Subtalar Dislocation

Epidemiology

 

Rare

 

Types

 

Medial

- 80%

- calcaneum dislocated medially

 

Lateral

- 20%

- higher energy injury

 

Subtalar Dislocation Xray 1Subtalar Dislocation Xray 2

 

Anterior / Posterior

- extremely rare

 

Pathology

 

Tearing of strong interosseous ligament

 

Dislocation of

- talonavicular joint

- talo-calcaneal

 

Reduction

 

Subtalar dislocationSubtalar dislocation 2

 

Conscious sedation

- flex knee to relax gastrocnemius

- increase deformity

- reduce calcaneum whilst holding talus

 

Blocks to reduction

- medially - talar head buttonholes through capsule / EDB

- laterally - tibialis posterior

 

Post reduction

 

CT

- exclude intra-articular fragments

- ensure congruent reduction

 

CT post subtalar dislocationCT post subtalar dislocation 2

 

Results

 

Main risk is restricted ROM

- very difficult to treat surgically

- usually stable after reduction

- don't immobilize for long or subtalar joint will stiffen

 

Risk of osteochondral injury and later OA