Comparison of symptomatic unstable ankle with and without os subfibulare.

BACKGROUND: This study aimed to compare the patients background, clinical scores, condition of the lateral ligament, mechanical instabilities, and chondral lesions in ankles with symptomatic os subfibulare compared to those in ankles with chronic lateral instability without os subfibulare. METHODS: Of the 212 ankles with a chronic lateral instability that were surgically treated, 72 ankles had an os subfibulare. All ankles were examined by arthroscopy during surgery. Age, sex, preoperative American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale scores, remnant condition of the lateral ligaments, and chondral lesions were compared between ankles with symptomatic os subfibulare and ankles with chronic lateral instability without os subfibulare. RESULTS: There were no statistically significant differences between the groups in terms of the sex ratio (males: females, 35:37 vs. 53:87, n.s.) and the AOFAS Ankle-Hindfoot Scale scores (median; 75 vs. 77, n.s.). There were statistically significant differences in patient age (median: 20 vs. 24.5 years, p < 0.01), talar tilt angle (median: 9.0° vs 12.0°, p < 0.01), anterior drawer distance (6.2 vs. 7.0 mm, p < 0.01), chondral lesions (G0:G1:G2:G3, 35:21:66:5 vs. 40:44:27:29, p < 0.01), condition of the anterior talofibular ligament (intact: repairable remnant: poor remnant, 0:70:2 vs. 1:112:27, p < 0.01), and condition of the calcaneofibular ligament (intact: repairable remnant: poor remnant, 44:26:2 vs. 77:35:28, p < 0.01) between the groups. CONCLUSION: This study suggests that the condition of the lateral ligaments including mechanical instability and cartilage of the ankle were less severe in the ankles with symptomatic os subfibulare than in those with chronic lateral instability without os subfibulare. The patients' age was lower in the ankles with symptomatic os subfibulare than in those with chronic lateral instability without os subfibulare. The clinical scores and gender ratio were not statistically different between the group.

Accessory Anterolateral Talar Facet Syndrome After Treatment of Neglected Fracture of the Lateral Process of the Talus: A Case Report.

Fracture of the lateral process of the talus has often been missed or confused with lateral ankle sprain, and this can lead to long-term untreated cases of nonunion, malunion, and subtalar joint osteoarthritis. In a review of the published data, accessory anterolateral talar facet syndrome was not found after treatment of nonunion of the lateral process of the talus fracture. This report presents the case of a 40-year-old male snowboard instructor who suffered from a neglected fracture of the lateral process of the talus and was treated with open reduction using an iliac autogenous bone graft. Subsequently, partial resection of the anterior aspect of the process was required to treat the impingement syndrome that developed secondary to the united but enlarged lateral process. The patient resumed his activities a year after the second operation. We describe the consequences of misdiagnosis of the lateral process of the talus and its management.

Short-term efficacy and safety of hyaluronic acid injection for plantar fasciopathy.

PURPOSE: Plantar fasciopathy is the most common cause of plantar heel pain and is considered to be a type of enthesopathy. The short-term efficacy, safety, and dose-response relationship of high-molecular-weight hyaluronic acid (HA) was investigated in patients with plantar fasciopathy. METHODS: In this multicenter, prospective, randomized, double-blind, placebo-controlled trial, 168 patients with persistent pain from plantar fasciopathy for more than 12 weeks were randomly assigned to receive 2.5 mL of 1% HA (H-HA), 0.8 mL of 1% HA (L-HA), or 2.5 mL of 0.01% HA (control group) once a week for 5 weeks. The primary endpoint was improvement in visual analogue scale (VAS) score for pain from baseline to week 5. RESULTS: The VAS scores (least squares mean ± standard error) in each group decreased gradually after the start of treatment, a change of -3.3 ± 0.3 cm for the H-HA group, -2.6 ± 0.3 cm for the L-HA group, and -2.4 ± 0.3 cm for the control group, with the H-HA group improving significantly more than the control group (P = 0.029). No serious adverse events were reported. There was no difference between the groups in the incidence rates of adverse drug reactions. CONCLUSION: The administration of five injections of high-molecular-weight HA is an effective treatment with no serious adverse drug reactions and is a conservative treatment option for plantar fasciopathy. This treatment contributed to alleviation of pain in patients with plantar fasciopathy and improvement in their activities of daily living. LEVEL OF EVIDENCE: I.

