Definition
Avascular necrosis of the navicular
Epidemiology
Most common age 3 - 10 years
Boys 5 x girls
Bilateral in 20%
Etiology
Repetitive compression to navicular
- interferes with blood flow
Last tarsal bone to ossify which makes it susceptible
Clinical Features
Medial midfoot pain
X-ray
Flattening / sclerosis / fragmentation of navicular
Natural history
Pain for 6 - 9 months
Xray resolution 2 - 4 years
No known long term sequelae even with abnormal navicular
Ippolito et al J Pediatr Orthop 1984
- 12 patients with Kohler's disease
- follow up for 33 years
- all symptomatic
- normal navicular and no OA on xray
Nonoperative management
Symptomatic relief
Rest from sport
Boot / cast for 6 - 8 weeks may help reduce symptoms more quickly
Ippolito et al J Pediatr Orthop 1984
- 12 patients with Kohler's disease
- cast: symptoms 3 months
- arch support: symptoms 7 months
- xray resolution took average 8 months