ARTICULACIONES

Isabel Pinedo Torres

UNIVERSIDAD NACIONAL MAYOR DE SAN MARCOSFacultad de Medicina Humana

Patología EspecialReumatología

ARTROSIS (OSTEOARTRITIS)A

Osteoarthrosis is a common degenerative joint disease characterized by primary abnormalities in the articular cartilage. When assessed radiologically, changes of osteoarthrosis are present in over 40% of individuals over the age of 50 years of age. Although only a few of these patients are symptomatic, osteoarthrosis is the most common cause of joint disability.

  Osteoarthrosis Rheumatoid Arthritis

Basic process Degenerative Immunologic, inflammatory

Site of initial lesion Articular cartilage Synovium

Age 50 plus Any, but peaks at age 20–40 years

Sex Male or female Female > male

Joints involved Especially knees, hips, spine; asymmetric involvement

Hands, later large joints; multiple symmetric involvement

Fingers Herberden's nodes Ulnar deviation, spindle swelling

Nodules No Rheumatoid nodules

Systemic features None Uveitis, pericarditis, etc.

Constitutional symptoms None Fever, malaise in some

Laboratory findings None Rheumatoid factor; erythrocyte sedimentation rate; anemia, leukocytosis, hyperglobulinemia

Joint fluid Clear, normally viscous; no inflammatory cells

Clear; low viscosity, high protein; neutrophils, some lymphocytes; immunoglobulins, complement, rheumatoid factor

Etiologìa

Osteoarthrosis is caused by degeneration of articular cartilage of joints . The exact cause of articular cartilage degeneration is not known. Abnormalities in the ground substance, collagen, increased activity of matrix-degrading enzymes such as collagenase and proteoglycanases, and changes in water content have all been demonstrated in the articular cartilage in patients with osteoarthrosis, but their role in pathogenesis is unknown. The role of trauma and weight-bearing stresses is controversial. Osteoarthrosis occurs mainly in the weight-bearing joints, and it has been suggested that the disease may be the result of failure of repair of repeated minor trauma. A few cases of osteoarthrosis occur secondary to articular cartilage diseases (eg, alkaptonuria) and severe trauma (eg, in football players).

Patología

• Fases iniciales:– Proliferación de condrocitos– Aumento del contenido de agua de la matriz y la disminución

de la concentración de proteoglucanos.– Microscopia: superficie articular granular mas blanda de lo

normal.• Fases avanzadas:– Las partes de todo el espesor de cartílago se desprenden, y la

placa ósea subcondral expuesta será la nueva superficie articular.

– Existe un refuerzo y esclerosis del hueso esponjoso subyacente.