An approach to research on congenital contractures.

We have described a study evaluating over 1,500 patients said to have arthrogryposis. It is clear that arthrogryposis is a sign and not a diagnosis. The approach was one of collecting information and sorting out specific groups of patients. We employed a flexible protocol that allowed us to go back and collect additional information from families. Our study was pared down to include 350 patients, who were studied in detail. A great deal of heterogeneity exists within what has been called arthrogryposis. We have developed an approach to patients with congenital contractures, which is to divide them into three groups, depending on whether they have primarily limb involvement, whether they have limb involvement plus other abnormalities, or whether they have limb involvement plus CNS dysfunction. In this manner, we arrived at a useful differential diagnosis for each of these categories. We have been able to recognize not only a number of specific entities, but also principles of therapies. The approach has allowed us to say something about recurrence risks, natural history, and also which treatment is most appropriate for an individual case. It would appear that our interest in, and study of congenital contractures, have also led to a better understanding of the factors involved in normal development of joints. This has occurred by accumulating a large group of patients and evaluating each of them systematically.