Osteoid osteoma of the spine: a novel technique using combined computer-assisted and gamma probe-guided high-speed intralesional drill excision.

Study Design. A report of five cases of thoracolumbar osteoid osteoma treated with combined computer-assisted and y probe-guided high-speed drill excision. Objectives. To document the surgical technique consisting of a combination of both computer-assisted and y probe-guided high-speed drill excision for osteoid osteoma of the spine. of Background Data. Curative treatment of spinal osteoid osteoma is performed by surgical intralesional excision of the nidus, but intraoperative localization of the nidus is often difficult. Although intraoperative γ-probe guidance facilitates accurate localization of the nidus, wide surgical resection of the bony structure is still mandatory to ensure removal of the nidus. Computer-assisted surgery has been proven to facilitate surgical intervention in spinal surgery. However, there is no clinical report regarding the application and usefulness of computer-assisted intralesional excision of the osteoid nidus. Excision of the nidus with a computer-assisted high-speed drill and intraoperative γ probe control may result in complete intralesional excision without sacrificing more bone than necessary. Methods. One day before surgery, patients were injected with radioactive 99 mTc-oxidronate. With a computed tomography-based electro-optical navigation system, real-time virtual images of the osteoid osteoma were generated by matching the intraoperative surface with preoperative computed tomography images. The osteoid osteoma was excised with the use of an image-guided high-speed drill, and complete excision was controlled with a y detection probe. Results. Excision of the nidus was confirmed by relief of symptoms, postexcision computed tomography scans, and histologic evaluation on clinical and radiographic follow-up observation. All five patients reported immediate complete relief of characteristic pain and no evidence of recurrence after 6 to 33 months of follow-up observation. There were no complications. Conclusions. The combination of both computer-assisted surgery and y probe-guided high-speed drill excision for osteoid osteoma of the spine helps to localize and excise the nidus of the osteoid osteoma with minimal bone resection of the posterior spinal structures.