Update on imaging of the cervical spine in rheumatoid arthritis

Rheumatoid arthritis is a multisystem, autoimmune, inflammatory disorder with numerous musculoskeletal manifestations. Involvement of the cervical spine is common and may result in severe complications due to synovitis, erosions, pannus formation, spinal instability and ankylosis. The purpose of this article is to review the current role of imaging in the rheumatoid spine, with emphasis on radiographs and MRI.

Bow hunter syndrome in rheumatoid arthritis: illustrative case

BACKGROUND

Rheumatoid arthritis (RA) frequently features degeneration and instability of the cervical spine. Rarely, this degeneration manifests as symptoms of bow hunter syndrome (BHS), a dynamic cause of vertebrobasilar insufficiency.

OBSERVATIONS

The authors reviewed the literature for cases of RA associated with BHS and present a case of a man with erosive RA with intermittent syncopal episodes attributable to BHS as a result of severe extrinsic left atlantooccipital vertebral artery compression from RA-associated cranial settling. A 72-year-old man with RA-associated cervical spine disease who experienced gradual, progressive functional decline was referred to a neurosurgery clinic for evaluation. He also experienced intermittent syncopal events and vertiginous symptoms with position changes and head turning. Vascular imaging demonstrated severe left vertebral artery compression between the posterior arch of C1 and the occiput as a result of RA-associated cranial settling. He underwent left C1 hemilaminectomy and C1–4 posterior cervical fusion with subsequent resolution of his syncope and vertiginous symptoms.

LESSONS

This is an unusual case of BHS caused by cranial settling as a result of RA. RA-associated cervical spine disease may rarely present as symptoms of vascular insufficiency. Clinicians should consider the possibility, though rare, of cervical spine involvement in patients with RA experiencing symptoms consistent with vertebral basilar insufficiency.

Iatrogenic Vertebral Artery Injury During Anterior Cervical Spine Surgery: A Systematic Review

BACKGROUND

Iatrogenic vertebral artery injury (VAI) during anterior cervical surgery is rare but potentially catastrophic.

METHODS

Causes, presentation, diagnosis, management, prognosis, and prevention of VAI were reviewed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. English language studies and case reports published from 1980 to 2017 were retrieved. Data on diagnosis, surgical procedures and approach, site and cause of VAI, management, outcomes, and vertebral artery (VA) status were extracted.

RESULTS

In 25 articles including 54 patients, VAI was diagnosed during or after surgery commonly indicated for cervical degenerative diseases (64%), tumors (14%), and trauma (9%). The incidence of VAI for each side was similar regardless of approach. Common presentations were unexpected copious surgical bleeding, delayed hemorrhage of pseudoaneurysm with neck swelling, dyspnea, hypotension, and cervical bruits caused by arteriovenous fistula. Causes included drilling (61%), instrumentation (16%), and soft tissue retraction (8%). Direct exposure or angiography confirmed VAI. Ten patients had VA anomalies; collateral status was verified in 9 before definitive treatment. Tamponade was adopted for urgent hemostasis in most cases but with a high incidence of pseudoaneurysm (48%). Unknown VA status increased occlusion risk and neurologic sequelae (41%). VA repair and stent placement had excellent outcomes.

CONCLUSIONS

Extensive lateral decompression, loss of landmarks, and anatomic variations or pathologic status of VA increased VAI risk. Evaluation of collateral vessels before definitive treatment helped determine appropriate management and avoid neurologic sequelae. Tamponade was not recommended as definitive treatment. Meticulous preoperative evaluation, cautious intraoperative manipulation, and real-time radiographic guidance reduced VAI risk.

Risk factor analysis and decision-making of surgical strategy for V3 segment anomaly: significance of preoperative CT angiography for posterior C1 instrumentation

BACKGROUND CONTEXT

Awareness of vascular anomalies is crucial to avoid iatrogenic injuries during surgical procedure. Although V3 segment anomaly has been well described, the incidence of V3 segment anomaly has been rather variable in the literature, and there are few reports regarding the adequate surgical strategy for each type of V3 segment anomaly.

PURPOSE

This study aimed to analyze the incidence of V3 segment anomaly and demonstrate the importance of recognizing vertebral artery (VA) anomaly in deciding the surgical strategy for C1 screw placement.

STUDY DESIGN

A retrospective cohort study was carried out.

PATIENT SAMPLE

The sample included 147 patients who underwent C1 posterior instrumentation and preoperative three-dimensional computed tomography angiography (3D CTA).

OUTCOME MEASURES

The primary outcome of this study was the incidence of V3 segment anomaly using preoperative CTA, and the secondary outcome was the risk factor analysis of the V3 segment anomaly.

METHODS

There were 147 patients who underwent C1 posterior instrumentation to treat various kinds of upper cervical disease. The 3D CTA of the patients were assessed preoperatively to identify the anomaly of the VA. Each surgical technique of C1 posterior instrumentation was decided upon the shape and the course of the VA around the atlas.

RESULTS

During the study period, 11 cases of V3 segment anomaly (7.5%) were found on 3D CTA. Persistent intersegmental artery was found in nine cases and was the most common variant of VA anomaly. Early branch of posterior inferior cerebellar artery was found in three cases. Most of V3 segment anomaly was found unilaterally, but there were two cases with bilateral V3 anomaly. Seven cases (63.6%) were associated with congenital bony abnormality around craniovertebral junction (CVJ), such as occipital assimilation, Klippel-Feil syndrome, and os odontoideum. V3 segment anomaly was significantly common in the cases with bony abnormality (29.2% (7/24) vs. 3.6% (4/123), p<.05). Compared with patient without bony abnormality, the odds ratio was 10.78 (95% CI: 2.88-40.37) for those with congenital bony abnormalities. Rheumatoid arthritis was not a risk factor of V3 segment anomaly (p=.391).

CONCLUSIONS

The course of the VA is heterogenous, and the V3 segment anomaly of the VA is more common in the cases with congenital bony abnormalities around CVJ. Therefore, preoperative radiological studies should be performed to identify V3 segment variations and reduce the risk of VA injury. To avoid significant morbidities associated with VA, surgical technique of C1 posterior instrumentation should be decided depending upon the V3 segment anomaly. A more optimal entry point and trajectory for C1 fixation can be selected.

Vertebral artery dissection in rheumatoid arthritis with cervical spine disease

A 59-year-old woman with long-standing active rheumatoid arthritis presented with posterior circulation ischemic stroke after vertebral dissection. She had severe multilevel degenerative changes of her cervical spine. She did not have classic stroke risk factors nor evidence of atherosclerotic disease or other systemic diseases. The most likely mechanism appears to be injury of the artery wall by an osteophyte, causing dissection that resulted in thrombosis and subsequent embolic strokes.