Single-Stage Posterolateral Transmass Corridor for Excision, Stabilization, and Open Vertebroplasty of C2 Vertebral Body Lesions: A Technical Note

ABSTRACT
AIM: Lesions of the C2 vertebral body and odontoid process are challenging to manage due to complex regional anatomy and the inherent risk of atlantoaxial instability. Conventional transoral and anterior approaches carry well-recognized limitations. We describe the first clinical application of a posterolateral transmass corridor for open C2 vertebroplasty, combined in a single session with intralesional excision and C1-2 fixation, in a case of odontoid-localized giant cell reparative granuloma (GCRG).
MATERIAL and METHODS: A 36-year-old woman presented with progressive neck pain. Imaging revealed an expansile osteolytic C2 vertebral body and odontoid lesion with preserved posterior cortical continuity confirmed on three-plane computed tomography (CT). Dynamic radiographs demonstrated functional atlantoaxial instability (atlantodental interval, 4.11 mm in flexion). After C1-2 instrumentation, a posterolateral transmass corridor was established by resection of the medial aspect of the C1 lateral mass with minimal removal of the medial edge of the C2 superior articular facet. Intralesional excision was performed under direct microscopic visualization, followed by open C2 vertebroplasty using polymethylmethacrylate (PMMA) under fluoroscopic guidance.
RESULTS: The patient awoke neurologically intact with significant pain relief and no surgical complications. Postoperative CT confirmed appropriate cement containment without leakage, secure instrumentation, and correction of atlantoaxial instability. Postoperative MRI documented absence of spinal cord compression. Histopathology with negative H3G34W immunostaining confirmed GCRG. At 6-month follow-up the patient remained asymptomatic, with stable instrumentation and cement position on follow-up CT.
CONCLUSION: In carefully selected patients with preserved posterior cortical integrity, the posterolateral transmass corridor enables safe single-stage intralesional excision, C1-2 stabilization, and open C2 vertebroplasty while avoiding anterior or mucosal corridors. This combined posterior strategy may represent an alternative to existing anterior and percutaneous techniques for selected upper cervical spine lesions.

Atlantoaxial instability Cervical vertebrae Craniovertebral junction Giant cell reparative granuloma Odontoid process Vertebroplasty