dislocation

Hip

Aims

 

Prevent contractures

Prevent dislocations

Improve walking 

Provide stable and painless sitting

Allow perineal care

 

Issues

 

Hip Dislocation

Adductor contractures

Flexion contractures

In-toeing

Windswept hips

 

Hip Dislocation

 

Natural History

 

Accepted that a dislocated hip in CP is painful

Atlanto Occipital Dislocation

Epidemiology

 

Deadly & rare

- usually post mortem

 

More common in children due to

- immature joints 

- larger head to body ratio

- relative ligamentous laxity

 

Aetiology

 

High velocity trauma

- MVA

 

Mechanism

- hyperextension, distraction & rotation

 

Types

 

Pure ligament injury usually

Facet Joint Dislocation

Definition

 

Facet joint dislocations secondary flexion distraction injury

 

Epidemiology

 

10%

 

Stages

 

1. Unifacet subluxation - interspinous process widening

2. Unifacet dislocation - 25% anterolisthesis

3. Bifacet dislocation - 50% anterolisthesis

4. Complete vertebral translation - 100% anterolisthesis

 

Unilateral Facet Joint Dislocation

 

Background

Definition

Dislocated Patella

 

Repeated dislocation of patella with minimal trauma

- 15-20% of paediatric acute patella dislocations

- more common girls 

- often bilateral

 

Dislocation occurs unexpectedly when quadriceps contracted with knee in flexion 

 

Direction

 

Complications

Intraoperative glenoid fracture

 

Avoid by

- careful reaming and drilling osteoporotic bone

 

Management

1.  Rotate metaglene

- use locking screws to stabilise glenoid

2.  PA screws

- cannulated 4.0 mm screws

- inserted percutaneously from posterior

 

Haematomas

 

Great deal of dead space is created

- always use a drain

Pisiform

Subluxation & dislocation

 

Diagnosis

 

Pisotriquetral view

- forearm positioned 30° supinated off the neutral position

- loss of symmetry between the pisiform and triquetrum is required for the diagnosis

- carpal tunnel view may be helpful in further assessment of the joint

 

Osteoarthritis

 

Clinical

 

More common problem