Analysis of iliac crest bone grafting process measures.

Autogenous iliac crest bone graft (ICBG) is the gold standard of materials for spinal fusion. We conducted a prospective observational study of posterior autogenous ICBG harvesting and used process measures to establish a normative database of bone harvesting for future comparative studies and analyses of bone graft substitutes. Between August 2000 and March 2002, we obtained posterior autogenous ICBG from 36 consecutive patients (29 men, 7 women). Mean age was 39 years (range, 22-62 years). For harvesting, the "trephine curettage" technique was performed through a skin incision separate from that of the primary surgery. Mean estimated blood loss (EBL) for harvesting was 71 mL (range, 20-200 mL). The index procedure consisted of transforaminal lumbar interbody fusion (27 patients), posterior spinal fusion (3), combined anterior and posterior spinal fusion (5), or anterior spinal fusion (1). Mean EBL for the index procedure was 790 mL (range, 150-1500 mL). Mean harvest time was 37 minutes (range, 20-51 minutes). Mean harvest volume was 38 mL (range, 25-65 mL). Donor site and sacroiliac (SI) joint were clearly visualized in 29 (81%) of the 36 patients; the SI joint (ligamentous portion) was violated in 1 patient (3%). With the emergence of bone graft substitutes, costs and benefits of autogenous ICBG harvesting will be scrutinized. This database establishes a prospective benchmark for additional EBL, harvest time, harvest volume, and SI joint violation for ICBG harvesting. To our knowledge at the time of manuscript preparation, this is the first report of routine use of postoperative computed tomography to determine incidence of SI joint violation after ICBG harvesting.