NAVIGATION ASSISTED CERVICAL SPINE OSTEOID OSTEOMA EXCISION: A CASE REPORT

Abstract: Introduction: Osteoid osteoma is a rare benign bone-forming tumor which is typically found in a patient less than 30 years of age. Males are more commonly affected than females with a ratio of 2:1. [1] . Spinal involvement accounts for about 10% of all osteoid osteomas, with the lumbar spine being the most affected area, followed by cervical spine. Case Presentation: A 16 years old male presented to our hospital with 18 months history of neck pain with occasional left upper limb numbness. There was no history of trauma or injury to the neck. Neck pain is worsened at night and improves with NSAIDs. Physical examination revealed decreased sensation over left C5 dermatome distribution and positive spurling test, and the rest of the physical examination was unremarkable. There were no signs of myelopathy. MRI was done for the patient in another hospital, which showed a C4 vertebral body lesion in the left neural foramen and paraspinal soft tissue measuring 2.7 x 1.8cm. Upon these findings, we admitted the patient to evaluate possible neoplastic or infectious causes. Laboratory tests, TB-PCR, acid-fast bacillus, inflammatory markers were all within the normal range. CT cervical, chest, abdomen and pelvis was done for the patient, and it was unremarkable except for what was found in MRI. As a result, further investigation such as a bone scan was done and it showed Osteoid osteomas. As conservative treatment was ineffective in relieving the patient's symptoms, we planned surgical excision. Due to the tumor's location, we preferred to do a posterior approach with a navigation-assisted excision system. The patient received general anaesthesia and was placed on a prone position. The posterior neck was prepped and draped in the usual manner. Under fluoroscopic guidance, entry point was located. After exposure of the posterior cervical spine from C3 proximally to C5 distally, a navigation marker with navigation was inserted, and then we excised osteoid osteoma in one piece . The resected tissue was sent for histopathologic examination and confirmation of osteoid osteoma. Postoperatively, the patient tolerated surgery well and mobilized the following day. A cervical x-ray was done before discharge on day three post-operation. Conclusion: Osteoid osteoma is a rare benign bone-forming tumor which is typically found in a patient less than 30 years of age. Spinal involvement accounts for about 10% of all osteoid osteomas, The difficulty of cervical osteoid osteomas is that it lies near adjacent vital structures such as vertebral artery, spinal cord, and nerve roots. The navigation served us several advantages in resecting the osteoid osteoma, we were able to utilize a less invasive approach with a smaller incision, we are able to visualize and remove the thick sclerotic cortex to gain access to the tumor, without violating the facet joint and cause an iatrogenic instability. Keywords: osteoid osteoma, cervical spine, navigation system