Comparative characterization of walking biomechanical parameters in hip prosthesis users with mechanical and electronic knee modules

Abstract

To compare spatial and temporal parameters of walking in patients after hip replacement using prostheses with electronic and mechanical knee modules. The study included 94 patients aged between 18 and 50 with hip prostheses. The patients were divided into two groups: Group 1 included 48 patients with a hip prosthesis with a mechanical knee module; Group 2 included 46 patients with a hip prosthesis with an electronic knee module. The groups were comparable in size, gender and age distribution, and mobility grade (grade 3 according to the MOBIS classification system). All patients had no comorbidities or injuries that could limit mobility. Spatial and temporal parameters of walking on hip prostheses with different knee modules were assessed using a video analysis system (SMART DX5000, Italy). Group 2 patients (prostheses with electronic knee modules) had the following spatial and temporal biomechanical walking indices: arbitrary walking speed 1.10-1.08 m/s, walking pace 105.82 steps/minute, step cycle 1.13-1.15 s, double step length 1.27 m, rhythm index 0.89. Group 1 patients (prostheses with mechanical knee modules) had worse outcomes according to the same indices: walking speed 0.81-0.87 m/s, walking pace 90.84 steps/minute, step cycle 1.33 s, double step length 1.07 m, rhythm index 0.74. Preferred walking speed and walking pace indices in patients with electronic knee modules in hip prostheses were at the lower limits of reference values in healthy individuals; the step length was insignificantly reduced; the rhythm index was close to that of healthy individuals (0.94-0.97). The results of the study show that the use of prostheses with electronic knee modules in patients with amputation at the hip level enables patients to learn better symmetrical walking and significantly increases their mobility compared to mechanical modules.