The basic goal of fracture fixation is to stabilize the fractured bone, to enable fast healing of the injured bone, and to return early mobility and full function of the injured extremity. Fractures can be treated conservatively or with external and internal fixation. Conservative fracture treatment consists of closed reduction to restore the bone alignment. Subsequent stabilization is then achieved with traction or external splinting by slings, splints, or casts. Braces are used to limit range of motion of a joint. External fixators provide fracture fixation based on the principle of splinting. There are three basic types of external fixators: standard uniplanar fixator, ring fixator, and hybrid fixator. The numerous devices used for internal fixation are roughly divided into a few major categories: wires, pins and screws, plates, and intramedullary nails or rods. Staples and clamps are also used occasionally for osteotomy or fracture fixation. Autogenous bone grafts, allografts, and bone graft substitutes are frequently used for the treatment of bone defects of various causes. For infected fractures as well as for treatment of bone infections, antibiotic beads are frequently used.

Injuries to the medial ulnar collateral ligament are common. Published success rates after reconstruction of the medial ulnar collateral ligament are highly variable. The present study illustrates how current reconstruction techniques fail to fully restore the true anatomy of the native ligament. Further studies are needed to investigate this issue.

Injuries of the intrinsic and extrinsic wrist ligaments can lead to chronic wrist pain and carpal instability, while injuries of the triangular fibrocartilage complex are a frequent cause of ulnar-sided wrist pain. Currently, magnetic resonance (MR) arthrography is the preferred imaging modality for the evaluation of these structures, but good results can also achieved with MR imaging without preceding arthrography and computed tomographic (CT) arthrography. Promising results have been published on ultrasonography (US) and sonoarthrography of the intrinsic wrist ligaments and the triangular fibrocartilage complex and on US of the majority of extrinsic wrist ligaments. Visualization of these structures can be achieved by using high-frequency linear transducers. US has the advantages of MR imaging and MR arthrography: lower cost, no known contraindication for imaging, and real-time technique with possible dynamic evaluation. This technique does not require imaging guided intraarticular injection of contrast medium prior to MR arthrography or CT arthrography and does not use ionizing radiation; however, US is operator dependent, which can be compensated for by using standardized imaging techniques. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.e44/-/DC1.

Perilunate dislocations, perilunate fracture-dislocations (PLFDs), and lunate dislocations are high-energy wrist injuries that can and should be recognized on radio-graphs. These injuries are a result of important sequential osseous and ligamentous injuries or failures. Prompt and accurate radiographic diagnosis aids in the management of patients with perilunate dislocations, PLFDs, and lunate dislocations while assisting orthopedic surgeons with subsequent surgical planning. CT may better show the extent of the injury and help in treatment planning particularly in cases of delayed treatment or chronic perilunate dislocation. A CT examination with coronal, sagittal, and 3D reformatted images is ordered at our institution in cases in which the extent of the carpal injuries is poorly shown on radiographic examination.