Glomus Tumor in the Tarsal Tunnel: A Case Report.

Glomus tumors are painful benign neoplasms. They commonly present in the hand and are mostly solitary lesions. We report a rare case of multiple glomus tumors in the lower leg. Moreover, 1 of the tumors was in the tarsal tunnel. Resection of the tumors resulted in the early diagnosis of glomus tumors and complete symptom relief. Because of its rarity, diagnosing an extradigital glomus tumor is difficult. Recognition of glomus tumors allows for an early diagnosis and resection, and preoperative magnetic resonance imaging helps in the detection of multiple lesions. Before resection, we considered tarsal tunnel syndrome in the differential diagnosis because of the symptoms and location of the tumor. Tarsal tunnel syndrome is a comparatively well-known disease in the foot. When tarsal tunnel syndrome is suspected, a glomus tumor should also be considered in the differential diagnosis.

The short-term effect after a single injection of high-molecular-weight hyaluronic acid in patients with enthesopathies (lateral epicondylitis, patellar tendinopathy, insertional Achilles tendinopathy, and plantar fasciitis): a preliminary study.

BACKGROUND: Hyaluronic acid (HA) with a high molecular weight of 2700 kDa is approved in Japan to treat osteoarthritis of the knee, periarthritis scapulohumeralis, and knee pain associated with rheumatoid arthritis. The purpose of this preliminary study was to investigate the short-term efficacy, safety, and injectable volume of HA in the treatment of enthesopathies. METHODS: A total of 61 patients (16 with lateral epicondylitis, 14 with patellar tendinopathy, 15 with insertional Achilles tendinopathy, and 16 with plantar fasciitis) were each administered a single injection of HA (up to 2.5 ml). Efficacy and safety were assessed by comparing the visual analog scale (VAS) for pain and local symptoms before injection (baseline) and at 1 week after injection. We also investigated the injectable volume by means of the difference in syringe weight before and after injection and by the judgment of the administering investigator. RESULTS: The injection of HA resulted in a change in VAS (mean ± SD) of -2.20 ± 2.26 cm for the four sites overall and -2.55 ± 2.43 cm for lateral epicondylitis, -2.01 ± 2.16 cm for patellar tendinopathy, -1.80 ± 1.91 cm for insertional Achilles tendinopathy, and -2.38 ± 2.61 cm for plantar fasciitis. The injection of HA also improved local symptoms in each site. It was also determined that 2.5 ml of HA can be injected in each of the four sites. CONCLUSION: A single injection of HA resulted in similar improvements of pain in each of the four enthesopathies (lateral epicondylitis, patellar tendinopathy, insertional Achilles tendinopathy, and plantar fasciitis). These results suggest that HA could be clinically effective in the treatment of enthesopathies.

Anterior Ankle Impingement Syndrome With Spur Fragmentation: Is It an Os Talotibiale?

Background: Bone fragments are often found in ankles with anterior bony impingement. However, whether they are detached osteophytes or accessory bones remains unknown. Methods: Among the 66 continuously enrolled cases of ankles with anterior bony impingement, 32 had a fragment located at the anterior margin of the tibia. The cases of posterior impingement, lateral instability, osteochondral lesions, or free bodies simultaneously treated were excluded. The enrolled subjects were classified into 2 groups: ankles without (group A) and with remarkable spurs (group B). The patients' backgrounds, location of the fragments, clinical scores, and other parameters required to resume sports were compared. The Japanese Society for Surgery of the Foot (JSSF) ankle rating scale was used to evaluate preoperative and postoperative ankle conditions, and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) was used to evaluate postoperative sports abilities. Results: Eight (seven subjects) and 11 ankles were classified into groups A and B, respectively, and the mean age of the 18 patients was 25.4 (range, 16-37) years. No statistical differences in patient backgrounds or fragment sizes between the groups existed. In group A, the fragments were located on the lateral plateau in 7 of the 8 ankles, whereas in group B, their locations varied. The patients were followed up for a median of 48 months (range, 24-168). No complications were observed. The postoperative JSSF and SAFE-Q sports activity scores were significantly higher in group A than in group B (P <.01 and <.001, respectively). The postoperative term to return to their original sports activities was significantly shorter in group A (P < .05). Conclusion: Anterior bony fragments of the ankle without a remarkable spur were located at a specific site, and the results of arthroscopic treatment were better than in those with remarkable spurs. Such a fragment may be called an os talotibiale. Level of Evidence: Level III, retrospective cohort study.

