[Natural course in pseudarthrosis of the scaphoid].

Knowledge of the natural history of scaphoid nonunion is important for establishing the indication for surgery. The late results after the Matti-Russe operation reveal carpal arthrosis in a relatively high percentage of cases. On the other hand, we see patients who have engaged in sports and have continued working without symptoms for years despite scaphoid nonunion. We now address the question as to the nature and time of the development of arthrosis and the factors affecting it. Forty-one patients with pseudarthrosis were followed up over a period of 3-39 years. For comparison, 55 patients in whom a Matti-Russe operation had been successfully performed were followed up for the same period. Both the clinical and radiological appearance seem to be better in patients operated on than in those who were not operated on. The time factor, the location and the form of the fracture determine the development of arthrosis. No patient was free of arthrosis after 10 years. Arthrosis begins in the scaphostyloid joint and progresses to the scaphotrapezoid, scaphocapital and scapholunar joint. Development of midcarpal arthrosis takes place over about 20 years. Unstable and displaced fractures accelerate the development of arthrosis. Proximally located pseudarthroses are unfavorable because of the danger of osteonecrosis of the proximal fragment. These pseudarthroses should be eliminated as soon as possible by surgery.