Tag Archives: brachymetatarsia

Congenital Bilateral First Brachymetatarsia: A Case Report and Review of Available Conservative and Surgical Treatment Options

by Mark J. Mendeszoon, DPM, FACFAS, FACFAOM1  , Yelena L. Kaplan, DPM2 ,
Robert S Crockett, DPM3 , Natalie Cunningham, DPM4

The Foot and Ankle Online Journal 2 (9): 1

Synonyms of first metatarsal brachymetatarsia include metatarsus primus atavicus, metatarsus primus brevis, metatarsus primus brevis varus syndrome, pied ancestral (French), pied de Neanderthal (French), short first metatarsal syndrome and Morton’s syndrome (Dudley Joy Morton). Brachymetatarsia is a condition in which the metatarsal physis closes prematurely yielding a pathologically shortened metatarsal length. The podiatric and orthopedic literature mostly agree that the most common metatarsals to be affected are the fourth and third, although any of the five metatarsals can be affected. The etiology of this condition can be genetic or idiopathic, with strong female to male predilection. Presentation of first brachymetatarsia is far less common than that of third or fourth metatarsals. Management of this condition can present as a challenge to the foot and ankle surgeon. This case report will review the present conservative and surgical treatment options.

Key Words: Brachymetatarsia, Morton’s syndrome, Hallux varus, metatarsus primus atavicus, metatarsus primus brevis, metatarsus primus brevis varus syndrome, short first metatarsal syndrome.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.  It permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ©The Foot and Ankle Online Journal (www.faoj.org)

Accepted: July, 2009
Published: September, 2009

ISSN 1941-6806
doi: 10.3827/faoj.2009.0209.0001


Brachymetatarsia of the first metatarsal is also known as “Morton’s syndrome”. [1] Tachdjian reported that first metatarsal is the most commonly affected metatarsal, although the incidence was found to be 1 in 10,000, whereas a majority of other podiatric and orthopaedic authors claim the fourth brachymetatarsia to be the most common. [2] The largest series of studies, which are from Japan, report the incidence of Morton’s syndrome to be somewhere between 1 in 1820-4586 (0.022%-0.05%), and bilateral congenital brachymetatarsia is noted to be 72 %. [3,4]

The etiology of brachymetatarsia can be associated with idiopathic congenital conditions and acquired disorders. Idiopathic congenital conditions can include such conditions as hereditary early epiphyseal plate closure, associated congenital disorders such as Down’s, Turner’s, Larsen’s, Albright’s syndromes, pseudohypoparathyroidism, poliomyelitis, dystrophic dysplasia, pseudohyperparathyroidism,, multiple epiphyseal dysplasia and myositis ossificans. Acquired disorders can include trauma, neurotrophic disorder, radiation exposure, surgical resection of metatarsal head, infection, or osteochondrosis. [5] There is a strong female to male predisposition in the majority of the podiatric and orthopedic literature. The average ratio is 25:1 [3,6], and the majority of the population studied is between the ages of 5 and 14 years of age. [7]

Anatomy

The first metatarsal secondary ossification center is located at the lateral aspect of the metatarsal base. In 1971, Lelievre [8] stated that the order from longest to the shortest metatarsal should be 1 = 2>3>4>5. Harris and Beath [9] studied 7167 military recruits and found that metatarsals 1>2 in 40 %, 1=2 in 22 %, 1 <2 in 38 %. According to Schmizzi and Brage [3] “the exact diagnosis of brachymetatarsia can be made when one metatarsal is 5mm or more proximal to the parabolic arc of the metatarsal heads.” [6,10]

Mechanics

Because of its location in the medial longitudinal arch the first ray plays an integral role in providing stability and maintaining structural integrity during weight bearing activities. [18] In fact, the base of the first metatarsal is the site for insertion of extrinsic muscles that are vital for medial column stability.

The peroneus longus, anterior tibialis and posterior tibialis muscles all provide significant mechanical stabilizing forces during the toe off (propulsion) phase of gait. When the structural component of the medial longitudinal arch is compromised, abnormal function of the soft tissue is to be expected.

Pain is the most common symptom and is caused by a variety of etiologies such as:

1. Pain caused by stretching of the deep transverse intermetatarsal ligament.
2. A short metatarsal and associated proximal phalanx position between adjoining metatarsal heads.
3. Cock-up toe deformity [3], claw toe [11], and painful digital callus due to dorsal displacement of short metatarsal, associated proximal phalanx and correlating shoe pressure/irritation.
4. Transfer metatarsalgia 12 and transfer lesions.
5. Contractures of extensor/flexor tendons, capsule and skin can be seen with chronic deformities.

