Tag Archives: Subtalar joint

Evaluation of the subtalar joint during gait using 3-D motion analysis: Does the STJ achieve neutral position?

by James M. Mahoney DPM1*, Eric So DPM1, David Stapleton BS2,3, Kevin Renner DPM1,2, Alayna Puccinelli DPM1,2, Vassilios Vardaxis2,3

The Foot and Ankle Online Journal 12 (1): 4

Background: One theory of hindfoot biomechanics claims that the subtalar joint (STJ) reaches neutral position during midstance, while another maintains that the STJ stays in an everted position throughout.  There is also evidence that STJ position during midstance changes with walking speed. The present study will compare four distinct STJ static positions to 3D kinematics of the STJ during self-selected and fast gait in over-ground level walking.
Methods: The right lower leg of 20 male participants was placed in three clinically used subtalar joint neutral static positions using biomechanical examination: SJNR (STJ neutral by calculation method), SJNP (STJ neutral by palpation method), NCSP (neutral calcaneal stance position), as well as in the resting bilateral standing posture RCSP (resting calcaneal stance position).  An eight-camera 3D motion capture system was used to capture and analyze the kinematics of the ankle complex during self-selected and fast walking conditions, as well as, the four static postures.
Results: The 3D subtalar joint movement pattern did not coincide with any of the three subtalar joint neutral positions (SJNR, SJNP and NCSP) during the midstance phase of self-selected or fast walking. Specifically, the subtalar joint remained in a significantly more everted and abducted position with greater deviations from neutral under the fast-walking condition.
Conclusions: None of the clinically used STJ neutral positions agree with the 3D pattern of the STJ during self-selected and fast gait. These results have implications related to clinical practice and the use of the STJ neutral position for evaluation and treatment purposes.    

Keywords: subtalar joint, biomechanics, gait

ISSN 1941-6806
doi: 10.3827/faoj.2018.1201.0004

1 – College of Podiatric Medicine and Surgery, Des Moines University, Des Moines, IA, United States
2 – Human Performance Laboratory, Des Moines University, Des Moines, IA, United States
3 – Department of Physical Therapy, Des Moines University, Des Moines, IA, United States
* – Corresponding author: James.Mahoney@dmu.edu

One of the prevailing concepts of STJ function was first advocated by Root [1].  He described his theory of subtalar joint neutral during walking as follows: “Shortly before heel lift, the subtalar joint reaches its neutral position.  During the remaining midstance period, the subtalar joint continues to supinate, and the rearfoot moves into a supinated position.” The validity of Root’s observation of subtalar joint neutral position, however, has been questioned in the biomechanics literature [2]. McPoil and Cornwall published a study in 1994, where they determined the pattern of the rear foot motion on the frontal plane during gait and compared it to the subtalar joint in the neutral position [3]. Contrary to Root’s theory, their findings concluded that the neutral position of the rearfoot during stance more closely resembled the resting calcaneal stance position than subtalar joint neutral position.  

Pierrynowsi et al. questioned the 2-D motion capture used by McPoil and Cornwall as describing the relative rear foot frontal plane motion accurately for only the first 4-36% of the gait cycle, and determined that 3-D motion capture was required to properly assess STJ motion during gait [4].  Pierrynowski et al. improved motion capture methodology and also concluded that the rearfoot did not achieve subtalar neutral position during the stance phase in gait. However, in their study, motion capture of the rearfoot, was taken while subjects walked at a slow speed on treadmill set at 0.89 meters/seconds the same for all subjects. The treadmill as the walking surface seems to affect foot motion during gait and as such it may alter the true rearfoot kinematics during the stance phase of gait [5].

Walking speed itself may also influence STJ position. Tulchin et al [6] findings concluded that when evaluating foot kinematics during gait it was imperative to account or control for walking speed because of the changes that occur with sagittal plane motion in the foot as walking speed increases; namely, an increase in plantarflexion of both the hindfoot and forefoot.  Rosenbaum et al [7] showed that with increasing walking speed there was also an increase in pronation. However, both Torburn and later Dubbledam showed that rearfoot motion in the frontal plane was not influenced by walking speed [8,9].

To further understand the function of the STJ during gait, we compared the 3D subtalar position during the midstance phase of gait at self-selected and fast walking speeds on a level walkway to three common clinically used subtalar joint neutral positions and the resting bilateral stance.



Twenty unimpaired, healthy adult male subjects volunteered to participate in the study (age 24.7 ± 1.7 years; mass 79.3 ± 12.0 kg; height 180 ± 7 cm). Inclusion criteria consisted of subjects who were active adults, free from injury over the last year, able to ambulate barefoot without the need for assistive devices, without any lower extremity/foot malalignment or had use of arch supports, shoe pads or foot orthoses. The study was reviewed and approved by the Institutional Review Board.

Experimental protocol

The subtalar joint neutral position is defined in three different ways.  Two involve non-weight bearing measurements: one by mathematical calculation and the second by palpation. The third way is in a weight bearing bilateral stance position.  In our study, we refer to the non-weightbearing mathematical calculation as SJNR (subtalar joint neutral by range of motion). Root provided a detailed explanation of how to find the subtalar neutral position in the non-weight bearing position which involved establishing the total range of motion for inversion and eversion followed by calculations with a formula he provided  which calculated the neutral position as 1/3 of the total range of subtalar joint inversion and eversion from the maximally everted position [10]. The second non-weightbearing STJ neutral position method employs a palpatory technique which we refer to as SJNP (subtalar joint neutral by palpation). This technique was not originally advocated by Root, but instead was adapted and modified over time based on Root’s principles. It involves palpating for the congruency of the talar head [11].   This SJNP technique is like that employed by McPoil and Pierrynowski [3, 4]. The third STJ neutral position is weight bearing NCSP (neutral calcaneal stance position). Root described it as follows: with the subject weightbearing in the normal angle and base of gait, the clinician “palpates the congruity of the medial and lateral edges of the talus in relationship to the calcaneus at the subtalar joint”, in addition to making sure “the concavity of the lateral surface of the foot is parallel to the concavity on the lateral surface of the leg”, and finally that “the lateral surface of the foot describes a straight line in the area of the calcaneocuboid joint” [12].  This technique has been modified over time so that it is most commonly measured by palpating for congruency of the medial and lateral aspects of the talus with the patient standing in the normal angle and base of gait [11]. Root also provided a technique for measuring the frontal plane position of the calcaneus, in the relaxed bilateral stance position, relative to the weightbearing surface which requires one to stand “in normal angle and base of gait” [12]. In the present study, this method is referred to as RCSP (relaxed calcaneal stance position) [See Table 1].

Data collection commenced after obtaining consent from each subject. First a clinical/biomechanical exam was performed on each subject bilaterally. During the clinical/biomechanical exam, subjects’ feet were inspected for any visible deformities and standard goniometric measurements were taken for the subtalar joint inversion, eversion range of motion (ROM), as well as the subtalar varus/valgus angle at each of the SJNR, SJNP, NCSP, and RCSP static positions (in random order), using frontal plane bisection lines of the posterior calcaneus and distal shank, according to Root’s protocol [10,12]. At the completion of the clinical exam, disposable, adhesive, radiopaque skin markers (2.0 mm pellets) were attached along the bisection line of the calcaneus and distal shank (0.33 mm diameter line), as well as the sustentaculum tali and the peroneal tubercle. Posterior and lateral x-rays were taken, and the relative locations of the radiopaque markers were used along with palpation for accurate skin adhered motion analysis marker placement for better bone alignment representation purposes.

The 3D rear foot joint angles at the four static positions and the average 3D rear foot joint angles over the midstance phase for the two different gait speeds were compared in this study. Two trials for each of the standing (RCSP and NCSP) and prone (SJNR and SJNP) static positions were collected prior to the walking trials. Each static trial captured consisted of three seconds while the positions described above were maintained. The gait speeds were self-selected typical and self-selected fast barefoot walking on a level grade walkway. The subjects were asked to walk first at their preferred typical self-selected speed (SSG) and then at a self-selected faster speed (FWS). Five successful gait trials per speed condition were captured after familiarization with the laboratory environment. A trial was deemed successful if the subject’s right foot completely contacted one of the force plates, while the subject did not adjust his step pattern. The average self-selected typical gait speed was 1.27 ± 0.11 m/s, with an average stride length of 1.38 ± 0.09 m, cadence of 109.6 ± 5.8 steps/min, and stance phase duration of 60.9 ± 1.4 % of the gait cycle. The respective gait parameters for the self-selected fast gait were the following: gait speed of 1.70 ± 0.20 m/s, with an average stride length of 1.82 ± 0.12 m, cadence of 124.9 ± 11.1steps/min, and stance phase duration was 58.7 ± 1.7 % of the gait cycle.

The shank (including tibia and fibula) and the calcaneus segments were assumed to be rigid and were tracked in the laboratory reference frame using retro reflective markers (7.9 mm diameter) adhered to the skin at specific anatomical landmarks to construct the respective segmental anatomical reference frames. Specifically: for the shank, markers were placed on the tip of the lateral malleolus (LM), the tip of the medial malleolus (MM), the tip of the fibular head (FH), and the top and bottom of the shank bisection line (TSB) and (BSB), respectively. For the hind foot, markers were placed at the top and bottom of the calcaneus bisection line (TC) and (BC) respectively, the lateral apex of the peroneal tubercle (PT), and the medial apex of the sustentaculum tali (ST).  Redundant markers on the shank and calcaneus were placed in the following places for tracking purposes: top and bottom lateral shank (TSL) and (BSL), along the line of the lateral epicondyle of the knee and the lateral malleolus; top and bottom tibia (TT) and (BT) on the medial surface; and the medial and lateral aspect of the calcaneus (MC) and (LC) on a transverse plane passing through the midpoint between TC and BC with the subject standing in the RCSP position. In addition, a toe marker was placed on the second metatarsal head (SMH), which was used as a guide to identify the midpoint between the posterior calcaneus markers TC and BC, at which level the MC and LC were placed, using a laser level during RCSP standing static position. The entire marker set was used for the two standing static positions (RCSP and NCSP), as well as a standing static reference position with the feet at shoulder width apart parallel to each other. The MM, PT and ST markers were removed and were created virtually for the two prone static positions and the dynamic gait captures.

Given the above marker placement, the anatomical reference frames were defined: (1) right shank; the frontal plane was defined by the mid-malleolus point MMP (mid-point between the MM and LM), the LM and the FH; the sagittal plane orthogonal to the frontal, containing the MMP and the mid-shank point MSP (mid-point between the TSB and BSB); the transverse plane for the shank was mutually perpendicular to its frontal and sagittal planes, (2) right hind foot (calcaneus); the sagittal plane was defined using the TC, BC and the midpoint between the MC and LC; the transverse plane orthogonal to the sagittal, containing the midpoints of the TC and BC, and the MC and LC; the frontal plane for the hind foot was mutually perpendicular to its sagittal and transverse planes.

The three-dimensional joint angles of the calcaneus with respect to the shank (representing both the subtalar and the talocrural joints) were calculated using Cardan angles. The sequence of rotations used was sagittal (plantarflexion (-) / dorsiflexion (+)), frontal (eversion (-) / inversion (+)), and then transverse (abduction (-) / adduction (+)) plane [13].   

