Abstract
1. Serial radiographs of fifty-two normal children's feet, taken at six-monthly intervals between two and five years, have been reviewed.
2. Twenty-one naviculars have been injected post-mortem and the vascularisation of the growing bone investigated.
3. The records of sixty-two children with a diagnosis of KoÌhler's disease have been studied.
4. It is submitted that abnormal ossification results from compression of the bony nucleus at a critical phase during growth of a navicular bone whose appearance is delayed.
5. Symptoms in KoÌhler's disease are related to further compression which produces vascular changes in the bony nucleus. Consequent ischaemia is followed by hyperaemia which produces local pain, tenderness and swelling.
6. Two radiographic types of KoÌhler's disease are described and attributed to variations in the basic vascular pattern of the affected bone.
7. The usual complete recovery of the navicular is ascribed in part to the basic arrangement of numerous radially penetrating vessels.
