Orthopaedics

Question 1

What are some indications for a THR?

Answer 1

• OA (primary or secondary)
• RA
• Fractured NOF
• Avascular necrosis
• Benign/malignant tumor
• Congenital hip diseases

Question 2

Indications for a revision THR?

Answer 2

• Aseptic loosening (mechanical failure/ wear)
• Recurrent dislocation
• Implant malposition
• Infection
• Peri-prosthetic fracture

Question 3

How long is a THR procedure?

Answer 3

60-90mins + 2 hours recovery
*up to 3 hours for revision

Question 4

Lateral Approach THR
- Incision:
- Muscles impacted:
- Dislocating position:

Answer 4

Incision: 10-15cm over greater trochanter
Muscles impacted: TFL dissected, glute med/min & vatsus lateralis cut
Dislocating position: Tractions, ADD, ER

Question 5

Posterior Approach THR
- Incision:
- Muscles impacted:
- Dislocating position:

Answer 5

• Incision: 10-15cm over posterior GT
• Muscles impacted: dissection on TFL, detach glute max, piriformis and obturator detached
• Dislocating position: ADD, IR, Flexion

Question 6

Anterior Approach THR
- Incision:
- Muscles impacted:
- Dislocating position:

Answer 6

• Incision: Mid-thigh wound
• Muscles impacted: TFL split from rectus femoris and fascia
• Dislocating position: Nil

Question 7

What nerves can be compromised from THR surgery:
- Posterior:
- Lateral:
- Anterior:

Answer 7

• Posterior: sciatic nerve
• Lateral: superior gluteal nerve
• Anterior: lateral cutaneous nerve

Question 8

Dislocation rates for THR

Answer 8

1-2% for posterior
0.8-1.4% for lateral
0.6% for anterior

Question 9

What are hip precautions for THR?

Answer 9

No flexion past 90deg
No adduction past midline
No internal rotation

Question 10

What are the Gardens classifications for Grade 1-4?

Answer 10

• Grade 1: Incomplete, stable
• Grade 2: Complete, non-displaced
• Grade 3: Compete, partially displaced
• Grade 4: Complete, displaced

Question 11

Fracture NOF fixation types:
- Grade I&II
- Grade III&IV
- Trochanteric

Answer 11

Grade I & II: Fixed with dynamic hips screws or cannulated screws
Grade III & IV: Hemiarthroplasty or THR (if hip has OA as well)
Trochanteric: Intramedullary hip screw (IMHS) or IM Nail

Question 12

Indications for TKR?

Answer 12

• OA
• RA
• Other inflammatory arthropathies
• Tumors or cancers
• Fragility or failed primary TKR

Question 13

TKR surgery time?

Answer 13

90mins + 2 hours recovery
3hrs for revision