Management of Isolated Medial Gutter Ankle Arthritis With Lateralizing Calcaneal Osteotomy and Allograft Lateral Ligament Reconstruction.

BACKGROUND

Isolated medial gutter arthritis is an uncommon subset of ankle arthritis characterized by complete loss of joint space within the medial gutter, without proximal tibiotalar joint surface narrowing or tilting. Although ankle arthrodesis and total ankle arthroplasty are conventional treatments, a promising alternative in addressing medial gutter arthritis is the combination of Dwyer calcaneal osteotomy, arthroscopic debridement, and hamstring allograft lateral ligament reconstruction. This study assesses the clinical and radiographic outcomes of this procedure with a minimum 2-year follow-up.

METHODS

Retrospective review was performed for cases done for isolated medial gutter arthritis (Takakura stage 3a) treated with a lateralizing (Dwyer) calcaneal osteotomy, anatomic lateral ligament reconstruction using hamstring allograft (ATFL/CFL), and ankle arthroscopy by a single surgeon between 2018 and 2022. Clinical patient-reported outcome measures (PROMs) were collected using Patient Reported Outcome Measurement Information System (PROMIS) and the Revised Foot Function Index Short Form (FFI-RS). Radiographic outcomes were evaluated by comparing pre- and post-operative joint space on weightbearing (WB) radiographs. Area of clear space ratio was examined on postoperative WB computed tomography (WBCT).

RESULTS

Six patients (mean age 64.2 years) completed follow-up at a mean of 3.9 years. Pre- and post-operative PROMs were available for 5 of 6 patients and showed significant improvement in pain and cumulative FFI-RS scores. On radiographs, tibiotalar varus tilt decreased by approximately 3 degrees, the lateral tibiotalar joint space decreased (4.7 ± 1.0 mm to 4.0 ± 1.2 mm; P = .033), and the medial clear space increased (median ~0.7 mm to 3.1 mm; n = 6; P < .05), whereas the lateral clear space modestly increased (2.2 ± 0.5 mm to 3.2 ± 0.9 mm; P = .005). The clear-space ratio (CSR) increased from 0.2 to 1.0 (n = 6; P < .05). Postoperative weightbearing CT (available in 5 of 6 patients) demonstrated a mean medial: lateral tibiotalar contact-area ratio of 0.61 ± 0.30.

CONCLUSION

In this single-surgeon case series (n = 6) of Takakura 3a ankles, a lateralizing calcaneal osteotomy combined with hamstring allograft lateral ligament reconstruction and arthroscopic debridement was associated with improvements in pain, function, and radiographic alignment at a mean 3.9-year follow-up. Findings should be interpreted cautiously given the small sample size.

LEVEL OF EVIDENCE: Level IV, case series.