Posterior iliac crest pain after posterolateral fusion with or without iliac crest graft harvest.

BACKGROUND CONTEXT: Considerable debate exists regarding the incidence of persistent pain from the iliac crest bone graft (ICBG) harvest site. Different study designs have led to a variety of reported rates.

PURPOSE: The purpose of this study was to determine the incidence and severity of bone graft site pain after iliac crest harvest.

STUDY DESIGN: Cross-sectional.

PATIENT SAMPLE: One hundred and twelve patients, who had a posterior lumbar fusion, seen at a tertiary spine center for a routine postoperative visit.

OUTCOME MEASURES: Numeric rating scales (0-10) for pain over lower back, right, and left posterior iliac crests.

METHODS: An independent investigator, not directly involved in the care of the patient and unaware of the type of bone graft used in the fusion, examined the patient for tenderness over the surgical site as well as the left and right posterior iliac crest. After the examination, data on the source of grafting material, complications during harvest, and backfilling of the graft site defect were collected from the medical records. The patients were then classified as to whether ICBG was harvested or not. Chi-square test was used to determine any difference in the proportion of iliac crest pain between the bone graft group and no bone graft group. Correlations between body mass index (BMI), time since surgery, and the incidence and severity of bone graft site pain were also determined.

RESULTS: There were 72 women and 40 men with a mean age of 56.6 years (range, 16-84). Mean follow-up was 41 months (range, 6-211 months) with a median of 25 months. Iliac crest bone graft was harvested in 53 (47.3%) patients through the midline incision used for lumbar fusion. In 59 patients (52.7%), recombinant human bone morphogenetic protein-2 was used with no graft harvest. There was no statistically significant difference in the proportion of patients complaining of tenderness over both or either iliac crest between the two groups. Only 10 patients had pain over the same crest from which the graft was harvested. No correlations between number of levels fused, levels fused, BMI, length of follow-up, and the incidence and severity of bone graft site pain were seen.

CONCLUSIONS: The results of this study highlight the difficulty in differentiating pain originating from the graft site versus residual low back pain. The incidence of pain over the iliac crest was similar in patients in which iliac crest was harvested and those in which no graft was harvested.