OA, also known as degenerative joint disease, is the most common joint disease and is considered to be the leading cause of disability in older adults. OA is characterized pathologically by progressive deterioration and ultimate loss of articular cartilage and simultaneous proliferation of new bone, cartilage and connective tissue. The proliferative response results in some degree of remodeling of joint contour.
Radiological and autopsy surveys show a steady rise in degenerative changes in joints from the age of 30, By the age of 65, 80% of people have some radiographic evidence of osteoarthritis although only 20% may have symptoms. Males and females are equally affected.
OA is classified as primary if the cause is unknown and secondary when degenerative joint changes occur in response to recognizable local or systemic factors.
Clinical manifestations of osteoarthritis include;
- Development of joint pain – early in the disease, pain results from joint use and is relieved by rest. With progression of disease, pain at rest may become common, as well as pain brought by minimal movement.
- Stiffness in joints.
- Associated limitation of movement.
- Enlargement may result from increased synovial fluid or bony proliferation.
- Commonly involved joints include DIP and PIP joints, base of thumb, hip, knee, and spine. Shoulder and elbow are involved rarely.
- The blood count and ESR are characteristically normal.
- Synovial fluid is viscous and has a low cell count. Apatite crystals can rarely be detected.
- Radiographs show loss of joint space and formation of marginal osteophytes.
- Subchondral bone sclerosis, bone remodeling and cyst formation are seen in advanced cases.
Treatment is directed towards relieving symptoms, maintaining and improving joint function and minimizing handicap. Management of OA is based on non-drug and drug treatments targeted towards prevention, modifying risk and disease progression.
- Analgesics like paracetamol (up to 4g/day) for mild to moderate pain. NSAIDS should be added or substituted in patients who respond inadequately.
- Intra-articular steroids- in patients who present with acute exacerbations of pain and signs of local inflammation with joint effusion
- Intra-articular hyaluronan- it is suggested that its effect is small and the placebo response is significant.
- Education – Encourage patients to participate in self- management programs, and provide resources for social support and instruction on coping skills.
- Weight loss – encourage overweight patients with OA of hip and knee to lose weight through a combination of diet and exercise.
- Exercise – increases aerobic capacity, muscle strength, and endurance and also facilitates weight loss.
Physical therapy - some basic approaches are enumerated as follows;
Pain control –
- Suitable electrotherapy modality is used. In acute phase pain relief is achieved by superficial heat modalities or cryotherapy. Ultrasound, TENS, pulsed diathermy and stimulation are also effective.
- Hydrotherapy is particularly useful when the weight bearing joints are affected.
- The compressive forces on the joint can be reduced by rest in proper position, splints or joint distraction by manual or mechanical traction.
- Improvement of muscle power, endurance and tone – graduated exercise program is initiated which consists of progressive resistance (PRE), strong and sustained repeated sessions of isometrics (5 minutes every hour) holding or sustaining muscle contraction in static mid- range position.
Improvement in range of motion (ROM);
- Active free relaxed rhythmic movements improve the range as well as promote relaxation of the joint.
- Relaxed passive movements to be started first to mobilize stiff joints.
Improvement of functional independence – function of whole body in relation to degenerated joint can be improved by;
- Proper guidance to relieve compression over the affected joints and
- Providing assistive aids, modified supports, orthoses, adaptations and ergonomic advice, on the performance of ALDS.
- Surgery: The typical indications of surgery are debilitating pain and major limitation of functions such as walking and daily activity or impaired ability to work or sleep.
Handbook of physical medicine and rehabilitation, ed 2nd page 61
Davidsons principles and practice of medicine, ed. 17th, page 887