THR complications

Question 1

causes of hip dislocation

Answer 1

patient factors
- obesity
- infection
- neuromuscular disorders - parkinson’s, CP
- hypermobility
- cognitive impairment
- excess drugs/ alcohol
- prior hip surgery - greatest factor
- NOF fracture - much higher rate than OA
- DDH
- fixed spinopelvic alignment

operative factors
Approach

Choice of implants
- metal-on-metal
- decreased femoral head/ neck ratio
- decreased offset

Surgical procedures
- malpositioning of components
- failure to repair external rotators and capsule

Implant Factors
- polyethylene wear
- trunionosis
- head size - 22mm high rate
- offset
- liner chosen

Question 2

management of hip dislocation?

Answer 2

reduce risk
- larger femoral head
- dual mobility
- constrained liner

revision
- for malpositioning and poly wear
- increase constraint - constrained liner
- lateralised liner
- larger head
- exchange poly
- reposition component
- dual mobility

constrained liner
- risk of failure and accelerated wear