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

Abstract

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-A1 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.

Level of evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Conflict of interest statement

The authors report no conflict of interest.

Figures

FIGURE 1

Measurement method for determining the amount of shortening along the helical blade. A, The amount of blade protruding medial to the barrel of the nail is measured and compared with the measurement of the entire blade once the nail has been placed intraoperatively. B, This is repeated for the follow-up radiograph 6 months after surgery. The change in percentage between these 2 measurements is applied to the actual length of the blade, which was recorded in the operative record. In this example, the percentage changed from 69% to 57% along a blade of length 90 mm, indicating that 10.8 mm of shortening had occurred [(0.69–0.57) × 90 = 10.8 mm]. Editor’s Note: A color image accompanies the online version of this article.

FIGURE 2

An 88-year-old woman sustained an IT fracture from a ground level fall (A and B). She was treated with a cephalomedullary nail, and the fracture was reduced to near-anatomic position (C and D). At 3-month follow-up (E and F), the patient was noted to have over 1.0 cm of shortening across the helical blade of the intramedullary nail.

FIGURE 3

Scatter plot of mean double stance time (in milliseconds) by amount of femoral neck shortening (in millimeter) (P < 0.001). Editor’s Note: A color image accompanies the online version of this article.