TRISPIRAL TOMOGRAPHIC STAGING OF KIENBOCKS-DISEASE

Trispiral tomography enhances the staging of Kienbock's disease and ai ds in surgical planning. The clinical records, plain x-rays, and trisp iral tomograms of 105 patients with Kienbock's disease were reviewed. When tomograms were used, upward revision of the classification stage was indicated in 73% of patients with stage I or stage II disease and in 10% of those with stage III disease. On tomograms, 91% of patients had lunate fractures, compared with 55% on plain films. The most commo n lunate fracture seen on trispiral tomograms was a transverse shear f racture that represented lunate collapse; the next most common was a m idcoronal fracture that may be displaced, causing fragment extrusion p almarly or dorsally. The most common instability pattern was nondissoc iative proximal row flexion, seen in stage III. Indices of carpal coll apse and ulnar translation may be useful in following up patients, but values vary widely among patients.