Primary articular osteochondroses.

Primary articular osteochondroses involve the primary articular and growth cartilage and the subjacent endochondral ossification, with resulting incongruity of the joint surface and potential degenerative osteoarthritis. Weight-bearing areas, such as the metatarsal head, are at greater risk than nonweight-bearing parts in the upper extremity, such as the capitellum of the humerus. Treatment has two phases: protected mobilization, followed by graduated functional activity; later, surgery may be required to correct the resultant degenerative osteoarthritis. The accepted period for protected mobilization of the symptomatic patient is two to three years in the upper extremity, but three years or even longer in the weight-bearing lower extremity. The longer the period of painful motion, the longer the period of indicated protected mobilization. The prognosis concerning degenerative osteoarthritis should not be estimated by the extent of acute articular involvement on roentgenograms, but rather by the duration of symptoms.