Abstract
Both knees of 50 normal children aged from birth to 18 years were examined by ultrasonography to measure the angles of the bony intercondylar and the cartilaginous sulcus on the patellar surface of the femur. The osseous angle was inversely related to the age of the child and was completely flat in the youngest children. During growth it gradually gained depth to assume the shape of the overlying articular cartilage by adolescence. At all ages, however, the angle of the cartilaginous sulcus was between 134 degrees and 155 degrees. This suggests that the configuration of the patellar articulation is already well developed at birth.