A morphology-based classification system and management strategy for postero-medial tibial plateau fractures

Background: Posteromedial tibial plateau fractures represent a distinct subset of proximal tibial injuries, characterized by coronal-plane fracture orientation and complex fragment morphology that may be overlooked on standard radiographs. Earlier classification systems such as the Schatzker and pre-2018 AO/OTA schemes did not adequately describe posterior or posteromedial fracture patterns, limiting their usefulness in surgical planning. However, the revised 2018 AO/OTA classification introduced axial-plane modifiers to specifically identify posteromedial involvement. Despite this advancement, considerable heterogeneity remains in fracture morphology and intraoperative behavior, highlighting the need for a dedicated morphology-based classification that more directly correlates fracture pattern with fixation strategy and clinical outcome. Methods: Forty adult patients with postero-medial tibial plateau fractures were prospectively studied. Fractures were classified by sagittal position of fracture line (L1-L3), apex orientation on AP view (A1-A2), and displacement on CT (Da <2 mm, Db >2 mm). Surgical approach and fixation strategy were selected accordingly, and intraoperative stability was assessed under fluoroscopy. Outcomes were evaluated with radiographs, range of motion, and Knee Society Score (KSS) at 6 months. Results: Of 40 patients (mean age 41 years), 24 fractures involved L1, 11 L2, and 5 L3 regions; 27 had medial apex (A1) and 13 lateral apex (A2). L1Db and L2 fractures showed marked instability, while L3Da patterns remained stable through flexion. All unstable patterns required buttress plating, with surgical approach dictated by apex orientation. Radiological union occurred in all cases at a mean of 14 weeks. At 6 months, 85% of patients achieved excellent or good outcomes; complications included stiffness in three cases and ACL laxity in one. Conclusions: This morphology-based classification reliably correlates fracture patterns with stability, surgical approach, and rehabilitation needs. It offers a practical framework for individualized management of posteromedial tibial plateau fractures and may improve functional outcomes. Further multicenter validation is recommended.