The combination of peri-articular and adductor canal infiltration was superior than peri-articular infiltration alone or adductor canal infiltration alone in decreasing pain when walking on day 1 after a knee replacement, according to a study presented here at the 2015 Annual Meeting of the Canadian Anesthesiologists’ Society (CAS).
“Knee surgery is very painful,” said Richard Bowry, MD, North York General Hospital, Toronto, Ontario. “We want to use techniques that do not cause too much disability afterwards and are able to get patients more mobile.”
Dr. Bowry explained proximal nerve blocks are criticised for diminishing quadriceps strength and limiting mobility for patients who undergo total knee arthroplasty.
For the current study, 159 patients were randomised to adductor canal and peri-articular infiltration (n = 54), adductor canal with saline acting as peri-articular infiltration (n = 51), or a sham block of adductor canal with peri-articular infiltration (n = 54).
Four patients in the first arm, 5 in the second arm, and 5 in the third arm either withdrew or had surgery cancelled.
“We had significantly less pain on walking in the group which had adductor canal and peri-articular infiltration,” said Dr. Bowry. “We saw the same statistically significant decrease [in pain on walking] on post-operative day two in the same group of patients.”
Specifically, on post-operative day 1, patients who received combined therapy had a pain on walking score of 3.3 versus a score of 6.2 among those who received adductor canal infiltration alone and a score of 4.9 among patients who received peri-articular infiltration.
Rapid mobilisation of patients means they can be discharged from hospital more quickly, noted Dr. Bowry, but he added that patients who receive both therapies received a relatively high dose of anaesthetic.
The study excluded patients who had chronic pain unrelated to their knee, were using opioids for 3 months or more, or had a peripheral neuropathy.