Degenerative cervical myelopathy caused by posttraumatic severe atlantoaxial dislocation over 10 years in patients with right vertebral artery hypoplasia: A case report of successful management

Abstract

Introduction

Degenerative cervical myelopathy caused by long-standing neglected AAD is rare, especially in severe cases. Combined with the exceptional right vertebral artery hypoplasia condition, treatment must be integrated into multitherapy to avoid fatal complications.

Case

A 55-year-old man presented with degenerative cervical myelopathy caused by posttraumatic severe atlantoaxial dislocation for more than 10 years in patients with right vertebral artery hypoplasia. After treatment with halo traction and C1 lateral mass, as well as C2 pedicle screw fixation combined with bone autoplasty, the condition was resolved.

Conclusion

This is an extremely rare and severe condition (anatomical damage, long-term sequelae, degree of paralysis on admission, and complete hypoplasia of the right vertebral artery). The treatment strategy is consistent with early favorable outcomes.

Highlights

• •Combined with the exceptional right vertebral artery hypoplasia condition, the surgery is might life-threatening, and multitherapy is needed to avoid fatal complications.
• •After treatment with Halo traction and C1 lateral mass and C2 pedicle screw fixation combined with bone autoplasty, the condition was resolved with early favorable outcomes.

1. Introduction

Traumatic atlantoaxial dislocation (AAD) is a rare but usually fatal injury. To our knowledge, no study has reported long-standing neglected AAD for more than 10 years in a patient with right vertebral artery hypoplasia who survived and later experienced degenerative cervical myelopathy (DCM). This case was written according to the SCARE statement guidelines, and the patient consented to this publication [1].

The singularity of our case is that the MSCT scan showed right vertebral artery hypoplasia, which could have required a more complex surgical procedure. In our institution, halo traction combined with C1 lateral mass and C2 pedicle screw fixation for severe AAD showed improved postoperative clinical improvement in patients [2]. Moreover, posterior C1 lateral mass and C2 pedicle screw fixation carry a potential risk of injury to the vertebral artery, which can be fatal [3]. A case of an anomalous single midline vertebral artery and AAD (no right vertebral artery) was a 34-year-old male patient who presented with features of high DCM. However, the patient's condition was accompanied with inadvertent intra-operative VA injury, which was ultimately sealed to control brisk bleeding that would require stenting. The patient did not survive and expired after 5 days due to brain edema secondary to compromised anomalous intracranial circulation [4].

However, no study has reported DCM caused by long-standing neglected traumatic posterior AAD and its late sequela involving the atlantoaxial joints. Therefore, in this report, we present a patient with DCM caused by long-standing neglected AAD in the special condition of right vertebral artery hypoplasia, which was successfully treated with halo traction and C1 lateral mass and C2 pedicle screw fixation combined with bone autoplasty.

2. Case report

A 55-year-old man presented with symptoms of DCM. Medical history: On history, the patient had experienced trauma in the neck after a work accident and was hit on the head and neck by a log 10 years ago. After the accident, cervical spine pain decreased and disappeared after 2 months, but he did not undergo surgery. Since then, he has worked as a farmer for 10 years without significant problems but almost impossible daily activity at admission. Signs and symptoms: For 2 months, he presented with neck pain (neck visual analog scale score: 5), decreased muscle strength, numbness of both upper and lower extremities, and hand clumsiness. On admission, neurologic examination revealed that muscle strength of both upper and lower extremities decreased with MRC at the left hand (2/5), right hand (3/5), and both legs (3/5). He reported mild dysuria, constipation, and exaggerated deep tendon reflexes in the bilateral upper and lower extremities. The Hoffman sign (+) on both sides was present.

2.1. Image evaluation

X-ray: Fig. 1. X-ray before halo traction with severe AAD.

Fig. 1.

Halo traction results.

Pre-traction lateral radiograph of the cervical spine showing severe AAD (1A) and after Halo Traction (B, C).

MSCT showed right vertebral artery hypoplasia (Fig. 2).

Fig. 2.

MSCT shows right vertebral artery hypoplasia.

Fig. 3 shows the computed tomography scan of the cervical spine with images of old fractures with severe AAD, a narrowing left C1-C2 joint, and an anteroposterior spinal canal diameter of less than 1 cm.

Fig. 3.

Computed tomography of the cervical spine

Images of old fractures with severe AAD, narrowing left C1-C2 joint; anteroposterior diameter of spinal canal less than 1 cm.

