A new overview of approaches to analgesia and anesthesia in people undergoing total knee arthroplasty (TKA) leaves no stone unturned (J Am Acad Orthop Surg2016;24:60-73). In just 12 pages of text, diagrams and tables, Calin Moucha, MD, and two other experts from the Icahn School of Medicine at Mount Sinai, in New York City, review all aspects of multimodal analgesia for the “notoriously painful procedure.”
This includes highlighting controversial treatments such as regional nerve blocks and liposomal bupivacaine. They determined that “current available evidence suggests no added benefit to using liposomal bupivacaine instead of a traditional LIA [local infiltration anesthesia] cocktail in primary TKA.” They do, however, all approve of the popular adductor canal block (ACB).
All TKA patients receive multimodal analgesia, beginning with oral agents such as cyclooxygenase-2 inhibitors and gabapentinoids a few days before surgery. For the surgery itself, neuraxial anesthesia (generally spinal) is used in all patients unless it is contraindicated. Peripheral or regional nerve blocks are often used as supplemental anesthesia and analgesia, with femoral nerve blocks (FNBs) and ACBs being among the most common, according to Dr. Moucha and his co-authors. The current evidence indicates there is a risk for postoperative fall with FNBs; moreover, a Cochrane review showed no significant difference in pain relief between epidural anesthesia and FNB in the three days after surgery (Cochrane Database Syst Rev 2014;5:CD009941).
Adductor canal block “has been shown to be a promising modality in several smaller studies”—three of which they provide details in a table accompanying the paper—although large randomized controlled trials (RCTs) have not yet been conducted, they noted.
Ralf Gebhard, MD, professor of anesthesiology at the University of Miami Miller School of Medicine, who was not an author of the review, said he favors ACBs.
“Many anesthesiologists have converted from femoral nerve block to [ACBs],” Dr. Gebhard said in a telephone interview. “The evidence is slow in coming out, but people are clinically so convinced [of its effectiveness in blocking sensory nerves—while not being associated with as much quadriceps weakness as FNBs] that they’re not waiting for the large [RCTs] to adopt it.”
Bupivacaine liposome (Exparel, Pacira), which is the subject of several recent favorable papers (e.g., J Knee Surg 2016 Feb 2. [Epub ahead of print]), is closely examined by Dr. Moucha and his co-authors. This includes citing the price comparison: “the average wholesale price of a single 20-mL vial containing 266 mg of liposomal bupivacaine is 95 times more expensive than a 10-mL vial of traditional 0.25% bupivacaine ($285 and $3, respectively). ” Three trials of the medication show only the industry-sponsored one had a favorable result. The other two, while having significant design or analysis flaws, found no benefit from liposomal compared with nonliposomal bupivacaine LIA cocktails.
Overall, Dr. Moucha and his colleagues make the benefits of multimodal analgesia/anesthesia very clear.
“It provides significant pain relief during and after surgery while minimizing opioid-related adverse effects, improving patient satisfaction and reducing the risk of postoperative complications,” Dr. Moucha said.
The American Academy of Orthopaedic Surgeons recently released guidelines on surgery for knee osteoarthritis that touched peripherally on anesthesia/analgesia for TKA.