21 July 2010
Osteoarthritis (OA) is undoubtedly one of the most widespread chronic diseases worldwide and its prevalence is expected to rise appreciably in the future. Not only does it cause chronic pain, it is associated with a decreased quality of life and extreme healthcare costs (Rosemann). Osteoarthritis is known by a multitude of names including degenerative joint disease, ostoarthrosis, and degenerative/ hypertrophic arthritis.
When the cartilage in a joint begins to deteriorate, that is considered to be the beginning of the chronic condition known as osteoarthritis. Healthy cartilage allows bones to move over one another by absorbing the impact of physical movement by acting as a cushion. The thinning of cartilage causes the bones to eventually contact each other, causing pain, stiffness, and loss of mobility of the affected joint.
As the condition progresses, osteophytes or bone spurs, may grow on the lateral and medial aspects of the joint. Fragments of the osteophytes can break off and extend into the joint space, which causes significant pain and further damage.
The main risk factor for OA is age; affecting more than 80% of people 75 years and older. Although OA and age go simultaneously together, OA is not a natural consequence of aging. While rheumatoid arthritis is a systemic disease and affects lungs, eyes and skin tissue, osteoarthritis does not share this characteristic (NIAMS).
Diagnosis
Physical Exam
Classic symptoms of OA include pain in the affected joint with or after activity. Other common symptoms are stiffness, swelling, loss of motion and pain. Bony nodules of the skin frequently develop when the hands are involved. When the nodule is along the proximal phalangeal joints they are referred to as Bouchard's nodes. When located on the distal digits, they are called Heberden's nodes. The joints eventually hypertrophy and can cause ulnar deviation of the digits (similar to that seen in rheumatoid arthritis). Less commonly, marginal erosive changes are seen within the phalangeal joints making the diagnosis Erosive Osteoarthritis.
Morning stiffness of 30 minutes or less is common. When more prolonged periods of stiffness occur, an inflammatory arthropathy (rheumatoid and lupus arthritis) should be considered.
Laboratory Studies
Serum analysis laboratory studies are not indicated for patients who present with the hallmark findings in OA. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level usually are normal. A low titer rheumatoid factor (RF) is common in older patients and should be reserved only if findings suggest an inflammatory process (systemic findings, erosions, hallmark distribution). Synovial fluid may be obtained if an effusion is present; the white blood cell count usually is less than 500/mm3, and crystals should be absent, excluding infection and gout arthropathy (Lawrence). If findings are most pronounced within the feet, then HLA-B27 can be obtained to evaluate for reactive arthritis. Often times chondrocalcinosis can be seen (calcium deposits within the joint space) especially in the knee, wrist, and pubic symphysis. This can lead to the possible diagnosis of underlying calcium pyrophosphate dihydrate (CPPD) disease, however chondrocalcinosis can commonly be seen in elderly patients without underlying CPPD.
Radiologic Imagery
Radiology provides a assistance when there is question in the type of arthropathy and monitoring treatment as well as disease progression. The classic radiographic findings in patients with Osteoarthritis vary depending on the joint involved. However, the triad of findings includes:
- Joint space narrowing (first manifestation of OA due to cartilage thinning)
- Sunchondral cyst formation (synovial herniation)
- Osteophytosis
The most common locations for OA to manifest are:
- First metacarpal phalangeal (MCP) joint space
- Proximal interphalangeal joint space
- Distal interphalangeal joint space
- Medial compartment of the knee (however all compartments eventually become involved)
While radiological assessments must be made, there has shown to be markedly little correlation between the common symptoms of osteoarthritis and what can be seen upon review of radiological records. In fact, a study was done that shows - according to their radiological assessment – two thirds of women in the study should have had osteoarthritis of the hands, while only 20% of those patients exhibited the symptoms commonly related with osteoarthritis (Dahaghin).
If a patient presents with strong, unquestionable osteoarthritis symptoms, it is medically safe to assume that osteoarthritis is in fact the diagnosis without performing any radiological reviews. Cases have been seen where a patient presents with significant osteoarthritis pain, but prove to be inconclusive on a diagnosis due to radiological findings. X-ray films of the knee should include weight-bearing views because other views underestimate the extent of joint-space narrowing.
CT and MRI are not typically indicated in patients with OA unless evaluating for osteonecrosis, occult fracture, or surgical planning.
Treatment
Unfortunately, there is no cure for osteoarthritis, and as such, treatment includes methodologies meant to improve the patient’s quality of life and ability to function during day-to-day activities. As being over-weight can cause significant stress on the joints, there has been evidence to show that those who maintain a normal weight reduce their risk of knee osteoarthritis. After the onset of osteoarthritis, however, all is not lost – if a patient still loses weight, they will find at least some of their painful symptoms to be abated (Ettinger).
Increasing physical exercise and physical therapy are essential in treating patients with OA. Topical capsaicin may be considered as an adjunct to core treatment for knee or hand osteoarthritis.
Although non-steroidal anti-inflammatories (NSAIDs) are the most effective pharmacologic treatment for patients with OA, the adverse effects with NSAIDs can be detrimental in older patients. With the withdrawal of several medications from the market due to cardiovascular side-effects, the remaining selective cyclooxygenase (COX)-2 inhibitor is Celecoxib (Celexa). These medications have similar results to NSAIDs but show less risk for side effects (Phillips). Topical NSAID’s are also available.
Intra-articular corticosteroid injections should be considered as an adjunct to core treatment for the relief of moderate to severe pain in people suffering with osteoarthritis.
Joint replacement surgery may be consideration when patients have a significant decrease in their quality of life and are refractory to non-surgical treatment. Once decided that surgery is the best option, a physician should make the referral to surgery, as it is possible to have permanent limitations in functioning (NICE).
References
Osteoarthritis. Naitional Institute of Athritis and Musculoskeletal and Skin Disease July 2002
Ettinger WH, Davis MA, Neuhaus JM, Mallon KP. Long-term physical functioning in persons with knee osteoarthritis from NHANES, 1: effects of comorbid medical conditions. J Clin Epidemiol. 1994;47:809-815.
Thomas Rosemann, Gunter Laux, Joachim Szecsenyi . Osteoarthritis: quality of life, comorbidities, medication and health service utilization assessed in a large sample of primary care patients Department of General Practice and Health Services Research, University of Heidelberg, Voßstrasse 2, 69115 Heidelberg, Germany Journal of Orthopaedic Surgery and Research 2007, 2:12
CHRISTOPHER R. PHILLIPS, MD RICHARD D. BRASINGTON Jr, MD Osteoarthritis treatment update: Are NSAIDs still in the picture? The Journal of Musculoskeletal Medicine. Vol. 27 No. 2 February 1, 2010
Lawrence RC, Helmick CG, Arnett FC, et al. Estimates of the prevalence of arthritis and selected musculoskeletal disorders in the United States. Arthritis Rheum. 1998;41:778-799.
Dahaghin S, Bierma-Zeinstra SM, Ginai AZ, et al. Prevalence and pattern of radiographic hand osteoarthritis and association with pain and disability (the Rotterdam study) [published correction appears in Ann Rheum Dis. 2005;64:1248]. Ann Rheum Dis. 2005;64:682-687
National Collaborating Centre for Chronic Conditions. Osteoarthritis. The care and management of osteoarthritis in adults. London (UK): National Institute for Health and Clinical Excellence (NICE); 2008 Feb. 22 p.