The kinematics data was collected at 120 Hz, using an eight-camera motion capture system (Motion Analysis Corporation, Santa Rosa, CA). Ground reaction force data was collected at 1200 Hz using three force plates (AMTI, Watertown, MA) mounted flush with the walking surface and aligned in the direction of walking. A 10 N threshold for the vertical component of the ground reaction force (GRF) was used to determine the stance phase of the gait cycle (heel contact to toe-off).

To remain consistent with Root’s theory that “shortly before heel lift, the subtalar joint reaches its neutral position”, the midstance phase is operationally defined here as the portion of the stance phase were the foot is flat on the ground from the instant of toe-down to the instant of heel-off. This is consistent with the “Ankle Rocker” definition of Jacquelin Perry where the foot is plantigrade with foot-flat support [14]. The timing of the toe-down and heel-off events were determined using a simple algorithm of threshold crossings of the vertical coordinate of the toe (SMH) and virtual heel (midpoint of TC and BC) markers relative to the average height of these markers during the RCSP static position. Specifically, the toe-down event was identified as the frame following the negative crossing when the vertical coordinate of the SMH marker crossed its respective level of the static RCSP position, and the heel-off event was identified as the frame prior to the positive crossing were the vertical coordinate of the virtual heel marker crossed its respective level plus 3mm higher than the static RCSP position. The plus 3mm level adjustment was needed for consistent event detection to account for the decompression of the heel pad.  

One-way repeated measures ANOVA design was used to test for differences in the subtalar joint position across all four static conditions and the mean STJ position during midstance for SSG and FWS gait for each of the 3D planes (at α < 0.05). A set of a priori comparisons were performed to test for significant differences in STJ position between gait and each of the 4 static conditions, controlling for Type I error with a Bonferroni adjustment by setting the alpha (α) level to 0.05/4 = 0.0125. Paired t-test procedures were used to test for subtalar joint position differences between SSG and FWS gait (at α < 0.05).  The Statistical Package for the Social Sciences (SPSS Version 24.0, Chicago, IL) was used for all data analysis.


The three-dimensional angles of the calcaneus with respect to tibia during the stance phase of gait are shown in Fig. 1. Specifically, the average kinematic curve patterns of an individual subject are shown for the (a) sagittal, (b) frontal, and (c) transverse planes along with his five individual trials during typical self-selected (SSG) walking speed. In the sagittal plane, the three functional arcs are visible starting with the plantarflexion motion of the calcaneus with respect to the tibia approximately until the toes are down (TD). This plantarflexion action is followed by a prolonged dorsiflexion arc where the tibia moves forward on the plantigrade foot, as the load on the foot moves towards the forefoot, and continues this dorsiflexion action beyond heel-off (HO). The final arc is a rapid motion of the calcaneus with respect to the tibia in the plantarflexion direction, probably due to high forces produced by the triceps surae during propulsion.  

In the frontal plane, the calcaneus remains in a relatively fixed inverted position until toe-down, followed by an eversion arc while the foot is plantigrade well beyond the heel-off, and during the latter part of the stance we see a rapid relative inversion motion until toe-off.

Figure 1 Exemplar single subject temporal profiles (5 trials and mean), of the three dimensional angles of the calcaneus with respect to tibia during stance phase of self-selected speed gait. (a) to (c) represent the sagittal, frontal and transverse planes, respectively. The midstance phase is identified between toe-down (TD) and heel-off (HO). Thin dashed lines denote individual trials (N=5), thick solid line is the average pattern.  

The transverse plane motion is characterized by two arcs, a rapid initial abduction until toe-down followed by a gradual prolonged adduction that lasts until toe-off. Overall, there was no difference in the shape of the kinematic curve patterns between trials, subjects, and walking speeds (Figure 1).

The calcaneus to tibia average midstance phase angles show the subtalar joint for the fast gait condition (FWS) in significantly greater dorsiflexion (p=0.026) and eversion (p=0.000) position relative to the self-selected (SSG) gait condition (Table 2).  

The one-way repeated measures ANOVA reveal significant differences in all three planes across all the static positions and the dynamic gait conditions (p<0.000). The calcaneus is in a significantly greater inversion (Figure 2) and adduction (Figure 2) position for all three subtalar neutral positions (NCSP, SJNP and SJNR) as related to the average midstance phase position during typical (SSG) and fast walking speed (FWS) gait. The non-weight bearing subtalar neutral joint positions (SJNP and SJNR) place the subtalar joint in a significantly greater plantarflexion position relative to the average subtalar joint position during the midstance phase of both SSG and FWS gait. The weight bearing subtalar neutral position (NCSP) places the subtalar joint in a significantly greater dorsiflexion position relative to the self-selected gait position (Figure 2).

The calcaneus to tibia joint position during the resting calcaneal stance position (RCSP) showed no differences with the average midstance phase position of the subtalar joint during either one of the gait conditions (SSG and FWS) on the sagittal plane (Figure 2). While the calcaneus was found to be everted and adducted with respect to the tibia during the RCSP static position which is consistent with the average midstance phase position during gait, it showed significantly less eversion and adduction angles (Figure 2).    


In the current study, we compared the average midstance position (toe-down to heel-off) of the STJ to the resting calcaneal stance position and the three STJ neutral positions: calculation by taking 1/3 of the total range of STJ motion from the maximally everted position (SJNR), palpation of the medial and lateral sides of the talar head non-weight bearing (SJNP), and neutral calcaneal stance position (NCSP).  Our data showed that the STJ during midstance in gait was everted and abducted relative to these three STJ neutral positions. We also found that eversion and adduction of the calcaneus in relation to the tibia increased during fast walking speed.

The protocol that we followed to measure the movement of the STJ during gait is based on the work of Leardini et al [15] who demonstrated that dynamic foot function is best measured by considering the foot as a multisegment structure, rather than a single, rigid body.  Furthermore, Tulchin [6] showed that increased walking speed changes the foot kinematics assessed using a multisegment foot model which led us to the protocol to evaluate the STJ motion during both self-selected and fast-walking gait.  

Figure 2 Group means (S.D.) of the calcaneus with respect to tibia angles (º), of the average midstance phase of the self-selected (SSG) and fast walking (FWG) speed gait, and the four static conditions (RCSP, NCSP, SJNP, and SJNR) for: (a) sagittal, (b)  frontal, and (c) transverse plane. Bonferroni adjusted significant differences ( p<0.0125) between SSG and FWG for each of the static conditions are denoted by * and † respectively.

Contrary to Root [1], our data showed that the STJ was in a relative everted throughout the midstance portion of gait, rather than achieving neutral position, in agreement with McPoil [3] and Pierrynowski [4], despite their methodological limitations of 2D analysis and fixed low walking treadmill speed, respectively.  

Recently, Buldt et al. [18] showed that clinical static foot postural and mobility measures can explain only a small amount of variation seen in foot kinematics during walking amongst asymptomatic individuals. Their data suggests that the clinical practice measures of foot posture (such as the STJ neutral) and mobility have limited application to foot function during dynamic tasks.   

One of the major points of contradiction between the work of Root and others regarding STJ neutral position during gait is probably due to Root’s misinterpretation of previously published data. Sobel and Levitz [16] maintain that Root developed his theories of STJ neutral from the work of Wright [17].  In his study, what Wright referred to as the RCSP, Root interpreted as STJ neutral. Whether it was the RCSP or neutral position that was described by Root, our data showed that the actual position of the STJ during gait was everted to both.

Measuring the neutral position of the STJ in a static position has been critical in clinical practice for predicting the “ideal” position of the foot as it functions during gait.  Root advocated that STJ neutral was the most stable position of the foot during gait [1], and therefore, foot pathology occurs when there is deviation from this “ideal” neutral position.  This applies to the fabrication of foot orthoses, when casts of the feet are taken in either static non-weight bearing or weightbearing STJ neutral position.

While our data showed a significant discrepancy between the static relaxed and the STJ neutral position(s) commonly used in clinical practice against the average dynamic STJ during the midstance phase of gait, there is a substantial concern in the literature related to the lack of STJ neutral position intra- and inter-rater reliability. According to Pierrynowski , experienced practitioners were within ±1° of the subtalar joint non-weight bearing neutral position only 41.3% of the time (within ±3°, 90% of the time)[19].  In Van Gheluwe et al’s study, five experienced podiatric physicians showed a high intra-rater reliability when measuring STJ pronation and supination, NCSP, and RCSP but very poor inter-rater reliability except for RCSP [20]. Elveru reviewed the literature concerning the non-weight bearing measurement of subtalar joint neutral position and subtalar joint passive range of motion and concluded that “their reliability is less than optimal [21].” Open and closed kinetic chain measurement of STJ neutral yielded poor intra-rater and inter-rater reliabilities when performed by two inexperienced testers, according to Picciano [22].  Smith-Oricchio found that measurements of calcaneal inversion and eversion and STJ neutral had low to moderate inter-rater reliability [23].


Our study has shown that the STJ during midstance in gait was more everted and abducted relative to all three STJ neutral positions performed under weightbearing or non-weight bearing conditions. This discrepancy between the STJ position during gait and the STJ neutral positions brings into question the clinical practice use of the STJ neutral position to determine the “ideal” functional position for the foot, as well as its use for orthosis prescription purposes.

Conflict of Interest

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article:  Des Moines University College of Podiatric Medicine and Surgery.

Abbreviation Definition Load
RCSP Relaxed calcaneal stance position Weight Bearing
NCSP Neutral calcaneal stance position Weight Bearing
SJNP Subtalar joint neutral by palpation Non-weight Bearing
SJNR Subtalar joint neutral by range of motion Non-weight Bearing

Table 1 Abbreviations, definitions and load conditions for the neutral and relaxed subtalar static positions of the foot.

Variable Self-selected speed gait (SSG) Fast walking speed gait (FWS)
Mean ± SD 95% CI Mean ± SD 95% CI t p
Sagittal Plane – DF:(+) -0.44 ± 2.35 -2.66 to 5.29 0.22 ± 2.80 -2.22 to 7.48 2.41 .026
Frontal Plane – IN:(+) -3.80 ± 1.66 -6.56 to -1.39 -4.80 ± 2.10 -9.57 to -1.95 4.46 .000
Transverse Plane – AD:(+) -3.51 ± 1.53 -6.31 to -0.75 -4.17 ± 2.17 -8.36 to -1.07 1.99 .061

Table 2 Calcaneus to tibia during midstance (toe down to heel off) average position parameters during gait. Mean, standard deviation, and 95% confidence interval for typical and fast self-selected walking speeds. Differences with walking speed: t-statistic and p values are shown.  


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Lateral subtalar dislocation: A case report

by Vijaykumar Kulambi1, Gaurav M2pdflrg

The Foot and Ankle Online Journal 7 (3): 4

Subtalar dislocation refers to the simultaneous dislocation of the distal articulations of the talus at the talocalcaneal and talonavicular joints. Closed reduction and immobilization remains the treatment of choice. However, if closed reduction is unsuccessful in some patients, open reduction is required. Open reduction can be associated with higher energy subtalar dislocations. A variety of bone and soft tissue structures may become entrapped, resulting in obstruction of closed reduction.  This is a unique case report which presents an unsuccessful closed reduction of an open lateral subtalar dislocation that required open reduction.

