Twenty-one post-irradiation fractures of the femoral neck are reported in seventeen patients who had been treated by radiotherapy for carcinoma of the uterus.

The clinical and radiological appearances are described and the diagnosis, prognosis and treatment of this type of fracture are discussed.

Histological material has been studied in three cases.

It is concluded:

1. That there is a characteristic clinical picture in which premonitory pain is of paramount significance.

2. That when the diagnosis is considered, the likelihood of irradiation damage should take precedence over the remote possibility of metastatic invasion.

3. That the disability varies, but in general the prognosis is favourable.

4. That there is no specific line of treatment applicable to these fractures.

5. That avascularity is not the underlying cause of this lesion.