TANGENTIAL VIEWS OF THE DISTAL RADIUS – AID TO OPERATIVE TREATMENT OF FRACTURES

Abstract

Open reduction and internal fixation of comminuted, displaced intra-articular or potentially unstable fractures of the distal radius with plate and screws has increasingly become a favoured treatment. Intra-operative assessment of fixation with the help of an image intensifier has always been difficult because of the anatomy of the distal radius which has an average ulnar inclination of 22 degrees and an average volar tilt of 14 degrees. These inclination and tilt produce superimposition of images and imaging of the implants placed as distal as possible to achieve satisfactory fixation often shows the screws to be penetrating the joint.

We describe two new radiographic views of the distal radius, which we used intra-operatively in ten patients undergoing open reduction and internal fixation of distal radius fractures. These are the tangential views of the articular surface of the distal radius taken by elevating the wrist so that the forearm makes an angle to the operating table to negate the effects of natural inclination and tilt in antero-posterior and lateral views. The images were compared with the images of standard antero-posterior and standard lateral views. Screws were thought to have been penetrating the joint in the standard lateral views of all of them and in the standard antero-posterior views of eight of them. However, no screw was seen penetrating the joint in these new views.

The tangential views showed correct relation of the screws with the articular surface and a more distal placement of the plate was possible. This enabled the screws to engage the sub-chondral bone and obtain bi-cortical purchase in presence of dorsal comminution. We recommend use of these views in open reduction and internal fixation of distal radius fractures.