Introduction:
The iliac crest is a common site employed for harvesting bone necessary for autologous grafting. Acute and chronic iliac crest donor site pain is a significant postoperative concern. Options to manage this pain perioperatively have primarily been limited to neuraxial and paravertebral approaches, as the iliac crest incision site lies in the T12/L1 dermatome.
The quadratus lumborum (QL) block is a variation of the transversus abdominis plane (TAP) block which theoretically functions by the spread of local anesthetic into the paravertebral spaces resulting in somatic abdominal wall analgesia and possibly even visceral pain relief (T6-L1 dermatomes coverage). In this case series, we describe the successful use of the quadratus lumborum block in two patients who underwent iliac crest bone grafts for an upper extremity fracture repair.
Methods:
Case 1- A 31 year old male was scheduled to undergo repair of his fourth metacarpal fracture with iliac crest bone graft. We performed a single injection supraclavicular block for the hand fracture site and placed a quadratus lumborum catheter for the iliac crest graft site. Via ultrasound, the appropriate anatomical landmarks were identified (Image 1, 2). A 17G tuohy needle was inserted via an in-plane technique targeting the QL muscle and 15 mL of 0.25% ropivacaine was injected hydro-dissecting the fascial layer from the muscle. A 19G styletted peripheral nerve catheter was advanced through the tuohy needle and placed at the anterolateral border of the QL muscle. Another 15 mL of 0.25% ropivacaine was injected through the catheter to confirm its location and local anesthetic spread within the fascial plane (Image 3 & 4).
Case 2- A 14 year old male scheduled to undergo repair of a scaphoid fracture with iliac crest bone graft. Single injection supraclavicular and quadratus lumborum blocks were performed (Image 5). For the QL, 20 mL of 0.25% bupivacaine was injected hydro-dissecting the fascial layer of the muscle.
Results:
Case 1- Intraoperatively, the patient received general anesthesia and consumed 100 mcg of fentanyl. Postoperatively, he had no pain and received no medication. He was discharged from the PACU with a portable infusion pump delivering 0.2% ropivacaine at 10 cc/hr into the QL catheter for three days. Daily telephone follow up with the patient revealed excellent postoperative pain control.
Case 2- Intraoperatively, the patient received general anesthesia and only consumed 100 mcg of fentanyl. Postoperatively, he did not require any pain medication for 24 hours (via telephone follow up).
Conclusions:
Traditionally, the QL block has been used following abdominal surgeries and the potential utility for the QL block to provide pain relief for musculoskeletal pain or procedures involving the T12/L1 dermatome have been infrequently described. Due to the degree of sensory blockade achieved in our patients, as demonstrated by the lack of obvious surgical stimulus during iliac crest bone grafting, it may be possible to perform these procedures without general anesthesia. In this case series, we demonstrated the successful use of the QL block in the management of acute postoperative pain following iliac crest graft harvesting.
