Assessing the knee joint biomechanics and trunk posture according to medial osteoarthritis severity

Abstract

Background During progression of knee osteoarthritis (KOA), coronal, sagittal, and horizontal biomechanical parameters are dramatically altered. The purpose of this study is to assess the three-dimensional knee joint biomechanics and trunk posture according to KOA severity. Methods Seventy-five patients (95 knees) with medial knee osteoarthritis and 19 young healthy controls (38 knees) were enrolled in this study. The Kellgren-Lawrence classification was used for radiographic evaluation. There were 20 patients with 24 knees with grade 2, 25 with 28 knees with grade 3, and 30 with 43 knees with grade 4. All patients walked at a self-selected speed using an optical motion capture system. Additionally, six-degrees-of-freedom kinematics of the knee joint were calculated using the point cluster technique. The three moment components of the knee joint were calculated using inverse dynamics. Results In grade 2 KOA, the relative contribution of knee adduction moment (KAM) increased significantly, and that of knee flexion moment (KFM) decreased at the first peak of total joint moment prior to significant progression of varus knee deformity. Grade 3 KOA showed significant exacerbation of varus knee deformity and increased KA. Maximum knee extension angle decreased and trunk flexion increased during gait in grade 4 KOA. Conclusions We showed that kinetic conversion occurred in grade 2 KOA prior to varus deformity appearance as in grade 3. Knee flexion contracture and trunk flexion during gait occurred in grade 4 KOA. The relative contribution of KAM increased significantly, and that of KFM decreased prior to progression of varus knee deformity. Trial registration: Not applicable

Static Plantar Pressure Distribution and Position Correlations in Early and Mid-term Knee Osteoarthritis Patients

“…Knee [24]. During the progression of KOA, there are t h r e e -d i m e n s i o n a l c h a n g e s i n g a i t biomechanics; however, the characteristics and trunk posture according to the severity of OA remain unknown [25]. Due to individual differences, compliance, and cognitive deficiency, there is no consensus on the impact of trunk posture such as high and low shoulders, scoliosis, and pelvic tilt on KOA, and further discussion is needed.…”