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

Submission Type: Ankle Arthritis Research Type: Level 4 – Case series Introduction/Purpose: Isolated medial gutter arthritis is an uncommon subset of ankle arthritis characterized by complete loss of joint space within the medial gutter, without proximal tibio-talar joint surface narrowing or tilting. Patients with hindfoot varus malalignment are particularly prone to medial gutter arthritis, associated with chronic lateral ankle instability. While 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 approach realigns the hindfoot and externally rotates the talus, thus reducing bone-to-bone contact in the medial gutter and alleviating arthritis symptoms. This study assesses the clinical and radiographic outcomes of this procedure, with follow-up evaluations conducted at a minimum of two years. Methods: Retrospective review was performed for cases done by a single surgeon between 2018 and 2022. Inclusion criteria consisted of patients diagnosed with Takakura stage 3a isolated medial gutter arthritis that underwent a Dwyer lateralizing calcaneal osteotomy, ankle arthroscopy and debridement, and hamstring allograft lateral ligament reconstruction. Clinical patient reported outcome measures (PROMs) were collected using Revised Foot Function Index Short Form (FFI). Radiographic outcomes were evaluated by comparing pre-operative and post-operative joint space on weight-bearing (WB) radiographs, using the various measurements depicted in figure 1a. Measurement of clear space ratio (CSR) as described by Lee and Wapner (FAI 2009) was performed (Figure 1a: D, E). Area of clear space ratio (medial clear space divided by lateral clear space) was examined on postoperative WB computed tomography (CT), using Curvebeam’s CubeVue software (Figure 1b). Results: Six patients with average follow up of 3.9 years and age of 48.1 years were included. Of the total patients, 88.3% had pre- and postoperative PROMs. Pain and Cumulative FFI scores significantly improved, respectively (18.6 ± 3.65 to 13 ± 5.87; p< 0.046), (94.6 ± 22.5 to 68 ± 30.97, p< 0.011). Comparing pre- to post-operative radiographs, tibiotalar tilt angle decreased (4.72 ± 0.97 to 3.98 ± 1.17; p< 0.032), and medial clear space increased (median: 0.45; Q1: 0.300-Q3: 0.525 to median: 3.1; Q3: 2.86-Q3:3.49), while lateral clear space remained stable, showing significant improvement in realignment. CSR 10mm distal of talar dome, had significantly increased (median: 0.082; Q1: 0.081-Q3: 0.138), (median: 0.907; Q1: 0.897-Q3: 0.923). On WBCT, average CSR area was 0.61 (± 0.3). Conclusion: The integration of a Dwyer calcaneal osteotomy with hamstring allograft lateral ligament reconstruction, and ankle arthroscopy represents a practical and effective treatment modality in addressing hindfoot varus deformity and isolated medial gutter ankle arthritis. This combined approach yields significant improvement on patient-reported pain, overall functional status, and radiographic outcomes, such as tibiotalar tilt and clear space ratio. The study’s findings underscore the approach’s efficacy, with notable clinical and radiographic improvement over a minimum follow up period of two years.