Pre- and post-fixation comparative study on the rehabilitation of transfemoral amputees using a patient-specific polycentric knee joint.

Abstract

Rehabilitation of transfemoral amputees remains a societal challenge due to the absence of natural knee joint motion. Despite progress in high-end prosthetic knee joints, issues of affordability, functionality, and patient-specific fitting persist. This study addresses these concerns through an indigenously developed, patient-specific configurable polycentric knee joint with improved functionalities. Five transfemoral amputees and ten healthy controls participated. The prosthesis is fitted to amputees, followed by a 12-week rehabilitation program. Pre- and post-fixation assessments are conducted using SF-36 and QTFA-70 to evaluate health-related quality of life (HRQL) and functionality. Kinematic and dynamic analyses during daily activities are performed using a high-speed video camera, Kinovea software, manual goniometer, and force plate. Results show a 55% improvement in HRQL and 88% improvement in global performance post-fixation. The measured knee flexion angles are 47.6°±5.9° (swing phase), 131.4°±6.6° (deep squat), 112.8°±5° (floor sitting), 125.1°±5.4° (chair sitting), and 99.2°±4.5° (bent knee sitting), closely matching healthy controls. Peak vertical ground reaction forces and gait symmetry also align with sound limbs and controls. These outcomes demonstrate the prosthetic design's potential in restoring near-anatomical motion and significantly improving the functional performance of transfemoral amputees.