Treatment of Symptomatic Os Supranaviculare in Athletes.

BACKGROUND: Although the incidence of os supranaviculare (OSSN) is generally low, symptomatic OSSN affects athletes. The aim of this study was to assess the variations of OSSN and the results of osteosynthesis between the OSSN and the navicular bone. METHODS: Eleven feet of 10 elite athletes with symptomatic OSSN were treated. There were 3 male and 7 female patients with an average age of 19 years. Eight feet exhibited navicular stress fracture (NSF). Operative treatment was performed in 9 feet of 8 patients and 2 conservatively. Seven OSSNs were fixed with 1 or 2 screw(s) according to their size, using an autologous bone graft. The accompanying NSF was also treated surgically in 4 feet. Foot condition was evaluated using the Japanese Society for Surgery of the Foot (JSSF) midfoot rating scale and sports activity score of the Self-Administered Foot Evaluation Questionnaire (SAFE-Q). RESULTS: The median OSSN was 12.7 mm in width, 5.6 mm in length, and 6.6 mm in height. The dorsal surface of the OSSN required at least 70 mm2 to be fixed using 2 screws. Seven OSSNs of 6 patients treated surgically successfully fused with the navicular. Two small OSSNs that were not stabilized with screws also fused after surgical treatment for NSF. However, one of the 2 OSSNs with NSF treated nonoperatively did not achieve fusion. The patients were followed up for 24-161 months. The median JSSF score improved from 87 to 97.7 postoperatively (P = .00312). The median postoperative SAFE-Q sports score was 84.8. All patients returned to their original activities. CONCLUSION: Our results suggest that osteosynthesis with autologous bone graft was effective for symptomatic OSSNs. Even when the OSSN was small and not suitable for internal fixation, treatment of NSF was effective for union of OSSNs. The OSSN possibly belongs to a part or subtype of NSF.

Advancement of Periosteal and Capsular Complexes With or Without Augmentation Using a Free Graft From Lower Extensor Retinaculum: A Comparative Study With Propensity Score Matching.

Background: This study compared the outcome of the L-shaped (L-AD) advancement of the periosteal and capsular complexes with or without augmentation using a free graft of the lower extensor retinaculum (AUG) in patients with chronic lateral ankle instability. Methods: A matched pair analysis was performed of retrospectively collected medical records of patients undergoing lateral ankle ligament repair who had completed at least 2 years of follow-up. Patients who underwent L-AD with AUG and patients undergoing L-AD alone were matched for age, sex, stress radiography findings, and body mass index. Patients with general joint laxity, osteoarthritic changes in the ankle, and subtalar symptoms and who underwent simultaneous surgical treatment for conditions other than that for lateral ankle ligament were excluded. A total of 46 patients were included in the study (23 patients in each group). Clinical outcome scores and postoperative mechanical instability were compared. Results: The median American Orthopaedic Foot & Ankle Society (AOFAS) score improved significantly (P < .001) from 72 to 97 in the L-AD alone group and from 77 to 100 in the L-AD with AUG group. The mean (±SD) talar tilt angles improved significantly from 11.1 to 4.7 degrees postoperatively (P < .001) in the L-AD alone group vs 9.7 to 5.2 degrees (P < .001) in the L-AD with AUG group. The mean anterior drawer distances were improved significantly postoperatively from 6.4 to 4.7 mm (P < .001) in the L-AD alone group, and from 6.5 to 4.5 mm (P < .001) in the L-AD with AUG group. Conclusion: The L-AD technique significantly improved AOFAS scores and mechanical instability of ankles with chronic lateral instability with a very low complication rate. Additional augmentation using a free graft showed no advantages in the ankle with a talar tilt of <20 degrees. Level of Evidence: Level III, retrospective case-control series.

Treatment of Intra-Articular Lesions After Posterior Inferior Tibiofibular Ligament Injury: A Case Series of Elite Rugby Players.

