Features
Jonathan Phillips is a specialist knee arthroplasty, trauma and revision surgeon, appointed at the Royal Devon and Exeter Hospital in 2015. He is a member of the ODEP and Beyond Compliance committees, as well as both the Primary and Revision BASK Knee Arthroplasty Working Groups.
Ben Waterson undertook his specialist training in orthopaedic surgery in Edinburgh and undertook the adult lower limb reconstruction fellowship in Vancouver. He was awarded a Medical Doctorate (MD) from Edinburgh University for his research in the field of knee surgery and the impact of alignment on total knee replacements. He has been working as a consultant in the Exeter Knee Reconstruction Unit since 2018 and is an Honorary Senior Lecturer at Exeter University.
Tourniquet use in knee replacement – the why, the what and how to do without Jonathan Phillips, Ben Waterson, Andrew Toms and Keith Eyres
A recent Cochrane review published in December 2020 re-opened the debate of tourniquet use during knee replacement and suggested we minimise its use. However, a 2016 survey of 547 consultant knee surgeons, members of the British Association of Surgery for the Knee (BASK), demonstrated that 90% used a tourniquet during total knee replacement surgery, the majority of whom did not wish to stop doing so1. Why use a tourniquet? Tourniquet advocates explain that the use of a tourniquet enables more accurate and quicker surgery due to the presence of a blood-free field2. There is also an argument that cement penetration into the bone is improved if there this a dry bed into which cement can interdigitate. There is evidence for this in hip replacement surgery too where obviously without the use of a tourniquet; modern cementing techniques involve washing and drying the prepared bone surfaces, suction catheters and pressurisation of cement both before and after implantation3. There is a risk that poor cementation and pressurisation may lead to earlier implant loosening, although this link in knees is not as clear as in hips. Surgical training is still largely apprentice-based. Therefore, if surgeons train to perform surgery using a tourniquet, it is likely that they will continue to use one throughout their career.
42 | JTO | Volume 09 | Issue 02 | June 2021 | boa.ac.uk
What is the argument not to use a tourniquet? While tourniquets may provide a bloodfree field to allow for more accurate and/or efficient surgery, it does so at the compromise of producing an essentially avascular limb for the duration of the surgery. When a limb is avascular, tissues are unable to undertake aerobic respiration, and as such this may lead to an increase in anaerobic metabolic products or rhabdomyolysis4. There are time limits suggested for the length of time for tourniquet use (a maximum of two hours is generally recommended). Beyond this time period, the use of a tourniquet may have a detrimental effect not only on the tissues of the limb, but it also increases the risk of reperfusion injury once the tourniquet is released. The release of anaerobic metabolites can cause an adverse effect to the cardiovascular system5.
