Reconstruction of the C-1 lateral mass with a titanium expandable cage after resection of eosinophilic granuloma in an adult patient.

Spinal involvement occurs frequently in cases of eosinophilic granuloma (EG), but surgical treatment is limited primarily to those with spinal instability. Involvement of the cervical spine is rare, but primarily occurs in the vertebral bodies, and is normally amenable to anterior corpectomy and spinal reconstruction. The authors describe a 27-year-old man with pathologically proven EG who presented with complete destruction of the C-1 lateral mass requiring spinal stabilization. A titanium expandable cage was used to reconstruct the weight-bearing column from the occipital condyle to the superior articular surface of C-2 from a posterior approach, with preservation of the traversing vertebral artery. To the authors' knowledge, this is the first reported instance of reconstruction of the C-1 lateral mass using an expandable metal cage, which facilitated preservation of the vertebral artery.