Musculoskeletal

Question 1

Osteoarthritis

Answer 1

• Chronic disease due to articular cartilage damage and degeneration
• Risk factor- Obesity
• MC in weight bearing joints (knees, hips, cervical/lumbar spine, hip). OA of hands MC in women.
• Narrowed joint space (loss of articular cartilage), sclerosis & osteophyte formation
• Chondrocyte inability to repair damaged cartilage
• Clinical manifestations
  
  • Evening joint stiffness, decreases with rest, worsens throughout the day and with changes in weather, decreased ROM, crepitus
  • Absence of inflammatory signs “hard bony joint”
  • Heberden’s node (palpable osteophytes at DIP joints).
  • Bouchard’s node: PIP osteophytes, NON inflammatory arthritis.
• Diagnosis
  
  • X-ray findings
    
    • Joint space loss, osteophytes, subchondral bone cysts/sclerosis
• Management
  
  • NSAID’s most effective
  • Acetaminophen preferred initial OA tx in elderly with bleed risk
  • Corticosteroid injections, sodium hyaluronate, glucosamine
  • Chondroitin knee replacement
  • Avoid high-impact exercises

Question 2

Gouty Arthritis

Answer 2

• Prevalence
  
  • Mostly adult men and postmenopausal women. Middle-aged.
• Joints affected
  
  • First MTP joint MC (Podagra). 50% initially; 90% eventually.
  • 80% monoarticular typically lower extremities (ankle, knees, foot)
• Diagnosis
  
  • X-ray findings
    
    • Mouse bite (punched out) erosions
  • Chemistry – Monosodium urate
  • Synovial fluid – negatively birefringent: needle-shaped
• Management
  
  • Acute attacks
    
    • NSAID’s 1^st line
    • Colchicine, Corticosteroids
  • Chronic management
    
    • Urate lowering agents (Allopurinol, Febuxostat, Probenecid)
    • Colchicine

Question 3

Pseudogout

Answer 3

• Prevalence
  
  • Female predominance
• Joints affected
  
  • Knees, wrists, MCP joints, elbows, MTP joints
• Diagnosis
  
  • X-ray findings
    
    • Chondrocalcinosis (calcification of the cartilage)
  • Chemistry – Calcium pyrophosphate dehydrate
  • Synovial fluid – Weakly positive; rhomboid shaped
• Management
  
  • Acute attacks
    
    • Steroids 1^st line (intraarticular)
    • NSAID’s, Colchicine
  • Chronic management
    
    • NSAID’s
    • +/- Colchicine

Question 4

Rheumatoid Arthritis

Answer 4

• Chronic inflommatory dz wtih persistent symmetric polyarthritis with bone erosion, cartilage destruction and joint structure loss (due to destruction by pannus)
• Pannus: granulation tissue that erodes into cartilage and bone.
• T-cell mediated
• Risk factor – Females, smoking
• Clinical manifestations
  
  • Prodrome- constitutional systemic sx: fevers, fatigue, weight loss, anorexia. Decreased ROM.
  • Small joint stiffness: (MCP, wrist, PIP, knee, MTP, shoulder, ankle) worse with rest
  • Morning joint stiffness >60 mins after initiating movement improves later in day
  • Symmetic arthritis; swollen, tender, erythematous, “boggy” joint.
    
    • Boutonniere deformity- flexion at PIP, hyperextension of DIP
    • Swan neck deformity- flexion at DIP, hyperextension of PIP
    • Ulnar deviation at MCP joint. Rheumatoid nodules.
  • Felty’s Syndrome: rare d/o triad of RA + splenomegaly + decreased WBC/repeated infections
  • Caplan syndrome: pneumoconfosis + RA