Tarsal navicular stress fractures.

Stress fractures of the tarsal navicular bone are being recognized with increasing frequency in physically active persons. Diagnosis is commonly delayed, and outcome often suffers because physicians lack familiarity with the condition. Navicular stress fractures typically present in a running athlete who has gradually increasing pain in the dorsal mid-foot with occasional radiation of pain down the medial arch. Because initial plain films are often normal, the next diagnostic test of choice is triple-phase bone scan, which is positive early in the process and localizes the lesion well. After a positive bone scan, a computed tomographic scan should be obtained to provide anatomic detail and guide therapy. Nondisplaced, noncomminuted fractures respond well to six weeks of non-weight-bearing cast immobilization. Displacement, comminution, and delayed or nonunion fractures are indications for surgical open reduction internal fixation.