No abstract

Impaction syndromes related to ulnar-sided pain include ulnar impaction syndrome, ulnar impingement syndrome, ulnocarpal impaction syndrome secondary to nonunion of the ulnar styloid process, ulnar styloid impaction syndrome, and hamatolunate impingement syndrome. The most common of these, ulnar impaction syndrome, is a degenerative condition of the ulnar side of the wrist related to excessive load bearing across the ulnar carpus, triangular fibrocartilage (TFC) complex, and ulnar head. In an adequate clinical setting, characteristic osseous findings at radiography include positive ulnar variance in ulnar impaction syndrome, a short ulna in ulnar impingement syndrome, nonunion of the ulnar styloid process in ulnar impaction syndrome secondary to ulnar styloid nonunion, an excessively long ulnar styloid process in ulnar styloid impaction syndrome, and type II lunate bone in hamatolunate impingement syndrome. Nevertheless, confirmation of clinical and conventional radiographic findings with magnetic resonance (MR) imaging is often necessary to exclude other entities with similar clinical manifestations. MR imaging allows earlier detection of an abnormality in the TFC complex, cartilage, or bone marrow of carpal bones and is helpful in formulating the extensive differential diagnosis in patients with ulnar wrist pain and limitation of motion.

Gadolinium-enhanced MR imaging is the most reliable imaging method for investigating the vascularity of the proximal pole in scaphoid nonunions.

No abstract

The study of the wrist represents a major diagnostic challenge because of its complex anatomy and the small size of individual structures. Recent advances in imaging techniques have increased our diagnostic capabilities. However, 3T magnets, multichannel specific wrist coils, and new MRI sequences have not restricted the indications of arthrographic imaging techniques (CT arthrography and MR arthrography). Distension of the different wrist compartments at CT arthrography and MR arthrography significantly improves the diagnostic accuracy for triangular fibrocartilage (TFC) complex injuries and carpal instability. Dedicated multichannel wrist coils are essential for an adequate study of the wrist, but the placement of these coils and the positioning of the wrist are also important for proper diagnosis. The development of dynamic multislice CT studies allows a diagnostic approach that combines dynamic information and the accurate assessment of ligaments and the TFC complex. New advances in arthroscopy have changed the anatomical description of the TFC with a functional division in the proximal and distal TFC complex, and they have allowed a better characterization of lesions of the TFC complex with subclassification of Palmer 1B and 1D lesions and description of new lesions not included in the Palmer classification, such as capsular injuries.