Snapshot A 60-year-old woman presents to her primary care physician with pain in her hands and knees. She reports to having this pain intermittently for at least 8 months and describes it being worse in the evening. On physical exam, there is bone deformity noted on the distal and proximal interphalangeal joints, swelling of the right knee, and tenderness upon palpation of the affected joints. Introduction Clinical definition a degenerative disorder affecting the articular cartilage Epidemiology Incidence most common articular disease Demographics more common in women and the elderly Risk factors modifiable obesity trauma repetitive use (e.g., heavy labor) non-modifiable age female gender family history Etiology Pathogenesis not completely understood but is more complex than "wear and tear" of the joint, and inflammation appears to be involved chondrocytes attempt to proliferate and synthesize proteoglycans when it is injured however, degradation exceeds synthesis, thus compromising the extracellular matrix inflammatory processes appear to promote proteolytic articular degeneration mediated by chondrocytes e.g., transforming growth factor-β (TGF-β) induces chondrocytes to secrete matrix metalloproteinase (MMPs) to degrade type II collagen eventually portions of the articular cartilage and subchondral bone is sloughed off into the joint space (synovial space) forming loose bodies (joint mice) subchondral bone becomes exposed and rubs on the adjacent bone, resulting in bone eburnation (polished ivory) osteophytes (bony outgrowths) develop due to bone remodeling can be appreciated in the distal interphalangeal joint as Herberden nodes proximal interphalangeal joint as Bouchard nodes late stage osteoarthritis is characterized by loss of chondrocytes and degraded extracellular matrix Biology and Anatomy Articular cartilage greatly decreases friction with movement and resists tension and compressive forces composed of type II collagen and proteoglycans which are synthesized and secreted by chondrocytes chondrocytes maintain cartilage with its anabolic and catabolic activities Presentation Symptoms pain worsens with use and improves with rest commonly involves the hands, hips, and knees Physical exam joint tenderness decreased range of motion bony swelling swelling of the distal interphalangeal (Herberden nodes) swelling of the proximal interphalangeal (Bouchard nodes) Imaging Radiography indication may be used to confirm the diagnosis and determine disease progression and severity findings joint space narrowing osteophytes joint mice subchondral sclerosis Studies Labs c-reative protein (CRP) and erythrocyte sedimentation rate (ESR) levels are normal Diagnostic criteria typically a clinical diagnosis Differential Rheumatoid arthritis Arthralgia Bursitis Tendonitis Treatment Conservative exercise and weight loss indication first-line in the management of osteoarthritis Medical topical or oral nonsteroidal antiinflammatory drugs (NSAIDs) indication for the symptomatic management of osteoarthritis in patients who do not adequately respond to conservative treatment adverse effects gastrointestinal side-effects such as ulcer formation Operative orthopedic surgery indication in patients with advanced pain who are unresponsive to conservative and pharmacologic therapy Complications Pain Bone deformity Functional impairment Prognosis Favorable with joint replacement