Kinesiologic and Biomechanical Assessment of the Charnley ‘Load Angle Inlay’ Knee Prosthesis

Abstract

Kinesiologic measurements were conducted on patients with rheumatoid or degenerative arthritis of the knee who had joint replacement using the Charnley ‘load angle inlay’ knee prosthesis. There was an increase in the stance phase flexion-extension and sagittal motion of the knee, thigh and calf three months after surgery but little difference from these three month readings was found at twelve months and a slight decrease two years after operation. However, the walking speed increased twelve months after surgery as did cadence and stride length but further increase did not occur twelve to twenty-four months after surgery. There was little relationship between the clinical examination of total passive movement and the stance and swing phase flexion-extension characteristics obtained from this gait analysis. The loading analysis showed there was a relationship between the total and medial compartment force occurring at the knee and the clinical assessment, higher loading was associated with a low grade of assessment, but no relationship between these loading parameters and gait analysis data was found.