Gait analysis after total hip replacement with hip resurfacing implant or Mallory-head Exeter prosthesis: a randomised controlled trial

Abstract

A key to the analysis of function after total hip replacement (THR) is the ability to identify gait adaptations specific to design features and surgical procedures. In a randomised controlled design, we evaluated the mechanics of gait after THR with a hip resurfacing system or conventional prosthesis. We also investigated whether gait adaptations returned to normal postoperatively. Similar improvements in mechanics of gait were found, except for peak abductor moments, which improved more in the conventional group. Gait speed increased significantly, but with no differences between groups. The increase in walking speed was reflected as significant improvement within groups in most kinematic and kinetic variables. Significant differences between the operated and non-operated hip were seen in all patients, but with no difference between groups. Mean curves of joint angle profiles and moments in all anatomical planes during a gait cycle revealed that gait impairment persisted with no differences between the conventional prosthesis and the resurfacing system.

Fig. 1

Progress through the phases of the study

Fig. 2

Averages of joint angle profiles (ROM) and moments in all anatomical planes during a gait cycle walking at a self-selected speed for the operated and non-operated hips in the hip resurfacing system (HRS) and conventional hybrid prosthesis (MHE) groups 12 weeks after surgery, and the average values of both hips in the control group. The HRS group is represented by the black lines (bold operated hip, narrow non-operated hip); the MHE group is represented by the grey lines (bold operated hip, narrow non-operated hip). The shaded areas represent equal boundaries of ±1 standard deviation (SD) for controls