Abstract
Introduction
Unicondylar knee replacements (UKR) may be more effective compared to Total knee replacements (TKR) in unicompartmental arthritis. We report patient outcomes & satisfaction data in an age matched cohort of patients with either a UKR or TKR.
Method
A single unit and single surgeon series of patients were recruited. Data was retrospectively collated for 68 patients with more than 24 months follow-up. UKR was undertaken in patients with isolated medial compartment osteoarthritis; stable ACL and less than grade 3 lateral patellar changes of the Outerbridge classification. TKR was undertaken for the rest. The patients were assessed with validated knee scores including the Total Knee Function Questionnaire (TKFQ) which focuses on recreational & sporting outcomes as well as activities of daily living (ADL). Patient satisfaction and perception of knee normality was measured on a visual analogue scale.
Results
34 patients with a TKR and 34 patients with a UKR were analysed. The average ages in the TKR and UKR groups were 69.25 and 67.26 years respectively. The patients were well matched for demographics and had equivalent preoperative morbidities and scores.
The UKR group had better WOMAC (p=0.003), SF36 (physical: p<0.001 mental: p=0.25), Oxford knee (p<0.001) and Knee Society scores (p=0.002, function: p<0.001). The UKR group showed better outcomes in the TKFQ including exercise and sport (p= 0.02), movement and lifestyle (p=0.02) and the ADL (p=0.002). There was however no difference in patient satisfaction scores (p=0.41) and perception of how normal the knee felt between the two groups (p=0.99).
Conclusions
A UKR procedure confers better functional outcome in terms of recreation and sport compared to TKR procedures. While UKR is an appropriate choice in the elderly yet active patient with unicompartmental knee arthritis, satisfaction is similar to that of patients with a TKR reflecting higher preoperative expectations. Further work is needed to assess this.
