Ankle Fusion Combined With Calcaneal Sliding Osteotomy for Severe Arthritic Ball and Socket Ankle Deformity.

BACKGROUND: Although a ball and socket ankle deformity is usually congenital and asymptomatic, abnormal inversion and eversion mobility can result in recurrent ankle sprain and osteoarthritis. This retrospective study was performed to evaluate the clinical and radiologic outcomes of ankle fusion combined with calcaneal sliding osteotomy for severe arthritic ball and socket ankle deformity.

METHODS: Fourteen patients with severe arthritic ball and socket ankle deformity were followed for more than 3 years after operation. The clinical evaluation consisted of American Orthopaedic Foot & Ankle Society (AOFAS) score, Foot and Ankle Ability Measure (FAAM), visual analog scale (VAS) for pain, and subjective satisfaction score. The period to fusion and union of osteotomy, the change of hindfoot alignment angle, and complications were evaluated radiologically.

RESULTS: AOFAS and FAAM scores were significantly improved from an average of 37.4 and 34.5 points to 74.6 and 78.5 points, respectively. VAS for pain with walking over 20 minutes was significantly improved from an average of 8.4 points to 1.9 points. The average satisfaction score of patients was 88.9 points. The difference in heel alignment angle (compared to contralateral side) was significantly improved from an average of 34.8 to 5.4 degrees. There were 2 cases of progressive arthritis in an adjacent joint and 1 case of failed fusion.

CONCLUSIONS: Ankle fusion combined with calcaneal sliding osteotomy can be an effective operative option for ball and socket ankle deformity with advanced arthritis. In spite of increased complication rate, reliable pain relief, and restoration of gait ability through correcting hindfoot malalignment could improve the quality of life.

LEVEL OF EVIDENCE: Level IV, retrospective case series.