Outcomes of Posterior Arthroscopic Reduction and Internal Fixation (PARIF) for the Posterior Malleolar Fragment in Trimalleolar Ankle Fractures

Abstract

Background: Posterior malleolar fractures within a trimalleolar ankle fracture pattern are challenging to manage. Posterior ankle arthroscopy provides a means to assess the intra-articular and syndesmotic reductions, while removing loose bodies. The purpose of this study was to determine the radiographic and patient reported outcomes of posterior arthroscopic reduction and internal fixation (PARIF) in trimalleolar ankle fractures. Methods: From November 2015 to March 2019, we prospectively enrolled consecutive trimalleolar ankle fractures that underwent PARIF by a single surgeon. Preoperative and postoperative computed tomography (CT) scans were interpreted by 2 blinded musculoskeletal radiologists for articular reduction, syndesmosis congruity, and presence of ossific loose bodies. Patient outcomes were assessed using the Foot and Ankle Disability Index (FADI), American Orthopaedic Foot & Ankle Society (AOFAS) ankle score, Olerud-Molander Ankle Score (OMAS), and visual analog scale (VAS). A total of 28 trimalleolar ankle fractures were treated with PARIF. Mean patient age was 36 years (range, 19-69). Results: Preoperative CT identified 18 intra-articular loose bodies (range, 0-4) in 36% of ankles and 75% (n = 21) syndesmosis incongruity. Postoperative CT scans demonstrated anatomic intra-articular reduction in all fractures, 41.7% (5/12) syndesmosis incongruity without fixation, and 0% (0/9) with suture-button fixation. At mean 2-year follow-up, the results were good to excellent with mean VAS score 1 (range, 0-4), AOFAS score 84 (range, 63-100), FADI 85 (range, 59-100), and OMAS 76 (range, 40-100). Conclusion: The PARIF technique for displaced posterior malleolar fractures was effective in achieving anatomic intra-articular reduction, syndesmosis congruity, and intra-articular loose body removal, while safely preserving the soft tissues. Level of Evidence: Level IV, prospective case series.