1. In a previous investigation, approximately 40 per cent of so-called "primary" degenerative disease or osteoarthritis of the hip appeared to have been the result of an abnormal joint mechanism caused by minimal epiphysiolysis in adolescence. Males were affected much more commonly than females. The residual abnormality of this disturbance, recognised radiologically, was termed the "tilt deformity" of the femoral head. 2. Three groups of young adult males, with different athletic backgrounds, have now been examined to assess the incidence of this abnormality and its relationship to athletic regimes. The condition was found to be more common in subjects who had been engaged in more active regimes and was also related statistically to a history of "growing pains". The deformity is compared with the gross disturbance of adolescent epiphysiolysis or slipped epiphysis, which is believed basically to be caused by chronic stress. 3. Degenerative disease of the hip of this type has a geographical and racial distribution corresponding to the degree of interest in and encouragement of competitive athletic activities. Many cases are therefore postulated to be the direct result of a minor and usually asymptomatic disturbance of this type, attributable to excess activity during adolescence.
1. The radiological features of skeletal hydatid disease are discussed. Osseous lesions occur in about 1 to 2 per cent of cases, bone being involved only after the embryos have passed the filters provided firstly by the liver and secondly by the lungs. At first, ill defined areas of translucency appear which are not diagnostic. In developed lesions, clear-cut destructive areas, with a surrounding sclerotic reaction, become visible. The cysts thin and expand the cortex and tend to spread throughout an affected bone. In advanced stages the cortex is ruptured, and exuberant hydatid cyst growth takes place in the adjacent soft tissue. Around this an ectocyst forms, which may later calcify, indicating death of the parasite. The progress of the disease is very slow. 2. Three cases of affection of the thoracic spine are described, and the differential diagnosis is considered, particularly from plasmacytoma and neurofibroma. Each case presented with cord pressure symptoms. Operative decompression relieved these totally in one case, incompletely in another, and not at all in the third and most advanced case. 3. With rapid and easy travel in the modern world hydatid disease is liable to be seen in areas where it is not endemic.
