Role of intraoperative 3D C-arm-based navigation in percutaneous excision of osteoid osteoma of long bones in children.

Failures of treatment of osteoid osteoma (OO) are related to errors in exact localization and incomplete excision of the nidus. We report the successful percutaneous excision of OO in five patients (upper end of femur - 3, tibia - 2). All patients had a minimally invasive reflective array fixed to the same bone followed by registration of anatomy by Iso-C three-dimensional (3D) C-arm. A tool navigator was used to plan the keyhole incision then a sleeve was introduced which allowed the usage of burr and curette to remove the tumor. After excision, the 3D C-arm was again used intraoperatively to confirm the complete eradication of the nidus. Adequate material for histology was obtained in four patients that confirmed the diagnosis of OO. In one child postexcision scans were successful in identifying incomplete removal requiring further excision of the nidus. All patients achieved excellent pain relief and were asymptomatic at an average follow-up of 3.2 years. 3D C-arm-based navigation offers the advantage of excellent localization, percutaneous excision, and intraoperative confirmation of adequate excision.