The purpose of the study is to evaluate the efficacy of local infiltration of liposomal
bupivacaine versus use of an indwelling femoral peripheral nerve block in controlling early
postoperative pain in primary total knee arthroplasty. The investigators hope to demonstrate
equivalency of treatment modalities to provide an alternative to the commonly used treatment
of femoral nerve blockade.
Postoperative pain control in total knee arthroplasty is generally managed by a multimodal
approach of premedication, epidural and/or peripheral nerve blocks, narcotic medications,
and anti-inflammatories. Multiple studies have evaluated the efficacy of anesthetic
"cocktails" of various medications for local tissue infiltration to aide in controlling
postoperative pain. A recent systematic review supported the use of local anesthetic
infiltration in a single intraoperative dose as an adjunct to femoral nerve block in the
relief of pain; with combinations of ropivacaine, ketorolac, and adrenaline providing the
best results. Several studies noted decreases in opioid consumption and overall pain scores
in the perioperative period.
A novel compound, liposomal bupivacaine (EXPAREL®, Pacira Pharmaceuticals, Inc., Parsippany,
NJ, USA), has been proposed for use in total knee arthroplasty. To our knowledge, only one
randomized controlled trial involving use of this compound in total knee arthroplasty has
been published and was performed as a phase two dose ranging trial comparing liposomal
bupivacaine to bupivacaine HCl. No statistically significant difference between the two
compounds was shown, but a trend towards benefit in short term pain control was shown with
Our current pain management regimen utilizes the multimodal approach of neuraxial
anesthesia, indwelling femoral nerve catheter, opioids, and anti-inflammatory medications.
The regional anesthesia service manages postoperative pain while the indwelling femoral
nerve catheter is in place. The epidural is utilized for early postoperative analgesia and
thromboprophylaxis. The epidural is discontinued on post-operative day 1 and the femoral
nerve catheter is removed by the morning of postoperative day 3. Although femoral nerve
catheters provide excellent pain control following TKA, there are associated disadvantages.
Most notably there is inherent quadriceps weakness which places the patient at increased
fall risk. To reduce the risk of falling, patients must wear a knee immobilizer with
ambulation until the catheter is removed and quadriceps function has returned. This may
delay the ability to actively participate in physical therapy.
The purpose of our present study is to evaluate the efficacy of local infiltration of
liposomal bupivacaine versus use of an indwelling femoral peripheral nerve block in
controlling early postoperative pain. The investigators aim to show equivalency between the
two treatment modalities. Our hypothesis is that a systematic local infiltration of
liposomal bupivacaine provided intraoperatively is equally efficacious as femoral indwelling
peripheral nerve blockade in immediate postoperative pain control with more rapid
progression with physical therapy.
- Age over 18 years old
- Undergoing unilateral primary total knee arthroplasty
- Revision total knee arthroplasty
- Bilateral total knee arthroplasty
- Prior allergy or adverse reaction to local anesthetic
- Hepatic dysfunction