0521779407-16 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:18
Osteoarthritis 1093■Swelling usually bony (from bony spurs), knee effusions in some
■Risk factors for primary osteoarthritis
➣Age
➣Obesity (for weight-bearing joints)
➣Trauma or major joint injuries
➣Occupational factors for knees, shoulders, hips
➣Hereditary factors (eg, finger involvement in women)
■Causes of secondary osteoarthritis
➣Previous inflammatory arthritis
➣Joint dysplasias
➣Underlying bone disorders (osteonecrosis, Paget’s disease)
➣Metabolic diseases (hemochromatosis, acromegaly, bleeding
disorders)
Signs & Symptoms
■Pain on motion
■Tenderness
■Limited motion
■Crepitus (palpable grating sensation on motion)
■Prominent bony enlargement, soft tissue swelling or effusion
■In finger joints, bony enlargement of proximal interphalangeal
(Bouchard’s nodes) & distal interphalangeal (Heberden’s nodes)
tests
Lab Tests
■All blood & serum lab studies are normal
■Synovial fluid has good viscosity, clear appearance, WBC <2,000, no
crystals
Imaging
■Plain radiographs are diagnostic
■Weight-bearing films are useful for knees
■Radiographic features
➣Joint space narrowing
➣Subchondral bony sclerosis
➣Osteophytes (spurs)
➣Subchondral bone cysts
➣Bone density is normal or increased
differential diagnosis
■Rheumatoid arthritis: more soft tissue swelling, morning stiff-
ness, systemic symptoms, different joint distribution (wrists, MCPs,