Iliac crest graft site pain after anterior lumbar interbody fusion: a prospective patient outcome assessment

Abstract

Purpose of study: Autogenous iliac crest bone graft is the gold standard for bone grafting for spinal fusion surgery. Unfortunately, there is a frequent incidence of graft site pain that persists well into the postoperative period. This study reports the results of a prospective study evaluating graft site pain after iliac crest harvest for anterior lumbar interbody fusion (ALIF).Methods used: A total of 208 patients underwent iliac crest bone graft for ALIF as the control group of four randomized prospective multicenter clinical trials evaluating recombinant human bone morphogenic protein (rhBMP)-2 vs autogenous iliac crest bone graft in a threaded cylindrical cages or threaded bone dowels. Most patients in the control groups had anterior iliac crest graft harvest, equally from the right and left side. Three grafts, 1.4%, were taken from the posterior crest, and six, 2.9%, were tricortical. Follow-up was obtained at hospital discharge, 6 weeks, 3, 6, 12 and 24 months. A pain evaluation score made up of two visual analog scales, one scale measuring intensity, the other frequency of pain on a scale of 0 to 10, was used. For the intensity scale, a rating of 0 meant no pain and 10 was “as bad as it could be.” For the frequency scale, a rating of 0 meant pain was present “none of the time” and 10 meant it was present “all the time.” Combining the scores, a total score of 20 indicated the worst pain was present all the time. Patients were also questioned about the graft site appearance.of findings: A total of 208 patients underwent iliac crest harvest and prospective data were available on 202 patients. At hospital discharge, two patients had no pain, 1%; this increased to 34 of 199, 17%, at 6 weeks after surgery and to 85 of 199 patients, 43%, at 3 months. However, 41% of patients (79 of 192) reported pain at 6 months postoperatively, and 33% of 168 reported pain at 1 year. Of 208 patients, 141 completed surveys at 24 months with 31% reporting some level of pain. At hospital discharge, the graft-site pain score ranged from 0 to 20 with a mean of 12.8, SD 4.5, decreasing to 7.3, (SD, 5.6; range, 0 to 20) at 6 weeks; 3.8 (SD, 4.6; range, 0 to 18) at 3 months; and scores of 2.9, 2.4 and 1.8 at 6, 12 and 24 months, respectively. At all time intervals p values were less than .001. Total pain scores combining intensity and frequency greater than or equal to 10, maximum possible 20, were collected at each interval. At discharge 80% (161 of 202) had a pain score of less than 10 (range, 10 to 20). This decreased to 35% (70 of 199; range, 10 to 20) at 6 weeks; 14% (28 of 199 at 3 months; range, 10 to 18); and at 6, 12 and 24 months postoperatively, 13% (25 of 192), 10% (17 of 168) and 7% (10 of 141) respectively. Graft site appearance at discharge was good in 49% of patients, fair in 40% and poor in 11%. At 6 weeks, 69% rated appearance as good, 27% as fair, 5% as poor. At 3 months 75% rated appearance as good, 24% as fair, 2% as poor. At 6 months 82% rated appearance as good, 15% as fair, 3% as poor. At 12 months 82% rated appearances as good, 19% as fair or poor. At 24 months 84% rated appearances as good and 16% as fair or poor. There was no significant difference between posterior and anterior harvest sites or with bicortical grafts, and all were included in the analysis. Right or left side demonstrated no differences.Relationship between findings and existing knowledge: This is the first study known to the authors presenting results of prospective data collected in a multicenter study evaluating iliac crest harvest site pain (intensity and frequency) as well as graft site appearance.Overall significance of findings: The results demonstrate that 31% of patients had persistent pain at 24 months postoperatively, and 16% reported fair or poor appearance of their graft site.Disclosures: No disclosures.Conflict of interest: Rick Sasso, grant research support and, consultant.