Perthes' disease: growth and aetiology.

During the last decade it has become evident that Perthes' disease can no longer be considered as a local ischaemic disorder in an otherwise normal child.1-3 The affected child's growth and development are unusual in several respects, namely (figure): * Bone aFe3-5 * Stature 8 and growth velocity9 * Disproportionate skeletal growth6 7 * Hormonesl'-2 * Congenital anomalies and defects13 14 * The unaffected hip3 13 15 16 Considering the new evidence, Harrison and Burwell concluded that Perthes' disease is a force orientated hip lesion based upon a constitutional defect that affects growing bones.3 Local and general disorders acting together result in a hip joint that is structurally inadequate for the loads that have to be borne, leading to a stress fracture. The purpose of this review is firstly, to summarise what is known about the underlying growth pattern; and secondly, to present a synthesis of knowledge as a theory of aetiology.