Iliac Crest Regeneration: A Retrospective Study of 14 Years of Follow-up.

Abstract

This is a retrospective study analysis. The purpose of our study was to evaluate the healing process of the ilium after being used as a bone graft donor site in the treatment of adolescent idiopathic scoliosis. Iliac crest bone grafts have been proven to be the most reliable means for solid fusion in spine surgery. Nevertheless, few reports in the literature describe the ability of the iliac crest to regenerate. Thirty-one patients with a mean age of 15.1 years had undergone posterior spinal fusion for idiopathic scoliosis. An autogenous bone graft was harvested from the right posterior iliac crest in all cases. Computed tomography scans of the pelvis were performed preoperatively and shortly after operation to evaluate the presence of any deformity and the size of the defect formed during surgery, respectively. All patients were reexamined 14 years postoperatively, and computed tomography scans were performed to evaluate the status of ossification at the donor site. In 21 cases (67.74%), bone deficits were fully restored (mean volume 12.053 cm), whereas partial regeneration was present in the remaining 10 cases (mean volume 8.766 cm). Hounsfield units (HUs) revealed that cancellous bone quality had been restored in 21 cases, whereas cysts with sclerotic bone margins were present in the remaining 10 cases. Immature patients [Risser sign (RS) 3, 4] have greater ability in restoring bone stock compared with patients with almost complete growth (RS 5; P<0.001). In addition, the gluteus maximus muscle preserved its volume and quality in cases with complete bone restoration (volume 51.3 cm, HU 55.9) compared with cases with partial regeneration (volume 43.43 cm, HU 38.35; P<0.001). The iliac wing of skeletally immature patients has considerable ability to fully regenerate and could probably be used as a graft donor site again.