Purpose: Harvesting of iliac crest graft for spinal fusions is associated with a number of patients reporting residual pain at the harvest site. Various interventions have been proposed to minimize the pain associated with this. The purpose of this study was to evaluate the efficacy of intra-operative infiltration of morphine into the iliac crest harvest site for reduction of postoperative pain.

Method: A double-blinded, placebo controlled study was performed comparing intraoperative infiltration of 5mg of morphine (treatment) vs. saline (placebo) into the iliac crest harvest site for patients undergoing elective spinal surgery. Patients with myelopathy, excessive preoperative opiod use (60mg equivalent morphine/day or more), or multilevel (greater than 3 levels) spinal surgery were excluded. Postoperative administration of morphine (recovery room and PCA) was standardized. Numerical pain scores specific for the iliac crest site were determined in the immediate postoperative period and at 3, 6 and 12 months. Ad hoc power analysis demonstrated that 36 patients would be able to detect a clinically significant difference of 2.4 points on a 10 point numerical pain scale (alpha = 0.05, power = 80%).

Results: 37 patients were randomized and evaluated with a minimum of one year follow-up. The groups were similar in baseline age, gender and comorbidity. There was no significant difference between groups in total use of postoperative morphine during the first 24 hours (treatment: 320mg +/− 268mg, placebo: 293mg +/− 182mg, p = 0.73). There was no significant difference in iliac crest activity pain scores at 1 year (treatment: 1.7 +/− 3.0, placebo: 1.1 +/− 2.4, p = 0.48) or at any of the earlier time points. The proportion of patients with moderate to severe iliac crest pain at one year follow-up was the same between both groups.

Conclusion: This study has demonstrated that there are no additional benefits for the use of intra-operative infiltration of morphine into the iliac crest harvest site during spinal fusions.

Superior mesenteric artery (SMA) syndrome is a rare medical complication of scoliosis surgery. In order to delineate the clinical features, progression and treatment of duodenal obstruction due to SMA syndrome after spinal fusions and to determine the relationship between spinal deformity correction and SMA syndrome, a retrospective study of all patients developing SMA syndrome following spinal fusion was conducted at a tertiary care center.

Charts were reviewed for symptoms of SMA syndrome, type and magnitude of spinal deformity, age at surgery, radiographic correction, complications, and other medical problems. The information gathered was divided according to non-orthopaedic and orthopaedic parameters.

All patients (five female and three male) in this study had spinal fusions performed. Overall, the patients were skeletally mature with a Risser stage average of 3.6. The average correction in the coronal plane was 28.4% in the thoracic spine and 44.6% in the lumbar spine. Sagittal correction averaged 25.9 % and 27% in the thoracic and lumbar spines respectively.. BMI index average was 17.6 (i.e. under-weight individuals). Signs and symptoms of SMA syndrome such as nausea, vomiting, epigastric pain, bloating, and weight loss developed at an average of 11.6 days. Seven patients were managed conservatively, and only one patient required surgery. All patients recovered fully.

This study identified purely asthenic body habitus (low BMI) and significant coronal correction in the lumbar region as risk factors for the development of SMA syndrome after spinal fusion Prolonged nausea and vomiting after spinal fusion requires GI imaging to rule out SMA syndrome, particularly within the first seven-ten days of surgery. Clinicians should also be aware of the possible delayed onset of symptoms in some patients. Nutritional support should be started immediately to prevent further adverse outcomes.