Search

Ulnar-sided wrist pain is a common presenting complaint, so a thorough understanding of the anatomy and biomechanics of the triangular fibrocartilage complex (TFCC) and distal radioulnar joint (DRUJ) is essential for the diagnosis and treatment of these disorders. Over the past 30 years, the knowledge of this complicated structure and its role in the biomechanics of the wrist has increased, leading to improved diagnoses of these injuries and to more effective reconstructive procedures for their treatment.

The most commonly studied regions of the skeleton remain to be the PA lumbar spine, proximal femur, and forearm in spite of the development of software applications that allow measurement of virtually any skeletal region. The manufacturers of DXA devices provide instructions for patient positioning for the different types of DXA studies that can be performed utilizing their device and software applications. While the manufacturer’s recommendations for positioning should always be given priority, an understanding of why certain aspects of positioning are recommended is useful. In particular, the technologist who understands the goals of positioning is better able to modify certain aspects of positioning when the patient’s anatomy demands it, without undermining the validity of the study. In reviewing the basic procedures and nuances of positioning for the three major scan types, the following discussion provides both the basic “how to” as well as the more detailed “why.”

Union with deformity continues to be the most common complication following fracture of the distal end of the radius.12,36,40 Malunion may be extraarticular, characterized by metaphyseal angulation and loss of radial length; intraarticular, involving distortion of the radiocarpal or radioulnar joints, or both; or a combination of the two.

Radiocarpal fracture-dislocations comprise an uncommon but complex group of distal radius fractures characterized principally by their association with complete dislocation of the radiocarpal joint. The dislocation may be in either a dorsal or palmar direction with the distal radius fracture(s) involving the marginal cortical rims, radial styloid, or both. It is commonplace also to find a fracture of the ulnar styloid (Fig. 8.1).

The triangular fibrocartilage complex (TFCC) is a structure that is composed of multiple ligamentous components that are tightly interrelated. The TFCC is intimately involved in the relationships between the distal ulna, distal radius, lunate, and triquetrum, and their associated articulations. Injury and degeneration of the TFCC can take many forms and is not always evident on plain radiographs. TFCC injury is commonly associated with other fractures of the wrist such as distal radius and ulnar styloid fractures.1 A TFCC injury may be easily overlooked when presenting with other associated injuries, especially a more obvious fracture.

Contrast opacification of the joint cavities (arthrography) and tendon sheaths (tenography) of the hand and wrist is not routinely employed in many hospitals although useful information may be derived from these procedures. This chapter summarizes indications, techniques, and normal and abnormal findings of arthrography and tenography of the hand and wrist.