Case Report

A nine year-old, Amish female presented to the outpatient clinic, accompanied by her mother. The mother related the child’s chief complaint as generalized soreness and pain in both feet and legs with the right foot being more painful than the left. The mother also explained that her daughter had difficulty ambulating and standing on her feet in the morning. While obtaining the history, both the patient and mother denied any history of injury or trauma to child’s feet or legs. The child was enrolled into an Amish school full time and during the warm months of the year did not wear shoes. The mother denied having any problems during pregnancy with this child or any complications during the delivery. She also related that her daughter went through normal developmental stages, did not have any medical problems or allergies and did not take any medication. The family history revealed that the mother has a heart murmur and father had a stroke. All other family members are free of medical problems. Upon the review of systems, no remarkable findings were noted.

On physical examination the patient’s neurovascular and the dermatological examinations of the lower extremities were completely within normal limits. We did not observe any transfer lesions or callosities. However, on musculoskeletal examination it was noted that both halluces were very short when compared to the adjacent digits. (Figs. 1 and 2) In addition, the child had pain at the insertion of Achilles tendon bilaterally and she was unable to dorsiflex her foot at the ankle joint beyond 90 degrees with the knee flexed and knee extended.

Figure 1  Dorsal view of bilateral feet with short halluces.

Figure 2  Plantar view of foot with short hallux.

On weight bearing examination, the child was unable to get the heel to the ground. The patient propelled on her forefeet during gait and the heels were in a varus alignment during the resting calcaneal stance position.

On evaluation of anteroposterior (AP) and lateral plain radiographs, a short first metatarsal with closed physis in both feet was observed. (Figs. 3 and 4) The left first metatarsal was noted to be shorter than the second metatarsal by 24 mm, and right first metatarsal was shorter than the second metatarsal by 20 mm. These findings were consistent with the definition of brachymetatarsia.

In addition, several other biomechanical factors were seen on radiograph. There is observed metatarsus adductus and decreased talo-calcaneal angles bilaterally, although the right is more pronounced than the left. This was combined with and possibly due to an uncompensated ankle equinus or talipes equinovarus.

 

Figures 3  Anteroposterior (AP) radiograph of left (A) and right (B) foot with first brachymetatarsia.

 

Figures 4 The Lateral radiograph of the right (A) and left (B) foot with first brachymetatarsia.

The findings were discussed with the mother and the patient in detail. The patient was advised to initially be placed in custom orthotic device to evenly distribute plantar load and support the medial longitudinal arch. If the condition remained symptomatic after initial orthotic therapy, surgical correction involving distraction callotasis would be indicated upon near closure of adjacent metatarsals physes.

Discussion

For this young patient with symptomatic pathology, and the presence of biomechanical abnormalities contributing to the pain, conservative therapy is initially recommended. The orthotic therapy would allow the necessary correction for the uncompensated ankle equinus. Three months following our patient’s initial consultation and orthotic therapy, the patient was doing well and not complaining of pain.

Taking into consideration this child’s ethnic background, after cold winter months, the patient will return to barefoot activities, as stated by the patient and her mother. If our patient begins to experience pain and discomfort after discarding orthotic therapy, surgical correction will be indicated. Indication for treatment is usually related to pain, prevention of progressive deformity or cosmesis. There are a variety of treatments available for conservative treatment and surgical correction of first brachymetatarsia:

1. Orthotic devices, metatarsal pads, wide toe-box shoe gear.
2. Metatarsal heads 2-4 resection.
3. Proximal ostectomy of metatarsals 2-4, followed by (Teflon prosthesis) implant arthroplasty in first metatarsal. [13]
4. Chiappara [19] procedure: First proximal phalanx shortening, combined with shortening of proximal aspect of metatarsals 2, 3, 4 and lengthening medial cuneiform – allowing hallucal interphalangeal joint (IPJ) to compensate for first metatarsophalangeal (MTP) joint. [13]

Surgical Lengthening procedures

1. One stage: distraction and bone graft.
2. Two stage: osteotomy and gradual distraction, followed by bone grafting.
3. Skirving and Newman procedure [20] = “callotasis“: osteotomy and gradual lengthening of first metatarsal with external mini external fixator, without bone graft utilization. [13,14]
4. Metatarsal slide lengthening procedure.

The one stage surgical approach is best for lengthening metatarsals up to 15 mm. Bone grafting can be wth allograft (such as tricortical iliac crest) or autograft (such as calcaneal or tibial strut). [3,6] If a greater than 15 mm lengthening is desired or indicated, recommendation is to perform distraction callotasis with a mini external fixator. Begin distraction approximately 1 week after surgery, and distract 0.5 mm to 1 mm per day. Keep the patient completely non-weight bearing for 8 – 12 weeks. Once the desired length is achieved, stop the daily distraction. As weight bearing status is progressed, the mini external fixator is kept in place until radiograph evidence shows bone consolidation.

