Periarticular liposomal bupivacaine mixture injection vs. single-shot interscalene block for postoperative pain in arthroscopic rotator cuff repair: a prospective randomized controlled trial.

Abstract

The pain control efficacy, postoperative opioid requirements, and costs among patients undergoing major shoulder surgery using different perioperative analgesia modalities have been topics of active debate. Several studies have compared periarticular injection (PAI) to interscalene block (ISB) in shoulder arthroplasty, but there is a paucity of data comparing them in arthroscopic rotator cuff repair. Patients aged 18-80 years with full-thickness rotator cuff tears and undergoing primary arthroscopic rotator cuff repair at 2 different shoulder centers were screened and subsequently randomized to receive either periarticular injection (PAI) of liposomal bupivacaine mixed with 0.25% bupivacaine (n = 41) or single-shot interscalene nerve block (ISB) (n = 36). Visual analog scale (VAS) pain scores, oral morphine equivalent (OME) use, Single Assessment Numerical Evaluation (SANE) scores, and costs were collected. Differences with P <.05 were considered statistically significant. Day of surgery VAS score and OME usage were significantly reduced with ISB vs. PAI (0.69 vs. 4.65, P < .001, and 18.66 vs. 34.39, P < .001, respectively). There were no significant differences between groups regarding VAS score on postoperative days (PODs) 1-3; however, OME usage on PODs 1 (50.5 vs. 38.8, P = .03) and 2 (48.1 vs. 37.8, P = .04) was significantly more in the ISB group. At POD 3, VAS score (4.13 vs. 3.97, P = .60) and OME use (28.60 vs. 31.16, P = .51) were similar. At 6 and 12 weeks, there were also no significant differences between groups regarding VAS and OME use. There was no difference in SANE score at 12 weeks following surgery between groups and no difference between average 12-week cumulative OME use between groups. The average charge for the PAI was $455, and the average charge for ISB was $745. Both ISB and PAI provide acceptable pain control following arthroscopic rotator cuff repair. Patients have less pain on the day of surgery with ISB, but rebound pain is significant after the block wears off, resulting in substantially increased opioid use in the first 2 PODs. However, cumulative opioid use between groups was similar. There were also no significant differences at the end of the12-week episode of care in any of the other variables studied. The charge per patient for PAI is approximately $300 less than ISB. Thus, PAI may offer surgeons and patients an effective postoperative analgesic modality as an alternative to ISB.