Advances in joint pain treatment
Reduced joint mobility begins around age 35, as natural fluids lubricating our cartilage become more scarce. For as many as one in seven of us, this is compounded by the inflammation of osteoarthritis. As new treatments to diminish pain and extend mobility emerge and compete with established ones, healthcare providers have faced the choice with caution, typically favouring the approach with the longest track record except in more severe cases.
Where oral anti-inflammatories fail, steroid injections (cortisone) have been standard treatment since the 1950s, targeting directly the inflammation of the joint lining that eventually leads to cartilage and bone damage. Where cortisone fails, the waiting list for joint replacement has often been the next recourse.
Hyaluronic acid injections, marketed as Synvisc® in Canada by Genzyme since 1997, are a “viscosupplementation” treatment aimed at replacing the naturally occurring molecule hyaluronan, secreted in diminishing quantities over time by our cartilage. Derived from eggshell membrane proteins, it offers the possibility of delaying the need for joint surgery. Its use is also widespread as a filler for scar reduction procedures, replacing shorter-lived collagen injections, and as a scaffolding material for cutting-edge tissue cloning and organ regeneration from stem cells.
Because of its widespread use in surgery and its mimicry of naturally secreted molecules, hyaluronic acid’s safety is not as much of an issue as its effectiveness versus cortisone or placebo. Clinical studies have been mixed, but a systematic literature review for the journal of the College of Family Physicians of Canada, looking at five case series and thirteen randomized controlled trials, concluded that hyaluronic acid “appears to have a slower onset of action than intra-articular steroids but the effects seem to last longer,” and that higher concentrations showed more consistent results in terms of pain relief and improved function. Effects of hyaluronic acid begin after one to three months and last up to a year, compared with cortisone injections, which act more quickly but lose effectiveness after three months.
Biologic Response Modifiers (BRMs) are a class of drugs whose novelty is discernible from their generic names – Enbrel (etanercept), Remicade (infliximab), Humira (adalimumab), Kineret (anakinra), Orencia (abatacept), and Rituxan (rituximab). They aid the immune system with fine-tuned targeting of molecular pathways involved in inflammation. Early results are promising, but by virtue of their newness, long-term studies of their efficacy and side effects are still over the horizon and many healthcare providers won’t yet have clinical experience prescribing them.
Small trials in Europe and the United States are frequently touted to show efficacy for the dietary supplements glucosamine sulfate and chondroitin sulfate, but have been criticized on methodological grounds. Most physicians won’t recommend supplements for osteoarthritis treatment, though few discourage patients from taking them if they have normal liver and kidney function.
Non-pharmacological approaches rely largely on weight control and exercise, which can reduce wear and tear on the joints. Low-impact exercise of affected joints can be of varying benefit among individuals, but it can’t hurt – the balance of evidence shows that it will not increase the development of osteoarthritis. Physical activity correllates strongly with greater and longer lasting mobility, and low-impact exercise classes for seniors are available in several community centres around Montreal.
- YMCA: swimming, stretching, pilates
514-486-7315 or centresymca.ca
- YMYWHA: aqua fitness, yoga, outdoor walks
514-737-6551 or ymywha.com
- Cummings Centre: chair aerobics and fitness
514-343-3529 x 7329 or cummingscentre.org
Hyaluronic acid injections for knee osteoarthritis - Systematic review of the literature
Anita Aggarwal, MD, CCFP Ian P. Sempowski, MD, CCFP(EM)
College of Family Physicians of Canada
Osteoarthritis: Current Concepts in Diagnosis and Management
Nisha J. Manek, MD, MRCP, Nancy E. Lane, MD
American Acadamy of Family Physicians
Explore Plastic Surgery - Archive: Hyaluronic Acid
Barry L. Eppley, MD, DMD