avascular necrosis

Kohler's Disease

DefinitionKohler's Disease

 

Osteonecrosis of the navicular

 

Epidemiology

 

Present at age 4-6 years

- same as Perthes disease

 

M:F 5:1

 

Bilateral in 20%

 

Aetiology

 

Repetitive trauma to maturing ossific nucleus

Management

Management Summary

 

Stage 0

 

Natural history mixed

- depends on size of lesion and diagnosis

- treat if becomes asymptomatic

- may benefit from bisphosphonates

 

Stage 1 / Normal X-ray, abnormal MRI

 

Forage: 80% G/E

Bisphosphonates

 

Stage 2 / Abnormal X-ray with cysts and sclerosis

 

A:  As for Stage I

Background

Bilateral Hip AVN Xray

 

Definition

 

Non-traumatic or traumatic condition of femoral head with bone death

 

Epidemiology

 

20 - 50 yo (average 38)

- M: F 4:1

 

NHx  

 

70-80% with AVN will progress within 1 year

 

Kienbock's Disease

Definition 

 

Avascular necrosis & subsequent disintegration of lunate

 

Aetiology

 

50-75% history of trauma

 

Occasionally seen in sickle cell / steroid use

 

Pathogenesis

 

Vascular Theory

 

Trauma disrupting vascularity

- single incident with disruption of blood supply

Talar body fracture

Definition

 

Body Fracture

- fracture line exits inferior surface behind lateral process

- into posterior facet

- intra-articular body fracture

 

Neck Fracture

- fracture line exits inferior surface anterior to lateral process

- in front of sinus tarsi

- extra-articular neck fracture

 

Types

 

1.  Shear

2.  Crush

3.  Posterior Process