Objective: The cervical spine presents challenges in treating metastatic cervical spinal tumors (MCSTs). Although the efficacy of cervical pedicle screw placement (CPS) has been well established, its use in combination with 5.5-mm rods for MCST has not been reported. This study aimed to evaluate the efficacy of CPS combined with 5.5-mm rods in treating MCST and compare it with that of CPS combined with traditional 3.5-mm rods.
Methods: This retrospective study analyzed 58 patients with MCST who underwent posterior cervical spinal fusion surgery by a single surgeon between March 2012 and December 2022. Data included demographics, surgical details, imaging results, numerical rating scale score for neck pain, Eastern Cooperative Oncology Group performance status, and Spine Oncology Study Group Outcomes Questionnaire responses.
Results: Preoperative Spinal Instability Neoplastic Scores were significantly higher in the 5.5-mm rod group. Greater kyphotic changes in the index vertebra were observed in the 3.5-mm rod group. Neck pain reduction was significantly better in the 5.5-mm rod group.
Conclusion: CPS with 5.5-mm rods provides superior biomechanical stability and effectively resists forward bending momentum in posterior MCST fusion surgery. These findings support the use of 5.5-mm rods to enhance surgical outcomes.
Keywords: 5.5-mm diameter rod; Cervical pedicle screw; Cervicothoracic junction; Kyphosis; Metastatic cervical spinal tumor; Posterior cervical spinal fusion.