Medial parapatellar approach may reduce anterior knee pain compared to transpatellar technique in tibial shaft fractures

BACKGROUND: Tibial intramedullary nailing (IMN) is the standard treatment for tibial shaft fractures, yet anterior knee pain (AKP) remains common, affecting nearly 47% of patients. Despite the reported advantages of suprapatellar techniques, infrapatellar approaches-medial parapatellar (MPP) and transpatellar (TP)-remain the most commonly used methods for tibial IMN. This systematic review and meta-analysis compares MPP and TP approaches regarding pain, AKP incidence, range of motion (ROM), knee function, and fracture healing. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, PubMed, Embase, Scopus, and Web of Science were searched up to November 2024. Randomized clinical trials (RCTs) and comparative observational studies in adults undergoing tibial IMN via MPP or TP approaches were included. Outcomes were AKP incidence, pain intensity, knee function, ROM, and union-related variables. Pooled mean differences (MDs) and risk ratios (RRs) were calculated using random-effects and common-effects models. RESULTS: Twelve cohort studies (782 patients) and 9 RCTs (462 patients) were included. Across cohort studies, MPP was associated with a significantly lower AKP risk at latest follow-up (RR = 0.76 [0.63; 0.90]) and at 6 months. Visual analog scale pain at 3-month postoperative also favored MPP (MD = -1.27 [-1.94; -0.60]) but did not reach the minimal clinically important difference. RCTs demonstrated similar trends toward lower pain and AKP with MPP, but without statistical significance. Functional outcomes and ROM generally favored MPP across both study designs, though findings were inconsistent and unsuitable for pooling. Fracture healing and union rates were comparable between approaches. CONCLUSION: The MPP approach for tibial IMN was linked to a lower incidence of AKP compared with the TP approach, while offering comparable or better functional outcomes, ROM, and pain intensity. These findings suggest MPP as the preferred infrapatellar approach in appropriate clinical settings. Nonetheless, high-quality studies with standardized outcome measures are essential to validate these findings. LEVEL OF EVIDENCE: Level III (systematic review of RCTs and retrospective comparative studies). See Instructions for Authors for a complete description of levels of evidence.