Key words: Subtalar joint, dislocation, open reduction

ISSN 1941-6806
doi: 10.3827/faoj.2014.0703.0004

Address correspondence to: Dr. Gaurav M
E mail : movement.gaurav@gmail.com

1 Professor, Dept. of Orthopaedics, J.J.M. Medical College, Davangere, Karnataka State, India.
2 Post graduate student, Dept. of Orthopaedics, J.J.M. Medical College, Davangere, Karnataka State, India.

Subtalar dislocation is an uncommon injury accounting for 1-2% of all joint dislocations [1]. It involves the disruption of the talocalcaneal and talonavicular joints, while the calcaneocuboid joint remains intact [2,3,4,5]. Medial dislocations comprise up to 85% of subtalar dislocations, whereas lateral subtalar dislocations are less frequent occurring in 15% to 20% of dislocations. In medial subtalar dislocation, the head of the talus is found laterally and the rest of the foot is dislocated medially. However, in a lateral subtalar dislocation, the talus can remain fixed while the remaining structures of the foot are dislocated laterally along the talus. Subtalar dislocations present with an impressive amount of deformity. The medial dislocation has been referred to as an acquired clubfoot, while the lateral dislocation has previously been described as an acquired flatfoot [6]. Many of these injuries are open as well, particularly when associated with a high-energy mechanism. Up to 40% of subtalar dislocations may present with an open wound [7].

We present a unique case report of a 30 year old male patient presenting with an open lateral subtalar dislocation following a fall from a height, with posterior tibialis tendon interposition posing difficulty in closed reduction.

Case Report

A 30 year old male patient presented with a history of a fall from a height as he climbed a coconut tree. Initial examination revealed diffuse swelling of the left foot with a laceration of 4 cm over the medial aspect of the left foot, extending distally from below the medial malleolus. The left foot was fixed in a pronated position. Distal perfusion and neurological status of both lower limbs and bladder functions were intact.

Radiographs revealed dislocation of the left talocalcaneal and talonavicular joints, without any regional bony injury (Figure 1, 2, 3).

Initially, closed reduction was attempted which was unsuccessful. The patient was taken to the operating room for open reduction. The talus was explored through the medial wound, and the tendon of tibialis posterior was found to be interposed between the talus and calcaneum.


Figure 1 Preoperative lateral view, demonstrating subtalar joint dislocation without fracture.


Figure 2 Preoperative ankle AP view, demonstrating subtalar joint dislocation without fracture.


Figure 3 Preoperative oblique foot view, demonstrating talonavicular joint dislocation without fracture.


Figure 4 Postoperative lateral view, demonstrating Kirschner wire fixation.

The posterior tibial tendon was retracted, and the talus was levered into a more anatomical position with reduction achieved. Adequate reduction was confirmed using a computer assisted radio monitor (c-arm). A thick Kirschner wire was inserted from the calcaneum into the talus to hold the reduction (Figure 4). A below knee splint was applied after placing a sterile dressing on the operative site.


Clinical reviews of subtalar dislocations are relatively infrequent and generally limited to a small numbers of patients. These injuries most commonly occur in young adult males, although Bibbo et al noted 36% of subtalar dislocations in their case series of 25 patients occurred in patients over 40 years of age [8].

The direction of subtalar dislocation has important effects with respect to management and outcome. The method of reduction is different for each type of injury. Lateral subtalar dislocations are often associated with a higher energy mechanism and a worse long-term prognosis compared to medial subtalar dislocations.

Subtalar dislocations can result from either high-energy or low-energy mechanisms. The distinction is important because outcome has been correlated with the severity of the initial injury. In the case series presented by Bibbo et al, high-energy mechanisms such as motor vehicle trauma and falls from a height accounted for 68% of subtalar dislocations [8]. Open subtalar dislocations and lateral subtalar dislocations are more common with a high-energy mechanism. Medial injuries are more common than lateral dislocations, suggesting that the forces required to produce it are less than those required to produce a lateral dislocation.

High-energy subtalar dislocations may be associated with other injuries, either regional or involving other body systems. Bibbo et al described associated foot and ankle injuries in 88% of patients with subtalar dislocations. In their series of subtalar dislocations from a major level 1 trauma center, other musculoskeletal injuries occurred in 48% of patients and 12% of patients had injuries to the head, abdomen, or chest [8]. Regional fractures include talus, ankle, calcaneus, navicular, cuboid, cuneiform, and metatarsal fractures [9]. Osteochondral shearing injuries to the articular surface of the talus, the calcaneus, or the navicular are common. These injuries occur in up to 45% of patients, and are difficult to detect on plain radiographs [3,10,11]. Injuries remote from the foot and ankle may occur as well.

All subtalar dislocations require a timely reduction. In most cases, closed reduction can be accomplished. Often times, the injury presents with skin tenting requiring a prompt reduction to reduce the possibility of skin necrosis. Open peritalar dislocations require a formal irrigation and debridement in addition to the reduction followed by wound closure [12].

In approximately 10% of medial subtalar dislocations and 15% to 20% of lateral dislocations, closed reduction cannot be achieved [13,14]. Soft tissue interposition and bony blocks have been identified as factors preventing closed reduction. With medial dislocations, the talar head can become trapped by the capsule of the talonavicular joint, the extensor retinaculum, the extensor tendons, or the extensor digitorum brevis muscle [13,14]. With a lateral dislocation, the posterior tibial tendon may become firmly entrapped and present as a barrier to closed reduction requiring open reduction [14,15].

In our case presentation, the patient had sustained a high-energy trauma leading to a lateral subtalar dislocation. Following the initial failed closed reduction attempt, open reduction was required. We identified the tibialis posterior tendon obstructing the possible closed reduction. This case report shows successful open reduction of a lateral subtalar dislocation with Kirschner wire fixation.


  1. Perugia D, Basile A, Massoni C, Gumina S, Rossi F, Ferretti A. Conservative treatment of subtalar dislocations.  Int Orthop 2002;26(1):56-60. – Pubmed citation
  2. Plewes LW, McKelvey KG. Subtalar dislocation.  J Bone Joint Surg Am 1944 Jul;26(3):585-8. – Online
  3. DeeLee JC, Curtis R. Subtalar dislocation of the foot. J Bone Joint Surg Am 1982 Mar;64(3):433-7. – Pubmed citation
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  5. Smith H. Subastragalar dislocation: a report of seven cases.  J Bone Joint Surg Am 1937 Apr;19(2):373-80. – Online
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  7. Merchan EC. Subtalar dislocations: Long-term follow-up of 39 cases.  Injury 1992;23(2):97-100. – Pubmed citation
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Subtalar Arthroereisis with Endorthesis in Adult-acquired Flatfoot: Classification of the Postoperative Rehabilitation Phases

by Massimiliano Polastri, MSc, PT1, Alessandro Graziani, MSc, PT1, Stefano Cantagalli, MD2

The Foot and Ankle Online Journal 5 (4): 1

Flatfoot is a biomechanical condition in which the medial longitudinal arch collapses, causing flattening of the foot towards the ground. In adult-acquired flatfoot, the subtalar joint has a greater range of motion than a normal foot, and multiple factors can cause the onset of this condition. Subtalar arthroereisis with endorthesis is a surgical procedure by which an implant is positioned in the sinus tarsi depression in order to limit the excessive pronation of the subtalar joint. Subtalar arthroereisis is often associated with adjunctive procedures. A period of three weeks of non-weight bearing is recommended after surgery and additional protection is achieved as the load is increased. In order to be able to discuss the postoperative course, it is useful to be able to classify it. Basically, the classification proposed in this paper is a practical/theoretical instrument which seeks to contribute to a better understanding and achievement of the aims and outcome desired at each stage described. Postoperative rehabilitation must be oriented to both protect the surgical site and to enhance foot mobility. We have proposed a classification of the rehabilitative pathway after subtalar arthroereisis with endorthesis based on our experience, also considering the related literature. Furthermore, we provide a synthetic description of the surgery, and the rehabilitation techniques are discussed. The ultimate goal of the rehabilitation project is centered on obtaining the physical condition closest to that required for the daily activity of the healthy population with the aim of returning to full recovery after surgery. To this end, a certain degree of multiprofessional cooperation is always recommended in order to ensure patient safety and obtain the best results.

Key words: Flatfoot, Gait, Prostheses and Implants, Rehabilitation, Subtalar Joint, Surgical Cast, Weight-Bearing.

Accepted: March, 2012
Published: April, 2012

ISSN 1941-6806
doi: 10.3827/faoj.2012.0504.0001

Flatfoot (FF) is a biomechanical condition in which the medial longitudinal arch collapses causing flattening of the foot towards the ground. The onset of this disorder may occur at different ages from the first years of life up to adulthood.

In adult-acquired flatfoot (AAF), the subtalar joint (STJ) has a greater range of motion than a normal foot, and multiple factors can cause the onset of this condition.[1] The STJ is a diarthrosis (trochoid) which connects, in two different locations (separated by the sinus tarsi depression), the posterior-inferior surface of the talus with the superior face of calcaneus and the anterior-inferior part of the talus with the anterior-superior surface of the calcaneus. The articular activities possible at this level are adduction and abduction of the rearfoot, associated with the supination and pronation of the foot, respectively. The realization of these complex movements is facilitated by Chopart’s joint (midtarsal).[2] Arthroereisis is a surgical procedure which limits the amount of motion possible in a joint which has become excessively mobile.[3] In subtalar arthroereisis (SA) with endorthesis, an implant is positioned in the sinus tarsi depression in order to limit the excessive pronation of the STJ, which is typically present in AAF.[4-6] Although it has proven to be an effective surgical technique, certain complications are described in the literature.[7-10] Essentially, in the past, major interest was focused on pediatric patients.[11,12] More recently, Evans (2008) has defined a therapeutic algorithm for rehabilitation treatment in children.[13] Originally, the insert of an expandable orthosis was used for the treatment of pediatric flat foot.[14-16] Characteristics of the implants are discussed in the literature.[17] Evans and Rome (2011), have found that there is limited evidence of the efficacy of non-surgical intervention in children with flexible flat feet. In their research, these authors have also provided a wide and complete overview of the surgical approaches available, including arthroereisis.[18] As introduced above, pronation is one of the movements (together with supination) possible at the subtalar level; one must be aware of this because valgus of the rearfoot characterizes AAF. Postan et al. (2011) have discussed the association of the anatomical variations of the spring ligament and sustentaculum tali with the risk of developing AAF.[19] Chang and Lee (2007) have provided a careful description of the kinematics, the surgical treatment, and the indications and contraindications as well as the postoperative management, and have described one condition which causes flexible AAF namely: the posterior tibial tendon dysfunction.

For the correction of AAF, adjunctive procedures are often carried out using SA. A period of three to four weeks of non-weight bearing in a cast is recommended after surgery and additional protection is achieved with the use of a walker for more three weeks as the load is increased.[20] The main purpose of this study was to classify the rehabilitation phases after surgical correction of AAF by means of SA with endorthesis. The literature was reviewed to identify studies which have investigated postoperative rehabilitation after SA. To our knowledge, no previous papers have been published on this matter.

