THE INTRA-OPERATIVE KNEE KINEMATICS STUDY USING NAVIGATION SYSTEM: COMPARISON OF TKA IN RHEUMATOID ARTHRITIS AND OSTEOARTHRITIS PATIENTS

BackgroundA navigation system is useful tool to evaluate the intraoperative knee kinematics. Rheumatoid arthritis (RA) patients often need to have TKA operation, however, there are few TKA kinematics studies comparing RA and Osteoarthritis (OA) patients.ObjectiveThe purpose of this study was to evaluate intraoperative TKA kinematics, and to describe the difference of kinematics between RA and OA patients.Materials and methodsSeventy-four patients, 86 knees were included in this study. Unilateral posterior stabilized TKAs were performed (male 14, female 72, age 70 ± 1.1 years) using navigation system. Sixty-one knees had OA and 25 had RA. Evaluation items are coronal gaps, AP translation and rotation. Coronal gaps were defined as the distance between the femoral and tibial cut surface. Medial and lateral gaps are also measured. AP translation was defined as the sagittal movement between the center of femoral and tibial condyle. Rotation was defined as axial difference of axis between femur and tibia. All i...