Background: Surgical intervention is not typically used to treat symptoms after mild tibiofibular ligament injuries without ankle dislocation or subluxation. Purpose: To describe outcomes in patients arthroscopically treated for unique intra-articular lesions after sustaining syndesmosis injury of the ankle. Study Design: Case series; Level of evidence, 4. Methods: A total of 11 elite male rugby players with a mean age of 21.0 years (range, 17-28 years) were referred to our hospital for prolonged posterior ankle pain after a high ankle sprain during rugby football. The patients were examined using standing view radiography, computed tomography (CT) and magnetic resonance imaging (MRI) to determine the extent of ligament damage. Posterior ankle arthroscopy was performed to examine intra-articular lesions. The patients were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle/hindfoot rating scale and sports activity score of the Self-Administered Foot Evaluation Questionnaire (SAFE-Q). Results: The average reduced tibiofibular overlap on the standing mortise view was 1.2 mm (range, 0.5-2.0 mm) compared with the opposite ankles. Mason type 1 fracture was detected on CT in 6 patients, and ossification of the interosseous membrane was detected in 2 patients. A bone bruise in the posterior malleolus was observed on MRI in all but 1 patient. Intra-articular fragments located in the posterior ankle were observed and removed arthroscopically. Symptoms improved rapidly after arthroscopic treatment in all patients. All patients returned to rugby games at a median of 11 weeks postoperatively. The median AOFAS scores improved from 77 preoperatively to 100 postoperatively (P < .01), and the median SAFE-Q sports activity subscale score improved from 49.4 to 100 (P < .01). Conclusion: All unique intra-articular lesions that developed in rugby football players after syndesmosis injury were able to be treated arthroscopically. Patients returned to playing rugby football without syndesmosis reduction. Posterior ankle arthroscopy was effective in patients with residual symptoms after syndesmosis injury.

Osteochondral Lesion of the Tibial Plafond Induced by Malposition of Soft Suture Anchors Used for the Deltoid Ligament Repair: A Case Report.

CASE: A 24-year-old elite female rugby player complained of prolonged symptoms after a surgical repair of the deltoid ligament performed 2 years previously. Ankle arthroscopy revealed an osteochondral lesion in the tibial plafond at the medial gutter, with the fibers of the soft suture anchor exposed in the joint. The anchors were removed, and the cysts were filled with autogenous cancellous bone. The patient returned to the elite-level rugby games 5 months after the operation without any symptoms. CONCLUSION: We must be aware that even soft anchors can cause arthritis if improperly positioned.

Fibrocartilaginous Bed Injury of the Posterior Tibial Tendon Sheath: A Report of 3 Cases.

CASES: Three athletes (2 female gymnasts and 1 male rugby player) complained of persistent posteromedial ankle pain after an ankle injury. Arthroscopy of the ankle and tendoscopy of the posterior tibial tendon (PTT) were performed in 2 patients with prolonged symptoms and in 1 patient with acute severe pain. A small rupture at the fibrocartilaginous bed of the PTT with pinhole communication between the PTT sheath and the ankle joint cavity was detected, and open repair of the fibrocartilaginous bed was performed. CONCLUSION: All patients returned to their respective sports without any residual symptoms after open repair of the fibrocartilaginous bed.

Arthroscopic Treatment of Posterior Ankle Impingement Syndrome: Mid-Term Clinical Results and a Learning Curve.

PURPOSE: To report mid-term clinical results of posterior ankle arthroscopy in the treatment of posterior ankle impingement syndrome (PAIS) and to assess the learning curve and its influence on the results. METHODS: This was a retrospective evaluation of the clinical outcomes of posterior ankle arthroscopy and its learning curve in a series of patients with PAIS. Demographic and clinical data, surgical time, the American Orthopaedic Foot Ankle Society (AOFAS) ankle/hindfoot scores, and time to resumption of sports were recorded. RESULTS: Fifty-nine patients with 72 posterior ankle arthroscopies were evaluated at a mean follow-up period of 60 months (24-133 months). Causes of PAIS were an os trigonum (50), a large posterior talar process (14), and soft-tissue impingement (8). There were 29 male and 30 female patients. The average age was 21.8 years (12-74 years). The average preoperative AOFAS score improved significantly from 79.6 to 97.6 postoperatively (P < .0001). The average time taken to resume training was 5.3 weeks, and the time to return to a competitive condition was 13.4 weeks. The times to resumption of training were shorter in elite athletes than local competitive athletes. The learning curve of the posterior ankle arthroscopy was detected and determined by a logarithmic trendline and moving averages. An experience of 26 cases was required to be proficient in posterior arthroscopies. The postoperative AOFAS scores were not statistically different between the initial and the latest 10 series each. CONCLUSIONS: The mid-term follow-up results of endoscopic treatment for the PAIS were good, with a high success rate in returning to sports activities. Although a learning curve effect was detected in our series of arthroscopic treatment for the PAIS due to os trigonum, a low volume of experience did not affect the results. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Morphologic Analysis of Nonosseous Talocalcaneal Coalitions Using 3D Reconstruction.

