Distal radioulnar joint replacement.

The resection of the ulnar head, as described by Darrach, has unfortunately become the standard of care despite the frequent problems of ulnar stump instability following this procedure. To offer better treatment to our patients, we have to appreciate the various roles and the importance of the ulnar head for the function of the distal radioulnar joint (DRUJ) in mechanically loaded forearm rotation. The ulnar head forms the load-bearing keystone of the DRUJ and the distal forearm, important for maintaining adequate tension within the radioulnar ligaments and the interosseous membrane. A DRUJ implant replacing the ulnar head should and has to be the fixed point and load-bearing part of the joint and will be exerted to large mechanical loads making a neutralization of these forces necessary. A partial resurfacing implant for the DRUJ can be used for primary procedures. The resection is minimal, and further, the attachments of the stabilizing ligaments, the triangular fibrocartilage complex in particular, are preserved with a maintained anatomy and stability. For revision and salvage procedure, a modular ulnar head can be used, which restores the ulnar head offset and stabilizes the ulnar stump, restoring a pain-free DRUJ. The modularity of these 2 implants addresses the majority of indications for prosthesis in the DRUJ.