[Traumatic etiology of Kienboeck's disease. (Perilunate subluxations and semilunate necrosis)].

The authors have studied the incidence of lunate necrosis in 110 perilunate dislocations. Twenty-one cases (19%) developed a necrosis. The classification into three types, according to the amount of damage to the perilunar ligaments, is of prognostic value. There is no risk of necrosis in type 1, 17% in type II, and 50% in type III. An associated fracture of the scaphoid does not modify the risk. In neglected lesions, reduction of the lunate dislocation should be attempted, even at a late date, the risk of necrosis then being 50%. Surgical reduction increases the risk of secondary necrosis to a greater extent than does orthopedic treatment, but it is generally use in the most complex cases too. The authors advocate a closed reduction with percutaneous pin fixation.