Hypertrophy and laminar calcification of cartilage in loose bodies as probable evidence of an ossification abnormality.

Of 83 loose bodies containing hyaline cartilage, 54 were composed of cartilage alone, and 29 of cartilage and bone. In both groups, hypertrophy of the cartilage was common but 53 per cent of the chondral bodies contained in laminar calcification close to the tidemark. The evidence suggested that this feature ante-dated separation of the loose body, and may have indicated a metabolic insufficiency because of the increased thickness of the cartilage. The most likely explanation for the hypertrophy was that it was secondary to a local retardation of ossification in the periphery of the epiphysis.