Ask The Doctors: August 2013
Metal-on-Metal Implants......Glucosamine and Chondroitin Supplements
Q. I am a younger woman who had a hip resurfacing procedure four years ago using a metal-on-metal (MoM) component. Based on the U.S. Food and Drug Administration (FDA)ís recent concerns, should I be worried about how the MoM implant could affect my future health?
A. There have been a lot of recent concerns raised about the safety of metal-on-metal (MoM) hip implants, both by the FDA and additional clinical studies that found blood cobalt ion levels to be significantly higher in asymptomatic patients (or those with no symptoms) who later needed revision of two types of MoM hip replacements. Current recommendations from the FDA for the follow-up of asymptomatic patients with MoM implants include physical examinations and routine radiographs every one to two years. The FDA indicates that there are certain patients who are at risk for increased device wear and/or adverse local tissue reactions (ALTR) and should be followed more closely, including patients with resurfacing systems with small femoral heads (44 mm or smaller) and female patients.
If a patient experiences local symptoms, including pain or swelling at or near the hip, a change in walking ability, or a noise from the hip joint more than three months after MoM hip implant surgery, he or she should have a thorough evaluation by their surgeon.
In patients who are presenting symptoms of complications, the FDA recommends an X-ray or CT scan to guide the need for future treatment. In some symptomatic patients, an MRI is needed to diagnose and assess soft tissue findings surrounding the implant. Additionally, patients who develop symptoms or physical findings indicating their MoM may not be functioning properly should be considered for metal ion testing, although the FDA does not currently believe there is enough evidence to demonstrate a correlation between metal ion level and the presence of localized lesions, clinical outcomes and/or the need for revision surgery. Overall, if you have a MoM hip implant or hip resurfacing system, itís important to follow-up with your surgeon for regular examinations.
Q.I have mild pain in my knee due to osteoarthritis (OA). What is the latest information about taking glucosamine and chondroitin sulfate supplements to help ease the pain and prevent further progression of my OA?
A. Since results from the Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT) were released in 2006, glucosamine and chondroitin sulfate supplements have been looked to for relief of moderate-to-severe osteoarthritis (OA) pain. GAIT was designed to test the short-term (six months) effectiveness of glucosamine and chondroitin sulfate in reducing pain in a large number of participants with knee OA.
In the trial, the supplements did not help those with mild OA pain. Yet, for a subset of patients with moderate-to-severe pain, the combination provided statistically significant pain relief. Updated data from a long-term two-year GAIT study released in June†2010 (Annals of Rheumatic Diseases) showed that the dietary supplements (taken alone or in combination) did not help relieve pain in patients with knee osteoarthritis.
Additional research has recommended that glucosamine sulfate taken alone is effective in minimizing osteoarthritis pain. The primary recommendation is 1,500 mg of glucosamine daily, and may be more effective if given as one dose. Generally if the supplement is helpful for your symptoms it is usually continued. The hope is that this medication might slow down the progressive cartilage loss that occurs in osteoarthritis.