Feasibility Study and Pilot RCT on Tourniquet Use in Total Knee Replacement Surgery

Introduction

More than 106,000 total knee replacements (TKR) were performed in the UK in 2018, with over 90% of surgeons preferring to use a tourniquet during the procedure. While a tourniquet may reduce intraoperative bleeding and improve cement interdigitation, it also increases risks such as thigh pain, deep vein thrombosis (DVT), and wound infection. The study aimed to determine the feasibility of a full trial comparing TKR with and without tourniquet use, focusing on recruitment, adherence to protocol, and follow-up.

Methods

The study was a single-centre, two-arm pilot RCT conducted at University Hospitals Coventry and Warwickshire. Participants were randomized to either have a tourniquet inflated or not during TKR. The study evaluated MRI for detecting postoperative ischaemic cerebral emboli and cognitive impairment using tools like the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and the Oxford Cognitive Screen (OCS).

Results

Recruitment was challenging, with 54% of approached participants agreeing to participate. The study found that MoCA was more sensitive for detecting cognitive impairment compared to MMSE and OCS. Only one ischaemic event was detected on MRI in 50 postoperative scans, indicating that MRI may not be a suitable outcome measure for a larger trial. Participants with a tourniquet inflated reported more thigh pain, and there was a trend towards more adverse events related to surgery in this group.

Discussion

The study demonstrated the feasibility of recruiting and following up patients in a trial comparing TKR with and without a tourniquet. MoCA was identified as a suitable primary outcome measure for cognitive assessment in future trials. The findings suggest that while a tourniquet may offer some benefits during TKR, it also increases the risk of thigh pain and adverse events, warranting further investigation in a larger, multicentre trial.