Quadratus Lumborum Block Versus Control for Total Hip Arthroplasty

Currently, regional anesthesia techniques for total hip arthroplasty are limited. Fascia
iliac blocks have been employed to provide analgesia for hip surgeries with blockade of the
femoral, lateral femoral cutaneous, and obturator nerves via injection of local anesthetic in
the iliacus fascia. In addition, lumbar plexus blocks have also been employed for
post-operative analgesia, but the complexity of the block is high, and complications
including epidural anesthesia are not infrequent. The quadratus lumborum block is an
abdominal truncal block in which local anesthetic is deposited into the thoracolumbar fascia
or the quadratus lumborum muscle itself with the goal of providing analgesia to the
ipsilateral T6 - L1 sensory dermatomes. It has already been demonstrated to provide effective
post-operative analgesia for certain abdominal and pelvic surgeries, but its use in total hip
arthroplasty is limited to case reports.

The block is accomplished by identifying the quadratus lumborum muscle, which originates from
iliac crest and iliolumbar ligament, and inserted on transverse processes of upper four
lumbar vertebrae and posterior border of the 12th rib. Local anesthetic is then deposited at
the anterior, posterior or middle thoracolumbar fascia, or intramuscularly, depending on the
technique used. Cadaveric studies8 have demonstrated dye spread to the lumbar nerve roots and
nerves within the transversus abdominis plane (TAP). Carney et al9 described a "posterior
TAP" block, now known to be synonymous with QLB, that demonstrated contrast spread to the
thoracic paravertebral space from T5-L1. Case reports have described analgesia in the
corresponding sensory dermatomes after QLB4, and have demonstrated efficacy in patient
undergoing THA. The QLB block has potential to cover lateral femoral cutaneous nerve, femoral
nerve, obturator nerve and portions of lumbar plexus.

This study has been designed to investigate the efficacy of the quadratus lumborum block as a
primary method of providing post-operative analgesia in patients undergoing THA. Previous
trials have demonstrated the effectiveness of the block for abdominal and pelvic surgeries,
and case reports have shown its applicability in hip arthroplasty. In this randomized
controlled study we aim to compare QLB (intervention) with control (no intervention) group in
patients undergoing THA with regard to the VAS pain scores (at PACU arrival & discharge12, 24
& 36 hours), duration of analgesia, time to first opioid medication, physical therapy
evaluations, time to discharge, and surgeon and patient satisfaction scores.

Inclusion Criteria:

1. Patients undergoing total hip arthroplasty

2. Adults 18 years of age and older

3. Patients with an American Society of Anesthesiology (ASA) physical status
classification of I, II or III

Exclusion Criteria:

1. Patients with ASA physical status classification other than I, II, or III

2. Patients with allergies/intolerances to local anesthetic

3. Patients with pre-existing neurologic or anatomic deficits in the lower extremity on
the side of the surgical site

4. Patients with coexisting coagulopathy

5. Patients that are pharmacologically anticoagulated will be excluded if placement of
peripheral nerve block would be contraindicated according to ASRA (American Society
for Regional Anesthesia) guidelines or if spinal anesthesia would be contraindicated
according to guidelines