Introduction. Total knee replacement (TKR) provides pain relief and functional recovery for patients with end-stage knee osteoarthritis. Although many patients report satisfaction with TKR outcomes, more than 20% of patients remain dissatisfied due to pain or functional difficulty in the contralateral knee. This study was designed to assess the outcome of the contralateral knee state following a unilateral TKR and will compare patients without a contralateral prosthesis to those with a contralateral prosthesis measuring postoperative quality of life (QoL) mainly. Materials and methods. This was a retrospective observational cohort study at a regional elective orthopaedic centre in the UK. Patients were split into groups on the basis of the contralateral knee state: a native knee (NC) group, 56 patients and a previous contralateral prosthesis (PC) group, 38 patients. The primary outcome measure was the change in health-related QoL, EuroQol 5-Dimensions (EQ-5D-3L) index, and the secondary outcome measure was the change in the Oxford Knee Score (OKS). Descriptive statistics and independent-sample t-tests were used to assess the results, along with paired t-tests and multivariable linear regression. Pre-study power calculations and propensity score-weighted regression were applied.Results. Both groups improved QoL and knee function at 6 months. EQ-5D scores increased similarly in NC (+0.22) and PC (+0.21) groups (p = 0.85). OKS improvement was slightly higher in the NC group (13.9 vs 10.6; p = 0.04), though not clinically meaningful. Clinically important QoL gains occurred in 79% native contralateral knee (NC) and 76% (prosthetic contralateral knee (PC).Conclusion. The status of having a native contralateral knee did not significantly influence postoperative changes in QoL or knee function when comparing TKR for osteoarthritis with that of previous contralateral prostheses. These findings suggest that the status of the contralateral knee plays a minor role in recovery. Further research is needed to explore the effects of age and other factors on postoperative outcomes.
Zainy et al. (Mon,) studied this question.