Comparison of Pericapsular Nerve Group (PENG) Block Versus Quadratus Lumborum (QL) Block for Analgesia After Primary Total Hip Arthroplasty Under Spinal Anesthesia: A Retrospective Study.

backgroundTotal hip arthroplasty (THA) is one of the most common operative procedures performed. Controlling postoperative pain following THA remains a challenge due to the complex innervation of the hip joint and the recent desire to preserve motor function following nerve blockade. Several nerve block techniques have been used for THA in the past, but the quadratus lumborum (QL) block and the blockade of the pericapsular nerve group (PENG) have emerged as opiate-sparing regional anesthesia techniques that preserve motor function. To date, little data comparing the two block techniques exists. The purpose of our study was to compare outcomes following these techniques in patients undergoing primary THA. MATERIALS AND

methodsThis retrospective analysis utilized data from three distinct groups who underwent primary THA at our institution: 45 patients who received PENG block, 38 patients who received QL block, and 77 control patients. Chart review analysis was performed by authorized personnel to obtain cumulative oral morphine equivalent (OME) data at 24 and 48 hours postoperatively (primary outcomes). In addition, visual analog pain scale (VAS) scores in the post-anesthesia care unit (PACU) and at 12, 24, and 48 hours, ambulation distance, and length of hospital stay data were obtained (secondary outcomes). Group comparisons were conducted using either analysis of variance (ANOVA) with Tukey's multiple comparison test for parametric data or Krustal-Wallis with Dunn's multiple comparison tests for nonparametric endpoints.

resultsThis study found a statistically significant difference in cumulative OME usage across all groups at 24 and 48 hours. Significant difference in OMEs was found between QL and control and PENG and control; however, no difference was found in OMEs between PENG and QL groups at either time point. There was a statistically significant difference in VAS scores in the PACU across all groups; QL showed significantly lower VAS scores in the PACU compared to PENG and control, while PENG only showed significantly lower VAS scores compared to control. There was a statistically significant difference in VAS scores at 24 hours across all groups; however, only QL showed significantly lower VAS scores compared to control at 24 hours. QL was associated with a statistically significant increase in the length of hospital stay compared to PENG.

conclusionThis study showed no difference between OME usage in patients who received PENG or QL nerve blocks for primary THA. VAS scores were similar between groups with the exception of QL outperforming PENG in the PACU. Optimizing postoperative pain via multi-approach strategies should remain a priority for patients undergoing THA. Future research is warranted in order to provide guidance on best practice for these patients.