Bilateral arthrography of the hip was performed in thirty-seven patients
with unilateral Legg-Calve-Perthes disease. Measurements made on the plain
roentgenograms and on the arthrograms of the diameter of the femoral head,
the width of the medial joint space, and the thickness of the acetabular
cartilage were compared. The acetabulum-head quotients also were
calculated. When present, evidence of flattening of the femoral head
cartilage and of pooling of the contrast material also was noted. These
data showed that in the early stages of Legg-Calve-Perthes disease the
articular cartilage is thickened, and that the cartilaginous femoral head
is deformed and protrudes from the acetabulum. Arthrograms made with the
hip in different positions also indicated the extent and location of
collapse of the (osteochondroal) femoral head and therefore proved useful
as a means to determine the best therapeutic position of the hip to provide
coverage of the head. In three patients with severe transient synovitis,
thickening of the articular cartilage resembling that seen in
Legg-Calve-Perthes disease was demonstrated.