With any lengthening procedure, the patient can experience complications, especially when the total lengthening is greater than 40 % of original length. [3] With excessive lengthening, there is possible risk of neurovascular compromise, vasospasm and toe gangrene, unless pre-surgical soft tissue releases, stress-relaxation techniques, and keeping the total increased length to less than 15 mm are employed. [3] Other complications can include stiff metatarsophalangeal or MTP joint, subluxation of the MTP joint, nonunion of the distraction site, ray angulation deformity, prolonged time to achieve osseous union and pin track infection. [3,15]

Considering the child in our case report will need to have the first metatarsal lengthened by greater than 15 mm, a two-stage approach or distraction callotasis seems to be the most appropriate procedures. Choi, et al., performed callotasis on 9 patients with average length gained 17.6 mm (15-23 mm), and the average time for “solid bony union” being 2.6 months (1.7 – 3.4 months). [16] Steedman and Peterson performed gradual first metatarsal distraction with the use of mini-external fixators (5/6 mini-Hoffman, 1/6 Orthofix), followed by fibular bone graft placement after gaining the desired lengthening. The average amount of lengthening was 10.3 mm (6 mm – 20 mm), with an average healing time of 3.5 months (1.9 months – 6.1 months). According to Steedman and Peterson, either the two-stage approach or the callotasis are acceptable surgical choices for correction of first metatarsal brachymetatarsia versus “procedures that shorten other metatarsals and destroy joints.” [13] Other factors to consider: bone grafting versus callotasis? When performing callus distraction with bone grafting, the surgeon should consider allograft versus autograft, graft incorporation, soft tissue adaptation (neurovascular damage) and status of adjacent metatarsal physes prior to the procedure. Timing of the surgical procedure should be aimed at “near closure of adjacent metatarsal physes” [17], thus assuring static relative correction. In addition, soft tissue stretching is recommended prior to the procedure.

Conclusion

Brachymetatarsia is a condition that has been described since ancient times, but the options for surgical correction did not become available until 1969, when McGlamry and Cooper began using a cylindrical autogenous calcaneal bone graft to lengthen the fourth metatarsal. [6] Brachymetatarsia is a relatively rare condition which most often affects the fourth metatarsal. We have presented a case of a nine year old female with bilateral short first metatarsals. Considering the patient’s age, length of deformities, the presence of uncompensated ankle equinus and metatarsus adductus, we have allowed this patient the opportunity for conservative management first. However, it is more than likely; a surgical correction of sorts will need to be performed to address this pathology. Many surgical options are available for correction of brachymetatarsia, but as with any surgery, the surgeon needs to be in tune with patient’s expectations. This relates to cosmesis versus pain relief, choosing the best surgical procedure based on digital position, amount of lengthening necessary and bone graft (if necessary). It is ideal to consider a reasonable expectation for post-operative healing, possible complications and outcome.

References

1. http://www.whonamedit.com/synd.cfm/270 Date of access is required.
2. Tachdjian MO: “Disorders of the foot” in Tachdjian’s Pediatric Orthopaedics. Ed by JA Herring JA, WB Saunders, Philadelphia, 1990.
3. Schimizzi A, Brage M: Brachymetatarsia. Foot Ankle Clin N Am 9: 555 – 570, 2004.
4. Sagiura Y, Nakazawa 0: Bone age: Roentgen diagnosis of skeletal development. Tokyo: Chugailgaku, 1968.
5. Munuera Martínez PV, Lafuente Sotillos G, Domínguez Maldonado G, Salcini Macías JL, Martínez Camuña L: Morphofunctional study of Brachymetatarsia of the fourth metatarsal. J Am Podiatr Med Assoc 94: 347 – 352, 2004.
6. Bartolomei FJ: Surgical correction of Brachymetatarsia. J Am Podiatr Med Assoc 80 (2): 76 – 82, 1990.
7. Goforth WP, Overbeek TD: Brachymetatarsia of the third and fourth metatarsals. J Am Podiatr Med Assoc 91: 373 – 378, 2001.
8. Lelievre J: Pathologie du pied [Pathology of the Foot]. Paris: Masson, 1971 (in French).
9. Harris RI, Beath T: The short first metatarsal: its incidence and clinical significance. J Bone Joint Surg 31A: 553 – 565, 1949.
10. Kim HT, Lee SH, Yoo CI, Kang JH, Suh JT: The management of brachymetatarsia. J Bone Joint Surg 85B: 683 – 690, 2003.
11. Magnan B, Bragantini A, Regis D, Bartolozzi P: Metatarsal lengthening by callotasis during the growth phase. J Bone Joint Surg Br 77B (4): 602 – 607, 1995.
12. Alter SA, Feinman B, Rosen RG: Chevron bone graft procedure for the correction of brachymetatarsia. J Foot Ankle Surg 34 (22): 200 – 205, 1995.
13. Steedman JT, Peterson HA: Brachymetatarsia of the first metatarsal treated by surgical lengthening. J Pediatr Orthop 12 (6): 780 – 785, 1992.
14. Ferrández L, Yubero J, Usabiaga J, Ramos L: Congenital brachymetatarsia: three cases. Foot Ankle 14 (9): 529 – 533, 1993.
15. Song HR, Oh CW, Kyung HS, Kim SJ, Guille JT, Lee SM, Kim PT: Fourth brachymetatarsia treated with distraction osteogenesis. Foot Ankle lnt 24 (9): 706 – 711, 2003.
16. Choi IH, Chung MS, Baek GH, Cho TJ, Chung CY:
Metatarsal lengthening in congenital brachymetatarsia: One-stage lengthening versus lengthening by callotasis. J Pediatr Orthop 19 (5): 660 – 664, 1999.
17. Solomon MG, Blacklidge DK: Brachymetatarsia: Case report and surgical considerations. J Am Podiatr Med Assoc 8: 685 – 689,1995.
18. Glasoe WM, Yack HJ, Saltzman CL: Anatomy and biomechanics of the first ray. Phys Ther 79: 854 – 859, 1999.
19. Chiappara P: Utilisation de la dure-mére dans la chirurgie de l’avant-pied rhumatoide. Mèd Chir Pied 7, 197 – 198, 1991.
20. Skirving AP, Newman JH: Elongation of the first metatarsal. J Pediatr Orthop 3 508 – 510, 1983.


