A study led by researchers at University Hospitals Coventry and Warwickshire (UHCW) NHS Trust and the University
of Warwick has recommended an alternative method of
pain relief for patients undergoing knee replacement
Over 250 patients having knee replacements at UHCW took part in the study, reported in The Bone and Joint Journal.
The study was funded by the National Institute for Health Research (NIHR) Research for Patient Benefit (RfPB) Programme.
A traditional option for pain relief during knee replacement surgery is a femoral nerve block; a single dose of local anaesthetic injected around the femoral nerve in the groin, which is typically administered by an anaesthetist. However, a newer alternative approach uses an injection of anaesthetic agents around the knee joint and is administered by the surgeon without the need for specialist equipment.
The study found that patients who had the knee injections required lower doses of powerful painkillers such as morphine after surgery. Also, unlike a femoral nerve block, there is no need for specialist equipment like ultrasound. This is therefore likely to save surgeons and anaesthetists valuable time and resources as well as improving patient care.
Mr Peter Wall, clinical lecturer at UHCW NHS Trust and University of Warwick, and lead author of the report, said: “Our study has demonstrated the advantages of injections of anaesthetic agents around the knee during knee replacement surgery over other methods. These injections are now shown to be safe and effective. They also involve fewer resources and reduce the need for powerful painkillers such as morphine.
“This is to be welcomed as the potential risks of morphine-type pain relief are well known and should be avoided where possible. We hope that these study findings, if put into practice, will benefit patients around the world.
A tribute was published in the article to Andrew Sprowson, a consultant orthopaedic surgeon at UHCW, and associate professor at the University of Warwick, who had been chief investigator in the study until his untimely death in March 2015.
“I want to emphasise the debt we owe to our late colleague Andrew Sprowson. Without his initiative and enthusiasm, this research study would not have taken place.”
Source: University of Warwick
Reference: P Wall and others, A pragmatic randomised controlled trial comparing the efficacy of a femoral nerve block and periarticular infiltration for early pain relief following total knee arthroplasty; The Bone and Joint Journal http://bjj.boneandjoint.org.uk/content/99-B/7/904, DOI: 10.1302/0301-620X.99B7.BJJ-2016-0767.R2