Treatment with a drug used to combat the bone-thinning disease osteoporosis appears to reduce the occurrence of osteoarthritis-related damage in the knee, according to a new report.

Bone is normally resorbed and replaced continuously, but when the turnover is unbalanced and too much bone is lost it can lead to osteoporosis. Anti-resorptive drugs like alendronate (better known as Fosamax), as well as other types of agents, are used to stop the disease process.

The current findings are based on a study of 818 post-menopausal women who participated in the Health, Aging and Body Composition Study and had symptoms of knee osteoarthritis.

Structural changes in the knee were assessed by MRI and X-rays, and knee pain severity was gauged using a standard scale.

Among the participants, 26 percent used anti-resorptive drugs - such as alendronate, estrogen, and raloxifene (Evista) - Dr. Laura D. Carbone, from the University of Tennessee Health Sciences Center in Memphis, and colleagues note in the medical journal Arthritis and Rheumatism.

Overall use of anti-resorptive agents was not associated with the presence of knee pain and osteoarthritic changes, the authors note. However, use of alendronate or estrogen did seem to reduce bone loss and bone marrow abnormalities.

Treatment with alendronate, but not estrogen, improved pain scores.

“Our study suggests that alendronate and estrogen may protect against the development of bone abnormalities associated with knee osteoarthritis, which may have a beneficial effect on the course of the disease,” the investigators conclude.

SOURCE: Arthritis and Rheumatism, November 2004.