Address correspondence to: Robert Crockett, DPM, Neshoba Foot and Ankle Clinic, 1004 Holland Ave. Philadelphia, MS
Email: drrcrockett@gmail.com.

Precision Orthopaedic Specialties, 150 Seventh Avenue, Suite 200 Chardon, OH 44106
1,2,3  Louis Stokes Veterans Affairs Medical Center, Podiatric Primary Care & Surgery, 10701 East blvd Cleveland, OH 44106.

© The Foot and Ankle Online Journal, 2009

Brachymetatarsia: One-Stage Correction using a Cadaver Bone Allograft

by Al Kline, DPM1 , Endolyn Garden, BS, (Hons)2

The Foot and Ankle Online Journal 2 (5): 1

Brachymetatarsia is defined as congenital shortening of the metatarsal caused by premature closure of the epiphysis. The condition most commonly affects the fourth metatarsal of young and adolescent females. Correction of this deformity is either by callus distraction using an external fixator, or by one-stage surgical lengthening procedure using autogenous iliac bone graft. A case of brachymetatarsia is presented that is corrected by one-stage cadaver bone graft sterilized by the Biocleanse ® method. Advantages include complete incorporation of the graft and healing characteristics similar to autogenic bone grafting without the need to harvest graft material.

Keywords: Brachymetatarsia, autogenous, allogenic, bone graft, allograft, biologics, Biocleanse® sterilization process

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.  It permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ©The Foot and Ankle Online Journal (www.faoj.org)

Accepted: April, 2009
Published: May, 2009

ISSN 1941-6806
doi: 10.3827/faoj.2009.0205.0001


 
The exact etiology of brachymetatarsia is not known. It is thought to be either idiopathic congenital, acquired, or associated congenital. [3] The idiopathic congenital etiology, which refers to the early closure of the epiphyseal plate, is thought to be the most common. The associated congenital etiology is accompanied by other conditions such as Albright’s Syndrome or Down’s Syndrome and parathyroid alterations. Acquired etiology refers to the early closure of the epiphyseal plate after suspected trauma. [3]

A variety of measurements have been described to define brachymetatarsia of the fourth metatarsal. [2,3,4,7] In 2003, brachymetatarsia was diagnosed “when one metatarsal ends 5 mm or more proximal to the parabolic arc”. [7]

In 2004, a morphofunctional study described a more specific measurement called the “angle of fourth metatarsal shortening or second-fourth angle” to quantify the definition of brachymetatarsia. [3] Brachymetatarsia is defined as a second-fourth angle of less than 52.2 degrees in males and 50.5 degrees in females. [3] Using both techniques, in our case report, the fourth metatarsal measured more than 5mm of shortening from the parabolic line and the second-fourth angle is less than 50.5 degrees respectively (45.2 degrees). The parabolic difference is a 10 mm shortening. (See radiograph Fig. 2)

It has been reported that the fourth metatarsal is more likely to be affected by this condition, although many studies vary in their reports. [3,4,10] The majority of cases are seen in females (98:4 female to male ratio respectively) and 72% of these cases occur in both feet. [4] Brachymetapody, a noticeable shortening of the toe, can also present with brachymetatarsia.

