Authors (including presenting author) :
Chan WY (1), Ong TYM (2), Tsang HC (1), To YL (1), Sun TF(3)
Affiliation :
(1) Physiotherapy Department, North District Hospital (2) Department of Orthopaedics & Traumatology, Faculty of Medicine, The Chinese University of Hong Kong (3) Hospital Chief Executive Office, North District Hospital
Introduction :
Total knee arthroplasty (TKA) is widely adopted in advanced knee osteoarthritic patients, with its promising effect on both functions and pain. Due to aging population, the demand for TKA is rapidly growing that posing a huge financial burden on the health care system. It is hypothesized that pre-operative clinical outcomes can predict functional improvement in patients following TKA.
Objectives :
To identify significant predictors of clinical outcomes following total knee arthroplasty (TKA) in Hong Kong population, and to enhance pre-operative training and planning in the future.
Methodology :
215 patients underwent TKA and finished rehabilitation in North District Hospital during 2017 to 2021 were included in this retrospective cohort study. Predictor variables included demographics, Numeric Pain Rating Scale (NPRS), active range of motions (AROMs) in knee flexion and extension, Modified Functional Ambulation Classification (MFAC), Oxford Knee Score (OKS) and the distance covered in 6-minute Walk Test (6MWD) at preoperative assessment (baseline). The primary outcome measures were the OKS and 6MWD upon discharge from the post-TKA rehabilitation. Secondary outcome measures were total hospital length of stay (LoS) and rehabilitation training attendance. Good subjective and objective improvement are defined by the change in OKS and 6MWD reaching minimal clinically important difference (MCID) respectively.
Result & Outcome :
Statistically significant improvement was shown in both the OKS (p<0.001) and 6MWD (p<0.001) upon discharge from post-TKA rehabilitation compared with preoperative performance. No between-group difference was found in LoS and rehabilitation training attendance with and without good subjective and objective improvement in OKS and 6MWD.
Age and baseline 6MWD are shown to be significant predictors of the post-TKA rehabilitation 6MWD and the change in 6MWD (p<0.001). Baseline OKS is a significant predictor of the OKS post-TKA rehabilitation and the change in OKS (p<0.001). Predictor of a good subjective improvement is reported as the baseline OKS (p<0.001), while that of a good objective improvement be the baseline 6MWD and age (p<0.001). For the LoS, age (p=0.004) and baseline AROM in knee extension (p=0.002) are the significant predictors.
Patients underwent TKA and postoperative rehabilitation enjoyed improvement in both subjective and objective outcomes. Better preoperative OKS and 6MWD predict for better postoperative subjective and objective functional outcomes. OKS could act as a screening tool for patients with higher chance of experiencing better postoperative outcomes during preoperative planning. Prehabilitation focusing on lower limb strengthening, endurance and aerobic training could be considered to achieve for better outcomes following TKA.
