Direct fixation of posterior malleolus fractures-posterolateral or posteromedial approach?

Abstract

Ankle fractures involving the posterior malleolus (PM) generally have worse prognosis. There is a trend towards it’s direct fixation, yet the exact indications are a subject of debate. The purpose of our study was to present our treatment protocol and to discuss the advantages and limitations of the direct posterolateral and posteromedial approaches. We present a prospective series of 35 ankle fractures involving the PM, operated for a period of 4 years (2018-2022). Direct posterolateral approach was used in 20 ankles, 15 were operated via a posteromedial approach. Clinical and functional assessment was performed according to the criteria of AOFAS. 14 patients received an excellent score, 16 had good and the rest had an average score. The overall score was 85,4 (54-100). The average range of motion was 50° (15°-55°).Eight patients had superficial skin necrosis along the surgical incision. Thirteen patients need their fibular plates removed due to local irritation. Five patients, operated through a posterolateral approach, had lateral heel numbness suggestive of a sural nerve disfunction. PM is important for normal ankle kinematics. When it’s direct fixation is considered appropriate, the safest and shortest route is optimal. It is determined by the preoperative CT. The posterolateral approach is more versatile, but lead to more complications in our study.