Conservative treatments include using metatarsal padding within the shoes. [1] Digital padding and toe splinting may also be attempted. When this is ineffective, surgical correction may be indicated if the patient is experiencing metatarsalgia or have difficulty getting shoes to fit properly. These patients may develop painful calluses, or have a dislocated digit (also known as a “floating toe”). [4] Many patients also express discontent with the appearance of the foot, but this alone is not usually an indication for surgery. [1] However, having the deformity may cause the patient to be overly self-conscious which can lead to psychological issues such as depression. This is particularly important because the abnormality usually presents between the ages of 5 and 14 years in young females. [4]

When surgery is performed, the desired result is to relieve pain and restore functionality. [5] The two methods used most often to correct this condition are gradual distraction using an external fixator, and one-stage surgical lengthening using a bone graft. Gradual distraction involves surgically placing an external fixator on the metatarsal to be lengthened. One-stage lengthening of the metatarsal involves using allograft or autogenous bone, and interposing the graft within the metatarsal. When using an autogenous bone graft, the bone is harvested from the patient’s own body and transplanted into another part of the body. A common site to harvest autogenous bone is the iliac crest. Other sites may also be used, such as the ribs, calcaneus and fibula. [12] An allograft is “any tissue harvested from one individual and implanted into another of the same species [13],” and is used as a substitute for autogenous bone. The allograft bone used in this case were prepared by sterilization and disinfection methods that include gamma irradiation and a low temperature chemical sterilization method known as BioCleanse®. [11]

Case Report

A 13 year old female presents to the office with pain and discomfort involving the left fourth toe. The toe ‘rides up’ on the foot and interferes while wearing closed shoes. (Fig.1)

Figure 1 Initial presentation of brachymetatarsia of the fourth metatarsal.  Typically, the 4th toe is short and contracted due to the immature growth and congenital shortening of the fourth metatarsal at 13 years age.

Radiographic evaluation reveals a congenitally short fourth metatarsal. (Fig. 2 A and B) The patient tried modifying her footwear, but with limited success. At initial visit, the patient was fitted with a digital Budin type splint in an attempt to help plantarflex the digit and eliminate pain. We also initiated dorsal digital padding to protect the toe while in the shoe. Most conservative measures were inadequate and we opted to bring the patient to surgery in order to correct the brachymetatarsia and lengthen the toe.

 

Figures 2A and 2B Radiographs show a typically short fourth metatarsal.  Notice how the fifth toe has rotated in a digital varus orientation.  All epiphyseal growth plates have already closed. (A)  The second-fourth angle measured 45.2 degrees which significantly less than the normal parameter of 50.5 degrees (B) 

The patient has an allergy to Suprax® and is taking Ibuprofen for pain and swelling. The patient has no medical conditions and is young and healthy.

Surgery was discussed with the patient and mother. We described the two options for surgery including callus distraction with an external fixator or a one stage procedure including inter-positional bone graft. Because of her age and health status, we opted for the one stage lengthening. We also described the various types of grafting techniques including autogenous bone grafting from the patient’s own iliac crest to using allogenic, cadaver sterilized bone graft.

Complications of this procedure were discussed including failure of graft material, vascular compromise to the fourth toe and metatarsophalangeal joint stiffness. Two weeks before her surgery, she was asked to manually place distal traction on the toe every night for about 5 to 10 minutes daily.

Surgical Technique

The patient was brought to the operating room. Under sterile technique, a small linear incision was made along the dorsal mid-shaft region of the fourth metatarsal. The extensor tendon was identified and lengthened by standard z-plasty technique. (Figs. 3 A and B)

 

Figures 3A and 3B A small linear incision is oriented along the long axis of the fourth metatarsal. (A)  An extensor z-slide tenotomy is performed to prevent dorsal contracture of the fourth toe during the metatarsal lengthening. (B)

Using blunt and sharp dissection technique, the mid-shaft region of the fourth metatarsal was identified. A small surgical bone saw was used to perform a transverse osteotomy through the metatarsal.

Using a laminar spreader, 2 cm of distraction is placed between the distal and proximal portions of the fourth metatarsal. It is important to gradually place increasing distraction stress through the metatarsal. (Figs. 4 A – C)

  

Figures 4A, 4B and 4C  The mid-shaft region of the fourth metatarsal is exposed taking care to not strip the periosteum from each side of the bone. (A)  A small bone saw is used to perform a transverse osteotomy perpendicular to the long axis of the fourth metatarsal. (B)  A laminar spreader is then used to place a distractive force along the long axis of the fourth metatarsal.  The laminar spreader is slowly spread apart over an hour to eliminate any incidence of vascular compromise. The metatarsophalangeal joint will become inherently stiff during the distraction process.  Plastic deformation of the surrounding tissues is promoted by gradual stress distraction.  (C)

This allows for gradual lengthening of the neurovascular structures of the fourth toe and promotes a gradual plastic deformation of the tissues.

