Abstract
PURPOSE: To compare intramedullary nailing (IMN; suprapatellar, infrapatellar, or parapatellar) with minimally invasive plate osteosynthesis (MIPO) for proximal tibial fractures by systematically evaluating clinical outcomes. MATERIALS AND METHODS: We included English-language randomized controlled trials (RCTs) and comparative studies evaluating adult proximal tibial fractures (AO/OTA 41-A2/A3, 41-C1/C2) treated with IMN or MIPO. Databases including PubMed, Embase, Cochrane, and Scopus were searched until June 9, 2025. Study selection, data extraction, and quality assessment were independently performed by two reviewers. Statistical analyses were conducted using STATA version 18.0. Dichotomous outcomes were expressed as risk ratios (RR) or odds ratios (OR), and continuous outcomes as weighted mean differences (WMD) or standardized mean differences (SMD), each with 95% confidence intervals (CI). Heterogeneity was assessed using I² statistic and Cochran's Q test, applying a random-effects model if I² >50% or p < 0.1. Publication bias was evaluated via funnel plots and Egger's regression test. RESULTS: Eleven studies comprising 829 patients (409 IMN; 420 MIPO) met the inclusion criteria. The IMN group demonstrated a significantly lower infection rate compared with the MIPO group (RR = 0.55; 95% CI, 0.33-0.91; p = 0.019). Conversely, traditional (infrapatellar and parapatellar) IMN approaches showed significantly increased anterior knee pain incidence compared to MIPO (RR = 6.27; 95% CI, 0.92-20.55; p = 0.002). Suprapatellar IMN studies did not report anterior knee pain outcomes. No significant differences were identified between IMN and MIPO in nonunion rates (RR = 1.04; 95% CI, 0.61-1.77; p = 0.88), malalignment incidence (RR = 1.29; 95% CI, 0.88-1.89; p = 0.19), knee range of motion (WMD = 0.08; 95% CI, -2.22-2.37; p = 0.95), or implant removal rates (RR = 0.69; 95% CI, 0.41-1.15; p = 0.16). CONCLUSION: IMN fixation for proximal tibial fractures significantly reduces infection risk compared with MIPO surgery, but traditional IMN approaches (infrapatellar/parapatellar) carry a greater risk of anterior knee pain. No differences were observed in nonunion rates, malalignment, knee range of motion, or implant removal rates between the two treatments. Further high-quality studies evaluating suprapatellar IMN approaches are warranted.