Surgery at a glance

We herein describe the procedure of subtalar arthroereisis with endorthesis in association with additional procedures on soft tissues for the treatment of painful and flexible AAF.[5,20] Subtalar arthroereisis locks the sliding between the talus and the calcaneus, restoring their positions; an implant (ProStop®, Arthrex Inc., Naples, FL 34108, US) is inserted within the sinus tarsi determining the reduction of the pronation of the STJ acting as a self-locking wedge, according to Vogler’s classification.[21] This system is composed of titanium cannulated screws, threaded and conical in shape, of different sizes (7 to 12 mm) and lengths (12 to 16 mm) so that they can be precisely adapted to the tarsal canal. The anesthesia is generally spinal and specific for the limb operated on. It is carried out by injecting anesthetic into the subarachnoid space with a 25 Gauge needle by means of a injection of the dura mater and of the arachnoid in the lumbar spaces below L2. To this end, the patient is positioned in a sitting position or in lateral decubitus, and the procedure is performed aseptically. Before placing the patient on the operating table, one must wait approximately 5-10 minutes to evaluate the level of the anesthesia. The surgical technique is performed with the patient in a supine position on the operating table with a tourniquet at the root of the thigh root after inserting the limb into an Esmarch bandage. The tourniquet is applied to induce lower limb ischemia so as to create a bloodless field in order to better identify the vascular structures, nerves and tendons.

An incision of approximately two cm on the lateral portion of the sinus tarsi is made, allowing the insertion of a guide wire between the two beams of the talar-calcaneal ligament and the interosseus ligament; this facilitates the introduction of a size tester. Under fluoroscopy, the correct implant dimension is determined and the surgeon can proceed with the insertion of the screw using a screwdriver until, the screw itself, is level with the outer edge of side wall of the talus neck. The guide wire is removed and a stitch is applied. At this point, the tension of the triceps tendon is evaluated and, if necessary, a Hoke’s percutaneous tenotomy is performed to achieve the appropriate dorsal flexion of the ankle joint.[22] Subsequently, to correct the talus protrusion, an additional internal procedure of tensioning of the posterior tibial tendon is carried out:[23,24] an incision of approximately four cm is made on the navicular tuberosity, the tendon is detached from the navicular tubercle maintaining the plantar extension of the fibers, and the periosteum is dissected. The prominence of the navicular is then tangentially excised and, if present, accessory bone is removed; tenolysis, repair and tensioning of the posterior tibial tendon are performed at this point. The surgery, including the additional procedures as described above, requires approximately 60 minutes.

Rehabilitation phases

Antithrombotic prophylaxis is managed at home with low molecular weight heparin for thirty days after surgery. During the postoperative course, the patient must use a walker for thirty-five days and walk without weight bearing for the first three weeks. Between days twenty-one and thirty-five, the load is progressively increased. In order to be able to discuss the postoperative course after SA with endorthesis, it is useful to be able to classify it. Basically, the classification proposed in this study is a practical/theoretical instrument which may help professionals to better understand and achieve the aims and outcome desired at each stage described. Each phase must be carefully evaluated both physically and clinically.

If we think of the STJ as two overlapped cylinders, we immediately realize that, at this level, the maximum range of motion is possible in the transverse plane: the cylinders can thus produce movements of pronation and supination. Conversely, flexion and extension are limited due to the anatomical surfaces (Fig. 1).

Figure 1 Schematic representation: sinus tarsi is an anatomical space present between the talus (top) and the calcaneus (bottom). Due to the anatomical surfaces, the two cylinders can roll one upon the other (pronation and supination).

Stage 1 (immobilization and pain)

After surgery, patients are advised not to put weight on the foot and to use a walker in order to protect the surgical site for a period of three weeks. In this initial phase, the patient is likely to be overcautious and have some degree of fear, in carrying out the usual daily activities. Both, pain and infection prevention procedures are similar to those provided in arthroscopic surgery of the ankle.[25] Conversely, patients undergoing ankle arthroscopic excision do not wear a cast after surgery and they are advised to limit the range of motion and to protected the load in the first twenty-four hours postoperatively.[26] On the other hand, in surgical procedures of the ankle more invasive than SA, patients are encouraged to exert weight after surgery.[27]

In patients undergoing SA, if a physiotherapist is involved in stage 1, in order to prevent/manage any complications, he/she must be present as a counselor and must refer every unusual condition (after clinical evaluation) which may compromise the postoperative course. When no red flags (severe pain, heat, inability to walk even with the walker) are present, the rehabilitation activity is limited to observation and advice (sleeping with minimum elevation of the feet putting a pillow under the mattress, walking short differences but often, maintaining proper alignment of the pelvis through the correct use of crutches, noting if there is blood in the dressing, regularly using the walker). Orthopedic procedures are recognized as the most painful because of the need to walk.[28] In stage 1, pain should be low to moderate and no additional treatment is usually required. Otherwise, the patient must be referred to a physician.

Stage 2 (edema, pain and weight-bearing)

When the dressing is removed after 35 days, the physiotherapist must check for the presence of edema. If, in the previous stage, pain control was obtained by means of anti-inflammatory drugs or painkillers, the residual -algic conditions must now be evaluated and eventually treated by referring the patient to a physician.

Permanence of the -algic symptoms represents a complication assuming that, after one month, in almost all cases, pain should be at a minimum. Nevertheless, a certain degree of discomfort is present during or after walking/standing. Furthermore, in this period, which covers the first 35-50 days, the presence or absence of possible algodystrophy must be evaluated. Tenderness, vascular instability, stiffness and swelling, if present, are red flags for this issue. On the other hand, if the foot is not swollen, not hot and not painful, the edema (if present) can be treated through massage, and elevation at night. Thanks to the surgical technique, manual treatment of the sinus tarsi scar is not usually necessary (minimal access); conversely, manual massage is performed to facilitate the disappearance of the scar on soft tissue procedure sites using an elasticizing cream (Rilastil® Laboratori Milano, Istituto Ganassini S.p.A. di Ricerche Biochimiche, 20139 Milano, IT) (Fig. 2). Usually, at the end of stage 2, the patients no longer need a walker and/or crutches. Weight bearing is progressively allowed and the patient can wear sport shoes. Articular mobilization should be pursued at the following levels: talocrural joint and forefoot.

Figure 2 Scar massage on the surgical access of the posterior tibial tendon.

To protect the implanted endorthesis, pronation and supination of the STJ are not required or even encouraged. As described above, this diarthrosis would be comparable to a pair of overlapped cylinders which move around the longitudinal axis of the foot. Why force pronation or supination at this level when, after surgery, they are protected? Conversely, mobilization of the areas peripheral to the surgery are recommended in order to achieve the maximum interest on the part of the patient in recovery. Plantar and dorsal flexion of the ankle and mobilization of the forefoot are carried out with the patient in a supine position with the knee supported in flexion: block the STJ with the proximal hand to avoid pronation or supination at this level during articular recruitment (Figs. 3 and 4). The proprioceptive component is important at this stage and should be composed of several levels, compatible with weight bearing. The manual approach should start with closed kinetic chain exercises stimulating coordinated muscle contraction in the articular segments of the lower limb increasing the capsular-ligament stability of the ankle itself.

Figure 3 The physiotherapist’s proximal hand blocks the STJ to limit eversion and inversion of the foot whereas plantar and dorsal flexion are performed.

Figure 4 Passive movement of the first ray with the STJ blocked by the proximal hand.

In addition to developing muscle strength, these exercises optimize the functional capacity of the individual by encouraging recovery of the physiological activities of the joint operated on. Closed kinetic chain exercises take advantage of the normal joint structure, and the entire proprioceptive system is stimulated. To perform exercises with patient in a supine position, the ankle is placed in a side panel in front of the subject. Making the first movements in an anterior-posterior direction is encouraged to recreate and improve neuromuscular coordination; the same movements are necessary in the lateral direction and then combined across multiple directions, always with the foot in contact with the wall. Once the patient is capable of tolerating an increased load, the physiotherapist can propose the same procedure with the patient first sitting and then standing with the foot resting on the ground. As this stage is focused on proprioception, unstable balance tools should be used in order to enhance both dorsal and plantar flexion.

Stage 3 (mobility and gait)

At approximately 50 days, assuming that pain and edema have been resolved or are in resolution, the patient must be encouraged to increase mobility. Exercises and mobility techniques are continue using an elastic band (Thera-Band®, The Hygenic Corporation, Akron, OH 44310, US) to develop progressive resistance in the various planes of motion (Figs. 5 and 6). The patient should be instructed and encouraged to do these exercises even in the absence of the physiotherapist, the so-called phase of self treatment at home is essential at this point in order to optimize the timing and results.[29] Hupperets, et al., (2009) have found that unsupervised proprioceptive home based training could benefit the general population.[30] Basically, rehabilitation at this stage is still focused on proprioception using unstable balance tools with both unilateral and bilateral weight bearing. The final phase of muscular strengthening is dedicated to all antigravity movements in which the foot is in a challenging biomechanical context. The patient undergoes a series of exercises which are in contrast to the body weight acting together with gravity.

Figure 5 Muscular self-administered strengthening in a supine position (plantar-dorsal flexion) using a Thera-Band®.

Figure 6 In a sitting position, the patient is encouraged to carry out movements in all directions regulating/increasing the elastic resistance with their own hands.

The starting point of these exercises begins with the full load step on the limb which was operated on; key element for ensuring recovery of the physiological gait. More challenging related exercises are represented by walking uphill with a gradual slope (for example treadmill), climbing the stairs one or two steps at a time and then coming down the stairs (to stimulate the eccentric component of the muscle contraction). Both strength and antigravity exercises are recommended to achieve the full recovery and return to the normal activity. In this phase, the patients should be referred to hydrokinesitherapy to maximize results and improve the postoperative outcome. Berger, et al., (2006), comparing the immediate effects of standard physiotherapy and balneotherapy on postural capacity in subjects with lower limb injuries, observed that exercising under water could reinforce proprioceptive input.[31] A good recovery of foot function can be achieved by proposing implementation of walking synergies such as walking backwards on one’s own toes, walking on heels or cross stepping.

The help of a mirror can provide valuable visual feedback in order to correct any altered patterns. One must research transition from normal to faster walking and then to running. The ultimate goal of the rehabilitation project is centered on obtaining the best physical condition closest to the daily activity of the healthy population with the aim of returning to full recovery after surgery.

Stage 4 (return to sports activities)

The last phase of antigravity training is completed with proper exercises such as jumping in place or on a trampoline. A gradual resumption of the sports activity previously carried out is allowed and a radiographic check-up is required to verify the implant positioning.


Despite the fact that SA was initially proposed for pediatric patients, it is being an increasingly used procedure in the adult population. In this paper we have proposed a classification of the rehabilitative pathway after SA based on our experience also considering the related literature. The main limit of our classification is represented by the absence of a sample with which to make statistical comparisons. Nevertheless, we wanted to address the matter when we realized the need for clarifying and classifying a patient’s physical condition after corrective surgery. Again, even with its limits, this overview should help and stimulate further research. After subtalar arthroereisis with endorthesis, postoperative rehabilitation must be oriented both to protect the surgical site and to enhance mobility of the foot. In order to maximize results and contain clinical risk, the physiotherapist must be able to carry out a functional evaluation and, if necessary, refer patients when complications occur. To this end, a certain degree of multiprofessional cooperation is always recommended in order to ensure patient safety and achieve the best results.


