Interbody allograft in a skeletally immature spine model.

The objective of this cadaveric biomechanical study was to establish further bovine spines as models for evaluating lumbar interbody allografts and to provide guidance for their use in pediatric humans. It is unknown whether interbody allografts can be used in the pediatric spine without failure of the host vertebral bone. Allografts were placed in cow and calf spines and loaded in compression. The cow spines were much stronger and stiffer than the calf, but moderate in vivo activities were estimated to result in loads on the allograft constructs that would result in host bone failure. Bovine spines were established as suitable models for the compressive behavior of interbody allografts in the human spine, when bone density is considered. Interbody allografts should continue to be used with adjunctive instrumentation so as to preclude host bone failure.