SAN DIEGO — Risedronate treatment preserved trabecular bone in patients with advanced medial compartment knee osteoarthritis, and at a high dose even appeared to build it, Christopher Buckland-Wright, Ph.D., said at the annual meeting of the American College of Rheumatology.
Despite the loss of cartilage, “high doses of risedronate appeared to protect joints against bone loss, and preserved the structure and integrity,” said Dr. Buckland-Wright, professor of radiologic anatomy at King's College London.
If the results are confirmed by additional studies, perhaps bisphosphonate treatment will be used to delay the onset of the compartmental collapse in knees affected by osteoarthritis.
Dr. Buckland-Wright presented the results of an analysis of a multicenter, placebo-controlled trial involving three different doses of risedronate in knee osteoarthritis: 5 mg/day, 15 mg/day, and 50 mg once a week.
His analysis included 100 patients randomly selected from each of the four groups. These patients were selected from the entire 1,200-patient cohort, which included 300 participants in each of the four study arms. The structure and density of trabecular bone in the medial tibial compartment were examined using an x-ray technique developed by Dr. Buckland-Wright.
Overall, most of the patients had evidence of vertical and trabecular bone loss during the 2-year course of the study. But among those who had progressive narrowing of the joint space, risedronate at the higher two doses appeared to preserve bone.
Patients taking 15 mg/day had stabilizing of both vertical and horizontal trabeculae. In the patients taking 50 mg per week, horizontal trabeculae stabilized, and there was an increase in vertical trabeculae, according to Dr. Buckland-Wright.
The patients with progressive narrowing on placebo and on the 5-mg a day dose continued to have bone loss, and had a greater degree of bone loss than those without progressive narrowing during the trial, who had no evidence of benefit at any dose.
The study was sponsored by Procter & Gamble Pharmaceuticals Inc., Mason, Ohio.