The metatarsal is gradually lengthened over 30 minutes to 1 hour. During this period, the graft can be shaped and prepared for implantation. It is important to realize that the fourth metatarsophalangeal joint will become inherently stiff and rigid during this process. The elastic properties of the surrounding tissues including the joint capsule will slowly begin to deform and relax. A too rapid distraction will cause soft tissue contracture leading to vascular spasm, so gradual distraction is recommended.

During the hour of controlled distraction, the cadaver graft is prepared. It is important, when preparing the graft, that one take bone approximating the thickness and length of the metatarsal. We chose to use a humoral graft and cut a 20 mm section to approximate the size and shape of the metatarsal. Although the metatarsal gap measured and desired length is measured at about 10 mm on radiograph, a larger graft is recommended to be initially used. The graft is easier to handle and drill, then can be remodeled to a smaller size prior to insertion.

Once the graft is to the desired shape, a .062mm Kirschner wire is used to drill a hole along the long axis of the graft. This is called pre-drilling the graft. This graft was completely cortical. Pre-drilling the graft will allow for easier placement in the final stages of the operation.

Once the graft is prepared, blood is drawn from the patient and a platelet and white blood cell concentrate is prepared and placed on the back table. The graft is then placed in the concentrate slurry while completing the distraction process. (Figs. 5 A – C)

  

Figures 5A, 5B and 5C  The allograft is cut directly from a hard cortical section of humeral cadaver bone. (A)  Once the bone is shaped, the graft is pre-drilled along the long axis of the bone to prepare for interpositional insertion of the graft to the fourth metatarsal. (B)  While the laminar spreader is distracting the bone, once the graft is ready, it can remain in the platelet and white blood cell concentrate taken from the patient’s own blood. (Biomet® Bioorthologics GPS® III)

When the distraction process is complete, the graft is now ready for placement. This stage can be technically challenging due to the persist tightness of the confined space. The graft often has to be re-shaped or slightly shortened for proper placement. That is why it is important to properly measure the distance of distraction prior to graft placement.

At this point the laminar spreader is removed and the wire is reverse drilled along the distal portion of the metatarsal through the digit. The bone must be angled and care must be taken to not plantarflex the digit too much once pinned.

Once the k-wire is in proper alignment, the graft is carefully inserted within the metatarsal. The most challenging aspect of this surgery is aligning the pre-drilled hole with the k-wire and through-drilling to the most proximal segment of the fourth metatarsal. (Figs. 6 A-C)

  

Figures 6A, 6B and 6C  The laminar spreader is removed after an hour of distraction.  The mini c-arm is used to determine the proper amount of distraction to attain the proper metatarsal length and parabola. (A)  The k-wire is directed distally first.  The bone is angulated and then drilled through the fourth digit. (B)  The graft is then interposed within the fourth metatarsal, drilled and stabilized with a .062 k-wire.  (C)

Once the graft is in place, the remaining platelet and white blood cell slurry is lavaged into the wound prior to closure. A small Jergen’s® ball is placed on the k-wire and the foot is then dressed in a smile gauze dressing and placed non-weight bearing in a posterior leg splint. (Figs. 7 A – C)

  

Figures 7A, 7B and 7C  Once the graft is securely in place, the patient’s own platelets and white blood cells are lavaged into the wound. (A and B)  The pin is protected with a Jergen’s® ball at the end of the k-wire and closed prior to application of dressings and a posterior leg splint. (C)

After 2 weeks in a posterior splint and when the sutures are removed, the patient is placed in a short leg fiberglass cast for an additional 6 weeks. The entire immobilization period is about 8 weeks before partial to full weight bearing can resume. Radiographs performed at the end of 8 weeks reveals solid and complete incorporation of the graft along the metatarsal shaft.

The patient has now been seen over the last year without pain or complication to the graft. The toe actually moves without any stiffness to the metatarsophalangeal joint on range of motion. She is very pleased with her surgical outcome. (Figs. 8 and 9)

Figure 8   At 8 weeks, the bone graft shows signs of bone interposition and callusing. Deformation stress is noted along the proximal half of the 4th metatarsal, but does not compromise the overall shape of the metatarsal.

Figure 9  After 6 months, the patient is very pleased with the restoration of metatarsal and toe length.  There is excellent fourth metatarsophalangeal joint range of motion without pain or discomfort.

Discussion

The author’s have found the use of an allogenic bone graft to have the same characteristics and properties as autogenous bone in one-stage metatarsal lengthening procedures, but without the need to harvest bone graft from the patient. They both have osteogenic, osteoconductive and osteoinductive properties. [18] Osteogenic properties refer to the properties that promote the synthesis of new bone. Osteoconductive properties are those properties of the graft that provide framework where the formation occurs. Finally, osteoinduction is the ability of the graft to “stimulate the host precursor cells to form new bone through differentiation into chondroblast or osteoblast”. [18] One of our concerns before surgery was whether the graft would incorporate as normal bone.

