of motion at the knee joint during overground running. There was a strong, negative correlation between great toe valgus angle and peak pronation such that increased great toe valgus was associated with a more negative peak pronation angle (increased pronation). There was also a strong, positive correlation between great toe valgus angle and frontal plane range of motion at the knee joint such that increased great toe valgus was associated with larger knee joint excursions in the frontal plane. Altered frontal plane hip and knee joint kinematics and pronation during the stance phase of running have been linked to running-related knee injury, and can differentiate injured from uninjured runners [4-6]. Knee abduction and foot pronation have also been theoretically linked to patellofemoral pain [7]. In light of this evidence, our results suggest that forefoot structure might be an important but largely unexplored factor in running-related knee injury.

As this is the first study to explore the association between great toe valgus, pronation and frontal plane knee joint excursions during running, there are no studies with a similar approach for comparison. Nevertheless, the strong relationships observed broadly support findings from previous comparative cross-sectional studies of habitually barefoot and habitually shod participants that differed in forefoot structure with respect to the spread/abduction of the great toe [19, 25]. Shu et al. [25] observed larger ankle eversion and internal rotation (which together comprise pronation) in habitually shod compared to habitually barefoot participants in the landing phase of jumping. As running is essentially a series of single-leg jumps, the strong association of great toe valgus angle with peak pronation observed in running in our study is not surprising. The reduced and more evenly distributed forefoot peak pressures of habitually barefoot participants reported by Mei et al. [19] alludes to greater forefoot stability during the period of stance when forces are highest. It is possible that as the stability provided by the great toe decreases with increasing valgus angle, instability of the foot could manifest as higher peak pronation. Increased forefoot instability with increased great toe valgus is a plausible mechanism that could explain the strong correlation of great toe valgus angle and peak pronation that we observed. Increased postural instability with great toe valgus [27] and with splinting of the great toe into flexion [28] have been observed in single-leg balance tasks. Though these studies examined static balance and not the dynamic single-leg balance characteristic of running, the underpinning link between the area of the base of support and subsequent stability could be assumed to be common to both. Instability at the foot could have kinematic consequences further up the kinetic chain, resulting in increased frontal plane motion at the knee. The strong, positive association of great toe valgus angle with frontal plane knee joint excursion observed in the current study is consistent with this suggestion. Moreover, the kinematic links between pronation and frontal plane knee joint range, as well as the link between these factors and running-related knee injury suggested here have been suggested previously elsewhere [7] and supported by previous studies [4-6].

The main limitation of this study is that the correlational design prevents any suggestion of a causal link between great toe valgus, peak pronation and frontal plane knee joint excursions. Another limitation is that great toe valgus angle was measured during static stance, not while running, so an assumption that valgus angle remains relatively unchanged when the foot is loaded during running is implicit in the interpretation of the results. Previous research, however, suffers from similar limitations, comprising only comparative studies of foot and ankle function and pressure distributions of groups with mean abducted versus mean valgus great toe positions. As such, a correlational study like this one does add to the understanding of how foot structure might relate to pronation and knee joint kinematics in dynamic tasks like running by examining a ‘dose-response’ type association, in addition to the ‘with and without’ type evidence of previous comparative studies. Moreover, there are plausible mechanisms of action for both key findings in this study, so the data provide both direct and mechanistic evidence towards establishing a causal link [29]. A logical next step for this area of research would be randomised control trials where pronation and knee kinematics are evaluated before and after an intervention to alter great toe valgus angle in one group, with the control group foot structure remaining unchanged. Interventions could potentially include corrective surgery or corrective devices that reposition the great toe. Additional comparative studies that measure knee joint kinematics during running would, however, be a useful intermediate step.

In summary, this study observed strong associations between great toe position, peak pronation and frontal plane range of motion at the knee joint during over-ground barefoot running. The results suggest that great toe position plays an important role in foot stability and subsequent knee-joint motion. Both pronation and frontal plane knee-joint motion have been implicated in the etiology of knee injuries. The role of forefoot structure as a factor for knee-joint injury has received little attention and could be a fruitful line of enquiry in the exploration of factors underpinning running-related injuries.

This study formed part of a PhD program collaboratively funded by Northumbria University and VivoBarefoot. VivoBarefoot had no input to the design, analysis or interpretation of studies or data, or the preparation of this manuscript.


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