Pathophysiology of Osteoarthritis Exam 1

Question 1

What is the most common form of arthritis?

Answer 1

OA

Question 2

What are the most common cause of long-term, lower extremity limitations?

Answer 2

• hip OA

- knee OA

Question 3

T/F; OA is among the 5 leading causes of physical disability in non-institutionalized elderly

Answer 3

T

Question 4

What are risk factors for developing OA?

Answer 4

• older age
• sex; under 45 -> male more prevalent; above 55, women more prevalent
• genetics
• obesity
• occupation
• sports
• any existing factors that can increase susceptibility of OA

Question 5

How is genetics a risk factor for developing OA?

Answer 5

Heberden’s nodes (OA of DIP joints) are more frequent in mothers and sisters of affected women

Question 6

What happens when you get older that contributes to a risk factor for OA?

Answer 6

• Reduced repair of cartilage
• Ligament laxity (less stable, susceptible to injury)
• Muscle weakness (less shock absorption, protection)
• INT-6, Neurologic slowing (reduced protection)
• Reduced non-calcified cartilage (increased shear stress)

Question 7

What is the normal physiology of the articular cartilage (cartilage of the joint)?

Answer 7

Thin, avascular (without blood vessels) and aneural (without nerves) covering of bone (subchondral plate) in joints

Question 8

What is cartilage composed of?

Answer 8

• water
• type II collagen
• proteoglycans

Question 9

What is the role of collagen?

Answer 9

provides structure, strength, and shape

Question 10

What are proteoglycans composed of?

Answer 10

protein cores with attached glycosaminoglycans (GAGs)

Question 11

What is the role of the GAGs?

Answer 11

draw in water which provides cartilage with resiliency, elasticity, and lubrication

Question 12

What are chondrocytes?

Answer 12

cells that control the synthesis and degradation of cartilage

Question 13

Alterations that occur in OA

Answer 13

• loss of extracell. matrix
• loss of chondrocytes
• decrease proteoglycan; aggregation -> cartilage softening, etc
• synovial membranes can become inflamed
• cartilage fails to repair itself
• cartilage degeneration
• new bone growth at joint margins - osteophytes
• sclerosis of subchondral bone
• microfractures and formation of bone cysts

Question 14

secondary causes of OA

Answer 14

• Trauma
• Abnormalities of the joint
• Genetic abnormalities of the cartilage
• Metabolic or endocrine abnormalities
• Crystal deposition
• Inflammatory conditions of joints
• Avascular necrosis
• Neuropathic

Question 15

symptoms of OA

Answer 15

• Pain
• Stiffness
• Impairment of motion
• Very gradual progression
• Functional impairment
• Numbness, tingling, pain, weakness
• Other neurological symptoms which results from nerve compression

Question 16

physical manifestations of OA

Answer 16

• Joint enlargement and other deformities
• Crepitus
• May have tenderness or get effusions (fluid)
• Usually no clinical signs of inflammation
• Decreased range of motion
• Instability
• Xray changes