Knee replacement is highly successful for treating severe arthritis. There are 100,000 people who undergo knee replacement surgery every year in the UK, with numbers set to rise significantly in future.
It remains however a painful procedure with nearly half of patients reporting severe pain post-operatively. Currently pain control is provided by injecting a local anaesthetic of bupivacaine hydrochloride around the knee during surgery providing good pain relief for 12 to 24 hours. However, patients typically experienced the worst pain the next morning when they are encouraged to bend their knee and get out of bed.
Researchers at the Universities of Oxford and Leeds developed the SPAARK (Study of Peri-Articular Anaesthetic for Replacement of the Knee) Trial, to test whether liposomal bupivacaine, a post-operative pain treatment widely used in the USA would be more effective at managing the pain compared to current treatments. The findings have been published in JAMA.
Lead author Thomas Hamilton, Academic Clinical Lecturer in Trauma and Orthopaedic Surgery at NDORMS said: "We found that liposomal bupivacaine injected at the surgical side during knee replacement did not improve post-operative recovery, compared to those receiving bupivacaine hydrochloride alone. We saw no difference in Quality of Recovery score at 72 hours, nor pain assessed using pain visual analogue scale area under the curve at 6 to 72 hours. The results of this study do not support the use of peri-articular liposomal bupivacaine for knee replacement ."
Prof Hemant Pandit (Professor of Orthopaedic Surgery, University of Leeds and University of Oxford) senior author and chief investigator of the study added: "This is the largest randomised controlled trial in the world to assess the effectiveness of liposomal bupivacaine in achieving superior pain relief in patients undergoing a knee replacement. The study results are timely and demonstrate that there is no additional benefit in the pain relief experienced by patients receiving Liposomal Bupivacaine and therefore the drug's use in routine NHS practice cannot be justified."
The research was funded by a grant from the NIHR Research for Patient Benefit Programme with the study drug (and additional funding) provided by Pacira Pharmaceuticals.