Quantitative computer assisted tomography (QCT) and mechanical properties of cancellous bone

The density of cylindrical cancellous bone samples was obtained by quantitative computer assisted tomography (QCT). Their compressive strength was measured. Two groups of purified bone graft cylinders (Pelican Tissue Bank) were tested. In one, the major trabecular orientation was vertical, while the other had random orientation. In addition, cancellous bone plugs were harvested from the femoral head, trochanter and condyles of both femurs of a fresh 40 year old cadaver keeping the samples orientation in the direction of physiological loading. The correlation between strength and bone mineral density by QCT showed a power law relationship for the processed bone graft samples with preferred trabecular orientation and unprocessed cadaver bone plugs. No correlation was seen for the group with random trabecular orientation. Thus trabecular orientation plays an important role in relating the strength to mineral density values by QCT.