The blood supply of the immature femoral head: The lateral ascending cervical artery (A) and the epiphyseal branches of both the lateral (B) and medial (C) ascending cervical arteries pass through the perichondral ring and not the epiphyseal plate. Reproduced with permission from Chung, S.M. (1976). The arterial supply of the developing proximal end of the human femur. Journal of Bone and Joint Surgery, 58A, 961–70.