OTA 1997 Posters - Spine Fractures

Three Cases of Atlantoaxial Rotatory Dislocation in Polytraumatized Patients

Makoto Kawai, MD, Akira Oizumi, MD, Yosiaki Hara, MD, Yasumasa Shirai, MD, Yasuhiro Yamamoto, MD

Dept. of Emerg and CCM, Nippon Medical School, Tokyo, Japan

Introduction: Traumatic rotatory dislocation at the atlanto-axial joint (aa joint) is a rare injury as a result of trauma in an adult. It may be difficult to diagnose early because of radiographic problems in visualizing the complex anatomical structures in polytraumatized or impaired consciousness patients. We are going to report three cases of this difficult to detect injury.

Case 1: A 22 year-old female MCA patient was diagnosed as cerebral contusion, open fracture of mandible and facial nerve injury, disturbed consciousness (GCS: 11). Her consciousness was improved after the surgery, however, her neck rotated and was fixed in one position. An unusual contour at aa joint was shown from conventional CAT scan and definitive diagnosis of rotatory dislocation of aa joint was made from 3D CAT scan. We immobilized her dislocated joint with the halo vest for 2 months after anatomical reduction was achieved by direct skull traction.

Case 2: A 52 year-old female MA patient with disturbed consciousness (GCS: 8) and hypotension (90mmHg) was diagnosed as left rib fracture with tension pneumothorax, open fracture of right tibia/fibula and cerebral contusion with cerebral hemorrhage. Her consciousness remained impaired and typical "Cock Robin" head positioning was found during hospitalization. Conventional and 3D CAT scan showed rotatory dislocation at aa joint. Two months immobilization with halo vest was used for her treatment.

Case 3: A 36 year-old female patient fell in a suicide attempt. Impaired consciousness (GCS: 6) and shock (70/40mmHg) were noted during the initial assessment, she was diagnosed as right rib fractures with hemopheumothorax, skull fracture with bilateral epidural hematoma, facial bone fracture, bilateral wrist fractures and pelvic fracture. Chest tube drainage, decompressive craniotomy with removal of epidural hematoma, open reduction and internal fixation of facial bone, pelvis and bilateral wrist fracture were performed, respectively. Unfortunately, we found abnormality at aa joint by chance from conventional CAT scan which was originally done for investigation of facial bone fracture, and definitive diagnosis was made from 3D CAT scan.

Discussion: It is extremely hard to detect rotatory dislocation of aa joint in polytraumatized patients at the initial assessment, especially in patients with impaired consciousness. In our cases, all of them were accompanied by disturbed consciousness due to craniofacial injury; this might contribute to our delayed diagnosis. However, a great rotatory force to the upper cervical spine should be given to those of craniofacial injury patients at the time of injury, the characteristic "Cock Robin" head positioning strongly indicates this type of dislocation despite the fact these patients cannot complain of any neck problems. Furthermore, since it is usually difficult to obtain open mouth x-ray projection for upper cervical spine in polytraumatized patients, we think conventional CAT scan is essential for screening and 3D CAT scan has the advantage for making definitive diagnosis of upper cervical spine injury, respectively.