Common pathologies of LL - OA

Question 1

What are risk factors for Hip OA?

Answer 1

Age
Female
Obesity
Joint morphology changes

Question 2

What are 5 pathophysiological changes seen in Hip OA?

Answer 2

Loss of joint space
Osteophyte formation
Subchondral Sclerosis
Subchondral Cyst
Bone deformity

Question 3

What are the four zones of articular cartilage?

Answer 3

I - superficial - few cells/ collagen fibres
II - intermediate zone - collagen fibres
III - deep zone - vertical collagen fibres
IV - calcified cartilage

Question 4

Describe normal cartilage homeostasis in a joint

Answer 4

Matrix Metalloproteinases degrade TII Collagen and aggregate, activity increased by IL1 and TNF
TIMP - inhibits degradation by MMPs

Question 5

What happens to articular cartilage in OA?

Answer 5

Increased in water
Progressive breakdown of collagen network
IL1 stimulates chondrocytes to produce plasminogen
Plasmin increase activates MMP causing collagen degradation

Question 6

Give the stages of the Kellgren-Lawrence OA classification

Answer 6

0 - normal
I - doubtful narrowing of joint space, possible osteophyte development
II - definite osteophytes, absent/ questionable narrowing of joint space
III - moderate osteophytes, definite narrowing, some sclerosis, possible joint deformity
IV - large osteophytes, marked narrowing, severe sclerosis, joint deformity

Question 7

What are the clinical symptoms of knee OA

Answer 7

Pain on most days of the month
Inactivity, stiffness
Crepitus
Bony tenderness
No palpable warmth 
Bony enlargement with osteophytes forming on joint margins