Reconstructive Surgery Using Pedicle Screws Fixation Systems for Metastatic Lesions of the Cervical Spine: A Retrospective Analysis of 32 Patients**

Purpose: Spinal cord lesions caused by metastatic tumors of the cervical spine are serious problems as they can lead to quadriplegia and significantly affect the quality of life. The purpose of this study was to evaluate the outcomes of the spinal reconstructions using pedicle screw fixation systems in metastatic lesions of the cervical spine.

Methods: From 1991, a total of 32 patients with metastatic tumors in the cervical spine underwent reconstructive surgery using pedicle screw fixation systems. The average age at surgery was 57.4 years (range: 37 to 78). The most common primary tumors were breast (20%), kidney (13%), and lung cancers (13%). Four patients presented craniocervical lesions, and 28 patients had subaxial cervical lesions. Both anterior and posterior columns were involved in 30 patients, while anterior column alone in two. All patients suffered from severe pain, and 30 patients presented neurological lesions. Seventeen of 32 patients were unable to walk before surgery due to spinal cord lesions. Spinal reconstruction using cervical pedicle screw fixation systems was conducted in all patients as follows: posterior fixation alone in 25 patients; posterior fixation combined with anterior strut graft in seven. Occipitocervical fixation was conducted in four patients and cervical fixation was performed in 28. The VSP was used for early four cases while cervical pedicle screw systems were utilized for latter 28 patients.

Results: The average survival period for the remaining 28 patients was 11.3 months with a range from two weeks to 36 months. No patients died due to complications directly related to the surgery. All patients postoperatively experienced pain relief or improvement. Of 30 patients with spinal cord or nerve root lesions 25 patients demonstrated neurological improvement and no patient presented neurological deterioration. Of 17 patients who were unable to walk, 14 patients could walk postoperatively. Postoperative complications were observed in five patients including a radiculopathy caused by pedicle screw perforation into the neural foramen in one case. Other four complications were not directly related to pedicle screw insertion. Local recurrence or progression of the tumor was observed in five patients; two of them presented neurological deterioration; and one demonstrated screw loosening. Overall, postoperative neurological function and spinal stability was maintained during the entire follow-up period in 30 of 32 cases.

Discussion/Conclusion: In this series, pain relief and neurological improvements were provided by pedicle screw fixations in most patients with metastatic cervical lesion. Moreover, these improvements were maintained throughout the survival period in most cases. Furthermore, instrumentation failure was rarely observed even if the patients underwent posterior fixation alone in spite of affected anterior columns. Therefore, additional anterior strut graft can be avoided. In conclusions, spinal reconstruction using cervical pedicle screws provides significant pain relief and sufficient stability and maintains neurological improvement throughout the survival period. Anterior strut is rarely necessary even if both anterior and posterior column are affected by the tumors. However, anterior tumor resection and bone graft should be considered to achieve long-term spinal stability if primary tumor is controllable and life expectancy is relatively long.

**The FDA has not cleared a drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed in an "off label" use).