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

Abstract

Tiejian Li,1,2 Jingyang Sun,1,2 Yinqiao Du,2,3 Zhisen Gao,2,3 Haiyang Ma,2,3 Yonggang Zhou1– 3 1Medical School of Chinese PLA, Beijing, 100853, People’s Republic of China; 2Department of Orthopedics, The First Medical Center of PLA General Hospital, Beijing, 100048, People’s Republic of China; 3Senior Department of Orthopedics, The Fourth Medical Center of PLA General Hospital, National Clinical Research Center for Orthopedics, Sports Medicine & Rehabilitation, Beijing, 100853, People’s Republic of ChinaCorrespondence: Yonggang ZhouDepartment of Orthopedics, PLA General Hospital, Fuxing Road, Haidian District, Beijing, People’s Republic of ChinaTel [phone]Email [email protected]: Total knee arthroplasty (TKA) is widely used as a treatment for knee osteoarthritis. Few studies have analysed the factors affecting the squatting ability of patients after TKA. The purpose of this study was to comprehensively analyse the factors affecting squatting ability after TKA and to determine which ones are important.Patients and Methods: Three hundred primary TKA cases with a minimum 3-year follow-up were retrospectively analysed. 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 squatting position and knee flexion angle while weight-bearing (Group I – inability to squat group, Group II – ability to squat group). Demographic, operative, and clinical data were collected. Radiographic assessment included joint line elevation, patellar position, posterior condylar offset (PCO), etc. Statistical analysis of the effect of all the above factors on squatting ability was performed.Results: The preoperative range of motion and joint line of Group I were 82.9± 12.6 and 3.24± 1.07, respectively, and those of Group II were 107± 9.6 and 1.83± 0.89 respectively. The univariate analysis showed that age, prosthesis size, preoperative ROM and joint line position were correlated with squatting ability. But in the final multivariate analysis, joint line position and preoperative ROM were independent influencing factors that affected squatting ability after TKA (p value < 0.01).Conclusion: Preoperative ROM and joint line position were independent influencing factors affecting squatting ability after TKA. Patients should be counseled accordingly and be made to understand these factors. To ensure that patients can squat postoperatively, we should improve surgical techniques to control joint line elevation.Keywords: squatting ability, joint line elevation, preoperative ROM, total knee arthroplasty

Keywords

• squatting ability · joint line elevation · preoperative rom · total knee arthroplasty