The history of the recognition of epiphyseal coxa vara as a definite clinical entity is sketched. The term coxa vara is defined and an anatomic and etiologic classification of the various types of coxa vara is given.

The incidence is given and the clinical picture and roentgenologic findings in epiphyseal coxa vara are described in detail. Twenty-four cases are reported.

The pathologic specimens reported in the literature are reviewed and discussed. The true pathology is unknown, as no early specimen has been described.

The various theories as to the etiology of the condition are critically reviewed and it is suggested that the condition is due to a weakening of the periosteum binding the head to the neck of the femur. The cause of this weakening is unknown, but it is usually coincident with a period of unusually rapid growth during adolescence.

The mechanics of epiphyseal coxa vara is discussed and the differential diagnosis is given. The end-results obtained in fourteen cases are discussed and these cases are reported in detail. In our experience the cases have all been seen some time after the onset of the condition and in such cases the prognosis without open operation is that of a hip usually somewhat painful and always limited in internal rotation and abduction and often limited in flexion. In many cases permanent flexion develops and persists. The hip may become practically ankylosed in severe cases. It is felt that forcible manipulation of an old case tends to result in increased stiffening of the hip and is not justified by the results obtained in our cases. The treatment of the condition in the various stages encountered in its natural evolution is given in detail.