As previously mentioned, there are two techniques commonly used to treat brachymetatarsia: gradual distraction with external fixation and one-stage lengthening using bone grafts.

The first method involves applying an external fixator that is used to gradually lengthen the bone. This is achieved by surgically placing the fixator into the metatarsal that is to be lengthened. About a week post-operatively, the lengthening begins at a rate of ¼ mm four times per day for a total of 1 mm per day. [2] This may take place over a period of several weeks. [5] After the desired result is achieved, the fixator remains static for twice the amount of time it took to perform the distraction, during which time the patient remains non weight-bearing. [5] The patient typically can tolerate full weight bearing once the fixator is removed. [2] The reported advantage to this technique is the soft tissues and neurovascular structures are lengthened at the same time the bone is being lengthened. This tends to maximize the ability of the metatarsal to lengthen. [2]

There are complications that could arise when using gradual distraction over a longer period, but this appears to be more associated with the external fixator. Some of these include hyper-pigmentation around pin sites, pain during distraction, stiffness, decreased range of motion, scarring, deformities, joint dislocation, prolonged bone consolidation and pin-track infections. [1,2,5,8]

One-stage lengthening is a process where autogenous or allograft bone is grafted to lengthen the metatarsal. The advantages of this procedure include a shorter bone consolidation period, smaller incision, and less morbidity. [8,10] Some of the disadvantages and complications involved with autogenous bone grafting include technical difficulty, neurovascular damage, small gain in length, and donor site morbidity. [8,10]

It appears that gradual lengthening in the operating room using a laminar spreading and applying distraction stress gradually over 30 minutes to 1 hour will not cause vascular compromise.

A number of studies have been reported on the viscoelastic properties of the surrounding soft tissues during metatarsal lengthening. [4,10] Stress relaxation will promote a lengthening of soft tissue when gradually performed, even in a relatively short period of time. A too rapid distraction of surrounding tissues will cause more contracture and vascular spasm with tissue compromise. Using this gradual distraction technique with a simple laminar spreader, we were able to achieve over 10mm of lengthening within an hour without vascular compromise to the toe.

Allogenic and autogenous bone grafts have similar properties including bone healing characteristics and incorporation rates. The process of bone healing occurs in four stages; inflammation, soft callus formation, hard callus formation and bone remodeling. During the first stage, there is bleeding at the site which results in a hematoma. Inflammatory cells then penetrate the hematoma to fight infection, secrete cytokines and growth factors and promote clotting. In the next stage chondrocytes and fibroblast produce a soft callus to provide mechanical support and a template for the bony callus. The third stage is where most of the osteogenesis occurs. There is a high level of osteoblastic activity and formation of mineralized bone. The soft callus is slowly removed and revascularization occurs. [20] In the final stage, remodeling of the bone occurs, blood circulation to the area improves and the bone becomes compact. Complete bone healing takes 6 – 8 weeks, although factors such as movement, smoking, poor nutrition, age and disease can affect the healing rate. [21]

An advantage to allogenic bone grafting is that there is no need to harvest bone from the patient, thus there is no donor site and a second surgery site. Having a second surgery site, or in this case, a donor site can potentially make surgery more complicated, and increase the risk of infection as well as creating increased pain along the donor site. It is very common for the donor site to be more painful after surgery than the recipient site, especially at the iliac crest. With allogenic bone, there is no donor site pain, no type matching or rejection, and the allogenic bone can be pre-shaped to decrease the surgery time. [16]  To our knowledge, this is the first reported successful correction of brachymetatarsia with complete incorporation of a cadaver allograft using the Biocleanse® sterilization process.

The BioCleanse® Sterilization Process

The BioCleanse® sterilization process is used by Regeneration Technologies to prepare allograft tissue for surgical uses. These implants are used in spinal, sports medicine, general orthopedic, cardiovascular, and dental surgeries. [17] Before any tissue is used, a medical and social history of the donor is obtained from the donor’s family. The tissue is then inspected and screened for diseases (such as HIV and hepatitis). [15] Upon approval, the tissue enters into the automated sterilization process. [14] In the first step of the sterilization process blood, lipids, and marrow are removed from the bone via a vacuum/pressure process to reduce the risk of immune response in the recipient. Next, chemical sterilants are used to eliminate pathogens. This process is designed to go deep within the tissue matrices to eliminate pathogens such as bacteria, viruses, and fungi. Finally, the germicides are removed, and the tissue’s biocompatibility is preserved in the process. [13] In order to ensure a low contamination rate, surface sterilization is incorporated during final packaging through low doses of gamma irradiation or hydrogen peroxide gas plasma. [13]

Mroz, et al., in analyzing the biomechanical properties of allograft bone treated by the sterilization process concluded “Sterilization of allograft bone with Biocleanse® does not significantly alter the mechanical properties when compared with untreated samples. The effect of this sterilization process on the osteoconductive and osteoinductive properties of allograft bone must be determined.” [22]
In this case report, it appears the allograft incorporated well within the surrounding bone and tissue and provided this patient with adequate bone lengthening without the need for autogenous bone harvest.

