Injecting a newer long-acting numbing medicine called liposomal bupivacaine into the tissue surrounding the knee during knee replacement surgery may provide a faster recovery and higher patient satisfaction.
While improvements in implantable devices and surgical technique has made knee replacement surgery highly effective, pain control after surgery remains a common but persistent side effect for patients.
“The pain scores for this injection technique averaged about 3/10, which is similar to the pain scores seen with our traditional method,” said senior author Jason Davis, MD, Henry Ford West Bloomfield Hospital, Detroit, Michigan. “Patients had pain relief for up to 2 days after surgery and better knee function compared with the traditional method.”
For the study, 216 patients were evaluated for pain control the first 2 days after surgery from October 2012 to September 2013. Half of the patients received the traditional pain control method with continuous femoral nerve blockade, in which common numbing medicine is injected into the groin area. This method uses a pain pump to extend pain control for two days but causes some leg weakness.
“Pain control came at the price of weakness and made patients somewhat tentative when walking during their hospital stay,” said Dr. Davis.
The other half of patients received the liposomal bupivacaine injection at the site of the surgery. Dr. Davis said many patients were able to walk comfortably within hours after surgery.
Dr. Davis said the injection around the knee itself optimises pain control early on without the side effects of the traditional technique.
“Function-wise, it was a lot easier for patients to move around more confidently,” he said. “In the past decade, we’ve made major advancements in pain control for knee replacement surgery. This option is a promising, viable one for our patients.”
The findings were presented at the Annual Meeting of the American Association of Hip and Knee Surgeons, which took place in Dallas, Texas, November 7-9, 2014.