• Atlantoaxial dislocation
• Closed reduction
• Spinal injuries
• Trauma

• Atlas
• Dens axis
• Geriatric patient
• Internal fixation
• Spine

• Aged
• Female
• Humans
• Atlanto-Axial Joint/injuries
• Atlanto-Axial Joint/surgery
• Atlanto-Axial Joint/diagnostic imaging
• Cervical Vertebrae/surgery
• Cervical Vertebrae/injuries
• Cervical Vertebrae/diagnostic imaging
• Joint Dislocations/surgery
• Joint Dislocations/diagnostic imaging
• Treatment Outcome

• Atlanto-axial dislocation
• Atlanto-occipital assimilation
• Case report
• Cervical spine dislocation
• Closed manual reduction
• Neurologic deficit

• Atlanto-axial subluxation
• Hand as the foot
• Medical education

• Humans
• Joint Dislocations/diagnostic imaging
• Joint Dislocations/surgery
• Hand
• Upper Extremity
• Foot

• atlantoaxial dislocation
• cerebrospinal fluid leakage
• infection
• open reduction
• posterior occipitocervical fusion
• transoral odontoidectomy

Posterior atlantoaxial dislocations (i.e., complete anterior odontoid dislocation) without C1 arch fractures are a rare hyperextension injury most often found in high-velocity trauma patients. Treatment options include either closed or open reduction and optional spinal fusion to address atlantoaxial instability due to ligamentous injury.

A 60-year-old male was struck while on his bicycle by a truck and sustained an odontoid dislocation without C1 arch fracture. Imaging findings additionally delineated a high suspicion for craniocervical instability. The patient had neurological issues due to both a head injury and ischemia secondary to an injured vertebral artery. He was stabilized and transferred to our facility for definitive neurosurgical care.

The patient underwent a successful transoral digital closed reduction and posterior occipital spinal fusion via a fiducial-based transcondylar, C1 lateral mass, C2 pedicle, and C3 lateral mass construct. This unique reduction technique has not been recorded in the literature before and avoided potential complications of overdistraction and the need for odontoidectomy. Furthermore, the use of bone fiducials for navigated screw fixation at the craniocervical junction is a novel technique and recommended particularly for placement of technically demanding transcondylar screws and C2 pedicle screws where pars anatomy is potentially unfavorable.

Traumatic posterior atlantoaxial dislocation (PAAD) without fracture of the odontoid process is a rare injury. Closed reduction by skull traction under C‐arm fluoroscopic guidance and open reduction have been reported previously for the treatment of PAAD.

To report a rare case of PAAD without fracture treated by closed manual reduction and posterior fixation. To provide a new method—atlantoaxial dynamic test—for confirming the integrity of the transverse ligament after reduction and evaluate the ideal treatment strategy for traumatic PAAD without fracture of the odontoid process or rupture of the transverse ligament.

A 54‐year‐old woman was riding in the passenger seat when her vehicle was rear‐ended by a car. X‐ray and computed tomography (CT) scans were used to diagnose PAAD without a related fracture. Closed manual reduction under C‐arm fluoroscopy was performed after applying general anesthesia via sober intubation, and the integrity of the transverse ligament was confirmed by the atlantoaxial dynamic test with C‐arm fluoroscopy. Then, pedicle screw internal fixation via the posterior approach was applied to maintain atlantoaxial stability.

The procedure was performed uneventfully, and the patient was able to move out of bed on the first day after surgery with Philadelphia cervical gear. During a 2‐year follow‐up period, imaging data demonstrated no instability of the atlantoaxial complex.

Closed manual reduction under C‐arm fluoroscopy is an easy and effective method for PAAD. The integrity of the transverse ligament can be confirmed by C‐arm fluoroscopy through the atlantoaxial dynamic test after reduction. Pedicle screw internal fixation via the posterior approach can provide sufficient stability.

• Atlantoaxial dislocation
• Manual reduction
• Sober intubation
• Transverse ligament

In general, atlantoaxial dislocation is rare due to the stability of the C1-C2 complex. Traumatic atlantoaxial dislocations are usually anterior and accompanied by odontoid fractures. Posterior atlantoaxial dislocations are rare, and complete posterior dislocation without associated fracture is even more rare. A case of early recurrence of posterior atlantoaxial dislocation without fracture being in therapy of first closed reduction and then open reduction has not been previously reported.

A 45-year-old female presented with traumatic posterior atlantoaxial dislocation (TPAD) of C1-C2 without associated fractures, and Frankel Grade B spinal cord function. She was successfully managed by immediate closed reduction under skull traction. Unexpectedly, 17 d later, re-dislocation was discovered. On day 28, closed reduction was performed as before but failed. Then, open reduction and posterior internal fixation with autologous iliac bone grafts was performed. By 6 mo after surgery, atlantoaxial joint fusion was achieved, and neurological function had recovered to Frankel Grade E. At 12 mo follow-up, she had lost only 15° of cervical rotation, and atlantoaxial complex instability in joint flexing and extending were no longer observed under fluoroscopy.

Early assessment of transverse ligament is critical for TPAD without fracture avoiding re-dislocation after closed reduction.

• Reoccurrence
• Traumatic posterior atlantoaxial dislocation
• Without fracture
• Transverse ligament
• Case report

Posterior atlantoaxial dislocation (PAD) is a rare type of upper cervical spine disease. We sought to describe a unreported case of old PAD with os odontoideum (OO) and atlas hypoplasia (AH) and our unique treatment approach consisting of C1 single door laminoplasty with C1-3 posterior fixation and fusion.

A 70-year-old male patient who suffered from progressive aggravating numbness and limb weakness for 4 years without trauma, was diagnosed with old PAD with OO and AH. The patient underwent closed reduction and C1 single door laminoplasty with C1-3 posterior fixation and fusion instead of C1 laminectomy with occipitocervical fusion. During the 3-year follow-up, he was able to walk by himself instead of using a wheelchair and with a ± 25° range of head rotation as well as a ± 10° range of flexion-extension. Three-year follow-up images showed satisfactory reduction and fusion.

C1 single door laminoplasty with cervical fusion in PAD combined with spinal cord compression could be a suitable and effective surgical option. Compared with laminectomy and occipitocervical fusion, it retains more cervical range of motion, has a smaller incision and provides an adequate bone grafting space for atlantoaxial fusion.

• Posterior atlantoaxial dislocation
• C1 laminoplasty
• Os odontoideum
• Atlas hypoplasia
• Case report

• Atlantoaxial dislocation
• Skull traction
• Transoral–posterior

• C1 Jefferson fracture
• Posterior atlantoaxial dislocation
• Vertebral artery occlusion

• Accidents, Traffic
• Atlanto-Axial Joint/injuries
• Humans
• Joint Dislocations/complications
• Joint Dislocations/surgery
• Male
• Middle Aged
• Quadriplegia/etiology
• Spinal Cord Injuries/etiology

• Atlanto-axial
• C1-C2
• Cervical traction
• Cervical trauma
• Odontoid fractures
• Posterior dislocation
• Vaccaro

• Posterior atlantoaxial dislocation
• posterolateral pedicle fixation
• transverse ligament
• traumatic