summary Kohler's Disease is a rare idiopathic condition caused by avascular necrosis of the navicular bone that occurs in young children and presents with pain on the dorsal and medial surface of the foot. Diagnosis is made with radiographs of the foot showing sclerosis, fragmentation, and flattening of tarsal navicular bone. Treatment is usually nonoperative with NSAIDs and a short period of cast immobilization as the condition typically resolves over time. Epidemiology Demographics occurs in young children (usually age 4-7 yrs) four times more common in boys than girls 80% of cases in boys Anatomic locations can be bilateral in up to 25% of cases Etiology Pathophysiology the blood supply of the central one third of the navicular is a watershed zone accounts for the susceptibility to avascular necrosis and stress fractures the navicular is the last bone to ossify increases its vulnerability to mechanical compression and injury Associated conditions infection Kohler's disease is often misdiagnosed as infection Classification There is no widely used classification system for this condition Presentation History patient may not have complaints as disease can be asymptomatic characteristically described as midfoot pain with an associated limp Symptoms pain in dorsomedial midfoot may have swelling, warmth, and redness point tenderness over the navicular Physical exam antalgic limp (may place weight on lateral side of foot) Imaging Radiographs characteristic sclerosis, fragmentation, and flattening of tarsal navicular most tarsal navicular bones reorganize after disease has run its course some continue to be deformed but almost all of those remain asymptomatic Treatment Nonoperative NSAIDs short course can be used to decrease symptoms immobilization with short leg walking cast indications pain with activities outcomes studies have shown treatment in a short leg walking cast will decrease the duration of symptoms radiographs improve at around 6-48 months from onset of symptoms no reports of long-term disability Operative surgery indications not indicated for this disease Prognosis Typically a self-limiting condition Intermittent symptoms for 1-3 years after diagnosis typically associated with activity