Use of an O-arm intraoperative computed tomography scanner for closed reduction of posterior sternoclavicular dislocations Jaron P. Sullivan, MD*, Brian A. Warme, MD, Brian R. Wolf, MD, MS Department of Orthopedics, University of Iowa Hospitals and Clinics, Iowa City, IA, USA Posterior sternoclavicular (SC) dislocations and fracture-dislocations are rare injuries that have been esti- mated to occur with an incidence of less than 0.1% of all dislocations. 5 They can be benign; however, there are reports of injury to the mediastinum and death if not treated appropriately. 4,6,8 In the acute setting it is imper- ative to make the appropriate diagnosis and for reduction to be performed. Patient history, clinical examination, and plain radiographs can help clinicians narrow down the differential, but the definitive diagnosis is sometimes elusive. Because an orthogonal view to the anteroposterior radiograph of the SC joint cannot be easily obtained, it is challenging to make the diagnosis with plain radiographs or fluoroscopy. Ultrasound has been used to confirm reduction, 7 but the images can be difficult for people to interpret, with unknown reliabilities at most institutions. Computed tomography (CT) scans are widely accepted as the gold standard for diagnosis. 1,2 However, use of CT for assessment of a closed reduction attempt is difficult because it requires patient transport to the CT scanner, either with intubation or after awaking the patient, knowing that if the joint remains dislocated, then the patient has to return to the operating room. We have recently used an O-arm intraoperative CT system (Med- tronic Navigation, Louisville, CO, USA) to verify reduc- tion in 2 cases, which to our knowledge has not been used previously. This obviated the need for immediate post- operative CT to verify reduction and the possibility of a second trip to the operating room with sedation for open reduction if the initial attempt had failed. Technique The reduction of a posterior SC dislocation is best accomplished in the controlled environment of an operating room with proper anesthesia, auxiliary teams, and moni- toring. Reduction can be painful for the patient, and general anesthesia can provide both pain control and skeletal muscle relaxation to assist with the reduction. It is also recommended that auxiliary teams such as vascular or cardiothoracic surgery personnel be made aware of the procedure in case a life-threatening complication occurs when the clavicle is reduced from its impaled position in the mediastinum. At our institution, we use the abduction traction technique. 3 The patient is placed supine on the table with a sandbag or towel under the center of the thoracic spine, elevating the affected shoulder off the table. Lateral traction is applied, and the arm is slowly extended. Manual anterior traction is applied directly to the clavicle at the same time. If the clavicle is unable to be grasped and reduction is not obtained with initial attempts, a sterile towel clamp is placed onto the medial one-third of the clavicle, which is in a sterile field. This allows for firm anterior traction and reduction. If this is unsuccessful, then open reduction is indicated. Often, with closed reduction, there is an audible or palpable pop as the joint is reduced; however, this does not prove reduction. After the reduction, No institutional review board approval needed. *Reprint requests: Jaron P. Sullivan, MD, University of Iowa Hospitals and Clinics, 200 Hawkins Dr, Ste 1700JP, Iowa City, IA, USA. E-mail address: jaron-sullivan@uiowa.edu (J.P. Sullivan). J Shoulder Elbow Surg (2012) 21, e17-e20 www.elsevier.com/locate/ymse 1058-2746/$ - see front matter Ó 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. doi:10.1016/j.jse.2011.07.015