This preliminary study showed that patients with marked cartilage loss (JSN>or=0.6 mm) receiving RIS 15 mg/day retained vertical trabecular structure, and those receiving RIS 50 mg/week increased vertical trabecular number, thereby preserving the structural integrity of subchondral bone in knee OA.

Bone loss occurred in all knees with medial compartment OA. Decrease in FD of vertical and horizontal trabeculae was consistent with decrease in trabecular number associated with loss. The pattern of bone loss was similar in knees with slow and detectable JSN.

The increase in FSA (consistent with increased trabecular number associated with thinning and fenestration in regions of dense cancellous bone) of most vertical and some horizontal trabeculae confirms that cancellous bone within the proximal tibia of OA patients is osteoporotic.