Risedronate (Actonel) May Slow Joint Destruction in Knee Osteoarthritis

Osteoporosis Drug May Also Delay Need for Joint Replacement Surgery

Risedronate brand name Actonel, one of the bisphosphonate drugs typically used in the prevention and treatment of osteoporosis, may slow joint destruction and delay the need for joint replacement surgery in patients with knee osteoarthritis (when taken in higher doses), according to research presented at the ACR Annual Scientific Meeting.

Joint Destruction

Osteoarthritis is the most common type of arthritis, especially among older people. Osteoarthritis is a joint disease that mostly affects the cartilage.

Cartilage is the slippery tissue that covers the ends of bones in a joint. Healthy cartilage allows bones to glide over one another. Cartilage also absorbs energy from the shock of physical movement.

In a healthy joint, cartilage maintains the separation between bones, allowing joints to move smoothly.

Osteoarthritis of the Knee

The knees are the body's primary weight-bearing joints. For this reason, they are among the joints most commonly affected by osteoarthritis. Osteoarthritis of the knee causes a loss of cartilage, which can be seen on X-ray as a narrowing of the joint space. This narrowing is used to quantify the progression of the disease.

Recent studies show that the bone under the cartilage is osteoporotic, resulting from the loss of the vertical trabecular bars that support the bony plate under the cartilage.

This loss can lead to a breakdown of the joint which, in turn, may require eventual joint surgery.

About Risedronate

Risedronate brand name Actonel, a bisphosphonate drug, is one of several osteoporosis medication options approved for the prevention and treatment of postmenopausal osteoporosis.

Other bisphosphonate drugs include:

  • alendronate brand name Fosamax
  • ibandronate brand name Boniva

Risedronate and the other bisphosphonates can:

  • increase bone density
  • slow bone loss
  • reduce the risk of bone fractures including fractures of the spine

According to the National Osteoporosis Foundation (NOF), when used for the prevention and treatment of osteoporosis, risedronate is normally taken daily (5 mg. dose) or weekly (35 mg. dose or 35 mg. dose with calcium). The NOF does warn patients, risedronate must be taken on an empty stomach, first thing in the morning, with eight ounces of water (no other liquid), at least 30 minutes before eating or drinking. Patients must remain upright during this 30-minute period.

Risedronate also is approved for use by men and women to prevent and/or treat steroid drug-induced osteoporosis that can result from long-term use of corticosteroid medications such as prednisone, triamcinolone, or cortisone.

    About the Study

    Researchers studied the changes in bone structure to determine if risedronate might halt or reverse the bone destruction associated with the loss of cartilage and thus decrease the risk of joint collapse.

    100 patients were randomly selected from treatment groups of 300 individuals already experiencing joint space narrowing due to knee osteoarthritis. These groups either received a placebo or the drug risedronate at doses of 5 mg. per day, 15 mg. per day or 50 mg. once per week. Patients were then followed for a two-year period.

    Using standard radiographs, a novel computational technique analyzed changes in trabecular (spongy) bone structure beneath the cartilage in patient's knees, that had been sub-grouped into those with either little or no (i.e., static) or advanced joint space narrowing.

    Study Results

    For patients with progressive joint space narrowing:

    • Those administered the higher doses of risedronate (15 mg. a day or 50 mg. once a week) halted and even reversed trabecular bone loss.
    • Those administered the lower dose of 5 mg. a day or placebo did not show any benefit in this aggressive disease subset.

    Patients with no progression in their joint space narrowing had a modest loss of bone structure regardless of treatment.

    Study Conclusions

    When administered in higher doses, the osteoporosis drug risedronate may:

    • preserve underlying bone for those patients with marked joint space narrowing.
    • delay ultimate joint destruction and stall off the need for joint replacement surgery.


    ACR Press Release, 11/13/05, Osteoporosis Drug May Delay Joint Destruction In Knee Osteoarthritis; NIH Publication No. 02-461

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