Factors for the prognosis of pilon variant posterior malleolar fracture: A retrospective study

Poor reduction quality in Pilon variant posterior malleolar (PVPM) fractures may lead to articular incongruity, resulting in functional impairment and eventual post-traumatic arthritis. Although intra-articular impacted fragments (IAIF) are frequently observed in PVPM fractures, the clinical necessity of IAIF reduction remains controversial, and the prognostic significance of IAIF presence or malreduction remains unclear. This retrospective study investigated prognostic factors in 64 surgically treated PVPM fractures with 24-month follow-up. Patients were divided into groups based on their reduction quality. Postoperative articular stepping and/or separation ≥ 2 mm were/was considered "poor" reduction, otherwise "optimal or good". AOFAS is the primary outcome while the VAS pain score, the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) are secondary outcomes. Statistical differences of in AOFAS, SF-36 and VAS were observed between reduction quality groups with the optimal reduction showing significantly better outcomes at postoperative 24 months. Statistical difference of AOFAS, SF-36 and VAS was also found between the sex groups with female cases showing significantly poorer outcomes. Neither IAIF's presence, size, morphological difference or location affected the prognosis. Based on linear regression analysis, "female", "poor reduction" and "syndesmotic fixation" are categorical variables that impair the functional prognosis of PVPM fractures at postoperative 24 months. This study indicates that the reduction quality based on articular stepping and separation was positively associated with clinical outcomes in PVPM fractures at 24 months postoperatively, which is independent of IAIF. Therefore, regardless of the presence of the IAIF, the reduction quality of the articular congruity positively affects the prognosis of PVPM fracture.