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 gamma probe-guided high-speed drill excision.

Objectives: To document the surgical technique consisting of a combination of both computer-assisted and gamma probe-guided high-speed drill excision for osteoid osteoma of the spine.

Summary 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 gamma-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 gamma probe control may result in complete intralesional excision without sacrificing more bone than necessary.

Methods: One day before surgery, patients were injected with radioactive 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 gamma 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 gamma 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.