CT

Background

DefinitionGarden 3 Displaced Subcapital

 

Fracture distal to articular surface & proximal to intertrochanteric region

 

Epidemiology

 

On average 4 years younger than intertrochanteric fracture

 

One year mortality as high as 36%

 

Only 1/3 will return to pre-fracture living environment

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

 

Burst Fractures

 

Definition

 

Burst fractures

- injury to anterior and middle columns +/- posterior column

 

Mechanism

 

Vertical compression

 

Epidemiology

 

10% cervical fractures

Most commonly C5/6

 

Pathology

 

Anterior & middle columns fail

- if severe, posterior ligament complex fails

Background

Anatomy

 

3 facets

 

1.  Posterior facet (STJ)

2.  Middle facet (sustenaculum tali)

3.  Anterior facet (on distal medial aspect)

 

Anterior process 

- forms calcaneocuboid (CCJ) articulation

 

Thalamic portion 

- under lateral process talus

 

Tuberosities

 

Posterior tuberosity 

- posterior process / T Achilles attachment

 

Femoral Head Fractures

Incidence

 

5-15% of posterior dislocations

 

Aetiology

 

Posterior hip dislocation

 

Pipkin Classification

 

Type I - head fracture below fovea

 

Undisplaced

- non operative

 

Displaced

- excise fragment if small

- ORIF fragment if large (can contribute to instability)

 

Chordoma

Definition

 

Primary malignancy arising from remnants of the notochord

 

Epidemiology

 

Rare malignant tumour

 

Middle-aged adults (50-70)

 

M>F

 

Location

 

In midline in axial skeleton

 

Base of skull 35%

 

Vertebrae 15%

- especially cervical

 

Sacrum 50%

 

Synovial Chondromatosis

DefinitionSynovial Chondromatosis Knee MRI

 

Chondroid Metaplasia of synovium affecting large joints

 

Nodules of hyaline cartilage

- formed in the subsynovial layer of joint capsules

 

Epidemiology

 

Rare lesion

Most common in 20's and 30's

Sex: M > F (2:1)

Monoarticular

 

Site