1.  Needleman RL. Current topic review: subtalar arthroereisis for the correction of flexible flatfoot. Foot Ankle Int 2005 26: 336-346. [PubMed]
2.  Ceccaldi A. Pratique de la rééducation du pied. Paris: Masson, 1967. [Website]
3.  Churchill’s Medical Dictionary. New York: Churchill Livingstone, 1989, p. 163.
4.  Highlander P, Sung W, Weil L. Subtalar arthroereisis. Clin Podiatr Med Surg 2011 28: 745-754. [PubMed]
5.  Arangio GA, Reinert KL, Salathe EP. A biomechanical model of the effect of subtalar arthroereisis on the adult flexible flat foot. Clin Biomech 2004 19: 847-852. [PubMed]
6.  Saxena A, Nguyen A. Preliminary radiographic findings and sizing implications on patients undergoing bioabsorbable subtalar arthroereisis. J Foot Ankle Surg 2007 46: 175-180. [PubMed]
7.  Van Ooij B, Vos CJ, Saouti R. Arthroereisis of the subtalar joint: an uncommon complication and literature review. J Foot Ankle Surg 2012 51: 114-117. [PubMed]
8.  Corpuz M, Shofler D, Labovitz J, Hodor L, Yu K. Fracture of the talus as a complication of subtalar arthroereisis. J Foot Ankle Surg 2012 51: 91-94. [PubMed]
9.  Rockett AK, Mangum G, Mendicino SS. Bilateral intraosseous cystic formation in the talus: a complication of subtalar arthroeresis. J Foot Ankle Surg 1998 37: 421-425. [PubMed]
10.  Oloff LM, Naylor BL, Jacobs AM. Complications of subtalar arthroereisis. J Foot Surg 1987 26: 136-140. [PubMed]
11.  De Doncker E. Treatment of static flatfoot. I. Orthopedic treatment: kinesitherapy. Rev Chir Orthop Reparatrice Appar Mot 1977 63: 756-757. [PubMed]
12.  Fregnani L, Droghetti I. Corrective gymnastics in the treatment of flatfoot in children. Arcisp S Anna Ferrara 1969 22: 629-640. [PubMed]
13.  Evans AM. The flat-footed child—to treat or not to treat: what is the clinician to do? JAPMA  2008 98: 386-393. [PubMed]
14.  Giannini S, Girolami M, Ceccarelli F. The surgical treatment of infantile flat foot. A new expanding endo-orthotic implant. Ital J Orthop Traumatol 1985 11: 315-322. [PubMed]
15.  Gutiérrez PR, Lara MH. Giannini prosthesis for flatfoot. Foot Ankle Int 2005 26: 918-926. [PubMed]
16.  Giannini S, Ceccarelli F, Benedetti MG, Catani F, Faldini C. Surgical treatment of flexible flatfoot in children a four-year follow-up study. JBJS 2001 83A(Suppl 2): 73-79. [PubMed]
17.  Villani C, Chiozzi F, Persiani P, Costantini A. Flat foot: a comparison of surgical methods. Chir Organi Mov 2003 88: 49-55. [PubMed]
18.  Evans AM, Rome K. A review of the evidence for non-surgical interventions for flexible pediatric flat feet. Eur J Phys Rehabil Med 2011 47: 69-89. [PubMed]
19.  Postan D, Carabelli GS, Poitevin LA. Spring ligament and sustentaculum tali anatomical variations: anatomical research oriented to acquired flat foot study. FAOJ 2011 4: 1. [Website]
20.  Chang TJ, Lee J. Subtalar joint arthroereisis in adult-acquired flatfoot and posterior tendon dysfunction. Clin Podiatr Med Surg 2007 24: 687-697. [PubMed]
21.  Maxwell JR, Cerniglia MW. Subtalar joint arthroereisis. In: Bank AS, Downey MS, Martin DE, Miller SJ. McGlamry’s Comprehensive Textbook of Foot and Ankle Surgery. 3rd ed. Philadelphia: Lippincott Williams & Wilkins, 2001, vol. 1, pp. 901-914.
22.  Hoke M. An operation for stabilizing paralytic feet. J Bone Joint Surg 1921 3: 494-507. [Website]
23.  Gould JS. Direct repair of the posterior tibial tendon. Foot Ankle Clin 1997 2: 275-279.
24.  Giannini S, Vannini F, Bevoni R, Romagnoli M, Di Gennaro V. Trattamento chirurgico delle lesioni del tibiale posteriore. In: Progressi in medicina e chirurgia del piede. Bologna: Timeo, 2007 16: 73-87.
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Address correspondence to: Massimiliano Polastri, Physical Medicine and Rehabilitation, Bologna University Hospital, Sant’ Orsola-Malpighi Polyclinic, Via G. Massarenti, 9. 40138 – Bologna, Italy. Email: gbptap1@gmail.com

1 Physical Medicine and Rehabilitation, Bologna University Hospital, Sant’ Orsola-Malpighi Polyclinic, Bologna, Italy.
2 Orthopedics and Traumatology, Bologna University Hospital, Sant’ Orsola-Malpighi Polyclinic, Bologna, Italy.

© The Foot and Ankle Online Journal, 2012

Plantar Exostosis in a Malunited Calcaneal Fracture: A rare complication

by Asif Sultan1   ,Tahir Ahmad Dar ,Mohd Iqbal Wani1 ,
Mubashir Maqbool Wani1 , Samina Shafi2

The Foot and Ankle Online Journal 3 (11): 2

Calcaneal fractures are very common and are associated with many complications irrespective of the treatment method chosen. We present a case of malunited calcaneal fracture with a rare complication of an exostosis in the middle 3rd of the plantar surface of calcaneus which clinically produced a large bony swelling on the sole of the foot causing pain and abnormal gait .This type of plantar calcaneal exostosis to our knowledge has not been previously reported. The patient was managed operatively by exostectomy with subtalar arthrodesis and had a good result at 2 years follow-up.

Key words: Calcaneus, fracture, complications, plantar exostosis, exostectomy, subtalar arthrodesis.

Accepted: October, 2010
Published: November, 2010

ISSN 1941-6806
doi: 10.3827/faoj.2010.0311.0002

The calcaneus is the most frequently fractured tarsal bone, with calcaneal fractures accounting for 65% of all tarsal injuries and approximately 2% of all fractures. [1] Most of these fractures occur in male industrial workers and lead to significant economic impact because of long-term disability. [1] Even though recent studies have shown better results with surgical treatment [2-5] and less invasive stabilization systems [3-5], the treatment of calcaneal fractures remains controversial because of the suboptimal results of treatment and the incidence of complications associated with both conservative and surgical methods. [6-9]

On reviewing the literature for the treatment of symptomatic, malunited calcaneal fractures, the general consensus suggests that resection of impinging bone with isolated subtalar arthrodesis for subtalar joint arthritis yields the best long term results. [10-23] Moreover, some surgeons also do endoscopic calcaneal ostectomies for calcaneofibular impingement with good results. [15]

We present a case of mismanaged, malunited calcaneal fracture in a young male laborer who had an unusual and rare complication of large exostosis on plantar surface of the middle portion of the calcaneus, which to our knowledge has not been reported. The patient presented with bony swelling on the sole of the foot with a painful limp and was managed operatively by excision of the exostosis with subtalar arthrodesis. The patient was symptom free after a 2 year follow-up.

Case report

A 19 year-old male, manual laborer, living in tribal hilly area presented to us with pain in left rearfoot with prominent swelling on the plantar surface and anterior part of the heel. He had difficulty in walking for the last year. He had suffered a crushing injury to his left foot while at work in his native place when a heavy stone fell on his left foot from the antero-lateral aspect.

He had sustained a crushed wound over the left foot which was accompanied by severe pain and the inability to walk. He was managed locally, only for wound care and had no proper medical or orthopedic consultation. This injury healed in 4 weeks, but he still was unable to walk for another two months. After three months of sustained injury, the patient began to walk with a limp and also had noticed hard swelling under the heel. He had always had difficulty in walking afterwards due to pain in the hind foot on weight bearing and abnormal prominence under the heel.

On clinical examination the patient’s left foot had an irregular scar of 4 cm over the anterolateral aspect of the foot. Range of motion at the subtalar joint was restricted and painful with increased heel width and no varus or valgus deformity of heel. There was a prominent bony projection on the plantar surface over the anterior aspect of heel which was tender to touch, with thick, firm, and hypertrophic overlying skin. This region of skin was having major contact with the ground during stance phase, and was associated with an antalgic gait style. Radiographic evaluation showed malunited calcaneal fracture with reduced Bohler’s angle, subtalar arthritis, minimally increased heel width and a large exostosis on the plantar surface of calcaneus. (Fig.1A and 1B) The patient was managed operatively under spinal anesthesia. A lateral approach with sharp dissection to raise a full thickness flap from skin to periosteum was performed. A large plantar exostosis was excised along with associated surrounding bursa. There was no cartilaginous cap on the exostosis. Subtalar arthrodesis was performed after denuding cartilage from both the articular surfaces of the calcaneus and talus. The exostosis was used as graft material and fixed with two staples and a short leg cast was applied after closure. (Fig. 2) Sutures were removed after 3 weeks and a short leg cast was reapplied for 3 months with non-weight bearing for 6 weeks and partial weight bearing for another 6 weeks. There were no post operative complications. At 2 years follow-up the patient was pain free with no limp and had a good subtalar fusion. (Fig.3) The patient had returned to his pre-injury employment as manual laborer and the result was deemed good.


Figure 1A and 1B Lateral (A) and axial (B) view radiographs showing large plantar exostosis, loss of Bohler’s angle and subtalar arthritis with normal tibiotalar alignment.

Figure 2 Immediate post operative lateral radiograph after removal of exostosis and subtalar arthrodesis.

Figure 3 Lateral radiograph at 2 years follow-up showing subtalar fusion with staples in-situ.


Complications of calcaneal fractures occur in the acute and late stages and after operative or non-operative treatment. [1,2,6-9,17,18] Acute complications include swelling, fracture blisters, and compartment syndromes. Late complications include arthritis, malunion, lateral exostosis, calcaneofibular abutment, tendon impingement, heel pad problems and reflex sympathetic dystrophy. Complications from non-operative treatment include arthritis, pain, malunion, and stiffness. Complications associated with operative treatment include wound dehiscence, infection, arthritis, stiffness, and iatrogenic nerve and tendon injury. [2] Heel pad pain is the second most common site of pain after pain over lateral aspect of heel after a calcaneal fracture [2] and have thinning with increased mobility of the pad, and a softer, less firm heel pad compared to the normal side. This pain has been attributed to crushing of the heel pad during injury. This was not the cause of pain in our patient as his heel pad was more firm, harder, thickened, and less mobile than the normal side.

Lateral exostosis usually develops after malunion of calcaneal fractures and is a very common complication. Heel exostosis (bony calcaneal spurs) sometimes develop after injury and may also cause chronic heel pain. These develop from the undersurface of the calcaneus in patients with injuries to the plantar cortex. These are as a consequence of proliferative bony changes at the origin of planter fascia. In our patient, the plantar exostosis was on the plantar surface of calcaneus in the middle third of the calcaneus, well anterior to the origin of plantar fascia, thus being a rare inferior surface exostosis rather than heel exostosis. We hypothesize that severe crushing force anteriorly and laterally caused collapse of the calcaneal body to the middle, also fracturing the inferior cortex and taking a large bony fragment plantarly which developed into large bony exostosis.