Diagnosis: DCM caused by posttraumatic severe AAD of more than 10 years in the patient with right vertebral artery hypoplasia.

2.2. Treatment plan

Planning: Consultation with spine surgeon, cardiologist - vascular specialist, vascular surgery specialist, imaging and radiographic intervention, anesthesiologist, ICU, and rehabilitation. Explain to the family the risks during and after treatment, especially the risk of residual vertebral artery damage (left side, causing cerebral ischemia, coma, and death).

Treatment strategy: Halo traction and C1 lateral mass and C2 pedicle screw fixation combined with bone autoplasty in a patient with severe AAD.

Step 1: Halo traction: In 5 days (Fig. 1: Halo traction results).

Step 2: Planning before surgery.

Step 3: Surgery: C1 lateral mass and C2 pedicle screw fixation combined with bone autoplasty (Fig. 4: Surgery).

Fig. 4.

Surgery.

2.3. Postoperative results

Clinical results: Post-operative days (POD) results: Extubation after surgery, self-breathing 3 h after surgery. POD 1: VAS score 3; improved the situation of weakness and numbness compared with before surgery with MRC of four limbs 3/5; No dysuria or constipation. POD 6: No numbness, dysuria or constipation; walking using U-shape support. POD 9: Discharged.

Image Results: Fig. 5: Postoperative CT image result and Fig. 5: Pre- and Postoperative MRI showed improvement after surgery (Fig. 6).

Fig. 5.

Postoperative CT image result.

Fig. 6.

Pre and postoperative MRI

A. Pre-operative show spinal cord decompression at C1, spinal cord edema.

3. Discussion

On cerebral angiography, the incidence of a unilateral aplastic distal vertebral artery was recorded as 0.2 % of patients. After combining BPAS-MRI and MRA to evaluate an asymptomatic population, aplasia of the unilateral distal vertebral artery was observed in 11 (4.6 %) of 237 asymptomatic individuals who received brain MRI during a “brain check-up examination.” [5]. One example of AAD with right vertebral artery hypoplasia was found in the literature. Transoral decompression and posterior fusion were proposed due to a fixed AAD. However, this case was unsuccessful; the patient died unexpectedly 5 days after surgery [4].

Consequently, proper therapy is necessary. Our facility has extensive experience treating AAD, particularly severe cases [2]. Furthermore, the rate of vertebral artery injury ranged from 4.1 % to 8.2 % for this type of surgery [6], [7]. Our study used C1 lateral mass and C2 pedicle screw fixation combined with bone autoplasty. In a study using 85 screws, no vascular injuries were observed. However, CT scans revealed that eight C2 pedicle screws (21 %) caused vertebral artery groove gross violations. This study highlights the significance of meticulous postoperative evaluation and surgical technique when inserting these screws [8]. CT angiography or magnetic resonance angiography was performed after surgery to determine the possibility of VA damage in instances with malpositioned screws [9]. Compared with the C1–C2 transarticular technique, the risk of vertebral artery injury is much lower with the placement of a pedicle screw [10]. Another study suggested that the surgeon can choose either approach and anticipate comparable anatomic risks of vertebral artery injury [11]. In percutaneous transarticular screw fixation, the anterior approach provides a lower anatomic risk of vertebral artery injury than the posterior approach. It is one of the reasons why percutaneous anterior transarticular screw fixing may become increasingly significant as an alternative surgical treatment for atlantoaxial subluxation [12]. Evaluation in three dimensions before surgery may be necessary for determining the optimal surgical strategy. In conjunction with past therapy results for severe AAD cases, our outcomes in this case are intended to assist another surgeon with options and experiences when faced with this type of situation.

4. Conclusion

This condition is extremely rare and severe (anatomical damage, long-term sequelae, degree of paralysis on admission, and complete hypoplasia of the right vertebral artery). The treatment strategy is consistent with early favorable outcomes.

Consent

Written informed consent was obtained from the patient to publish this case report and accompanying images.

Ethical approval

Ethical approval is exempt/waived by our institution.

Funding

None.

Guarantor

H.G.D.

Registration of research studies

N/A.

CRediT authorship contribution statement

Hoang Gia Du: Conceptualization, Writing – review & editing. Dinh Cong Pho: Writing – original draft. Vu Xuan Phuoc: Writing – original draft. Nguyen Van Trung: Conceptualization, Writing – original draft.

Declaration of competing interest

None.