- self limiting avasulcar necrosis of the navicular;
- usually unilateral and affects children, most often boys;
- onset is at age 4 in boys and age 5 in girls;
- navicular is subjected to repetitive compressive forces during wt bearing which may be a risk factor for AVN;
- navicular is last bone in foot to ossify & delayed ossification appears to make the navicular more vulnerable to compressive damage;
- compressive forces can occlude the vessels of the soft ossification center redering it avascular;
- disease is self limiting & prognosis is excellent;
- navicular typically regains its normal shape before foot completes growth, and normal ossification is usually completed in two years;
- Clinical Manifestations:
- painful limp, shifting weight to lateral edge of foot to relieve pressure on longitudinal arch;
- pain tenderness, and swelling develop in the region of the navicular;
- contraction of tibialis posterior muscle may be painful;
- Radiologic Findings:
- navicular shows patchy areas of sclerosis and rarefication w/ loss of normal trabecular pattern;
- navicular may appear collapsed or in some cases will have normal shape with a uniform increase in density and minimal fragmentation;
- it is occassionally seen on opposite, asymptomatic foot;
- symptomatic treatment is needed for the pain and swelling;
- soft longitundinal arch supporters, medial heel wedge, and limitation of strenuous activity;
- if pain is severe or persists, a short leg walking cast may be used for 4 to 6 weeks, followed by use of shoe modifications
Köhler's disease of the tarsal navicular: long-term follow-up of 12 cases.
Köhler's disease of the tarsal navicular.
The Ossification and Vascularisation of the Tarsal Navicular and Their Relation to Köhler's Disease.