Post-traumatic arthritis after intra-articular calcaneal fractures may affect the subtalar or calcaneocuboid joint. It may develop either due to articular surface depression or may occur due to secondary cartilage damage from the initial trauma. Subtalar joint arthritis causes pain on weight bearing, aggravated by varus or valgus stressing of the subtalar joint without significant tenderness to the lateral aspect of heel with or without radiological evidence. [2]

In our patient, operative intervention was performed using a lateral approach as both inferior wall exostectomy (resection of exostosis)[10] and isolated subtalar arthrodesis [11-13] were performed using a single incision. This was indicated for painful subtalar arthritis with normal heel height and normal tibiotalar alignment. (Fig.1) Our result was good with pain free arthrodesis of the subtalar joint. [23] This procedure of isolated subtalar arthrodesis has been well documented with good results, [11-14, 23] and is consistent with our case.

Conflict of interest

There is no conflict of interest related to this article


Written informed consent was obtained from the patient’s guardian for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.


1. Sanders R. Current concepts review: Displaced intraarticular fractures of the calcaneus. JBJS 2000 82A: 225-250.
2. Makki D, Alnajjar HM, Walkay S, Ramkumar U, Watson AJ, Allen PW. Osteosynthesis of displaced intra-articular fractures of the calcaneum: a long-term review of 47 cases. JBJS 2010 92B(5): 693-700.
3. Hernanz González Y, Díaz Martín A, Jara Sánchez F, Resines Erasun C. Early results with the new internal fixator systems LCP and LISS: a prospective study. Acta Orthop Belg 2007 73(1): 60-69.
4. DeWall M, Henderson CE, McKinley TO, Phelps T, Dolan L, Marsh JL. Percutaneous reduction and fixation of displaced intra-articular calcaneus fractures. J Orthop Trauma 2010 24(8): 466-472.
5. Shan SL, Xu JL, Yao SZ, Yu GS, Liu YQ. Minimally invasive plate internal fixation for calcaneal fractures. Chin J Traumatol 2010 13(5): 313-315.
6. Lim EVA, Leung JPF. Complications of intraarticular calcaneal fractures. Clin Ortho Related Research 2001 391:7-16.
7. Walter JH Jr, Rockett MS, Goss LR. Complications of intra-articular fractures of the calcaneus. JAPMA 2004 94(4): 382-388.
8. Reddy V, Fukuda T, Ptaszek AJ. Calcaneus malunion and nonunion. Foot Ankle Clin 2007 12(1): 125-135.
9. Clare MP, Lee WE 3rd, Sanders RW. Intermediate to long-term results of a treatment protocol for calcaneal fracture malunions. JBJS 2005 87A (5): 963-973.
10. Abend L, Berstein DA, Wagreich C. Post-traumatic heel deformity. J Foot Surg 1986 25(2): 146-148.
11. Myerson MS, Quill GE Jr. Late complications of fractures of the calcaneus. JBJS 1993 75A: 331-341.
12. Easley ME, Trnka HJ, Schon LC, Myerson MS. Isolated subtalar arthrodesis. JBJS 2000 82A (5): 613-624.
13. Radnay CS, Clare MP, Sanders RW. Subtalar fusion after displaced intra-articular calcaneal fractures: Does initial operative treatment matter? JBJS 2010 92A: 32-43.
14. Sanders R, Fortin PT, Walling, AK. Subtalar arthrodesis following calcaneal fracture. Orthop Trans 1991 15: 656.
15. Lui TH. Endoscopic lateral calcaneal ostectomy for calcaneofibular impingement. Arch Orthop Trauma Surg 2007 127(4): 265-267.
16. Stapleton JJ, Belczyk R, Zgonis T. Surgical treatment of calcaneal fracture malunions and posttraumatic deformities. Clin Podiatr Med Surg 2009 26(1):79-90.
17. Manasseh N, Cherian VM, Abel L. Malunited calcaneal fracture fragments causing tarsal tunnel syndrome: a rare cause. Foot Ankle Surg 2009 15(4): 207-209.
18. Lui TH. Posterior ankle impingement syndrome caused by malunion of joint depressed type calcaneal fracture. Knee Surg Sports Traumatol Arthrosc 2008 16(7): 687-689.
19. Robinson JF, Murphy GA. Arthrodesis as salvage for calcaneal malunions. Foot Ankle Clin 2002 7(1): 107-120.
20. Huang PJ, Fu YC, Cheng YM, Lin SY. Subtalar arthrodesis for late sequelae of calcaneal fractures: fusion in situ versus fusion with sliding corrective osteotomy. Foot Ankle Int 1999 20(3): 166-170.
21. Romash MM. Reconstructive osteotomy of the calcaneus with subtalar arthrodesis for malunited calcaneal fractures. Clin Orthop Relat Res 1993 (290): 157-167.
22. Chen YJ, Huang TJ, Hsu KY, Hsu RW, Chen CW. Subtalar distractional realignment arthrodesis with wedge bone grafting and lateral decompression for calcaneal malunion. J Trauma 1998 45(4):729-737.
23. Rammelt S, Grass R, Zawadski T, Biewener A, Zwipp H. Foot function after subtalar distraction bone-block arthrodesis. A prospective study. JBJS 2004 86B(5): 659-668.

Address correspondence to: Asif Sultan , Government Hospital for Bone and Joint Surgery. Barzullah, Srinagar, India 190005.

 Government Hospital for Bone and Joint Surgery, Barzullah. Srinagar, India 190005.
2  Resident Government Medical College, Srinagar, India 190005

© The Foot and Ankle Online Journal, 2010

Lateral Subtalar Dislocation of the Foot: A case report

by J. Terrence Jose Jerome, MBBS, DNB (Ortho), MNAMS (Ortho)1 , Mathew Varghese, M.S. (Ortho)2 , Balu Sankaran, FRCS, FAMS3 , K. Thirumagal, MD4

The Foot & Ankle Journal 1 (12): 2

Subtalar dislocation is the simultaneous dislocation of the distal articulations of the talus at both the talocalcaneal and talonavicular joints. It can occur in any direction and always produce significant deformity. Most common is the medial dislocation. Less common presentations are lateral, anterior and posterior dislocations. These dislocations are associated with osteochondral fractures. Closed reduction and immobilization remains the mainstay of treatment. Radiographs and computed tomography scan confirms the post reduction alignment stability of subtalar joints and intra-articular fracture fragments. We report a case of lateral subtalar dislocation without osteochondral fracture fragments in a 30-year-old man.

Key words: Subtalar dislocation, dislocated talus, closed reduction, immobilization

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 & Ankle Journal (www.faoj.org)

Accepted: November, 2008
Published: December, 2008

ISSN 1941-6806
doi: 10.3827/faoj.2008.0112.0002

Subtalar dislocations are rarely found in routine orthopedic practice. Many of these dislocations result from high-energy injuries such as falls from a height, athletic injuries or a motor vehicle accident. [1] Inversion or eversion force is dissipated through the weak talonavicular and talocalcaneal ligaments, which eventually result in subtalar dislocation.

There are two types of subtalar dislocation. In lateral subtalar dislocation, the head of talus is found medially and the rest of the foot is dislocated laterally. In medial subtalar dislocation, the head of the talus is found laterally and the rest of the foot is dislocated medially.

Medial dislocation has been referred to as an “acquired clubfoot”, while the lateral injury is described as an “acquired flatfoot”. We present a case of an adult with lateral subtalar dislocation following a fall.

Case Report

A 30-year-old man who sustained a fall from the stairs came to our emergency department with pain and swelling of the right foot. The foot was diffusely swollen with minimal laceration and tenting of the skin over the prominent talar head which was felt medially. The rest of the foot was found dislocated laterally. (Figs. 1 and 2) Pulse of the posterior tibial and dorsalis pedis artery were not felt due to massive soft tissue distortion. Radiograph of the right foot showed lateral subtalar dislocation. (Figs. 3 and 4) Doppler ultrasound showed normal arterial flow in both posterior tibial and dorsal pedis arteries.

Figure 1   The foot was diffusely swollen with minimal laceration and tenting of the skin over the prominent talar head which was felt medially.

Figure 2   The right foot was found to be dislocated laterally.

Figure 3   The dorsoplantar view shows the dislocation of the talo-navicular and subtalar joints. Head of the talus was seen lying medially. Normal alignment of calcaneo-cuboid joint is appreciated.

Figure 4   The lateral view again shows the dislocation of the talo-navicular and subtalar joints. Head of the talus is severely declinated.

Closed reduction was done under spinal anesthesia. Firm manual foot traction with counter-traction on the leg combined with direct digital pressure over the head of talus aided in smooth reduction, which was associated with an audible clunk.

Post reduction radiographs showed normal and stable alignment of subtalar and talo-navicular joints without osteochondral fractures. (Figs. 5 and 6)

Figure 5   The post reduction anterior posterior radiograph showed normal and stable alignment of subtalar and talo-navicular joints without osteochondral fractures.

Figure 6   The post reduction lateral radiograph showed normal and stable alignment of subtalar and talo-navicular joints without osteochondral fractures.

Computer tomography (CT) scan confirmed the absence of osteochondral fractures and the stability of the subtalar joints. The patient was immobilized in a short-leg posterior plaster splint for 4 weeks. Following immobilization, the patient underwent a vigorous, active exercise program. The patient progressed to weight bearing and active range of motion exercises to regain subtalar and midtarsal joint motion. Two years after the injury, the patient had a stable, relatively good functional foot with minimal pain on walking on uneven ground.


Subtalar dislocation by definition has a normal tibiotalar joint. Most dislocations occur in males (6:1) of early age. Subtalar dislocation can occur in any direction and always produce significant deformity.

Most commonly (80% to 85%), the foot is displaced medially with the calcaneus lying medially, the head of the talus prominent dorsolaterally, and the navicular medial and sometimes dorsal to the talar head and neck. [1,2,3] Less commonly (15% to 20%), lateral dislocation occurs.

Inversion of the foot results in a medial subtalar dislocation, while eversion produces a lateral dislocation. The strong calcaneonavicular ligament resists disruption, and the inversion or eversion force is dissipated through the weaker taloavicular and talocalcaneal ligaments. This disrupts these two joints which causes displacement of the calcaneus, navicular and all distal bones of the foot as a unit, either medially or laterally. [2,3]

The sustentaculum tali acts as a fulcrum about which the foot rotates to lever apart the talus and calcaneus in medial subtalar dislocation. The foot pivots about the anterior process of the calcaneus, again causing the talus and calcaneus to separate in lateral subtalar dislocation. [1,2,3,4]

Rare cases of anterior [5] and posterior [1] displacement of the foot after subtalar dislocation have also been reported. It is important to distinguish the medial or lateral subtalar dislocations because the method of reduction is different and the long-term prognosis appears to be worse with the lateral dislocation.

Between 10% and 40% of subtalar dislocations are open.6 Open injuries tend to occur more commonly with the lateral subtalar dislocation pattern and probably as the result of a more violent injury. [6] Long term follow-up demonstrated very poor results with the open subtalar dislocations.

The keystone of treatment for all subtalar dislocations is prompt and gentle reduction under general or spinal anesthesia. [7] All open injuries must be thoroughly debrided at the time of reduction, and the wound should be left open, with delayed primary closure anticipated in 3 to 5 days. Due to the high incidence of associated articular fracture and associate poor prognosis, CT scan of the foot and ankle should be obtained after reduction and splinting.

