Joint Disorders: Types, Causes, Symptoms, and Treatments

Abnormal Joint Conditions

Joints (articulations) permit movement and provide stability. Pathology affects synovium, cartilage, bone, capsule, ligaments, or tendons.

Common Disorders

Condition	Pathology
Osteoarthritis (OA)	Degenerative cartilage loss, osteophytes, subchondral sclerosis
Rheumatoid Arthritis (RA)	Autoimmune synovitis, pannus formation, erosions
Gout / CPPD	Crystal deposition (urate / calcium pyrophosphate)
Bursitis	Bursal inflammation (prepatellar, olecranon, trochanteric)
Tendinitis / Tendinosis	Tendon inflammation / degeneration
Ligament Sprain / Tear	Traumatic stretching/rupture (ACL, MCL, ATFL)
Dislocation / Subluxation	Loss of articular congruity
Septic Arthritis	Joint space infection (emergency)
Osteochondritis Dissecans	Subchondral bone necrosis, fragment separation

Etiologic Categories

• Mechanical/Traumatic (injury, overuse, malalignment)
• Inflammatory/Autoimmune (RA, SLE, spondyloarthropathies)
• Metabolic/Crystal (gout, CPPD, hemochromatosis)
• Infectious (septic, Lyme, viral)
• Neoplastic (pigmented villonodular synovitis, sarcoma)
• Developmental/Congenital (dysplasia, Legg-Calvé-Perthes)

Red-Flag Symptoms

• Acute hot, swollen joint (septic arthritis, gout)
• Inability to bear weight
• Deformity
• Systemic signs (fever, weight loss, rash)
• Neurologic deficits

Management Principles

• Accurate diagnosis (history, exam, imaging, labs, aspiration)
• Conservative: Activity modification, PT, NSAIDs, bracing, injections
• Surgical: Arthroscopy, realignment, arthroplasty, fusion, ligament reconstruction
• Disease-specific: DMARDs/biologics for inflammatory; urate-lowering for gout