Lower limb biomechanics during gait do not return to normal following total hip arthroplasty

Although total hip arthroplasty (THA) is known to be a successful surgical procedure to alleviate hip pain and to improve health-related quality of life, these outcome measures in THA patients do not reach those of the general population. As a result, several investigators have assessed THA patients' gait mechanics, but most of them have ignored adjacent joints, as well as the effect that THA may have on the non-operated limb. The purpose of this investigation was to determine the effect of THA on the pelvis, hip, knee and ankle joint kinematics, as well as the hip, knee and ankle kinetics of both the operated and non-operated limbs during walking. These data were recorded for 20 patients having undergone unilateral THA and 20 healthy, matched control participants. Results revealed that the gait mechanics of THA patients did not return to normal 10.6 months, on average (+/-2.6 mo), following surgery. THA patients walked with lower operated-hip abduction moments, sagittal-plane range of motion, as well as lower generated and absorbed power, that may be consequential to pain-avoidance strategies adopted pre-operatively or to apprehensions associated with their new prosthesis. They also displayed various kinematic adaptations at the ankle joint of the operated limb and at the non-operated hip joint that may be leaving them at risk of developing other joint diseases. Further investigation is needed to confirm the reasons why THA patients' gait mechanics do not return to normal following surgery to develop better surgical techniques and/or rehabilitation programs.