Simple dislocation that is reduced readily by closed reduction and do not have associated fracture, do very well. [1] In approximately 10% of medial subtalar dislocations and 15% to 20% of lateral dislocations, closed reduction cannot be achieved. [3,8] Soft tissue interposition and bony blocks have been identified as factors preventing closed reduction. Another common obstruction to closed reduction in medial dislocations is an impaction fracture of the articular surface of talus and navicluar. [7]

In comparison, the most common obstruction to closed reduction in lateral subtalar dislocation is the interposed tibialis posterior tendon. [8]

Open reduction is done for irreducible medial, lateral subtalar dislocations and osteochondral fracture fragments which blocks closed reduction. Any small, loose articular fracture fragments should be removed. Large intra-articular fractures should be reduced and fixed with Kirschner wires or small screws to restore joint stability and congruity. [9]

The only consistent complication in simple uncomplicated dislocations is limitation of subtalar joint motion, with the occasional associated symptoms of difficulty in walking on uneven ground and pain in the foot with weather changes. [2,7]

Lancaster and co-workers noted a poorer prognosis when there were associated injuries such as soft tissue injury, open contaminated injuries, extra-articular fracture, intra-articular fracture, infections, lateral subtalar dislocations, neglected subtalar dislocations and osteonecrosis. [10]

Our patient, who had sustained a fall from stairs, came with a diffusely swollen foot with the head of talus felt medially and the rest of the foot dislocated laterally as a unit. Radiographs confirmed the lateral subtalar dislocation. There was no associated osteochondral fracture. Simple closed reduction was successful. Our literature review showed few reports of isolated lateral subtalar dislocation.

We emphasize the importance of proper diagnosis and timely management of dislocations around the subtalar joint, as these tend to result in a significant deformity with joint stiffness. Lateral subtalar dislocation is one such type dislocation which is not mentioned in the literature and should be carefully treated. There should always be a high index of suspicion concerning associated osteochondral fractures. CT scan should be performed after reduction to assess for the intra-articular fractures of the subtalar joint. Open reduction is recommended for irreducible dislocations and fixation is recommended in large displaced, articular fractures that can produce subtalar joint incongruity.


1. DeLee JC, Curtis R. Subtalar dislocation of the foot. J Bone Joint Surg 64A: 433 – 437, 1982.
2. Grantham SA. Medial Subtalar dislocation: five cases with a common etiology. J Trauma 4 (11): 845 – 849, 1964.
3. Heppenstall RB, Farahvar H, Balderston R, Lotke P. Evaluation and management of subtalar dislocations. J Trauma 20 (6): 494 – 497, 1980.
4. Monson ST, Ryan JR. Subtalar dislocation. J Bone Joint Surg 63A (7): 1156 – 1158, 1981.
5. Inokuchi S, Hashimoto T, Usami N. Anterior subtalar dislocation: case report. J Orthop Trauma 11(3): 235 – 237, 1997.
6. Goldner JL, Poletti SC, Gates HS 3rd, Richardson WJ. Severe open subtalar dislocations: long-term results. J Bone Joint Surg 77A (7):1075 – 1079, 1995.
7. Bohay DR, Manoli A 2nd. Subtalar dislocations. Foot Ankle Int 16(12): 803 – 808, 1995.
8. Leitner B. Obstacles to reduction in subtalar dislocations. J Bone Joint Surg 36A (2): 299 – 306, 1954.
9. Naranja RA Jr, Monaghan BA, Okereke E, Williams GR Jr. Open medial subtalar dislocation associated with posterior process fracture of the talus. J Orthop Trauma 10(2): 142 – 144, 1996.
10. Lancaster S, Horowitz M, Alonso J. Subtalar dislocations: a prognosticating classification. Orthopedics 8 (10): 1234-1240, 1985.

Address correspondence to: Dr. J. Terrence Jose Jerome, MBBS.,DNB (Ortho), MNAMS (Ortho)
Registrar in Orthopedics, Dept. of Orthopedics
St. Stephen’s Hospital, Tiz Hazari, Delhi 54, India

1 Registrar in Orthopedics, Department of Orthopedics, St. Stephens Hospital, Tiz Hazari, Delhi, India.
2 Head Professor, Department of Orthopedics, St. Stephens Hospital, Tiz Hazari, Delhi, India.
3 Professor Emeritus, Orthopedics, St. Stephens Hospital, Tiz Hazari, Delhi, India. E-mail: pasle@bol.net.in
4 Professor , Orthopedics, Tamilu, India.

© The Foot & Ankle Journal, 2008

Bony Ankylosis of the Subtalar Joint in Gout: A case report

by S.M. Shareef1, S. Sinha2 , A.C. Campbell3

The Foot & Ankle Journal 1 (11): 2

Bony ankylosis is a rare consequence of gouty arthritis. Ankylosis is typically a complication of long standing arthritis. Literature reports have shown that anti-hyperuricemic agents can reverse the urate deposition in a joint, but has no effect on the progression of eventual anklyosis of a joint. In this case, gouty ankylosis of the subtalar joint is reported after a relatively short episode of gout despite the use of anti-hyperuricemic agents and NSAID therapy.

Key words: Gout, anti-hyperuricemic agents, ankylosis, subtalar joint

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 & Ankle Journal (www.faoj.org)

Accepted: October, 2008
Published: November, 2008

ISSN 1941-6806
doi: 10.3827/faoj.2008.0111.0002

Bony ankylosis in gout is extremely rare. The few cases that have been reported in literature typically occur in patients with chronic, sub-optimally treated or severe gout. We report a case of bony ankylosis in a patient with gouty arthritis of short duration.

Case Report

A 43-year-old female presented with pain and swelling of the left ankle of four-month duration. There was no previous history of trauma, infection, or any other joint problem. Physical examination revealed fullness over the medial aspect of the ankle with mild tenderness. There was some restriction of movements of the ankle and subtalar joints. Laboratory tests revealed a normal ESR and CRP with Rheumatoid factor, Anti-nuclear antibody and HLA B27 antigen being negative. Serum uric acid was elevated.

Skin and nails did not show any psoriatic features. Radiographs of the ankle showed minor degenerative changes with slight narrowing of the subtalar joint space.

Patient was started on colchicine as an initial management, and subsequently commenced on allopurinol and NSAID’s. In spite of these measures pain and swelling of the ankle worsened. A bone scan showed increased activity within the subtalar joint. Debilitating nature of symptoms, even with optimal medical treatment, warranted fusion of the subtalar joint. Synovial biopsy revealed a patchy chronic inflammatory cell infiltrate, but monosodium urate crystals were not detected.

At one-year follow up, the joint remained solidly fused both clinically and radiologically, and the symptoms had resolved completely. However, the patient complained of pain in the opposite ankle. Examination revealed pain with restriction of movement of the right subtalar joint. Patient was advised to continue with allopurinol and NSAID.

At review three months later, the right ankle pain had ceased. Radiographs revealed spontaneous ankylosis of the right subtalar joint without any intervention. (Figs. 1 A and B)


Figures 1 A and B  AP and lateral radiograph of the right ankle showing ankylosis of the subtalar joint. (A) Lateral radiograph clearly showing the ankylosed subtalar joint. (B)


Bony ankylosis is exceptional in gout patients. The first case was reported by Virchow in 1868. Most reported gout patients with ankylosis had severe disease with onset during adolescence or early adulthood. [1,2] Another common feature was suboptimal medical treatment. The most common sites of ankylosis were the carpus, tarsus and ankles. [3]

A highly unusual feature in our case was the fact that the patient developed ankylosis within a short duration of the first acute attack on that side. The patient had no evidence of rheumatic disease known to cause ankylosis, such as ankylosing spondylitis, psoriatic arthritis, or diffuse idiopathic skeletal hyperostosis.

Although biopsy did not reveal gouty crystals, Pascual, et al., [4] have shown total disappearance of crystals from joints in patients who were treated with urate lowering drugs, and have also determined the time needed for this to happen.

The pathophysiology of bony ankylosis in gout is not known. Anti-hyperuricemic agents can reverse urate deposition but may have no effect on the progression of ankylosis. [5,6]


1. Hughes GR, Barnes CG, Mason RM. Bony ankylosis in gout. Ann Rheum Dis. 27 (1): 67-70, 1968.
2. Ludwig AO, Bennet GA, Bauer W. A rare manifestation of gout: widespread ankylosis stimulating rheumatoid arthritis. Ann Intern Med. 11: 1248-1276, 1938.
3. Good AE, Rapp R. Bony ankylosis. A rare manifestation of gout. J Rheumatol. 5(3): 335- 337, 1978.
4. Pascual E, Sivera E. Time required for disappearance of urate crystals from synovial fluid after successful hypouricaemic treatment relates to the duration of gout. Ann Rheum Dis. 66: 1056-1058, 2007.
5. Cortet B, Duqesnoy B, Amoura I, Bourgeois P, Delcambre B. Gout with ankylosis. Rev Rheum [Engl. Ed.]. 61(1): 44-47, 1994.
6. Shoji A, Yamanaka H, Kamatani N. A retrospective study of the relationship between serum urate level and recurrent attacks of gouty arthritis: evidence for reduction of recurrent gouty arthritis with antihyperuricemic therapy. Arthritis Rheum. 51 (3): 321-325, 2004.

Address correspondence to: S. Sinha. Department of Orthopaedics
Monklands, Hospital. Monkscourt Avenue. Airdrie ML6-OJS
United Kingdom

1,2,3 Department of Orthopaedic Surgery, Monklands Hospital, Airdrie, UK.

© The Foot & Ankle Journal, 2008

An Unusual Case Report of Two Bone Osteomyelitis With Long-Term Follow-up

by Brian Carpenter, DPM, FACFAS1, Jeffrey Taylor, DPM2, Travis Motley, DPM, FACFAS3, Jason Smith, DPM4

The Foot & Ankle Journal 1 (4): 1

A 49 year-old patient, with a history of rheumatoid arthritis, presents with suspected septic arthritis of the ankle and subtalar joints. The patient was found to have osteomyelitis of both the talus and calcaneus. The patient was treated by debridement, antibiotic impregnated PMMA beads, and ultimately, a subtalar joint fusion. This case illustrates the importance of the early recognition and diagnosis, the possible sequelae, and the need for aggressive treatment of a septic joint.

Key words: Osteomyelitis, rheumatoid arthritis, subtalar joint, PMMA beads

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 & Ankle Journal (www.faoj.org 

Published Online: April 1, 2008

ISSN 1941-6806
doi: 10.3827/faoj.2008.0104.0001

Osteomyelitis is traditionally subdivided into three categories based on etiology. The first type is hematogenous osteomyelitis. This form is commonly monomicrobial, with staphylococcal organisms isolated most frequently. [7] The second type is direct extension osteomyelitis. It is usually polymicrobial in origin and seen more frequently in the general population. [6] Sources of direct extension osteomyelitis include puncture wounds, surgery, implants, contiguous ulcerations, and septic arthritis.

The third type is osteomyelitis secondary to vascular insufficiency. It is also polymicrobial in origin and seen mostly in those over 55 years of age as the result of tissue hypoxia. [1]

Septic arthritis is the most destructive form of arthritis. It is classified by its offending pathogen or etiology. Neisseria gonorrhea is commonly isolated from sexually active adults with associated superficial lesions. [8] Haemophilus influenza is commonly isolated from children under the age of two. [8] Staphylococcus and Streptococcus species, which are the most common offending pathogens overall, are seen in children over the age of two and in adults. [8] The etiologies are very similar to osteomyelitis.

