# Lower cervical C6/C7 andersson lesion with upper cervical C1/C2 fracture in ankylosing spondylitis: a case report and literature review

## TL;DR

This case report describes a rare combination of cervical spine injuries in a patient with ankylosing spondylitis and details a two-stage surgical approach that led to successful recovery.

## Contribution

The paper presents a rare case of combined upper and lower cervical spine injuries in ankylosing spondylitis and proposes a surgical treatment strategy.

## Key findings

- A two-stage surgical approach achieved satisfactory recovery in a complex cervical spine trauma case.
- Radiological follow-up showed successful fracture union and optimal reduction of the atlantoaxial segment.
- Posterior fixation combined with corpectomy/fusion may be an effective treatment for this rare condition.

## Abstract

Cervical andersson lesions (ALs) are rare in patients with ankylosing spondylitis (AS), and even more rare in patients with simultaneous superior cervical atlantoaxial fracture and dislocation. Here, we present a case of C1 Jefferson fracture (C1 bilateral posterior arch fracture), C2 odontoid, lateral mass, vertebral fracture (nonclassic C2 hangman fracture), traumatic posterior atlantoaxial dislocation (AAD) and C6/C7 AL in a long-standing AS cervical spine. The patient with traumatic AS-related cervical fractures underwent a two-stage surgery. The stage I surgery involved a posterior atlantoaxial reduction and fixation surgery combined with C5/C6/T1/T2 posterior pedicle screw fixation plus C6/C7 decompression. One week later, C6/C7 anterior cervical corpectomy decompression and fusion (ACCF) with long anterior plate stabilization combined with iliac crest bone graft transplantation was performed for stage II surgery. The patient recovery observed during follow-up was satisfactory. Nine-month postoperative radiological images revealed fracture union of the upper and lower cervical spine with optimal reduction of the atlantoaxial segment. In conclusion, lower cervical ALs with simultaneous upper cervical C1/C2 fractures in the AS are very rare. Posterior C1-C2 fixation combined with C6-C7 AL corpectomy/fusion and posterior pedicle screw fixation may offer a desirable alternative approach for this complex case of cervical trauma. During treatment, complete decompression, effective reduction, and potent stabilization can comprehensively improve the clinical prognosis.