Realignment of Basilar Invagination by C1-C2 Joint Distraction: A Modified Approach to a Paradigm Shift

A Case Report of Complete Dislocation of Atlantoaxial Joint due to a Traumatic and Pathological Axial Lesion

BACKGROUND

Atlantoaxial dislocation usually results in sudden death. The patient had never found any axial lesion before, and the atlantoaxial joint dislocation was caused by rotation of the neck due to discomfort of the neck. The patient was given surgical treatment after the rescue of respiratory and cardiac arrest during transportation, which was extremely rare and rarely reported.

METHODS

A 62-year-old male patient presented with limited cervical mobility after a violent rotation of the neck due to neck discomfort. X-ray and computed tomography (CT) scan suggested atlantoaxial dislocation. Sudden respiratory and cardiac arrest during transportation was immediately followed by continuous cranial traction and successful occipital and neck fusion operation.

RESULTS

After the successful rescue of endotracheal intubation, the patient was given continuous cranial traction. After the completion of CT scan, the patient was given occipital neck fusion, and 6 days after the surgery, the patient wore the skull-neck-thorax brace and walked freely.

CONCLUSION

Continuous cranial traction and posterior occipitocervical fusion are effective methods for treating axial pathological fracture with atlantoaxial dislocation.

LEVEL OF EVIDENCE

5.

Computed tomographic angiography to analyze dangerous vertebral artery anomalies at the craniovertebral junction in patients with basilar invagination

OBJECTIVE

Failure to detect dangerous anatomic vertebral artery anomalies (AVAAs) and dangerous functional vertebral artery anomalies (FVAAs) at the craniovertebral junction (CVJ) in patients with basilar invagination (BI) can result in major complications such as intraoperative vertebral artery injury, brain infarctions, and even death. Iatrogenic vertebral artery injury is a rare but severe complication of cervical spine surgery. We aimed to evaluate dangerous vertebral artery anomalies at the CVJ in patients with BI using computed tomographic angiography (CTA).

METHODS

CTA images of 61 BI patients were retrospectively analyzed to evaluate AVAAs and FVAAs at the CVJ. Dangerous AVAAs include a persistent first intersegmental artery (FIA), fenestration of the vertebral artery (FEN), and posterior inferior cerebellar artery with an extradural C1/2 origin (PICA-C1/2). Dangerous FVAAs include a dominant vertebral artery (DVA) and hypoplastic vertebral artery ending in the PICA (HVA-PICA) without joining the basilar artery.

RESULTS

Overall, 31 female and 30 male patients (mean age, 42.3 years) were included. The incidences of FIA, FEN, and PICA-C1/2 were 29.5 % (18/61), 3.3 % (2/61), and 3.3 % (2/61), respectively, whereas the incidences of DVA and HVA-PICA were 36.1 % (22/61) and 1.65 % (1/61), respectively.

CONCLUSION

Dangerous vertebral artery anomalies at the CVJ have a high incidence in patients with BI. Preoperative CTA is highly recommended in such patients to identify anomalous vertebral arteries and reduce the risk of intraoperative injury.

Reconsideration of the transoral odontoidectomy in complex craniovertebral junction patients with irreducible anterior compression

Background

Although the single-stage posterior realignment craniovertebral junction (CVJ) surgery could treat most of the basilar invagination (BI) and atlantoaxial dislocation (AAD), there are still some cases with incomplete decompression of the spinal cord, which remains a technique challenging situation.

Methods

Eleven patients were included with remained myelopathic symptoms after posterior correction due to incomplete decompression of the spinal cord. Transoral odontoidectomy assisted by image-guided navigation and intraoperative CT was performed. Clinical assessment and image measurements were performed preoperatively and at the most recent follow-up.

Results

Eleven patients were followed up for an average of 47 months. Symptoms were alleviated in 10 of 11 patients (90.9%). One patient died of an unknown reason 1 week after the transoral approach. The clinical and radiological parameters pre- and postoperatively were reported.

Conclusion

Transoral odontoidectomy as a salvage surgery is safe and effective for properly selected BI and AAD patients after inadequate indirect decompression from posterior distraction and fixation. Image-guided navigation and intraoperative CT can provide precise information and accurate localization during operation, thus enabling complete resection of the odontoid process and decompression of the spinal cord.