A new 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 surgery.

knee pain 2Over 250 patients having knee replacements at UHCW took part in the study, reported in The Bone and Joint Journal, a highly-regarded specialist international publication for Orthopaedic surgeons.

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. Morphine can cause serious and troublesome side effects in postoperative patients and is best avoided if possible. 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 and improve 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.

Source: University of Warwick
Full bibliographic information: The Bone and Joint Journal
A pragmatic randomised controlled trial comparing the efficacy of a femoral nerve block and periarticular infiltration for early pain relief following total knee arthroplasty