Biomechanical correlates of gait and stair climbing are associated with ex vivo cartilage quality in gonarthrotic patients.

Previous evidence highlights the important role of knee joint malalignment and excessive joint moments for the development to knee osteoarthritis. The present study aimed to systematically investigate the interrelationship between three-dimensional knee kinematics during walking and stair climbing and ex-vivo electromechanical measured cartilage quality in 119 patients with end-stage knee osteoarthritis. Patients scheduled for total knee arthroplasty surgery underwent radiographic assessment and biomechanical analysis in gait and stair climbing assessing in vivo knee joint angles and moments during movement dynamics prior to surgery. Electromechanical properties of the excised tibial cartilage as an indicator of cartilage quality were evaluated using Arthro-BST. Peak knee adduction angle was found to be a significant predictor of medial cartilage quality during walking (R = 22 %, p < 0.001) and stair climbing (R = 13 %, p < 0.001). During walking, knee flexion moment was found to be a strong predictor of medial (R = 9 %, p = 0.002) and lateral cartilage quality (R = 12 %, p < 0.001). Knee adduction (R = 19 %, p < 0.001) and abduction angles (R = 44 %, p < 0.01) during x-ray was significantly associated with dynamic assessments during 3D kinematics. Medial joint space width significantly predicted medial tibial cartilage quality (R = 16 %, p < 0.001). The results showed that biomechanical parameters such as varus malalignment during walking and stair climbing are significantly associated with tibial cartilage deterioration and contribute to a variance explanation of 13-22%.