Impact of Tip Apex Distance, Cortical Reduction, and Lateral Wall Integrity on Radiological Union of Unstable Trochanter Fracture Treated with Proximal Femoral Nail: A Retrospective Observational Study.

INTRODUCTION

The global elderly population is steadily increasing, and among the fractures commonly observed in this age group, trochanteric hip fractures are particularly prevalent. Over time, various implant designs have been developed to manage these fractures, with the proximal femoral nail (PFN) emerging as the preferred choice for treating unstable trochanteric fractures due to its biomechanical advantages. However, despite its benefits, the application of PFN is not without challenges. Complications such as screw cut-out, Z-effect, reverse Z-effect, and suboptimal functional outcomes have been reported in some cases. This study aims to evaluate the individual and combined effects of key factors - tip-apex distance (TAD), lateral wall integrity, and the type of cortical reduction observed in immediate post-operative images - on the final radiological outcomes in elderly patients with unstable intertrochanteric fractures managed using PFN.

MATERIALS AND

METHODS

This retrospective observational study was conducted in our institution from June 2021 to December 2023. After fulfilling the inclusion and exclusion criteria, we had 100 patients (35 males and 65 females) with a mean age of approximately 71 years, all of whom had unstable intertrochanteric fractures managed with a PFN. All patients were followed for at least 6 months. Regular anteroposterior (AP) and lateral view X-rays of the operated femur were taken when patients came for follow-ups and were analyzed for signs of radiological union and any mechanical failure.

RESULTS

Patients with all three parameters in the acceptable range (i.e., TAD <25 mm, positive cortical reduction (PCR) in AP and lateral views, and maintained/restored integrity of the lateral cortical wall) showed comparatively better radiological outcomes with fracture union. Eight patients experienced mechanical failure and had two or more unmet radiological criteria.

CONCLUSIONS

This study highlights that achieving positive cortical support, preserving lateral wall integrity, and maintaining a TAD <25 mm intraoperatively are critical factors in reducing mechanical failure and improving radiological outcomes in intertrochanteric fractures treated with PFNs.