Quadratus Lumborum vs Erector Spinae Supplementary Blocks With Lumbar Plexus Blocks for Hip PAO

The Bernese periacetabular osteotomy (PAO) is currently performed at this institution as a non-arthroplasty option to treat developmental hip dysplasia in symptomatic adolescents and young adults. Extensive orthopedic surgical procedures of the hip such as this are associated with severe postoperative pain and benefit from regional anesthesia which provides dense, targeted analgesia to selected dermatomes. These blocks have the potential to decrease opioid exposure intraoperatively and postoperatively, thus avoiding opioid-related side effects such as nausea and vomiting. Other well-known benefits of regional anesthesia in other surgeries include earlier extubation, shorter ICU admissions, shortened post anesthesia care unit (PACU) stays, earlier mobilization, facilitation of physical therapy, improving patient satisfaction, and improved comfort during recovery process. The opioid sparing advantages of regional anesthesia are particularly relevant given the current concerns over the opioid epidemic and data relating opioid administration around surgery recovery and long-term opioid use.

Innervation of the hip is very complex with contributions from various neural structures arising from the lumbar plexus, including branches of the femoral nerve (L2-L4) innervating the anterolateral capsule and obturator nerve (L2-L4) innervating the anteromedial capsule. The posterior and inferior part of the hip joint are innervated by the sacral plexus consisting of the superior gluteal nerve (L4-S1) and branches of the sciatic (L4-S3) including the nerve to rectus femoris (L4-S1).

The skin areas involved in the two most common hip PAO surgery incisions (ilioinguinal incision or the iliofemoral incision) include territories that are innervated by subcostal nerve (T12) and ilioinguinal and iliohypogastric nerves (L1), 4 neural structures not reliably covered with the lumbar plexus block given their origin far more superior from the point of injection which is usually between L2 and L4. For this reason, supplemental blocks such as the ESB and QLB have been employed to improve nerve block coverage and pain control. The lateral femoral cutaneous nerve (L1) which is a sensory branch of the lumbar plexus that supplies skin of the lateral thigh, has a less important role in this context given that the surgical incisions are far more anterior to its territory of innervation.

Surgical osteotomies commonly associated with the Bernese procedure are performed on the anterior portion of the ischium, superior pubic ramus, posterior; partial osteotomies of the ischium below the acetabulum are common as well. Arthrotomy is only performed in selected cases if there is concern for intraarticular pathology, such as a torn labrum, lesions of the femoral neck, or loose bodies. The pelvic bone with its respective osteotome (i.e. bone) innervation includes territories ranging from L2 to S1.7 Some evidence suggest that the iliac crest receives its main sensory innervation from femoral nerve while the gluteal surface of the ilium comes from the sciatic nerve.

Given the many dermatomes and osteotomes that are involved, various regional anesthetic techniques have been described, including LPB, fascia iliaca block, femoral nerve block, obturator nerve block, sacral plexus block, paravertebral blocks, and also interfascial plane blocks like QLB and ESB.