We performed superselective angiography in 28 hips in 25 patients with Perthes’ disease in order to study the blood supply of the lateral epiphyseal arteries (LEAs). Interruption of the LEAs at their origin was observed in 19 hips (68%). Revascularisation in the form of numerous small arteries was seen in ten out of 11 hips in the initial stage of Perthes’ disease, in seven of eight in the fragmentation stage and in five of nine in the healing stage. Penetration of mature arteries into the depths of the epiphysis was seen in four of nine hips in the healing stage. Vascular penetration was absent in the weight-bearing portion of the femoral head below the acetabular roof. Interruption of the posterior column artery was seen where it passed through the capsule in seven hips when they lay either in internal rotation or in abduction with internal rotation. We suggest that in Perthes’ disease the blood supply of the LEAs is impaired at their origin and that revascularisation occurs from this site by ingrowth of small vessels into the femoral epiphysis. This process may be the result of recurrent ischaemic episodes

We reviewed 32 children after the treatment of simple bone cysts by intralesional injections of methyl-prednisolone acetate. The age of the child and the activity and size of the cyst did not significantly affect the radiological outcome. The earliest time at which the radiological response could be reliably determined was three months. After a median period of review of five years, four (13%) cysts had healed, 20 (62%) cysts were partially visible but sclerotic, four (12.5%) were still visible but opaque and four (12.5%) were clearly visible. The healed and partially visible but sclerotic cysts were classified as having satisfactory radiological healing. This was observed in 13 of 32 cysts (41%) after the first injection, in eight of 21 (38%) after the second injection, but in relatively few of the remaining cysts after subsequent injections. A satisfactory symptomatic outcome was achieved in all of the 18 children with humeral cysts and in the one child with a fibular cyst irrespective of the radiological outcome, but only in nine (67%) of the 13 children with femoral or tibial lesions, in whom the cysts were healed or sclerotic. The remaining four children had exertional bone pain and repeated fractures of their femoral or tibial cysts which were incompletely healed with sclerosis in one and opacities in three. We conclude that the healing response to intralesional corticosteroids is unpredictable and usually incomplete even after multiple injections. The failure rate in weight-bearing bones is too high