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Key information


Safety and Feasibility Evaluation of Tourniquets for Total Knee Replacement

Chief Investigator: Peter Wall

Sponsor: University of Warwick

Funder: National Institute for Health Research

Registration Number: ISRCTN20873088


Arthritis of the knee is a common problem (approximately 1 in 2 people may develop knee arthritis with symptoms before the age of 85). Knee arthritis causes pain and restricts function. Total knee replacement (TKR) is a surgical procedure performed for the relief of pain from arthritis with 91,703 TKRs being performed within England, Wales and Northern Ireland in 2013.

Most surgeons would apply a tourniquet around the thigh before starting the operation. A tourniquet is a device wrapped around your thigh and when inflated squeezes the thigh, to reduce the blood flow, helping to create a bloodless operative field. There is some limited evidence that a bloodless field during surgery helps to improve the fixation of the knee replacement implant to the bone which could help the implant to last longer.

However, there is some evidence that suggests using a tourniquet during knee replacement surgery may have some risks. Potentially, these include an increased risk of developing a blood clot (so called Deep Vein Thrombosis and Pulmonary Embolism) after surgery. There is also a theoretical risk that when the tourniquet is deflated at the end of the operation that small blood clots that have accumulated in the leg could travel to the brain and cause damage. In addition using a tourniquet during surgery may lead to increased swelling and pain after the operation.

The aim of this study is to determine if a full randomised controlled trial comparing clinical outcomes using a thigh tourniquet compared to patients who have had surgery without a thigh tourniquet would be feasible.

Sample size:


Primary outcome:

To assess the effect a thigh tourniquet has on the quantity of post cerebral emboli compared to those patients undergoing surgery without a tourniquet.


December 2020



SAFE-TKR Trial Team

Tel: 02476 968 626