E2192. Carpal Dislocations Simplified
  1. Nisha Pande; University of Tennessee Health Science Center
  2. Bhumin Patel; ROH
  3. Chinky Patel; ROH
  4. Karsten Parker; University of Tennessee Health Science Center
Carpal fractures and dislocations are caused by high-energy wrist trauma, commonly seen in active young adults, and can result in dysfunction if not treated timely. Accurate identification of these injuries on the initial radiographs is crucial for prompt management.

Educational Goals / Teaching Points
Our goal is to provide the reader with a simple checklist to read the wrist radiographs in an emergency setting and avoid missing carpal dislocations. First, we would get accustomed to the wrist anatomy with the help of diagrams and radiographs. We will emphasize the arcs of Gilula on frontal projection and alignment of the distal radius, lunate, capitate, and middle metacarpal base on the lateral projections. Knowing the ligamentous anatomy at the wrist and a brief overview of the wrist kinematics will further aid in understanding the fracture dislocations.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Up to 25 % of carpal dislocations can be missed on the initial radiographs. Perilunate dislocations occur in a sequential pattern as the supporting ligaments or carpals fail, starting at the scapholunate joint and proceeding to lunocapitate and finally affecting the lunotriquetral with lunate dislocation. We will present multiple examples of lunate and perilunate dislocations on plain radiographs and the role of CT when initial radiographs are indeterminate or detailed anatomy is warranted for surgical planning.

Radiography is the first line modality for evaluating a suspected wrist injury. Missing the diagnosis can lead to a significant limitation of movement and pain to the patient and medicolegal consequences to the radiologist. Being aware of radiographic signs of carpal injuries increases the diagnostic accuracy and helps in suggesting further modalities for evaluation.