Hip OA

Question 1

Which movements are usually lost first in Hip OA?

Answer 1

Extension

Rotation

Question 2

What are the two types of gaits that might be seen in hip OA?

Answer 2

Antalgic gait

Trendelenburg gait - fixed flexion deformity in end-stage disease

Question 3

What are the finding on an x-ray of RA?

Answer 3

Loss of joint space
Erosions - marginal
Softening of bone (osteopenia)
Swelling of soft tissue

May show acetabular protrusion in Hip RA

Question 4

What are the management options for hip OA?

Answer 4

Conservative: adequate pain relief, lifestyle modifications - smoking cessation + weight loss + increase exercise, physio, steroid injections in early stages where joint space still present

Surgical: total hip replacement, hemiarthoplasty

Question 5

What are the common complications of total hip replacement?

Answer 5

Dislocation 
Thromboembolic disease 
Aseptic loosening 
Leg length discrepancies 
Damage to surrounding structures 
Iatrogenic fracture 
Prosthetic joint infections

Question 6

How long do joint replacement in the hip last?

Answer 6

15-20 years

Question 7

What are the secondary causes of hip OA?

Answer 7

Trauma
Infection
DDH
Perthes disease

Question 8

What chemical prophylaxis are used for VTE?

Answer 8

LMWH - dalteparin/enoxaparin

Question 9

What mechanical prophylaxis is used for VTE?

Answer 9

TED stockings

Intermittent pneumatic compression (IPC) - FLOWTRON

Question 10

What does NICE say about VTE prophylaxis after an elective total hip replacement?

Answer 10

10 days of LMWH followed b 28 days of aspirin (75mg/150mg)

Question 11

What does NICE say about VTE prophylaxis after an trauma total hip replacement

Answer 11

35 days of LMWH

Question 12

Why is LMWH heparin stopped at least 12 hrs before surgery?

Answer 12

Due to spinal block been given for surgery therefore need to reduce the risk of spinal haematoma

Question 13

What are the risk factors for HIP OA?

Answer 13

Increasing age 
Obesity 
Female gender 
Vitamin D deficiency 
Genetic factors 
History of trauma 
Anatomical abnormalities 
Muscle weakness/ joint laxity 
Participation in high impact sport

Question 14

What are the differential diagnosis for hip OA?

Answer 14

Trochanteric bursitis
Gluteus medius tendinopathy
Sciatica
NOF

Question 15

What further imaging may be requested for hip OA, other then X-ray?

Answer 15

CT/MRI for surgical planning

Question 16

What are the three surgical approaches that can be taken for hip replacement surgery?

Answer 16

They are defined in relation to gluteus medius:

• posterior - most common - preserves abductor mechanism but risk to sciatic nerve
• anterolateral (modified Hardinge approach)- disturbs the abductors and risk to superior gluteal nerve but less chance of AVN
• anterior (smith-Peterson approach) - rare - often used for open washouts of infected native hips.