Comparison of Biomechanical Results about the Effect of Three Surgery Methods in Decompression of Lunate Bone.

Objective  Kienbock's disease is an unusual disorder caused by osteonecrosis and the collapse of lunate bone which leads to pain and a chronic decrease in wrist function. The treatments in this disease aim to relieve pain and maintain wrist function and movement. Various surgical procedures have been recommended for the subjects with Kienbock's disease; however, the main question posed here is which of the selected procedures are more successful in relief of the pressure applied on lunate. Methods and Materials  Computed tomography (CT) scan images of a normal subject were used to create a three-dimensional model of the wrist joint. The effects of several surgical procedures, including radial shortening, capitate shortening, and a combination of both radial and capitate shortening, on the joint contact force of the wrist bones were investigated. Results  The pressure applied to the lunate bone in articulation with radius, scaphoid, capitate, hamate, and triquetrum varied between 19.7 and 45.4 MPa. The Von Mises stress, maximum principal stress, and minimum principal stress decreased in the model with a combination of radius and capitate shortening. Conclusion  It can be concluded from the results of this study that the combinations of radius and capitate shortening seem to be an effective procedure to decrease joint pressure, if the combined surgery could not be done, shortening of radius or capitate would be recommended. Level of Evidence  This is a Level III study. Thieme. All rights reserved.