A COMPREHENSIVE STUDY OF PHYSICAL PARAMETERS, BIOMECHANICAL PROPERTIES, AND STATISTICAL CORRELATIONS OF ILIAC CREST BONE WEDGES USED IN SPINAL-FUSION SURGERY .2. MECHANICAL-PROPERTIES AND CORRELATION WITH PHYSICAL PARAMETERS

Iliac crest wedges have been the most frequently used bone graft in sp inal fusion procedures since the 1970s. Physical parameters and correl ations among physical parameters of allogeneic iliac crest wedges have been described in part I of this series. This article discusses the m echanical properties, as well as their correlations with physical para meters, of iliac crest wedges. A total of 250 frozen-thawed, freeze-dr ied, and rehydrated iliac crest wedges were used in this study. The ax ial load-bearing capacities for wedges in the three subgroups showed n o statistically significant differences, however, rehydrated wedges ap peared to have the greatest load bearing capacity and compressive stre ngth. In addition, rehydrated wedges were more deformable than either the frozen-thawed or freeze-dried wedges. Based on biomechanical prope rties, it is suggested that rehydrated (1 hour in vacuo), or frozen-th awed iliac crest wedge should be used in spinal fusion procedures, and the direct clinical application of nonrehydrated freeze-dried wedges should be avoided.