Osteoarthritis (OA) is a chronic and progressive disease of the joints, which occurs in patients middle aged and old. Synonymous terms used are degenerative arthritis, arthrosis and arthritis deformans.

The damage mainly in the articular cartilage (the surface layer of the joint which is made by the piece and sliding between the two bones), however, involved and the other a hinge elements, namely the synovium, subchondral bone (i.e. the bone just below the cartilage) and surrounding soft tissues. The main features of the (CA) is the destruction and degeneration of cartilage, inflammatory thickening of the film, the hardening of subchondral bone, development of osteophytes, the disorder of the stack and the anatomical relationship of the articular surfaces, pain and restriction reaches until the abolition of joint movements.

The (OA) is classified into primary, secondary and unexplained, where known specific cause, such as injury, inflammation, endocrine or metabolic. Mainly joints subject to chronic stress, such as the knee and the hip rather than the shoulder joints of the fingers of the hand. The (OA) today with the increase in life expectancy is one of the intractable problems of pathology of the skeleton, which employs a large number of our fellow human beings. The multitude of known and unknown causes that cause it, and the complexity and interaction of pathogenetic mechanisms makes it particularly difficult to deal with, which is still mainly symptomatic despite recital. The main predisposing factors for (OA) is the age (> 50 years), female gender, genetic predisposition, race (occurs rarely in African-Americans compared to whites and Hispanics), obesity, trauma, occupational stress and muscle weakness. Pathophysiology initial defect is the articular cartilage, of which the water content is increased while that of proteoglycans decreases. This defect of cartilage leads to corrosion and a subsequent disruption of subchondral bone, synovium and synovial advanced. Reactive new bone formation in the hinge region (osteophytes) without structural equivalence is typical.

The onset is slow and involves slight pain after fatigue decreases with rest. Gradually the pain becomes more intense, it occurs at rest and night. Apart from the pain gradually installed stiffness (after periods of inactivity), swelling of soft tissue, continuous and progressive joint deformity, muscle atrophy, localized tenderness, crackle, instability and loss of functionality. Main causes of pain is the synovial fibrosis, muscular fatigue and increased bone pressure.

Figurative joint radiographs are sufficient (anteroposterior and lateral receiving) particularly in charge when it concerns the lower extremities. Moreover downloads help in locating. Main characteristics of the radiographic joint space narrowing, osteophyte presence, the hardening of subchondral bone, and the presence of subchondral cysts. For the treatment of (DL), depends on the stage of disease. In the initial stages where there is intermittent pain without significant limitation of motion chosen conservative management, which includes:

1. Common painkillers (eg paracetamol)
2. Weight loss and modification of daily activity
3. Non-steroidal anti-inflammatory (with caution)
4. Strong painkillers (opioids)
5. Exercise and Physical Therapy Program
6. Use of splints / guardians discharge
7. intra-articular corticosteroid injection
8. intra-articular injection of viscoelastic eg hyaluronic

When (OA) has progressed, the destruction of cartilage is great and the symptoms are severe and continuous, to influence everyday life of the patient, recommended surgery. This can be:
1. arthroscopic cleaning (when meniscal damage to non-advanced age)
2. High tibial osteotomy (in young patients with unicompartmental knee OA, where only suffer a joint Chamber)
3. unicompartmental knee arthroplasty (in unicompartmental OA)
4. Total joint replacement (in advanced OA and concerns knee, hip, shoulder, elbow, wrist and ankle). Replace that entire articulation of metallic implants specific alloys and polyethylene.