Osteochondrosis dissecans.

Osteochondrosis dissecans ia an osteochondrosis limited to the periphery of secondary ossification centers of diarthrodial joints. It is most frequently diagnosed in the second decade of life, and the knee is the most frequently involved joint; other commonly involved joints include the ankle, hip and elbow. Concepts of pathogenesis consist of reaction to mechanical trauma or spontaneous focal avascular osteonecrosis, but the etiology is not known; however, there is a definite correlation between skeletal maturation and outcome. The objective of treatment should be to prevent the formation of a partially detached or free osteochondral fragment. The preferred treatment in younger individuals is primarily immobilization with bivalved casts or splints. Surgery is to be recommended infrequently in the younger age group but with relatively increasing frequency with older individuals. In the older individuals, tomography, arthrography, and arthroscopy are helpful diagnostic aids in determining the appropriate treatment program. The primary objective of treatment in the older patient is preservation of a congruous articular surface.