Should the diameter of the proximal femoral nail be large enough to fill the canal in the treatment of intertrochanteric femoral fracture in patients over fifty?

Purpose Many studies have been conducted to evaluate the effects of nail shape, design, or length on the treatment of intertrochanteric fractures. However, the clinical implications of the nail diameter remain unclear. Methods This study was conducted with 191 patients aged ≥ 50 years with unilateral intertrochanteric fractures treated with the same type of short cephalomedullary nail and followed for at least one year. We recorded the reduction type, tip–apex distance, cortical contact of the nail, and nail/canal diameter ratio (NCR) just distal to the locking screw. The effects of nail diameter on the clinical results were evaluated. Results The average NCR was 68.7. The average union time was 4.78 months. Delayed union or nonunion was seen in 17 patients. Eight patients underwent additional surgery. The mean change in the modified Koval activity score was –0.84. The NCR did not significantly affect the clinical results. Comparisons of cases with NCRs above and below the average and the average – 1 standard deviation revealed no significant difference. The clinical outcome was not related to any variable associated with the nail diameter. Conclusion With this specific proximal femoral nail, a small diameter relative to that of the femoral canal had no adverse effect on the union of osteoporotic intertrochanteric fractures, even in patients with unstable fractures and those who had unsatisfactory reductions.