BACKGROUND: Resection of talocalcaneal coalitions has generally involved osseous coalitions. We attempted to evaluate the morphology of nonosseous talocalcaneal coalitions. This study aimed to investigate if the calcaneal articular surface area of feet with talocalcaneal coalitions is different than that of normal feet. METHODS: Twenty nonosseous talocalcaneal coalition cases with analyzable computed tomography (CT) scans were compared to 20 control cases. Three-dimensional models of the talus and calcaneus were constructed, and the surface areas of the posterior facet (SPF), whole talocalcaneal joint of the calcaneus (SWJ), and coalition site (SCS) of each 3D-CT model were measured. "Calibrated" values of the 2 groups were created to adjust for relative size of the tali and then compared. The preoperative and postoperative AOFAS Ankle-Hindfoot scale was calculated for 9 cases that had undergone single coalition resection. RESULTS: The calibrated SPF and SWJ were significantly greater in the coalition group than in the control group (40% and 12%, respectively). No significant difference was detected between the calibrated (SWJ - SCS) value of the coalition group and the calibrated SWJ value of the control group. The AOFAS scale was improved postoperatively in all 9 cases analyzed. CONCLUSION: The calcaneal articular surface of nonosseous talocalcaneal coalition feet in our series was larger than that of the normal feet. This study indicates that the total calcaneal articular surface after coalition resection may be comparable to the calcaneal articular surface of normal feet. We suggest that the indication for coalition resection be reconsidered for nonosseous coalition. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Severe Talonavicular Osteoarthritis After a Neglected Navicular Stress Fracture: A Case Report.

CASE: A 17-year-old high school rugby player complained of right midfoot pain for 18 months. Radiographs showed severe osteoarthritic changes in the right talonavicular joint. A navicular fracture, talonavicular joint narrowing, a talar head cyst, and proximal navicular fragmentation were detected on computed tomography (CT). The patient underwent removal of the osteochondral fragments and fracture reduction and returned to rugby 8 months postoperatively. CT showed a remodeling of the talonavicular joint 2 years postoperatively. CONCLUSION: In a young athlete, reconstruction of the talonavicular joint should be attempted before joint fusion, even if the joint shows signs of secondary osteoarthritis.

A zinc(II)-included hemicryptophane: facile synthesis, characterization, and catalytic activity.

A zinc(II)-included hemicryptophane, which has a zinc(II) center embedded in the cavity, was synthesized and characterized. The catalytic activity of the hemicryptophane was tested in the hydrolysis of methyl para-nitrophenyl carbonate (MPC). A direct comparison between the hemicryptophane and the model complex, which lacks a cavity, demonstrated that the cage structure enhanced the catalytic activity.

Computed tomography-based custom-made stem for dysplastic hips in Japanese patients.

We investigated 55 hips of 53 patients with dysplastic hips. Individual computed tomography data were used in the manufacturing of cementless custom-made stems made of Ti-6Al-4V. The proximal one third was coated using porous coating covered with hydroxyapatite coating. The average age at surgery was 60 years and the average follow-up was 7 years. Five patients (9%) complained of postoperative thigh pain. According to Engh's radiologic classification system, there was bone-ingrown fixation in all hips. The cortical index and canal flare index were lower, and stem diameter was greater in the 11 hips (20%) with severe stress shielding than in the remaining 44 hips. Although the results obtained with this custom-made stem system for dysplastic hips were excellent, stress shielding is still an issue.

