The distal radioulnar joint. Anatomy, biomechanics, and triangular fibrocartilage complex abnormalities

The distal radioulnar joint plays an intricate part in the function of the wrist and thus in the function of the entire upper extremity. The radius and hand move in relation to and function about the distal ulna. Significant loads are transmitted to the forearm unit through the distal ulna via the triangular fibrocartilage complex. The anatomic relationships between the distal radius and ulna and ulnar carpus are precise, and even minor modification in these relationships leads to significant load changes and resultant pain syndromes. Evaluation of a patient with ulnar wrist pain is, at best, difficult. Despite a careful and thorough history and physical examination and the use of sophisticated ancillary diagnostic studies, some patients with distal radioulnar joint and ulnar carpal complex problems remain diagnostic and therapeutic mysteries. These patients are best followed; exploratory surgery is rarely satisfying to either the patient or the surgeon. Armed with an understanding of the normal anatomy and biomechanics, the examination of such a patient and subsequent treatment should become a challenge that is rewarding for both patient and treating physician.