Sagittal Malalignment and Unsatisfactory Fracture Gap Reduction are Risk Factors for Conversion to Total Knee Arthroplasty After High-Energy Bicondylar Tibial Plateau Fractures.

Abstract

Objectives: To assess the incidence of and risk factors for conversion to total knee arthroplasty after bicondylar tibial plateau fractures.

Methods: Design: Retrospective, prognostic study.

Setting: Tertiary-referral, single-center, Level I trauma center.

Patient selection criteria: From 2008-2021, patients were included if they had an operative 41C1-C3 tibial plateau fractures and had ≥2 years of follow-up.

Outcome measures and comparisons: Age, sex, BMI, smoking status, injury mechanism, medical history, surgical details (meniscal repair, external fixation, time to fixation), and radiographic data (Kellgren-Lawrence grade, reduction quality (defined as gap <2 mm after reduction), medial proximal tibial angle (MPTA), posterior proximal tibial angle (PPTA)) were collected and compared between patients that went onto require total knee arthroplasty (TKA) and those that did not.

Results: 243 patients were included with mean age of 49.7 (19-89) years and 58.8% were male. Mean follow-up was 5.2±2.6 years. 13.6% (33) required total knee arthroplasty (TKA) after an average of 23.4 months. TKA patients were older (54.0 vs. 49.0 years, p=0.042) and had larger fracture gaps (2.9 vs. 1.7 mm, p=0.024). They also had less satisfactory reductions in fracture gap (42.4% vs. 62.9% achieving reduction with a gap of <2mm, p=0.026) and PPTA (33.3% vs. 61.9%, p=0.002). Risk factors for TKA included fracture gap >2.45 mm after fixation, age >50.5, and PPTA >15°.

Conclusions: Sagittal malalignment, age, and poor fracture gap reduction increased the risk of TKA conversion after OTA41C1-C3 fracture fixation.

Level of evidence: III, prognostic.