Towards Kinematic Assessment of Trendelenburg Gait After Total Hip Arthroplasty Using Mocap Systems

Total hip arthroplasty (THA) is a surgical procedure advised to treat end-stage osteoarthritis. There are several surgical approaches involving different biomechanical effects, potentially affecting the outcome. A possible consequence of THA is the Trendelenburg gait, which consists of a pelvis drop and trunk lean during walking due to a unilateral weakness of the hip abductors. Gait analysis can be useful in assessing the disorder. The purpose of the present research is twofold: i) to assess the Trendelenburg disease in patients undergoing THA through gait analysis; ii) to investigate the relationship between the disorder and surgical approaches. Patients’ gaits were recorded 7 days after THA surgery, using two Microsoft Kinect V2 sensors and virtual skeletons were reconstructed by iPi Soft software. A customized tool was developed to automatically identify walking phases and recognize characteristics compatible with the Trendelenburg gait. In addition to pelvic drop and trunk lean in the frontal plane, kinematic measurements are proposed for a more complete assessment of the Trendelenburg gait. These variables are found to be effective in highlighting the differences between surgical approaches.