Occipitocervical Reconstruction Through Direct Lateral and Posterior Approach for the Treatment of Primary Osteosarcoma in the Atlas

Study design. Case report. Objective. To report a new surgical technique of the primary cervical osteosarcoma in the atlas. Summary of Background Data. Primary osteosarcoma of the atlas is extremely rare. This is the first report that describes a surgical treatment of the primary osteosarcoma in the atlas. Resection of an osteosarcoma in the atlas is very difficult because of the complex and important anatomic structures that surround it, and secure reconstruction of the atlas is difficult as well. Methods. A 48-year-old man was referred to our institute with a 10-month history of a palpable painful mass on the right posterior neck. His neck mass was diagnosed as chondroblastic osteosarcoma by open bone biopsy. The plain radiograph of the lateral cervical spine revealed the osteoblastic lesion of the vertebra and an extraosseous mass formation from the C1 to C3 vertebrae. Computed tomography of the cervical spine revealed approximately a 7 x 3 x 7 cm(3)-sized extraosseous calcified mass that originated from the right lateral mass of the atlas. The magnetic resonance imaging of the cervical spine did not show any spinal cord compression. Results. The patient underwent excision of this tumor using the direct lateral approach and reconstruction of the lateral mass of the atlas. On gross examination of the mass, there was a reactive thin membrane ("pseudomembrane") between soft tissue and tumor. At 3 months after surgery, the computed tomographic scan showed the solid fusion state of the occipitocervical joint. He rarely complained of any problems except for mild limitation of neck motion. Conclusion. We report a rare case of complete excision of an osteosarcoma of the C1 lateral mass in our patient via a direct lateral and posterior approach to secure additional fixation of occipitocervical joint. We describe our technique for reconstructing the lateral mass of the atlas. This reconstruction technique will also be applicable to other resection surgeries involving the occipitocervical junction.