A COMPREHENSIVE STUDY OF PHYSICAL PARAMETERS, BIOMECHANICAL PROPERTIES, AND STATISTICAL CORRELATIONS OF ILIAC CREST BONE WEDGES USED IN SPINAL-FUSION SURGERY .1. PHYSICAL PARAMETERS AND THEIR CORRELATIONS

Iliac crest bone wedges are commonly used in spinal fusion procedures and must be capable of withstanding considerable mechanical stress dur ing the healing process. The variability of ''quality'' of bone materi als used in the production of bone wedges suggests that some bone mate rials may not be suitable for use in vertebral fusion procedures and s ome quantifiable means of predicting the suitability of bone wedges wo uld be desirable. A total of 250 iliac crest wedges were used in this study. Physical parameters of iliac crest wedges, such as total cross- sectional area, cancellous cross-sectional area, cortical cross-sectio nal area, percentage of cortical cross-sectional area, ''width,'' and apparent density were determined. The statistical correlations among p hysical parameters were investigated. These correlations revealed that the relative percentage of cortical and cancellous bone remained fair ly constant at 41% and 59%, respectively, regardless of total cross-se ctional ares of a wedge, that apparent density did not appreciably cha nge with donor age, and that ash (inorganic) and organic content (weig ht) correlated well with the apparent density.