Total Knee Arthroplasty Performed With Long-Acting Liposomal Bupivacaine Versus Femoral Nerve Catheter
Inadequate pain management after total knee arthroplasty (TKA) can interfere with participation in and progression of physical rehabilitation, and thereby prolong hospital stay, and increase costs and overall dissatisfaction with the procedure. At our institution, TKA traditionally has been performed with femoral nerve catheters (FNCs) for postoperative pain control.
We conducted a retrospective, longitudinal, repeated -measures study to compare FNC and long-acting liposomal bupivacaine (LALB) with respect to pain control, range of motion, ability to ambulate, and hospital length of stay. Twenty-three patients underwent separately staged bilateral TKAs, the first with FNC and the second with periarticular injection of LALB.
Statistically significant differences favoring LALB over FNC were found for hospital length of stay (P < .01), per-attempt walking distance during hospitalization (P < .01), total range of motion (extension plus flexion) at 3-week follow-up (P = .02), and total morphine-equivalent dose during hospitalization (P = .02).
Our results showed that, compared with patients who received FNC, patients who received LALB had comparable pain control, improved knee range of motion, and shorter hospital stays. Additional clinical studies are needed to better determine the efficacy and cost-effectiveness of LALB and other long-acting local anesthetic formulations.
Take-Home Points
- At our institution, LALB has shortened our hospital stay.
- There is a trend towards decreased opioid consumption with LALB.
- With the opioid epidemic we face today, LALB can be one of many options in our toolbox towards a solution.
- As stated in prior publications, the effectiveness of LALB is definitely technique dependent.
- Additional clinical studies are warranted to better determine the efficacy and cost-effectiveness of LALB.
Almost 1 million total knee arthroplasties (TKAs) are performed in the United States each year, and the number continues to grow.1.2 For patients about to undergo TKA, a significant concern is postoperative pain.3 Fear of postoperative pain is often cited as a reason for delaying surgery.3 Recent literature suggests that patients with poor pain management during the first 48 hours after surgery have a 50% chance of gaining satisfactory long-term pain relief.4 In addition, inadequate postoperative pain management can interfere with participation in and progression of physical rehabilitation, prolong hospital stay, and increase patient dissatisfaction.5 Poorly controlled pain results in decreased range of motion (ROM), strength, stability, and ambulation thereby prolongs hospital stays, and increases costs and overall dissatisfaction with the procedure.
Post-TKA pain management has received much attention in recent years. A multimodal pain management protocol is now a key component of clinical pathways in TKA. Appropriate postoperative pain control lowers postoperative complications and accelerates recovery.6 Pain-caused loss of function makes surgical patients more susceptible to edema, deep vein thrombosis, and pulmonary embolism.4 Various oral and intravenous medications are used to lessen the pain response during the perioperative period. In addition, regional or neuraxial anesthesia is often added to blunt the immediate surgical pain response.7,8 At our institution, TKA traditionally has been performed with femoral nerve catheters (FNCs) for postoperative pain control. Although effective, this method often results in decreased quadriceps musculature function, which delays rehabilitation and increases the fall risk. Recently, there has been a shift toward using local anesthetic infusions about the knee to provide adequate pain relief and restore motor function, which is often sacrificed with use of regional nerve blocks and continuous catheter infusions.9
Many institutions have started using a new long-acting local anesthetic in their multimodal pain management pathways: Exparel (Pacira Pharmaceuticals), a liposomal membrane-bound bupivacaine with sustained release of approximately 72 hours. Several studies have verified the safety of this medication.10 A systemic review of prospective studies revealed that, compared with bupivacaine, long-acting liposomal bupivacaine (LALB) in therapeutic doses had a higher safety margin and a favorable safety profile.10 However, no study has compared the effectiveness of LALB and FNC in a matched TKA cohort with each patient serving as his or her own control.
We recently reviewed our multimodal pain management protocol for any areas in need of improvement and decided to compare the effects of the indwelling FNC protocol that was in use with the effects of injecting the local anesthetic LALB. We conducted a study to compare the 2 methods with respect to pain control, ROM, ability to ambulate, and hospital length of stay (LOS). We hypothesized that the longer acting local anesthetic would provide comparable post-TKA pain control and post-TKA opioid use but would accelerate post-TKA rehabilitation.
Materials and Methods
This retrospective, longitudinal, repeated- measures study was approved by the Greenville Hospital System Institutional Review Board and conducted at the Steadman Hawkins Clinic of the Carolinas, Greenville Health System.
Interventions
Twenty-three patients underwent separately staged bilateral TKAs between 2010 and 2013. For each TKA, a Genesis II implant (Smith & Nephew) was used, and the surgery was performed with the patient under spinal anesthesia. In each case, FNC was used for pain control after the first TKA, and periarticular injection (PAI) of LALB for pain control after the second TKA.
