Osteoarthritis

Question 1

Osteoarthritis?

Answer 1

Inflammatory problem within the joints

Question 2

Which joints does osteoarthritis occur in? Give some examples

Answer 2

Weight bearing joints; shoulders, hips, knees

Question 3

Is osteoarthritis due to wear and tear?

Answer 3

No, it is pathologic -> it is progressive and gradual so ageing is a risk factor, but it is not a direct cause

Question 4

Briefly explain what occurs in osteoarthritis

Answer 4

articulating cartilage is lost and the underlying bone is exposed -> bone to bone contact resulting in pain and slow degeneration of joints.

• loss of cartilage and subchondral bone
• cartilage cannot be replaced

Question 5

Etiology of osteoarthritis?

Answer 5

Primary- idiopathic

• genetic predisposition
• age
• gender
• race
• secondary in young people (eg. athlete -> tennis player continuously uses shoulder joint)
• repetitive motion or injury can breakdown joint and cause osteoarthritis
• obesity

Question 6

Name the lesion that forms in osteoarthritis.

Answer 6

Osteophytes

Question 7

Chondrocytes?

Answer 7

produce and maintain cartilage (through chondroblasts and chrondoclasts)

Question 8

Articular cartilage?

Answer 8

• very smooth
• strong weight-bearing -> receives force and dissipates it to the underlying bone (bone absorbs the force)
• bone can withstand force if it is applied in the direction that is expected

Question 9

Patho of osteoarthritis?

Answer 9

altered genes -> affect cytokines -> impact chondrocyte function -> composition and properties of cartilage change [proteases released in an uncontrolled fashion resulting in cartilaginous destruction. chondrocyte damage -> impaired ability to maintain and heal cartilage] The outer articular cartilage will crack and synovial fluid will move into the cracks causing inflammation because it does not belong in this cavity. cartilage erodes -> exposes the bone -> as a compensatory measure the bone hardens [eburnation/sclerosis of bone]. With more bone-bone friction, more fissures develop resulting in fluid getting into the bone and forming cysts. Osteophytes form.

Question 10

Osteophytes?

Answer 10

bony outgrowths into the joint

Question 11

eburnation?

Answer 11

bone hardening

Question 12

manifestations of osteoarthritis?

Answer 12

• early -> generalized aching pain
• later -> as pain advances it becomes localized at affected joint and brought on by activity
• decreased mobility at joint d/t inflammation within joints
• instability

Question 13

dx of osteoarthritis?

Answer 13

• hx & px, clinical presentation
• xray (oued later)
• exclusion labs
• look @ what joint is affected

Question 14

FIrst line therapy?

Answer 14

Tylenol

Question 15

Treatment?

Answer 15

• initially, use mono therapy PRN
• Tylenol is first line therapy
• then COX-2 inhibitors
• steroids [intra-articular injections]
• PT + OT
• Joint replacement (surgery of hips, knees etc)

Question 16

COX-2 inhibitors?

Answer 16

Cyclooxygenase-2 inhibitors. Enzyme involved in the synthesis of prostaglandins that mediates pain, so blocking this enzyme prevents pain