LIPID EXTRACTED BANK BONE IMPLANTS IN THE ILIAC CREST EVALUATED BY CT, MRI AND BIOPSY

During hip surgery on four patients with severe rheumatoid arthritis, bank bone was used to refill the emptied iliac crest. The course of gr aft incorporation was followed by CI, MRI and biopsies. In the first t hree cases, biopsies were taken after 3, 6 and 12 months respectively. Since the results indicated a process of incorporation which would pr obably be detectable by MRI, we designed a meticulous follow up on a f ourth patient. Repeated axial projections with Cr and MRI were perform ed at 0.5, 3, 6, 12 and 18 months after the operation. CT demonstrated a higher density corresponding to the size and shape of the implanted graft. MRI indicated initial oedema, but within 1 year the signals ch anged to that of normal marrow. At 6 months, contrast infusion of Gd-D TPA confirmed blood perfusion in the graft. The 12 month biopsy in thi s patient showed full incorporation. This patient also received oxytet racycline preoperatively, and the biopsy showed tetracycline labelling throughout. The results support the use of lipid extracted bank bone in the iliac crest to produce new autografts for future use. MRI, espe cially in combination with CT, could be a useful clinical tool to moni tor graft incorporation.