A Prospective, Randomized, Double-Blind Study Evaluating the Efficacy of Postoperative Continuous Local Anesthetic Infusion at the Iliac Crest Bone Graft Site After Spinal Arthrodesis

Abstract

Parallel design, prospective, double-blind, randomized, controlled trial composed of two independent groups treated with a continuous infusion catheter (saline vs. Marcaine) placed into the iliac crest bone graft (ICBG) site. To determine the effects of postoperative continuous local anesthetic agent infusion at the ICBG harvest site in reducing pain, narcotic demand and usage, and improving early postoperative function after spinal fusion. Harvesting iliac crest bone has been shown to be a source of pain and morbidity. Long-term patient complaints may be more closely associated with the procurement of the iliac crest graft rather than the primary surgical site. Thirty-seven patients were enrolled in a prospective, randomized, double-blind parallel-designed study after informed consent and IRB approval was obtained. Twenty-eight patients had ICBG harvested for lumbar arthrodesis and nine for cervical arthrodesis. During spinal arthrodesis surgery, patients were randomly assigned to receive 96 mL (2 mL/hr x 48 hours) of either normal saline (control group, n = 22) or 0.5% Marcaine (treatment group, n = 15) delivered via a continuous infusion catheter placed at the ICBG harvest site. All patients received Dilaudid PCA after surgery. Pain scores, narcotic use/frequency, activity level, and length of stay (LOS) were recorded. Physicians, patients, nursing staff, and statisticians were blinded to the treatment. Mean patient age was 60 years and similar between groups. Narcotic dosage, demand frequency, and mean VAS pain score were significantly less in the treatment (Marcaine) group at 24 and 48 hours (P < 0.05). The average LOS was 4.1 days with no difference between Marcaine or control groups. No complications were attributed to the infusion-catheter system. Continuous infusion of 0.5% Marcaine at the ICBG harvest site reduced postoperative parenteral narcotic usage by 50% and decreased overall pain scores. No complications were attributed to the infusion-catheter system. The use of continuous local anesthetic infusion at the iliac crest may help in alleviating acute graft-related pain, hastening patient recovery and improving short-term satisfaction.