Ulnar shortening osteotomy as a treatment of symptomatic ulnar impaction syndrome after malunited distal radius fractures

Based on anatomic and biomechanical studies and review of our clinical experience of the past 10 years, a classification of injuries to the triangular fibrocartilage complex is presented. This classification is based on the clinical examination, routine x-ray films, wrist arthrograms, wrist arthroscopy, and wrist arthrotomy. The classification recognizes both traumatic and degenerative lesions. Traumatic lesions are classified according to their location. Degenerative lesions are classified by the location and severity of degenerative changes of the triangular fibrocartilage complex, ulnar head, ulnocarpal bones and lunotriquetral ligament.

Palmar plate fixation of unstable distal radial fractures is quickly becoming the standard treatment for this common injury. The literature reporting complications consists mainly of isolated case reports or small case series.

Fifty preserved cadaver wrist specimens were studied. The anatomy of the distal radioulnar joint is complex, with varying configurations in the transverse and midcoronal planes. There is disparity in the radii of curvature of the sigmoid notch and the ulna-articular surface in the transverse plane, with resultant articular incongruity. Motion at the distal radioulnar joint is, hence, likely to be a combination of sliding and rotation with a small area of true appositional contact. The palmar osteocartilaginous lip of the sigmoid notch, along with the interosseous membrane, may be of importance in distal radioulnar stability. Palmar and dorsal radioulnar ligaments may act as "check-rein" ligaments, especially when seen with the "flat face" (type A) sigmoid notch.