Published online Aug 16, 2022. doi: 10.12998/wjcc.v10.i23.8107
Peer-review started: November 29, 2021
First decision: May 11, 2022
Revised: May 20, 2022
Accepted: July 11, 2022
Article in press: July 11, 2022
Published online: August 16, 2022
Processing time: 245 Days and 5.6 Hours
Total knee arthroplasty (TKA) has been shown to improve quality of life and reduce pain. High-flexion activities such as squatting, kneeling, and floor transfers are mainly listed as demanding tasks. Among them, squatting is an important position.
To provide a new squat position classification and evaluate the different squatting positions of a series of patients after primary TKA.
From May 2018 to October 2019, we retrospectively reviewed 154 video recordings of the squatting-related motions of patients after TKA. Among the included patients, 119 were women and 35 were men. Their mean age at the index surgery was 61.4 years (range, 30 to 77).
The median follow-up was 12 mo (range, 6 to 156 mo). We classified those squatting-related motions into three major variations according to squatting depth: Half squat, parallel squat, and deep squat. The angles of hip flexion, knee flexion, and ankle dorsiflexion were measured in the screenshots captured from the videos at the moment of squatting nadir. A total of 26 patients were classified as half squats, 75 as parallel squats, and 53 as deep squats. The angles of hip flexion, knee flexion, and ankle dorsiflexion all differed significantly among the three squatting positions (P < 0.001). In the parallel squat group, the mean knee flexion angle (°) was 116.5 (SD, 8.1; range, 97 to 137). In the deep squat group, the mean knee flexion angle (°) was 132.5 (SD, 9.3; range, 116 to 158).
Among the three squatting positions, deep squat showed the highest hip, knee, and ankle flexion angles, followed by the parallel squat. With the improvement of squatting ability, the patient's postoperative satisfaction rate was also significantly enhanced. However, the different squatting abilities of the patients cannot be effectively distinguished from the scoring results (P > 0.05). Our squatting position classification offers a pragmatic approach to evaluating patients’ squatting ability after TKA.
Core Tip: Few studies have focused on squatting ability after total knee arthroplasty (TKA). Most squatting-related items in patient-reported outcome measures present as binary options of “can” or “cannot” or a subjective sense of difficulty along with this motion. The main finding of this study is the squatting position classification based on squatting depth. And our squatting position classification offers a pragmatic approach to evaluating patients’ squatting ability after TKA.