Comparative efficacy analysis of ultrasound-guided quadratus lumborum block and lumbar plexus block in hip arthroscopy: a pilot prospective randomized controlled trial

Controlled trials assessing quadratus lumborum block (QLB) for post-operative analgesia in hip surgery are scarce. This study aimed to compare ultrasound-guided QLB and lumbar plexus block (LPB) for clinical efficacy in hip arthroscopy. Patients undergoing hip arthroscopy in Beijing Jishuitan Hospital in January-June 2019 were randomized to the lumbar plexus (L) and quadratus lumborum (Q) groups (n = 25/group). After either ultrasound-guided block for 30 min, both groups were prepared for surgery after muscle strength measurement in the affected limbs. Opioid doses for patient-controlled analgesia (PCA), visual analog scale (VAS) scores in the resting and active states, upon leaving the post-anesthesia care unit (PACU), and at 2-48 h post-surgery were recorded, and post-operative complications were also recorded. Muscle strength in the affected limbs was significantly higher in the Q group compared with the L group (4.0 versus 2.0, P < 0.001). VAS scores were similar in both groups post-surgery (P > 0.05). One patient had epidural spread in the L group, with no other complications. Compared with ultrasound-guided LPB, ultrasound-guided QLB provides similar and good post-operative analgesia after hip arthroscopy, with less impact on muscle strength and fewer complications. These results should be confirmed in larger trials.