Abstract
Knee osteoarthritis (OA) is a major cause of pain and disability in elder people. The prevalence of radiographic OA in a population aged 35–74 years is 5–15% and about one third of involved people complain of symptoms. In the „Ulm Osteoarthritis Study“ patients undergoing total knee replacement reported a mean duration of knee pain of 10 years prior to surgery.
Multiple genetic, constitutional and environmental factors contribute to the development of OA. Initial cartilage degradation leads to joint space narrowing and early osteophyte formation which can be observed radiographically. Whether elevated subchondral bone mineral density is contributing to manifestation of the disease or just a secondary reaction process is still under debate. OA finally involves not only cartilage and subchondral bone but also soft tissues in and around the joint (synovial membrane, ligaments and muscles), which often results in painful effusions, muscular shortening and stiffness.
Many conservative treatment options have been developed in the past to relief these symptoms and to slow down or even stop the cartilage degradation process. Evidence to support the effectiveness of individual treatments, however, is variable. Recently the EULAR Committee for Clinical Trials determined an approach for the development of evidence based guidelines for conservative treatment of knee OA (Pendleton et al, Ann Rheum Dis2000;59:936–944). Through a process of quality assessment of available publications and determination of expert consensus employing a Delphi approach propositions relating to a rationale conservative management could be made:
Treatment of knee OA must be tailored to individual patients, taking into account factors such as age, comorbidity and the presence of inflammation. Optimal management requires a combination of non-pharmacological treatment modalities (regular education, exercise, appliances and weight reduction) and pharmacological approaches. Paracetamol generally is the preferred analgesic and there is enough evidence to support its application, as the pain controlling effects are comparable to NSAIDS and long term application is safe enough. NSAIDS (oral or even topical) can be considered in patients with effusion. Although some studies found NSAIDS to have better efficacy than paracetamol in the treatment of painful knee OA, the gastrointestinal side effects limit their long-term application. Therefore most experts consider their application only in patients unresponsive to paracetamol and in major effusions. In such situations long-acting steroids can be injected intra-articularly as well. While the effects of steroids in knee OA have been assessed in a number of studies, the predictors of response are still somewhat unclear and further investigations are necessary.
Recent data seems to support the theory that some symptomatic slow acting drugs (glucosamine sulfate, chondroitin sulfate, diacerein and hyaluronic acid) may possess structure modifying properties. Further studies, however, are necessary to determine the pharmacoeconomic aspects of that treatment and to define the indications more precisely.
Education should be an integral part in the management of knee OA. Several large randomised controlled trials have shown benefits of different educational techniques in reducing pain and increasing coping skills. Function can reliably be improved by quadriceps strengthening exercises and there is enough evidence to show the positive effects of weight reduction on the progression of the disease process.
In conclusion, evidence based guidelines in the conservative management of knee OA exist. Orthopaedic Surgeons should have knowledge of the various approaches and be aware of the fact that certain clinical propositions are supported by substantial research based evidence, while others are not.
The abstracts were prepared by Mrs Anna Ligocka. Correspondence should be addressed to IX ICL of EFORT Organizing Committee, Department of Orthopaedics, ul. Kopernika 19, 31–501 Krakow, Poland
