Comparison of day-case versus inpatient uni-compartmental knee replacement

Uni-compartmental knee replacement (UKR) is an alternative to total knee replacement for patients who have isolated compartment osteoarthritis. Studies have demonstrated that UKR can be safely performed as a day-case procedure without a negative impact on complication rates. The aim of this study was to compare the clinical outcomes between day-case and inpatient UKRs.

A single surgeon prospective case-controlled study was performed, comparing data between day-case UKRs and inpatient UKRs. This included longitudinal analysis of patient reported outcome measures (PROMs); including the Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score, Short Form 12-item Health Survey, EQ-5D-5L and the Self-administered Comorbidity Questionnaire. Post-operative pain scores (visual analogue scale), unplanned post-operative hospital reattendance rates and complications were also analysed.

Overall, 100% of day-case patients were successfully discharged on the same day. Both inpatient (n = 23) and day-case (n = 23) UKRs demonstrated a significant within group longitudinal improvement of PROM scores (p < 0.05) following surgery. However, the post-operative PROM scores were significantly higher in the day-case group as compared to the inpatient group (p < 0.05). Both groups had comparable post-operative pain scores, but the day-case group demonstrated fewer unplanned reattendances and post-operative complications.

The clinical outcomes of day-case UKR are superior to inpatient UKR. Careful patient selection and a robust multidisciplinary patient pathway are the key components to success of day-case joint replacement surgery.

Prospective Case-Control Study, level III.