Hematogenous septic arthritis may be secondary to upper respiratory and skin infections, most frequently encountered with gram-positive organisms. [8]

A joint is susceptible to infection because of the profound vascular supply within the synovial joint lining. The joint may be even more prone to an infective process given an existing arthritide, such as rheumatoid arthritis.

Arthritis not only causes direct damage to the joint, but may also be treated with repeated corticosteroid injections that can decrease the joint’s immunocompetence.

Direct extension septic arthritis shares its etiologies with direct extension osteomyelitis, but septic arthritis may also originate from an adjacent osteomyelitis. [1]

The following case report describes a middle-aged female with a history of rheumatoid arthritis, who developed osteomyelitis of the talus and calcaneus. The joints were never proven to be septic by joint aspiration and culture. The ensuing destructive sequelae raises many questions about the origin and the development of the infective process. [1]

Case Report

A 49 year-old white female with a past medical history of long term rheumatoid arthritis and a sedentary lifestyle, presented to the clinic complaining of a painful left ankle. The ankle became painful, erythematous, and edematous three months prior, and was accompanied by fever and chills. The patient did not initially seek treatment. Ten to fourteen days later, with rest and a decrease in activity, the erythema and edema subsided without the use of antibiotics, however, the pain persisted. The patient then went to see her rheumatologist, who treated her with physical therapy, an NSAID, and a steroid injection of the left ankle. The patient denied trauma, but did note a superficial cat scratch to the anterior aspect of her left lower leg one to two weeks prior to the onset of pain, which she treated with a topical antibiotic.

On initial physical examination significant findings revealed a globally edematous left ankle. The swelling was markedly more edematous on the lateral aspect of the ankle. There was pain on palpation of the anterior, lateral, and posterior aspect of the ankle joint. Pain was elicited with eversion and dorsiflexion of the ankle and there was no pain of the subtalar joint with range of motion. The neurovascular status of both extremities was intact.

Plain films of the left foot and ankle, taken on a previous presentation did not reveal a fracture or dislocation, although there was significant degenerative joint disease of the left ankle joint.

The patient returned to the clinic two weeks later with an additional complaint of a painful left heel on weightbearing. Physical exam revealed severe pain with compression to the body of the left calcaneus. There was no apparent cellulitis of the left foot or ankle. Computerized tomography (CT) scan findings of the left foot and ankle revealed degenerative joint disease of the subtalar joint with an irregular calcaneal-cuboid joint that includes significant destruction of bone. A large lytic lesion in the posterior inferior aspect of the calcaneus is seen with a small lytic lesion of the medial talar dome. There were trabecular changes of the lateral talar body with surrounding soft tissue inflammation. (Fig. 1)

Figure 1  CT scan revealed joint narrowing consistent with degenerative arthritis.  A large area of bone lysis is seen in the body of the os calcis.

Plain films, taken shortly after that time, corresponded with the CT findings. We concluded that degenerative changes of the talus, calcaneus, and subtalar joint were probably the result of an infective process.

Five days later, surgical debridement of osteomyelitic bone of the left talus and calcaneus was performed to an intra-operative viable periphery. Tobramycin impregnated beads were inserted into the dead space, and the patient was placed on cephazolin 2 gm IV every 8 hours. (Fig. 2)

Figure 2  Following surgical debridement of osteomyelitic bone, antibiotic impregnated PMMA beads were inserted.  Cultures revealed staphylococcus aureus osteomyelitis.

The wound was closed over the implanted beads with a drain in place. Bone biopsy of debrided bone was positive for osteomyelitis, and biopsy of peripheral bone and residual bone was negative. Cultures of the debrided necrotic bone were positive for Staphylococcus aureus. The postoperative period was unremarkable. A Ceretec WBC-labeled bone scan performed six weeks after the initial debridement. This was negative for osteomyelitis (Fig. 3)

Figure 3  Ceretec white blood cell bone scans performed six weeks after insertion of PMMA beads were negative for any signs of active osteomyelitis.

Ten weeks after debridement of the left talus and calcaneus, the beads were removed. The residual bone of the talus and calcaneus were clinically viable, and a subtalar joint fusion with talar and calcaneal reconstruction using autogenic iliac bone graft was performed. The patient was placed in a below-the-knee cast. Plain film findings two weeks after STJ fusion demonstrated intact internal fixation from anterior dorsal to plantar posterior with good placement and joint alignment. A portion of increased density of both the talus and calcaneus corresponded to generalized osteopenia of the bone grafts. (Fig. 4)

Figure 4 Iliac bone graft is used with a single cannulated cancellous screw to fuse the subtalar joint.

Intravenous antibiotics were discontinued and the patient was put on a two-week course of oral cephalexin.

The postoperative course involved a non-weightbearing, below-the-knee cast for eight weeks with progression to a non-weightbearing removable cast walker (RCW) for three weeks. The patient was then placed in a weightbearing RCW for another three weeks. Proper foot orthoses and ankle brace was fitted when the patient progressed to her shoes.

After casting, the patient underwent eight weeks of physical therapy to increase range of motion, proprioception, and strength. The patient was pain free six months after fusion. The plain films demonstrated approximately 90% fusion of the left subtalar joint with the heel in rectus position. (Fig. 5)

Figure 5 Six months after fusion, the subtalar joint is stable and without pain on ankle and foot range of motion. 

The patient is now ten years post surgery. She is enjoying a healthy lifestyle that includes jogging without pain.


There are many questions that arise from this case report and should be addressed to make any pertinent conclusions.

The patient’s history suggests clinical sepsis prior to presenting and the etiology remains unclear. First of all, the cat scratch she reported was probably not the cause. We were unable to isolate the most common organism isolated from cat scratches or bites, Pasteurella multiocida. [2] Also, the location and depth of the laceration are not consistent with an infectious introduction of the ankle or subtalar joint. Secondly, a steroid injection, which has been demonstrated as a source of joint sepsis in the literature, was administered to the patient early in the presentation. Injections of corticosteroid into a septic joint may increase the propagation of the infectious process, but cannot be labeled as the cause due to the onset of symptoms prior to the injection. [3,4] Finally, the patient’s long term rheumatoid arthritis must be recognized as a significant factor as to increased risk of joint sepsis, but cannot be labeled as a cause. [5,6] Given the exclusion of these three factors and the absence of other complicating trauma, although rarely seen in middle aged adults, we hypothesize the septic arthritis must be attributed to a hematogenous route. [5,6]

Assuming bacteremia one must decide on the location of the infection. Given the patient’s report, it is easy to assume ankle joint sepsis. The suspicion is heightened by the possible propagating of infection by a local joint injection to the ankle joint. The clinical and radiographic findings also suggest extra-tibiotalar sepsis. An effusion of the subtalar joint may present with ankle joint swelling that is more prominent below the lateral malleolus, given the communicating lateral anatomy of the subtalar and ankle joints. [7] Computerized tomography of the foot and ankle further supports the hypothesis of subtalar sepsis by displaying adjacent boney lesions located in the inferior talus and superior calcaneus.

Therefore, the original septic joint may have been the subtalar joint in isolation or in combination with the ankle joint. It appears the detrimental sequelae of osteomyelitis developed only in the subtalar joint.

Sequelae of septic arthritis may include persistence of the infection secondary to inadequate drainage. It can also be caused by damage to the articular cartilage, tenosynovitis, and secondary osteomyelitis. As intra-articular exudate increases, the joint attempts to accommodate its increased volume through posture, which causes more pain and stiffness. When the joint can no longer handle the intra-articular pressure, the corresponding cartilage is compressed, synovial blood supply is compromised, capsular erosions and sinus tracts form, and contiguous spread to underlying bone results. [5]

When osteomyelitis is recognized secondary to joint sepsis, joint resection arthroplasty, staged arthrodesis, or even amputation can be performed to alleviate the patient’s symptoms and stop further spread of the infection. [5] Surgical debridement of all necrotic bone must be performed. In this case, it was followed by implantation of PMMA antibiotic beads for the treatment of existing infection and prophylaxis of further infection in the anatomical dead space. The use of antibiotic laden beads is efficacious in the treatment of acute and chronic osteomyelitis. [8] PMMA beads have been in use for over 30 years. The beads are typically left in the wound for 5 to 14 days after debridement or until soft tissure coverage or primary closure can be achieved. [13] Studies have shown that minimum inhibitory concentration of antibiotics are released from PMMA beads from the first 2 days after implantation up to multiple weeks. [12] Following proper debridement and antibiotic prophylaxis, a Ceretec bone scan, which is a sensitive and specific for osteomyelitis, can be utilized to confirm the absence of infection or persistent infection. An isolated talocalcaneal arthrodesis, employing an iliac crest bone graft, has been described by many authors as an excellent way to treat various degenerative processes of the subtalar joint, and has proven to be a more functional alternative to a pan-talar fusion. [9,10]

This patient most likely developed subtalar septic arthritis from an uncommon hematogenous route. The infection was not drained and may have been even propagated with a corticosteroid injection and spread contiguously to the talus and calcaneus. Once recognized, the osteomyelitis was aggressively treated with surgery and appropriate intravenous antibiotic therapy. The case illustrates three important points about the septic joint. First, the suspicion of a septic joint must be diagnosed and treated appropriately and aggressively by joint aspiration, if possible, and proper cultures and definitive antibiotics. Secondly, early intervention in these cases is paramount, as demonstrated graphically by this case. Finally, if complications, such as osteomyelitis, do occur, proper aggressive surgical treatment must be performed promptly.


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8. Sternbach, G., Baker, F. : The Emergency joint: Arthrocentesis and Synovial Fluid Analysis. JACEP 5: 787-792, October 1976.
9. Calhoun, J., Mader, J. : Antibiotic Beads in the Management of Surgical Infections. American Journal of Surgery 157: 443-449, April 1989.
10. Russotti, G. et al. : Isolated Talocalcaneal Arthrodesis. Journal of Bone and Joint Surgery 79-A: 1472-1478, December 1988.
11. Thomas, F. : Arthrodesis of the Subtalar Joint. Journal of Bone and Joint Surgery 49-B: 93-97, February 1967.
12. Perry, A. et al : Antimicrobial Realease Kinetics From Polymethylmethacrylate in a Novel Continous Flow Chamber. Clinical Orthopaedics and Related Research 403, pp. 49-53 2002.
13. Walenkamp, G. et al : Osteomyelitis Treated With Gentamicin-PMMA Beads. Acta Orthop Scand 69 (5): 518-522, 1998.

1Director of Residency Training, Associate Professor, University of North Texas Health Science Center, John Peter Smith Hospital, Department of Orthopaedics, 1500 South Main Street, Ft.Worth, Texas 76104.

2Private Practice; North Texas Podiatry, 401 Westpark Way, Euless. Texas

3Staff Physician, Assistant Professor, University of North Texas Health Science Center, Department of Orthopaedics. 1500 South Main Street, Ft. Worth, Texas 76104.

4Resident, PGY-2,John Peter Smith Hospital, Department of Orthopaedics. 1500 South Main Street, Ft. Worth, Texas 76104

© The Foot & Ankle Journal, 2008

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