Two-year gait analysis controls of the minimally invasive total hip arthroplasty by the direct anterior approach.

BACKGROUND: The purpose of the study was to determine the long-term functional outcome of two hip approaches by gait analysis. Patients were selected by prospective randomization, and operated on either by the anterolateral approach or by a minimally invasive direct anterior approach.

METHODS: 33 patients (17 anterolateral approach; 16 direct anterior approach) were analyzed using a Vicon 870 system. Gait analysis was performed two years after total hip arthroplasty. Temporo-spatial and kinematic variables were obtained.

FINDINGS: On chest and pelvic kinematics, no patient group demonstrated significant differences. The time-distance parameters showed significant differences with the anterior approach in cadence and stride time.

INTERPRETATION: The study indicates that the direct anterior approach exerts positive effects compared with the anterolateral approach two years after surgery. The muscle-sparing concept of direct anterior approach results in significant differences in gait compared to the anterolateral approach 2 years after surgery.