Predictors of Implant Breakage Following Intramedullary Nailing of Long Bone Fractures: A Systematic Review and Meta-Analysis

Background: Implant breakage following Intramedullary (IM) nailing of long bone fractures is an uncommon but potentially catastrophic complication that often necessitates complex revision surgery. Robust estimates of its incidence and predictors are needed to guide surgical planning and postoperative management. Methods: PubMed and Google Scholar were systematically searched for studies published between January 2005 and December 2024 reporting IM nail breakage or mechanical failure requiring revision in femoral, tibial, or humeral fractures. Eligible studies provided extractable event counts and denominators. Data extraction was performed independently by two reviewers. Risk of bias was assessed using the ROBINS-I tool. A random-effects meta-analysis of proportions was conducted to esti-mate pooled incidence, with subgroup analysis by fracture location. Results: Ten studies involving 15,627 patients met the inclusion criteria. A total of 125 implant breakage events were reported, yielding a pooled incidence of 0.94% (95% CI 0.52% - 1.65%; I2 = 92%). Subtrochanteric fractures demonstrated a higher pooled incidence of breakage (1.16%) compared with other long bone fractures (0.58%). Predictors consistently associated with implant breakage included subtrochanteric fracture location, varus malreduction, complex fracture patterns (AO/OTA 42C), and delayed union or nonunion. Conclusions: Implant breakage following IM nailing of long bone fractures is rare but strongly associated with fracture-specific biomechanical demands and technical factors. Optimizing fracture reduction, implant selection, and postoperative management may reduce the risk of mechanical failure.