LOCO Total Hip Replacement

Question 1

Indications for Hip replacement

Answer 1

• OA
• Trauma
• Osteonecrosis/AVN
• Developmental dysplasia of the hip

Question 2

What is the surgical approach for hip replacement

Answer 2

Most commonly a posterior approach.

• 10-15cm skin incision centred on posterior aspect of greater trochanter
• Split fascia lata and gluteus maximus in line with fibres
• Short external rotators disected off femur and retracted back over the sciatic nerve to protect it through op
• Capsulotomy and hip dislocated

Question 3

What are the different options for bearing surfaces in hip replacement

Answer 3

Metal on metal
Metal on polythene (polythene acetabular liner)
Ceramic on ceramic

Question 4

What angle should the joint be set at in hip replacements

Answer 4

Should be in a mild degree of valgus but should not exceed 140 degrees. Excessive valgus strains the knee whilst varus angles increase loosening and stem failure and can result in dislocation

Question 5

What angles should the different components of hip replacement be set at

Answer 5

Acetabular: 20 degrees of anteversion with 45 degree inclination
Femoral: 10-15 degree anteversion

excessive anteversion or retroversion could lead to dislocation

Question 6

What are the complications of THR

Answer 6

-Aseptic loosening
-Infection
- Fracture or failure of a component
- Dislocation
- Malpositioning
-Instability
-Pain
Surgical errors (nerve damage)