Posterolateral wall integrity in reverse oblique intertrochanteric fracture fixation: A new perspective in evaluation.

Background: Treatment of reverse oblique fractures has the highest complication rate among proximal femur fractures. Although intramedullary nailing is the preferred treatment option, a high failure rate has been reported. Previous studies have identified several contributing factors to these failures, yet the significance of posterolateral wall integrity in ensuring postoperative stability has not been emphasized. This study aims to investigate the impact of posterolateral wall integrity on the failure rates of reverse oblique intertrochanteric fractures treated with intramedullary nails (IMN) and assess the vulnerability of certain IMN designs to these failures.

Methods: Between 2010 and 2016, 53 patients with reverse oblique fractures were analyzed to identify factors associated with IMN failure. Variables such as posterolateral wall integrity, quality of reduction, posteromedial support, and IMN design were considered as potential risk factors. Logistic regression analysis was conducted to evaluate these risk factors, with statistical significance defined as p<0.05.

Results: Eleven cases of implant failure were identified. Univariate statistical analysis indicated that loss of posterolateral support (p=0.002), IMN with single-screw proximal fixation (p=0.048), poor reduction quality (p=0.004), and loss of posteromedial support (p=0.040) were associated with implant failure. Multivariate analysis confirmed loss of posterolateral support (p=0.009), poor reduction quality (p=0.039), and loss of posteromedial support (p=0.020) as independent risk factors for failure. However, IMN with single proximal fixation (p=0.859) did not significantly impact fixation failure.

Conclusion: Reverse oblique intertrochanteric fractures with compromised posterolateral support exhibit a high rate of mechanical failure when treated with IMN. Additionally, poor reduction quality and loss of posteromedial support increase the risk for failure of these fractures. An IMN design featuring dual separate proximal screw fixations could provide better stability compared to a design with a single proximal screw, thereby reducing the risk of mechanical failure.