Factors Affecting Squatting Ability in Total Knee Arthroplasty Using High Flexion Prosthesis

Abstract

Background: Total knee arthroplasty (TKA) is widely used as a treatment for knee osteoarthritis. Few studies have analyzed the factors affecting squatting ability of patients after TKA. The purpose of this study is to comprehensively analyze the factors affecting squatting ability after TKA and to determine which important factors should be paid attention to.Methods: Three hundred primary TKA cases with a minimum 3-year follow-up were retrospectively analyzed. All patients received a conventional posterior-stabilized TKA implant and underwent a standard perioperative care pathway. The patients were divided into two groups according to the knee flexion angle (Group I -squatting group, Group II - inability squatting group). Demographic, operative, and clinical data were collected. Radiographic assessment included joint line joint line elevation, patella position, posterior condylar offset (PCO) , etc. Statistical analysis of effect of all the above factors on squatting ability was done. Results: The univariate analysis showed age, prosthesis size, preoperative ROM and joint line position were correlated with squatting ability (p-values ≤0.10). In the final multivariate analysis, joint line position and preoperative ROM were independent influencing factors that affecting squatting ability after TKA (p-values < 0.01). Conclusion: Preoperative ROM and joint line position were independent influencing factors affecting squatting ability after TKA. Patients should be counseled accordingly and made to understand these factors. In order to ensure patients can squat postoperatively, we should improve surgical techniques to control joint line elevation.