October 15, 2015

Joint injections speed knee replacement recovery: study

Another non-opioid option besides nerve blocks works better for patients recovering from knee replacement surgery, according to a study by Andrew Shinar, M.D., associate professor of Orthopaedic Surgery and Rehabilitation.

concept illustration of knee with pain radiating from it
(iStock)

Another non-opioid option besides nerve blocks works better for patients recovering from knee replacement surgery, according to a study by Andrew Shinar, M.D., associate professor of Orthopaedic Surgery and Rehabilitation.

His study compared 40 patients who received combined femoral and sciatic nerve blocks to 40 patients who received intra-articular, or joint, injections of a numbing medicine. The patients who got the non-opioid, numbing medicine reported less pain and were able to walk farther 24 hours after their surgeries.

Andrew Shinar, M.D.

The results led the Vanderbilt Joint Replacement Center to stop administering nerve blocks during knee replacements.

“Our patients are leaving earlier, and they are walking more,” Shinar said. “We haven’t looked into what the long-term effect is in terms of eventual range of motion and recovery. It may not have a big effect on the long-term, but it sure does have a big effect on the short-term.”

Another plus is that it eliminates the need for Foley catheters, bypassing the potential hospital complication of a urinary tract infection, he said.

“If people have a Foley catheter, they just don’t walk,” Shinar said. “It’s really hard to take all these tubes attached to you and get up and move around. That early mobility is just so helpful for people to feel more comfortable after their surgery.”

He noted that nerve blocks, in rare cases, can cause permanent numbness or weakness.
Shinar’s study was different from others comparing the effectiveness of the two pain control treatments in that it looked at a more extensive nerve block.

“This is a femoral and sciatic nerve block so it gets the front and the back of the leg,” Shinar said. “You’d think this would be nearly perfect in terms of pain relief. It turns out that it’s really not, and the injections about the knee are superior to it.”

Composite pain scores among patients who received the intra-articular injections were a full point lower than those who received nerve blocks. They also walked about four times the distance a day after their surgeries than patients who received nerve blocks, Shinar said.

“That’s the remarkable part of it all,” he said. “What the patients find remarkable is that they are up and about the evening of the surgery and walking around the nurses’ station the next day. It is more independent for them. They are less reliant on nursing care, less reliant on everything. They can often go home and are less likely to go to a rehab facility.”

Shinar presented the findings from his study at the 2015 annual meetings of the Southern Orthopaedic Association and Tennessee Orthopaedic Society.