Use of allografts in spinal surgery.

This is a review of 118 patients operated between January 1989 and February 1999, 78 for posterior fusions and 40 for anterior spinal reconstructions. For posterior fusion, meticulous preparation of the fusion bed was essential. The author strongly advocated using autografts from spinous processes for achieving facet joint fusion. Deep frozen allografts were used as a 50% allograft-autograft mixture. Good results were achieved -- no infection in all cases and implant failure with clinical non-union in only 5 cases. Massive anterior spinal reconstruction following corpectomy was performed in 34 cases. Allografts used included 15 femoral cortical rings, 11 tibial rings and 3 humeral cortical rings. The author advocated the use of an allograft-autograft composite by packing the medullary canal of the allograft with autografts. Deep-frozen cortical rings have been used (25 cases). Recently, more freeze-dried cortical rings made available were used (9 cases). The results of massive reconstructions were good. There was no infection and no implant failure in all cases. Both deep-frozen and freeze-dried cortical allografts were strong enough to withstand loads taken by the reconstructed spine.