Adductor canal block reduced pain and patient fall risk after TKA

Significantly fewer opioids were consumed at postoperative day 1 by patients who had a femoral nerve block vs an adductor canal block.

During total knee arthroplasty, patients who received an adductor canal block had a significantly lower rate of falls and near-falls, and had a greater reduction in pain, compared with patients who received a femoral nerve block, according to study results.

“As we continue to improve and refine pain management techniques and do what we can from a patient safety and quality standpoint, this study points out that we can get the same, effective pain relief with less risk to the patient,” Jeffrey A. Geller, MD, who is the Nas S. Eftekar professor of orthopedic surgery and chief of orthopedic surgery at New York Presbyterian, Lawrence Hospital Westchester, told Orthopedics Today.

Geller and his colleagues retrospectively reviewed 129 patients and 150 patients who received femoral nerve block and adductor canal block, respectively, during TKA. They studied the patients’ outcomes regarding perioperative falls or near-falls during physical therapy and inpatient care.

Pain relief equivocal with improved safety

Results showed patients who received femoral nerve block had significantly more near-falls with documented episodes of knee buckling, which began occurring at an average of 21.1 hours postoperatively.

“As we increasingly see that knee surgery is becoming more of an ambulatory surgery with a lower risk of stay … we should have a little bit more comfort in the fact there is going to be less of a risk of falling at home if the patients are home postop day 1 with [adductor canal block],” Geller said.

Although the risk of falls in patients after either a femoral nerve block or an adductor canal block was intuitive, according to Geller, he said pain control was another outcome they wanted to review.

Results of the study showed no significant differences in pain scores between the two groups at any time periods measured. However, researchers found patients in the femoral nerve block group consumed significantly fewer opioids at postoperative day 1 vs. patients in the adductor canal block group.

Injection sites

“We wanted to make sure we would still have adequate pain control because there is always the concern that, although we think we are only getting sensory fibers to the knee by doing the adductor canal block, if you are infiltrating the whole nerve more proximally, does that give you better pain control?” Geller said.

With the study being limited by its retrospective nature, Geller and his colleagues decided to perform a prospective study into the effects of adductor canal block with and without periarticular injection.

“We then did a prospective, randomized study which is going to be presented at the [American Academy of Orthopaedic Surgeons] AAOS,” Geller said. “We did a prospective randomized study comparing adductor canal block to just periarticular injection compared to both.”

He noted the results have provided more information on pain control and the utility of nerve blocks after surgery. – by Casey Tingle

Reference:

Thacher RR, et al. Arthroplast Today. 2017;doi:10.1016/j.artd.2017.02.008.

For more information:

Jeffrey A. Geller, MD, can be reached at 622 West 168th St., PH 1147, New York, NY 10032; email: jgeller@columbia.edu.

Disclosure: Geller reports no relevant financial disclosures.