References

1. Gilbody J, Nayagum S: Lengthening of the first metatarsal through an arthrodesis site for treatment of brachymetatarsia: A case report. Journal of Foot Ankle Surgery. 47 (6): 559 – 564, 2008.
2. Houshian S, Skov O, Weeth R: Correction of congenital brachymetatarsia by gradual callus distraction. Scand J of Plast Reconstr Surg Hand Surg. 36 373 – 375, 2001.
3. Pedro V. Munuera Martínez PVM, Guillermo Lafuente Sotillos G, Domínguez Maldonado G, Luis Salcini Macías J, Martínez Camuña L: Morphofunctional Study of Brachymetatarsia of the Fourth Metatarsal. J Am Podiatric Assoc . 94 (4) 347-352, July-Aug. 2004.
4. Goforth W. et al Brachymetatarsia of the Third and Fourth Metatarsals. J Am Podiatric Assoc. 91 (7) 373-378, 2001.
5. Wilusz P, Van P, Pupp GR: Complications associated with distraction osteogenesis for the correction of brachymetatarsia: A review of five procedures. J Am Podiatric Assoc. 97 (3) 189 – 194, 2007.
6. Allmendinger A, Yeghiayan P, Perone R, St. Vincent’s Medical Center in New York City: Case of the month. diagnostic imaging 31( 1) [online] Accessed February 7, 2009.
7. Kim HT, Lee SH, Yoo CI, Kang JH, Suh JT: The Management of Brachymetatarsia. Journal of Bone Joint Surgery. 85B (5) 661 – 665, 2003.
8. Kim J, Baek GH, Chung MS, Yoon PW: Multiple Congenital Brachymetatarsia: One-Stage Shortening and Lengthening Procedure Without Iliac Bone Graft. Journal of Bone Joint Surgery. 86B (7): 1013 – 1015, 2004.
9. Bone Graft Alternatives. North American Spine Society [online]Assessed February 15, 2009.
10. Baek GH, Chung MS: The Treatment of Congenital Brachymetatarsia by One-Stage Lengthening. Journal of Bone Joint Surgery. 80B (6): 1040 – 1044, 1998.
11. (2003) BioCleanse Tissue Sterilization :Sterilization Validation. Regeneration Technologies, Inc. [online] Accessed March 21, 2009
12. Finkemeier C. Bone-Grafting and Bone-Graft Substitutes. Journal of Bone Joint Surgery. 84A (3): 454-463, 2002.
13. Bostrom MPG, Seigerman DA: The Clinical Use of Allografts, Demineralized Bone Matrices, Synthetic Bone Graft Substitutes and Osteoinductive Growth Factors: A Survey Study. Hospital for Special Surgery, 2005 [online] Accessed March 21, 2009.
14. No author: A New Standard for Tissue Sterility. Regeneration Technologies (2006) [online] Accessed March 21, 2009.
15. No author: From Donation to Implantation. Regeneration Technologies (2006) [online] Accessed March 21, 2009.
16. No author: Biologics vs. other materials. Regeneration Technologies (2006) [online] Accessed March 21, 2009.
17. No author: Biologics Implants. Regeneration Technologies (2006) [online] Assessed March 21, 2009.
18. Sen MK, Miclau T: Autologous Iliac Crest Bone Graft: Should it Still be the Gold Standard for Treating Nonunions?. Injury. 38 (1) S75-S80 2007.
19. Malay DA: Closer look at bone graft substitutes. Podiatry Today (18) 1 Sept, 2005 [online] Accessed April 15, 2009
20. Schindeler A, et al Bone Remodeling During Fracture Repair: The Cellular Picture. Seminars in Cell & Developmental Biology 19: 459 – 466, 2008
21. No author: Bone Healing (2008, May 26). American College of Foot and Ankle Surgeons [online] Accessed April 15, 2009.
22. Mroz TE, Lin EL, Summit MC, Bianchi JR, Keesling JE Jr, Roberts M, Vangsness CT Jr, Wang JC: Biomechanical analysis of allograft bone treated by novel tissue sterilization process. Spine Journal 6 (1): 34 – 39, 2006.


Address correspondence to: Al Kline, DPM
3130 South Alameda, Corpus Christi, Texas 78404.
Email: al@kline.net

Adjunct Clinical Faculty, Barry University School of Podiatric Medicine. Private practice, Chief of Podiatry, Doctors Regional Medical Center. Corpus Christi, Texas, 78411.
2  Texas A&M Graduate (Hons), Corpus Christi, Texas, Incoming first year student, Barry University School of Podiatric Medicine.

© The Foot and Ankle Online Journal, 2009