Spinal fusion using tissue engineered bone. A prospective, randomized clinical pilot trial

Spinal fusion is performed using bone harvested from the ilium. However, graft harvest is associated with frequent complications and pain. If a tissue engineered bone (TEB) was available, spinal fusion could be performed without damaging normal tissues. In 8 patients, 10-20 mL of marrow fluid was collected from the iliac crest to fabricate. After primary culture in the standard medium, marrow mesenchymal cells were combined with porous tricalcium phosphate block and were cultured in osteogenic medium containing dexamethasone, b-glycerophosphate, vitamin C phosphate, and estriol. After 3 weeks of subculture, spinal fusion was performed using TEB. Nine patients who had undergone spinal fusion using iliac autografts served as the controls (AG group). In all patients, significant improvement in JOA score was seen in both TEB and AG groups. The radiographic fusion rate was 87.5% (7/8) in TEB group and 77.8% (2/9) in AG group at 6 months after surgery. The mean operating time in TEB group was shorter than in the AG group. Compared with the AG group, the patients receiving TEB graft had significantly less total blood loss. In the AG group, all of the patients complained of graft site pain for 2 to 4 weeks after the operation. Two patients (22.2%) still had graft site pain at 6 months postoperatively. Bone regeneration therapy using the TEB graft introduced in this report makes it possible to perform spinal fusion as is done using autogenous bone grafts, but with the minimally invasive procedure of bone marrow aspiration.