Arthroscopic repair of the anterior talofibular ligament with retrograde drilling and allograft bone grafting for chronic lateral ankle instability with hepple stage V osteochondral lesions of the talus.

Abstract

Background: Chronic lateral ankle instability (CLAI) often arises from inadequately managed injuries to the lateral collateral ligaments, potentially leading to osteochondral lesions of the talus (OLT) and subsequent osteoarthritis. Hepple Stage V OLT, characterized by subchondral cysts, presents a significant therapeutic challenge. This study aimed to evaluate the efficacy of arthroscopic anterior talofibular ligament (ATFL) repair combined with retrograde drilling and allograft bone grafting in patients with CLAI and Hepple Stage V OLT with an intact talar articular surface.

Methods: This retrospective, small-sample exploratory study included 12 patients (ten men; median age: 35 years) who underwent arthroscopic treatment (between January 2020 and December 2022) for chronic lateral ankle instability with subchondral cysts, specifically Hepple Stage V OLT cases with an intact talar articular surface, after failing non-surgical interventions. The ATFL was repaired using the all-inside Internal Brace (IB) augmentation with the arthroscopic modified Broström operation. Treatment for OLT involved simultaneous retrograde drilling and allograft bone grafting. The median follow-up duration was 24 months (range: 20-35 months). The improvement of postoperative ankle pain was assessed using the Visual Analogue Scale (VAS), and the improvement of ankle function was evaluated using the American Orthopedic Foot ༆ Ankle Society (AOFAS) score and Foot༆Ankle Outcome Score (FAOS). Radiographic assessments were conducted at a minimum of 12 months postoperatively.

Results: All 12 patients (12 ankles; 100%) returned for clinical and radiological follow-up at an average of 24 months (20-35 months) postoperatively. Subjective improvement was reported after arthroscopic surgery. The median AOFAS score demonstrated a substantial improvement from 67 preoperatively (range: 58-70) to 94 at the final follow-up (range: 90-98), with P < 0.05. Similarly, The FAOS score improved from 65 preoperatively (range: 58-75) to 91 at the final follow-up (range: 89-97), with P < 0.05. Radiographic follow-up results indicated satisfactory healing of the ATFL and favorable bone ingrowth post-subchondral cyst bone grafting.

Conclusion: Arthroscopic ATFL repair combined with retrograde drilling and allograft bone grafting yields favorable clinical and radiographic outcomes in patients with CLAI and Hepple Stage V OLT. This integrated approach addresses both ligament instability and subchondral cyst pathology, potentially delaying the progression of osteoarthritis.