Accepted 18.vii.72Osteochondritis dissecans of the femoral head occurring as a complication of coxa plana appears to be extremely rare. Despite the numerous publications on Perthes' disease, only six cases of osteochondritis dissecans following this condition could be found in the literature by Ratliff (1967), who presented another two cases of his owm. In addition to these, there is one case reported by Stillman (1966) who, reviewing the whole literature relating to the association of these two conditions, could trace another four cases, making thirteen the whole number of published cases of osteochondritis dissecans following Perthes' disease.A condition identical or very similar to Perthes' disease occurs in congenital dislocation of the hip whenever ischaemic necrosis of the capital femoral epiphysis develops, which is also widely accepted as the pathology of coxa plana in childhood. We could not find in the literature any case of osteochondritis dissecans following osteochondritis which develops as a complication in the course of treatment of congenital dislocation of the hip.The aim of this paper is to report two cases of osteochondritis dissecans of the femoral head, one following Perthes' disease and the other osteochondritis of the upper femoral epiphysis complicating a case of congenital dislocation of the hip.
Case 1A young man aged 17 was first seen in March 1970 complaining of slight pain in the left groin and limping after prolonged walking. The pain was first experienced about two years previously. There was no history of injury or acute illness at that time, but at the age of 7 years he had sufferred from Perthes' disease of the left hip for which he was treated by a weight-relieving caliper for one and a half years.On examination he could walk in a normal way. There was 1 cm shortening of the left limb and some wasting of the thigh. Abduction and external rotation of the left hip were restricted by 15" while internal rotation exceeded that of the opposite hip by 10". The radiographs (Figures 1, 2 and 3 ) showed a broad left femoral head with a short widened neck and, in the lateral view, a large well-outlined fragment of osteochondritis dissecans in the superior aspect of the femoral head. Because of the mildness of the symptoms no particular treatment was advised. The patient's condition has been practically unchanged since.
Case 2A young lady aged 16 was seen in October 1970 because of mild pain in the left hip and a slight limp. The pain had started two years previously for no apparent reason at that time and it gradually became 534 TH. PANTAZOPOULUS ET AL. slightly worse. Over the last few months she had also experienced episodes of loud mechanical blockage of the hip joint accompanied by momentary acute pain. At the age of one and a half years, congenital dislocation of the left hip was diagnosed which was treated conservatively in "frog" plasters for 9 months. At the end of that time it was realized that osteochondritis of the upper femoral epiphysis had developed. She was then treated in ...