Kohler's Disease
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
Osteonecrosis of the navicular
Present at age 4-6 years
- same as Perthes disease
M:F 5:1
Bilateral in 20%
Repetitive trauma to maturing ossific nucleus
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
Non-traumatic or traumatic condition of femoral head with bone death
20 - 50 yo (average 38)
- M: F 4:1
70-80% with AVN will progress within 1 year
Largely related to degree of displacement
Hawkins Type I
- 0% to 13%
Hawkins Type II
- 20% to 50%
- usually only patchy and not a problem (rarely collapses)
Xray
- sclerosis
CT
Avascular necrosis & subsequent disintegration of lunate
50-75% history of trauma
Occasionally seen in sickle cell / steroid use
Trauma disrupting vascularity
- single incident with disruption of blood supply