Defination of osteoarthritis
|Osteoarthritis of Knee|
• OA is that the commonest sort of arthritis and therefore the commonest joint disease.
• Characterized by degeneration of articular cartilage.
• Leads to fibrillation, fissures, gross ulceration and finally disapperance of the full thickness of articular cartilage.
Commonly Affected Joints
• Cervical spine
• Lumbar spine
• MTP joints
Uncommonly Affected Joints
• Metacarpophalangeal joint
Joint protective mechanisms
• Joint Capsule
• Sensory afferents
• Underlying bone
OA is primarily disease of cartilage. II – 1 is a potent pro – inflammatory cytokine, which capable of inducing chondrocytes and synovial cells to synthesis MMPs. MMPs is responsible of degradation of articular cartilage.
In addition, IL-1 inhibits synthesis of collagen II, proteoglycans and growth factor B stimulated chondrocyte proliferation.
In a normal joint, health cartilage, lubricated by synovial fluid, cushions the bones and allows them to move easily.
Osteoarthritis causes the cartilage to start breaking down, first making it thinner then creating cracks in its surface. Gaps within the cartilage can expand until they reach the bone itself.
Synovial fluid leaks into cracks which can form in the bone’s surface when this replacement cartilage wears away. This causes further damage and in some cases can lead to cysts in the bone or other deformities.
If not treated, damage can reach the purpose where the bones within the joint become seriously and permanently deformed.
• Age is that the most potent risk factor for OA
• OA is rare in under age 40
• OA occurs in additional than 50% of persons over age 70
In general, Osteoarthritis (OA)mainly occurs in female than in men. Before age 45, OA occurs more frequently in men after age 45, OA is more common is more common in women. OA of the hand is particularly commmon among women.
Heriditary gene defect
A defect in one of the genes responsible for the cartilage component collegen can cause deterioration of cartilage.
People with joints that moves ot fit together incorrectly, like bow legs, a dislocated hip, or double jointedness, are more likely to develop OA within the those joints.
Overweight during later years or the midlife is among the strongest risk factors for OA of the knee.
Joint overuse or injury
Traumatic injury ( ex.ligament or meniscal tears) to the knee or hip increase your risk for developing OA in these joints. Joints that are used repeatedly in certain jobs could also be more likely to develop OA due to injury or overuse.
Sources of pain
• ↑ hemostatic pressure within bone
• Bone marrow edema
• Synovial inflammation
• Joints effusions
Symptoms and Signs
• Pain increase with activity and worse at night
• Morning stiffness less than 30 mins
• Loss of function
• Neurological signs if spine involved
• Muscle wasting
Diagnosis- Blood tests
Blood test are not indicated for workup of patients with OA unless symptoms & signs suggest inflammatory arthritis.
Diagnosis- Synovial fluid
• Examination of the synovial fluid is more helpful diagnostically than x-ray.
• Synovial fluid in OA
- Clear color
- High Viscosity
- Patient with mild and intermittent symptoms may need only non pharmacotherapy.
- Patients with ongoing ,disabling pain are likely to need both non pharmacotherapy and pharmacotherapy.
- Reduce load on the joint -Avoid unnecessary stress
-Increase muscles strength
- Correction of malalignment