Single Shot Quadratus Lumborum Block in THA

We reviewed eight high quality randomized clinical trials that represented the best available evidence to assess the effectiveness of fascia iliaca compartment, lumbar plexus nerve, and quadratus lumborum regional nerve blocks to reduce pain and/or opioid consumption following primary THA.[2-9] Although additional regional nerve blocks have been studied with randomized clinical trials following primary THA, the workgroup excluded these alternative regional nerve blocks because of limited evidence and lack of clinical relevance. For instance, the use of a femoral or sciatic nerve block is not as anatomically relevant compared to more widely used regional nerve blocks following primary THA. Additionally, the only comparison between types of regional nerve blocks was the single high quality randomized clinical trial comparing the fascia iliaca compartment and lumbar plexus nerve blocks to reduce pain and/or opioid consumption postoperatively following primary THA.[10] The same limitations encountered in the prior clinical practice guidelines prevented the use of meta-analysis due to the inconsistency in the reporting of outcomes and timepoints for reporting the outcomes.[11-14] Therefore, qualitative review of the available literature was used to develop the recommendations.

Among the regional nerve blocks evaluated for the clinical practice guidelines, five high quality studies investigated single-shot fascia iliaca compartment block, two high quality studies investigated single-shot lumbar plexus nerve block, and one high quality study investigated single-shot quadratus lumborum block.[2-9] Qualitative analysis of each regional nerve block consistently demonstrated an overwhelmingly significant response of a reduction in postoperative pain and opioid consumption for all three types of regional nerve blocks.[2-9] Although no significant difference was observed in adverse events between the regional nerve blocks and controls, the reporting was focused on adverse events related to opioid use (e.g., nausea/vomiting, pruritus, somnolence, and respiratory depression).[2-9] The lumbar plexus nerve and quadratus lumborum blocks are technically demanding procedures and are considered “deep blocks,” which have the same anticoagulation restrictions as neuraxial anesthesia.[15] In addition, lumbar plexus nerve and quadratus lumborum blocks require post-procedure monitoring because there is the possibility of bilateral spread due to placement in the epidural or intrathecal spaces.[15] In contrast, the fascia iliaca compartment block is a less technically demanding procedure without the same safety concerns, and is not considered a “deep block.”[15]

The workgroup downgraded the strength of the recommendations for fascia iliaca compartment, lumbar plexus nerve, and quadratus lumborum blocks based on the increased cost associated with the blocks, particularly in light of our advancements with effective multimodal analgesia of oral medications and peri-articular local anesthetic infiltration for THA. In addition, the lack of appropriate reporting of adverse events for lumbar plexus nerve and quadratus lumborum blocks were an additional concern cited for downgrading the strength of the recommendation for lumbar plexus nerve and quadratus lumborum blocks. Although the workgroup would advocate for reporting of adverse events specific to the nerve blocks, the relatively small sample sizes may not be large enough to accurately represent the frequency of these adverse events.

Among the clinically relevant regional nerve blocks for primary THA, only a single high quality randomized clinical trial offered a comparison between nerve blocks.[10] When comparing the fascia iliaca compartment and lumbar plexus nerve blocks, it demonstrated no significant difference in postoperative pain and opioid consumption.[10] Therefore, when a regional nerve block is used after primary THA, the workgroup would favor a fascia iliaca compartment block, as the increased risks and technical demands of a lumbar plexus nerve block do not come with any additional benefit.