Proximal Femoral Shortening After Cephalomedullary Nail Insertion for Intertrochanteric Fractures.

Abstract

To assess the incidence of proximal femoral shortening (PFS) and its effect on the patient outcomes when intertrochanteric fractures were treated with a cephalomedullary nail (CMN). Retrospective cohort study. Level II trauma center. Forty-eight consecutive patients with OTA/AO 31-A intertrochanteric fractures. All patients were treated with a Gamma3 CMN (Stryker, Kalamazoo, MI). PFS was assessed for abductor lever arm (x vector), femoral height (y vector), and overall shortening (z vector) on anteroposterior radiographs. Fixation success and retained ambulatory capacity were noted. Shortening of >5 mm of the x, y, and z vectors was evident in 18, 20, and 29 patients, respectively. Shortening of >10 mm of the x, y, and z vectors was measured in 5, 6, and 8 patients, respectively. Mean shortening of the x, y, and z vectors was 4.5, 5.5, and 7 mm, respectively. Greater PFS was found to be associated with fixation failure and inability to retain ambulatory capacity, independently (P ≤ 0.05 and P ≤ 0.025, respectively). Of note, an unstable fracture pattern was not found to be associated with greater PFS. PFS is a common phenomenon after CMN of intertrochanteric fractures with a Gamma CMN. In addition, greater PFS seems to be associated with fixation failure and inability to retain ambulatory capacity postoperatively. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.