Definition
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
- avascular necrosis
Clinical Features
Pain & soft tissue swelling over navicular
X-ray
Flattening & sclerosis of navicular
NHx
- usually resolves within 18 - 36 months
Management
Aim to provide symptomatic relief
- rest from sport
- analgesia
- SL cast for 6-8 weeks if required