Sclerotherapy for intractable ganglion cyst of the hallux.

BACKGROUND: We devised a method of sclerotherapy using OK432. The present study comprised a retrospective followup of sclerotherapy outcomes. MATERIALS AND METHODS: Eighteen feet in 18 consecutive patients (seven men, 11 women; mean age, 55 years) were treated with sclerotherapy. Previous surgery had been performed one to four times for seven feet. After aspirating the contents of the ganglion cysts, 0.2 to 0.3 ml of suspension of OK432 (lyophilized strep pyogenes) was injected. The volume of fluid aspirated was from 0.2 to 2.5 ml, with an average of 0.9 ml. Mean duration of followup was 3 years 6 months. Clinical evaluation was performed using the AOFAS hallux scale. RESULTS: All ganglion cysts disappeared after sclerotherapy. However, recurrences were observed in eight feet. Mean duration until recurrence was 13 months. Sclerotherapy was again performed for all patients with recurrence. Re-recurrence occurred in three feet. A third sclerotherapy was performed for all three patients. All ganglion cysts had disappeared by final followup. Mean AOFAS score improved from 75 points before therapy to 95 points at followup. Six patients had complications with local redness and pain for 1 to 6 days after injection. CONCLUSION: Sclerotherapy using OK432 is a minimally invasive treatment of symptomatic ganglion cysts of the hallux. Recurrence is common but complications are infrequent and self-limited.

Proximal spherical metatarsal osteotomy for the foot with severe hallux valgus.

BACKGROUND: A proximal spherical metatarsal osteotomy was devised to correct not only varus deviation of the first metatarsal, but also dorsiflexion. We expected to increase the medial longitudinal arch by adding plantar flexion at the osteotomy site. To investigate the limitations of this procedure for feet with severe hallux valgus, a followup study was performed on patients with preoperative hallux valgus angles greater than or equal to 40 degrees. MATERIALS AND METHODS: Forty-eight feet in 37 patients (10 male, 27 female) (60 years; range, 20 to 84 years) were investigated. Mean followup was 4 years and 1 month, ranging from 2 to 8 years. The spherical osteotomy was performed using a curved chisel. A distal soft tissue procedure was done at the same time. Twenty feet received combined operations for their combined deformities. RESULTS: While 81% of patients were satisfied with the results, 50% of those with preoperative hallux valgus angles greater than or equal to 50 degrees had postoperative hallux valgus angle greater than or equal to 20 degrees. In these patients, correction of metatarsus primus varus was good, but correction of valgus deviation of the hallux was fair. Mean correction toward plantar flexion was 1.5 degrees and no increase in arch height was achieved. CONCLUSION: The proximal spherical osteotomy could consistently achieve satisfactory results for the patients with hallux valgus angles less than 50 degrees. However, the corrections were worse in feet with more severe deformities. Furthermore, plantarflexion at the osteotomy site was offset by displacement at the first tarsometatarsal joint. If plantarflexion is indispensable, arthrodesis of the tarsometatarsal joint is recommended.

Correlation of compensatory alignment of the subtalar joint to the progression of primary osteoarthritis of the ankle.

BACKGROUND: The etiology of primary osteoarthritis of the ankle is not well understood. The varus deformity of the ankle and the compensatory function of the subtalar joint are expected to be important factors in the progression of osteoarthritis. The purpose of this study was to document joint inclination at the various stages and to try to deduce the mechanism of primary, varus osteoarthritis of the ankle. MATERIALS AND METHODS: Weightbearing ankle anteroposterior (AP) views, lateral views and subtalar views were taken for 133 ankles in 80 patients (OA group) and 62 ankles in 50 subjects (control group). The OA group was divided into 5 radiographic stages. The inclination of the articular surface of the tibial plafond, the talar dome and the posterior facet of the calcaneus were measured from the radiographs. The inclination of the subtalar joint against the ankle was also calculated. At each stage, each value of the OA group was compared with the control group. RESULTS: The varus inclination of the articular surface of the tibial plafond progressed by stages; however, anterior opening was not significant at all stages. The valgus inclination of the subtalar joint progressed until the intermediate stage and converted to varus position at the later stage. CONCLUSION The compensatory function of the subtalar joint was most pronounced at the intermediate ankle arthritis stage.