Note the patchy fragmented markedly small and somewhat flat navicular. This reflects avascular necrosis of the Navicular in a skeletally immature patient: Kohler’s disease.
This is a self-limiting entity and almost always resolves completely. It is important to alert the referring clinician to this diagnosis as on an x-ray it can be mistaken for an aggressive process. This is not an aggressive process and almost always completely resolves with conservative therapy.