Posterior Sagging After Cephalomedullary Nailing for Intertrochanteric Femur Fracture is Associated with a Separation of the Greater Trochanter

INTRODUCTION: Cephalomedullary nailing presents several biomechanical benefits for treatment of intertrochanteric fractures, but posterior sagging (PS) of the proximal fragment occurs postoperatively in some patients despite intraoperative achievement of an adequate reduction. We investigated the risk factors for PS in those patients, with specific attention to posterior split fragment involving the greater trochanter (GT separation) as a possible significant risk factor. METHODS: We retrospectively reviewed 50 (12 males, 38 females) patients ≥50 years old at diagnosis of an intertrochanteric fracture after low-energy trauma who underwent cephalomedullary nailing between April 2015 and February 2017 and were not lost to follow-up within 12 months postoperatively. RESULTS: Thirteen (26%) patients experienced PS postoperatively. Average time to bone union was significantly longer in the PS (9.5 months) than in the non-PS (4.8 months) groups (P = .002). Three patients in the PS group experienced nonunion compared to none in the non-PS group (P = .015). Significant difference was found in postoperative level of ambulatory ability (Koval score) and deterioration of the score after the injury between 2 groups (4.2 vs 2.8, P = .043 and 2.5 vs 0.8, P = .005). On multivariate logistic regression analysis, GT separation (P = .010) was a significant risk factor for PS. DISCUSSION AND CONCLUSION: The presence of GT separation in cases of intertrochanteric fractures seems to weaken posterior stability in the proximal fragment, thus showing poor clinical outcomes.