gms | German Medical Science

Objectives: 3D gait analysis is not yet a standard diagnostic tool although available since mid-1970s. Newer high resolution 3D-analysis could reveal minor alterations after surgical interventions. A recent paper showed the improvements during an early rehabilitation programme (AHB). So which improvements could be expected subsequently about 6 months postoperatively?

Methods: We analysed 15 patients (8 male, 7 female, mean 56.5years, SD 9.8years) in the mean 12days (SD 11.2days) before and 28 weeks (SD 3.5weeks) after unilateral hip arthroplasty by 3D gait analysis on a walkway, ambulatory without crutches, and Harris-Hip-Score(HSS). Time- and distance-gait-parameters were preoperatively normal.

The albavision 3D Motion System (single-frame-single-plane-calibration) and GaitLab-Software were used for 3D Gait analysis using 15 reflective markers on the skin.

The Friedman-Test was used to analyse the pre- and postoperative measurements statistically; Wilcoxon-Rank-Sum-Test was used to compare arthroplasty- to contralateral-side.

Results and Conclusion: The first analysis before surgery unveiled a HHS of 55.33 (mean, SD 12.6) with an increase to 80.46 (SD17.23,p=0.001) at the second test. The HSS-Pain-Score improved by 20.93 (mean, p=0.001).

The walking-speed increased as expected postoperatively by 0.09m/s (0.32km/h, p=0.013) as well as the single-step-length of the hip arthroplasty side (p=0.001). Cadence did not show any significant changes. Pre-operatively the stance-phase was significantly shorter compared to the healthy side (p=0.023). It did not show any significant difference at the second test. So the healthy side reduced the stance-phase significantly (p=0.019).

The 3D gait analysis did show significant changes in joint motion:

It unveiled a significant average-increase of hip- range of motion (ROM) in flexion/extension (arthroplasty side) during walking (9.62degree,p=0.001). With a normal hip-ROM of avg. 32.82 degrees the hip preoperatively was far below with 27.78degrees and in the normal range with a value of 37.40 degrees on avg. 28 weeks after surgery. A reduction of the flexion-contraction by 5.17degree, p=0.046) and an increase in abduction/adduction of the hip (4.32degree,p=0.016) was measured. Also the knee received an ROM-increase (4.97degree,p=0.016). Signs of compensatory movement: pelvic tilting-ROM was reduced (1.75degree, p=0.006), contralateral increase in hip-abduction/adduction (4.30degree,p=0.002) and knee-flexion/extension (3.59degree,p=0.001).

3D gait analysis is a valuable tool to reveal also minimal changes in joint motion in order to help the ongoing rehabilitation process after hip arthroplasty.