The exact etiology of osteochondritis of the head of the femur 1 is still undetermined. Various theories of the cause of this disease have been advanced, the most reasonable of which may be considered under the headings of infection, trauma, embolism and maldevelopment. The evidence in favor of infection as the etiologic agent is based on a few bacteriologic studies. Legg 2 scraped tissue from a large area of rarefaction in the neck of the femur of a patient suffering from this disease and found that staphylococci grew in cultures from the material so obtained. Kidner 3 obtained staphylococci from the granulation tissue found in necrotic areas in the metaphyseal region of the upper end of the femur in a similar case. McWhorter 4 likewise found the staphylococcus in a single case. Phemister 5 removed part of the upper femoral epiphysis after curetting the interior, and obtained no microbic growth