Gait Analysis After Intertrochanteric Hip Fracture: Does Shortening Result in Gait Impairment?

Objective: To determine the association between fracture collapse with altered gait after intertrochanteric (IT) fracture using the trochanteric fixation nail (TFN) and helical blade. Design: Prospective cohort study. Setting: Academic Level I trauma center. Patients: Seventy-two patients with IT hip fractures (OTA/AO 31) treated between 2012 and 2016. The average age was 79.7 years (range, 51-94 years); there were 59 women and 13 men. Intervention: All patients were treated with cephalomedullary nailing using the TFN (DePuy-Synthes, West Chester, PA) with a helical blade. Main Outcome Measures: At follow-up appointments, temporospatial gait parameters were measured and recorded. Radiographs were analyzed at the time of surgery and at each follow-up visit. Amount of radiographic femoral neck shortening was measured radiographically. Patients completed the Harris Hip Score, visual analog scale for pain, Short Form-36 Physical Component Score, and Short Form-36 Mental Component Score. Results: The mean length of follow-up between the surgery and the gait analysis was 8.6 months (+/- 0.7 months). The mean amount of shortening was 4.7 mm (+/- 0.6 mm). Out of the 72 patients analyzed, there were 15 patients (20.8%) who shortened more than 8 mm, 7 patients (9.7%) who shortened 10 mm or more, and 2 patients (2.8%) who shortened more than 20 mm Mean shortening was 3.0 mm for stable OTA/AO 31-Al fractures, whereas the unstable patterns (OTA/AO 31-A2, 31-A3) demonstrated a mean shortening of 5.9 mm (P = 0.02). There was significant correlation between increased shortening and decreased cadence (P = 0.008), increased double support time (P < 0.001), decreased step length (P = 0.001), and increased single support asymmetry (P = 0.04) during gait analysis. The threshold of 8 mm of shortening predicted decreased cadence (P = 0.008), increased double support time (P < 0.001), and decreased step length (P = 0.006). Analysis of patient-reported outcome scores, including the Harris Hip Score, visual analog scale, SF-36 Physical Component Score, and SF-36 Mental Component Score, revealed no significant association with shortening. Conclusions: Results from this study indicate that shortening after cephallomedullary nailing of IT hip fractures using the TFN with a helical blade is associated with altered gait, specifically decreased cadence, increased double support time, decreased step length, and increased single support time asymmetry.