Summary

Prolonged bed stay post-operatively can lead to increased morbidity and complications. This study aims to identify patient and surgical factors affecting same-day discharge following unicompartmental knee replacement.

Abstract

Introduction

Prolonged bed stay post-operatively can lead to increased morbidity and complications. This study aims to identify patient and surgical factors affecting same-day discharge following unicompartmental knee replacement.

Methods

A total of 54 patients who underwent unicompartmental knee replacement at a single elective surgical centre by 8 different surgeons was prospectively evaluated over 10 months. Data was extracted from clinical software. Data on whether same day discharge was achieved post-operatively is compared with patient and surgical factors. These factors include gender, age, post-operative haemoglobin, tourniquet use, surgical time, intra-operative blood loss, mobilisation status post-operatively (>3 metres of walking), tranexamic acid use (TXA), cemented or uncemented, discharge pain score and same day discharge.

Results

The mean age was 65 years old. There were 19 female patients. Post-operative haemoglobin was recorded for 15 patients, the mean was 136. A tourniquet was used for all patients. Surgical time was recorded for 52 patients, the mean was 65 minutes. Blood loss was recorded for 50 operations and was minimal in all cases. 38 patients were mobilised on the same day. TXA use was recorded for 38 patients. 23 patients received both intra-articular and intravenous (IV) TXA and 15 patients received only IV TXA. 42 patients had uncemented implants. The mean discharge pain score was 1.6 for patients with same day discharge and 2.9 for patients that failed same day discharge. 30 patients achieved same day discharge.

Multivariate regression analysis was performed. This model explains approximately 70% variance in same day discharge. Mobilisation status post-operatively (p<0.05) and discharge pain score (p<0.05) are the only statistically significant variables.

Conclusions

Mobilisation status on the day of surgery may have the greatest influence on same day discharge. We advocate for prompt physiotherapy and adequate post-operative analgesia to allow for earlier mobilisation and discharge home.