Importance of firm isthmic fixation in high-energy induced subtrochanteric fracture of the femur: retrospective observational study in a level I trauma center.

INTRODUCTION

This study aimed to report the surgical outcomes in patients with high-energy induced subtrochanteric fracture and determine the risk factors for nonunion using statistical analysis.

METHODS

This study evaluated 88 patients with high-energy induced subtrochanteric fractures who underwent surgeries with indirect reduction technique and intramedullary nailing between March 2015 and December 2020. Outcome measures, including union time and nonunion incidence, were assessed by radiologic evaluation. Multiple logistic regression analyses were performed to identify the risk factors for nonunion, using age, sex, injury severity score, body mass index, preoperative mobility score, implant, and isthmic fixation as covariates.

RESULTS

Five nonunions and two delayed unions were identified. The average union time was 17.4 weeks. Multiple logistic regression analyses showed that poor isthmic fixation was the only risk factor for nonunion (odds ratio 15.294, 95% confidence interval 1.603-145.894, P value 0.018). Out of five nonunion cases, four were confirmed as hypertrophic, and one was confirmed as atrophic.

CONCLUSION

Although surgical treatment using an indirect reduction technique and intramedullary nailing showed good outcomes, hypertrophic nonunion due to distal instability could occur if a firm fixation at the level of the isthmus cannot be achieved.

LEVEL OF EVIDENCE: Level III, retrospective cohort study.