Acute knee sepsis after intramedullary nailing of open tibial shaft fractures: a comparison of intra-articular and extra-articular approaches

Abstract Objectives: To compare the incidence of acute knee sepsis after intramedullary nailing of open tibial shaft fractures via intra-articular and extra-articular approaches. Design: Retrospective cohort analysis. Setting: Two academic Level I trauma centers. Patients/Participants: Adults treated with intramedullary nailing for open tibial shaft fractures between 2010 and 2023 with a minimum of 3-month follow-up. Intervention: Intramedullary nailing using an intra-articular (suprapatellar) or extra-articular (medial parapatellar, transtendinous, or lateral parapatellar) approach. Main Outcome Measurements: Acute knee sepsis, deep/superficial infection, reoperation, and nonunion. Results: A total of 293 patients with 295 fractures met inclusion criteria (75% male, median age 41 years, 28% active smokers). Ninety fractures underwent intra-articular nailing, and 205 underwent extra-articular nailing. There were no differences in injury energy, Gustilo–Anderson classification, or rates of external fixation between groups. Acute knee sepsis occurred in one patient (1.1%) in the intra-articular group and one patient (0.5%) in the extra-articular group. Deep infection occurred in 8.9% for intra-articular and 9.3% for extra-articular ( P > 0.999), and aseptic nonunion in 8% vs 7%, respectively ( P > 0.999). Conclusions: Acute knee sepsis after intramedullary nailing of open tibial shaft fractures was rare (0.7%). Knee sepsis was more common after suprapatellar nailing than extra-articular approaches (1.1% vs 0.5%), but the results are not statistically significant, and the study lacks power to draw definitive conclusions about relative risk with such low base rates. These findings may assist surgeons with approach selection and patient counseling, taking into account injury characteristics and technical considerations related to the procedure that are case-specific.