[Osteochondritis dissecans and osteonecrosis of the lower end of the femur. Value of bone marrow functional exploration].

The authors report the results of 19 functional investigations carried out for osteochondritis in 11 cases, and osteonecrosis of the knee in 8 cases. The 8 cases of osteonecrosis all had hemodynamic disorders with increased pressure in the bone marrow and stasis due to circulatory obstruction. On the other hand, 5 cases of osteochondritis out of the 11 explored had no disturbance of marrow blood supply. However, of the 6 cases of osteochondritis with vascular disorders, there were 5 who had some other reason which might explain the disorder blood supply within the bone. It thus seems that one may contrast two types of disease: -One, characterized by an intra-osseous circulatory disorder for which one might reserve the terms osteonecrosis, which occurs in patients aged over 60 years, but which may be observed in juvenile forms. - The other, characterised by the absence of any hemodynamic disturbance and in which the foreign body seems to result from a very localised disorder which does not affect the bone marrow blood supply. One may use here the term, osteochondritis. We propose to substitute this physiopathological classification for the classical division based on age and on X-rays. Investigation of the blood supply of the bone, permits, as with strontium, early diagnosis at a pre-radiological stage.