Joint Disorders

Arthritis is a group of inflammatory diseases of joints with severe causes:

  • Degenerative joint disease from wear and tear over time, i.e. osteoarthritis
  • Autoimmune joint disease where the body makes antibodies against synovial cells in the joint, i.e. rheumatoid arthritis
  • Metabolic, where protein synthesis is inadequate and crystals form, i.e. gouty arthritis
  • Infection within the joint cavity, i.e. septic arthritis

Osteoarthritis

Degenerative joint disease where cartilage is degenerated.

Site: localised or generalised (more than 3 joints), affects weight bearing joints, knee, hip, spine and joints of hands and feet

Age: over 50

Cause: primary or secondary, due to trauma, defects of joint structures or inflammatory diseases

Characteristics: progressive loss of articular cartilage

Risks: age, obesity, occupation (e.g. heavy lifting), crystal deposition and inflammation

Symptoms: joint pain increased by night, cold and damp weather and relieved by heat and rest, stiffness, limitation of movement, crepitus (sounds from bones in unstable joint), joint instability and deformation

Pathogenesis: mechanical injury stimulates a chondrocyte response to release cytokines, causing the production and release of protease enzymes which destroy joint structures. When destroying the smooth cartilage surfaces, surface cracks also form causing destruction of the subchondral bone and forming osteophytes (small protrusions of bone).

Diagnosis: X-ray shows 'more bone'

How is pain relieved? Rest

Rheumatoid Arthritis

Autoimmune form of arthritis that is a chronic systemic inflammatory disease with bilateral involvement of synovial (diarthrodial) joints.

Cause: immune-mediated, genetic predisposition from Human Leukocyte Antigen (HLA)

Age: 40-60 years

Gender: women

Pathogenesis: HLA stimulates T cell mediated response, which release cytokines which then destroy articular cartilage and underlying bone. The T cells also by a series of steps using complement proteins recruit inflammatory cells to release enzymes and prostaglandins to destroy articular cartilage and underlying bone. Panes invasion also occurs, where the synovial membrane overgrows into the space of the synovial cavity.

Symptoms: symmetrical (in both hands or knees), polyarticular (more than one joint), joint pain, morning stiffness, limitation in motion due to pain and subsequent fibrosis, ulnar deviation or 'swan neck' deformity (fingers all move towards little finger), low-grade fever, fatigue, pleural effusion, pulmonary fibrosis, pericarditis, nephropathy, increased erythrocyte sedimentation rate → anaemia

Site: fingers, hands, wrists, knees and feet

Diagnosis: serum rheumatoid factor (not specific), anti-cyclic citrullinated peptide (highly specific), X-ray shows 'less bone'



How is pain relieved? Movement

Gouty Arthritis

Recurrent attacks of severe articular and periarticular inflammation that may be associated with tophi (uric acid crystalline deposits). Tophi results from kidney damage/disorders or metabolic disorders.

Gout is either primary or secondary, but is more commonly primary.

Cause of primary: increased uric acid in blood due to unknown cause of congenital enzyme defects

Cause of secondary: chronic renal disease caused by thiazide diuretics use (reduce urate excretion by increasing urate reabsorption and decreasing urate secretion)

Age: 40-60 years

Gender: men

Site: first metatarsophalangeal joint

Symptoms: pain and swelling at first metatarsophalangeal joint, abrupt onset of pain, redness and swelling (at night).

Risk: excessive exercise, medications and certain foods (liver, kidneys, sweetbreads and sardines)

Diagnosis: presence of monosodium rate crystals in synovial fluid

Septic Arthritis

An infection (usually monoarticular) in the joint commonly caused by the following factors:
  • Staphylococcus aureus
  • Neisseria gonorrhoea (common in young sexually active adults)
  • Streptococci (common in those with inadequate immune function)
  • Pseudomonas aeruginosa (comon in injecting drug users)
Site: sternoclavicular, sacroiliac joints, shoulder, ankle, wrist, knee

Age: children and young adults, older adults when prosthetic surgery undergone

Cause: rheumatoid arthritis

Characteristic: pannus formation (overgrowth of synovial membrane), cartilage erosion in lateral aspects of joint

Result: hematogenous spread, abrupt onset of severe pain and swelling, red and warm skin over affected joint, fever

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