The skeletal manifestations of clubbing: a study in patients with cyanotic congenital heart disease and hypertrophic osteoarthropathy.

The skeletal manifestations of clubbing of the digits have been occasionally noted and only briefly discussed in the literature. We investigated the radiographic features of digital clubbing in 37 patients with diverse diseases including cyanotic congenital heart disease, lung malignancy-associated hypertrophic osteoarthropathy, and idiopathic cases. We identified two types of bone changes--osteolysis or bone dissolution, and bone formation or hypertrophy. The changes were more evident in the feet than in the hands, and the degree of soft tissue change did not always reflect the underlying osseous abnormalities. The relationship of these changes (ie, osteolysis, hypertrophy) to each other appear to depend in part on the underlying disease as well as the time course or disease duration. Thus, clubbing and hypertrophic osteoarthropathy may not represent distinct entities; our data suggest that they may be stages in an evolving, more generalized process of new bone formation or hypertrophy followed by osteolysis or atrophy affecting many parts of the skeleton.