Complications and TKA conversion rates in unicondylar vs. bicondylar tibial plateau fractures: a retrospective cohort analysis.

BACKGROUND: Tibial plateau fractures are associated with a high incidence of posttraumatic osteoarthritis. This study aims to compare the rates of medical and surgical complications, as well as the rate of conversion to total knee arthroplasty (TKA), among patients undergoing operative fixation of tibial plateau fractures. METHODS: The TriNetX database was queried to identify patients aged 18 and older who underwent operative fixation of unicondylar (CPT 27535) and bicondylar (CPT 27536) tibial plateau fractures between January 2005 and January 2020. Patients with bilateral fractures, and those with a prior history of TKA were excluded. Medical and surgical complications were analyzed during the immediate (7d, 14d, and 30d), intermediate (90d, 180d, 1y, and 2y), and long-term (5y and 10y) postoperative periods. A multivariate model, adjusted for age, sex, and comorbidities, was used to further evaluate the risk of conversion to TKA. RESULTS: A total of 15,634 patients met all inclusion criteria and were included in this study (8,680 unicondylar and 6,954 bicondylar). Bivariate analysis revealed a higher risk of medical complications including DVT, PE, pneumonia, and death in the bicondylar group. The risk of surgical complications including superficial skin infection, deep infection, rehospitalization, arthrofibrosis, malunion, and nonunion were also higher in the bicondylar group. No differences were found in the rates of MI, stroke, cardiac arrest, pneumonia, ARDS, ED visits, or UTIs between groups at any time point. After multivariate analysis, the risk of conversion TKA was greater in the bicondylar fracture group at 5y (HR [95% CI] 1.43 [1.14, 1.79], p = 0.002) and 10y (HR [95% CI] 1.40 [1.14, 1.72], p = 0.001) follow-up. CONCLUSIONS: Patients undergoing operative fixation of bicondylar tibial plateau fractures experience higher rates of medical and surgical complications, as well as an increased incidence of conversion to TKA, compared to those with unicondylar fractures. LEVEL OF EVIDECE: Prognostic Level III.