Osteoarthritis

Question 1

Describe the pathogenesis of secondary osteoarthritis

Answer 1

1. Muscle weakness, ligament injury and/or abnormal anatomy
2. Causes instability/malalignment
3. Instability/malalignment (plus obesity) increases load on joint
4. This causes joint microtrauma
5. Accumulation of microtraumas - cycle of damage, inflammation (synovitis) and repair - leads to OA

Question 2

What history will an OA patient typically give?

Answer 2

Activity-related joint pain PLUS “start-up” pain/stiffness
- if there is morning stiffness it lasts no longer than 30 minutes
Gradual onset of pain
Patient is usually over 45 years of age unless there is some underlying anatomical abnormality

Question 3

Describe the features of OA on x-ray

Answer 3

Joint space narrowing
Sclerosis (at joint margins)
Osteophytosis (bone spurs)

Question 4

Describe non-pharmacological management options for OA

Answer 4

Physiotherapy; strengthen muscles to improve stability
Heat/cold packs
OT aids and devices
Weight loss (refer to dietician)
Electrotherapy; uses gate theory to distract from pain
Manual therapy

Question 5

Describe pharmacological management options for OA

Answer 5

NSAIDs (short term use only, i.e. for flare ups)
Steroid injections
Topical treatments; NSAIDs or Capsaicin

Question 6

Describe surgical management options for OA

Answer 6

NOT arthroscopy
Joint replacement surgery
- last resort
- decision is based on effect of OA on QoL
- typical hip/knee replacement lasts 10 years

Question 7

What are the main clinical features of hip OA?

Answer 7

Hip/thigh pain
Reduced range of movement
Abnormal gait

Question 8

Describe the pain associated with hip OA

Answer 8

Worse on weight-bearing and movement
Can also occur at rest, may disturb sleep
May be referred to the knee

Question 9

How does hip OA impact range of movement?

Answer 9

Hip becomes stuck in flexion, adduction and external rotation

• Fixed flexion deformity
• Adduction causes apparent shortening of that leg

Question 10

What is the purpose of Thomas’ test?

Answer 10

To detect a fixed flexion deformity

Question 11

How can hip OA cause back pain?

Answer 11

Fixed flexion deformity results in hyperextension of the lower back to compensate, causing lower back pain

Question 12

Describe the radiological changes associated with hip OA

Answer 12

Narrowing of the joint space
Cyst formation in femoral head and/or acetabulum
Sclerosis of subchondral bone
Osteophyte formation
Subcortical thickening on the medial side of the femoral neck
Disturbance of Shenton’s line - indicates collapse of the femoral head

Question 13

Describe the conservative management options for hip OA

Answer 13

Anti-inflammatory drugs
Weight loss
Walking aids, aids at home e.g. to pick objects up off the floor or help with dressing
Orthotics to raise the shoe of the shortened leg

Question 14

What is a total hip replacement?

Answer 14

Replacement of both articular surfaces of the hip (i.e. the femoral head and the acetabulum)