Osteoarthritis/Degenerative Joint Disease

Question 1

What is an AKA for osteoarthritis?

Answer 1

Degenerative joint disease; ‘wear and tear’ arthritis

Question 2

What is a definition of osteoarthritis?

Answer 2

A chronic degenerative disorder primarily affecting the articular cartilage of synovial joints with eventual bony remodeling and overgrowth at the margins of the joint; there is also progression of synovial and capsular thickening and joint effusion.

It is marked by progressive deterioration of articular cartilage and subchondral bone in synovial joints and vertebrae.

Question 3

What are some clinical signs and symptoms of osteoarthritis?

Answer 3

Joint changes associated with osteoarthritis include changes associated with joint pain, morning stiffness, and limitations of motion. As it progresses there is joint instability and deformity.

• Impaired mobility – decreased and possibly painful joint play
• Impaired muscle performance – mechanical imbalances in flexibility and strength of supporting muscles
• Impaired balance – altered sensory input from mechanoreceptors and the muscle spindle
• Functional limitations – alteration in ability to perform ADLs. May use assistive devices.
• There is eventual cartilage degeneration, altered joint architecture and osteophyte formation (bony changes), loss of articular cartilage/subchondral bone, synovitis, and formation of osteocytes or spurs.

Question 4

Does osteoarthritis normally present symmetrically or asymmetrically?

Answer 4

Normally asymmetrically

Question 5

How is mild osteoarthritis (early-stage OA) characterized?

Answer 5

• Repeated stresses increase wear to the load-bearing portions of the articular cartilage
• Articular cartilage is avascular and aneural; there is no inflammation or pain (also has poor healing capability))
• Most over age 25 have a mild form of OA
• The stage may last for years

Question 6

How is moderate osteoarthritis (Beginning of late stage OA) characterized?

Answer 6

• More pronounced break down the articular surfaces
• As it progresses, the breakdown causes superficial collagen fibres to fray from the surface of the articular cartilage (fibrillation)

Question 7

How is severe osteoarthritis (late-stage OA) characterized?

Answer 7

• Significant damage to the articular surfaces reaching down to the subchondral bone (subchondral bone is the bony structure that supports the articular cartilage)
• Vertical clefts develop in the cartilage (fissures) – the first change visible to the naked eye
• Small fragments from fissuring can irritate the synovium and cause inflammation:‘synovitis’
• Fissures in the cartilage extend further into the subchondral bone eventually exposing the subchondral bone: ‘central erosion’
• Subchondral bone is highly innervated (high potential for pain)
• As the subchondral bone is exposed and there is bone on bone articulation, it becomes polished and ivory like in appearance: ‘eburnation’
• Joint becomes increasingly unstable; osteophytes begin to form around joint edges in an attempt to stabilize the joint
• Osteophyte formation at joint margins may also be referred to as the lipping or spurring​ (Usually takes 10 to 15 years to develop)

Question 8

What is the medical term for synthetic synovial fluid?

Answer 8

hyaluronic acid

Question 9

Primary OA is idiopathic and less common than secondary OA. What are some common causes of secondary OA?

Answer 9

• Trauma/injury/surgery
  
  • Damage to the joint’s soft tissues and/or bones
  • Compensatory use of other joints to reduce stress on tissues
  • Repetitive use and overuse injuries
  • Biomechanical problems
    
    • Altered gate
    • Leg length discrepancy
    • Scoliosis
    • Osteoarthritis in another joint
• Obesity
• Nutritional deficiencies
• Reduced mobility
  
  • Fracture immobilization
  • Disuse from pain
  • Bedridden or use of wheelchair

Question 10

What are the components of a synovial joint?

Answer 10

• Articular cartilage
• Subchondral bone
• Fibrous joint capsule
• Supporting ligaments
• Synovial membrane

Question 11

Cartilage is mostly water and:

Answer 11

• Collagen: a fibrous protein that is the building block of connective tissues
• Proteoglycans: give cartilage flexibility and the capacity to shock absorb
• Chondrocytes: cells that produce cartilage
• Hyaluronic acid: attracts the water which increases resilience to pressure

Question 12

What are the two essential mechanical roles of articular cartilage?

Answer 12

• Reduce friction
• Dissipate mechanical stress

Question 13

What are the terms denoting nodes in proximal phalanges and distal phalanges in the hand?

Answer 13

• Proximal: Bouchard’s nodes
• Distal: Heberden’s nodes