Biomechanical characteristics of iliac crest bone in elderly women according to osteoarthritis grade at the hand joints.

Postmortem iliac crest trabecular bone specimens were tested in compression to determine their mechanical characteristics. Trabecular bone volume and width were evaluated by histomorphometry and radiographic grading of osteoarthritis (OA) of hand joints was also done. Patients were divided into 2 groups: no or low grade OA (Group 1) and manifest OA Grades II-IV (Group 2). From the 27 specimens tested (women 56-80 years old), 17 were in Group 1 and 10 in Group 2. Significant differences in stiffness (E), compressive strength, trabecular bone volume and trabecular width between the 2 groups were found. In the group with manifest OA, bone was significantly stiffer, had a significantly increased compressive strength value, a significantly higher trabecular bone volume and trabecular width, compared to the group with no or low OA grade. Significant correlations were found between elastic modulus and trabecular bone volume and width, and also between compressive strength and trabecular bone volume and width. Our findings support the hypothesis that the primary defect in OA is not in the articular cartilage but in the subchondral bone and that primary OA is part of a more general bone disease.