Impact of Fixation Length for Single-Level Spinal Metastasis Surgery in the Elderly: A Multicenter Study

Purpose Spinal metastases are common and affect most patients with metastatic cancer. Surgery is crucial for managing symptoms such as pain and paralysis but carries a high risk of complications, especially in the elderly. This study aimed to investigate the impact of short versus long fixation on outcomes mainly focused on surgery-related complications in elderly patients ≥60 years old undergoing surgery for single-level spinal metastasis. Methods This study is a retrospective multicenter cohort study. We retrospectively analyzed data from 153 patients who underwent spinal metastasis surgery between 2014 and 2023, focusing on 44 patients aged ≥60 years with single-level lesions. Out of 151 patients, those under 60 years old, those who underwent only decompression surgery, and those with missing data were excluded, resulting in a final inclusion of 44 patients. Patients were divided into short fusion (four or fewer vertebrae) and long fusion (five or more vertebrae) groups. This study aims to compare the impact of short (four or fewer vertebrae) versus long (five or more vertebrae) spinal fixation on surgical and patient-centered outcomes in elderly patients undergoing surgery for single-level spinal metastasis. Patients' demographics, surgical details, and complications were compared between the groups. Results The study included 44 patients: long fusion group (n = 24) and short fusion group (n = 20). No significant between-group differences were found in demographics or surgery-related factors. Minimally invasive surgery was performed in 29.2% of long fusion group patients and 10% of short fusion group patients, but this difference was not statistically significant. Survival analysis showed no significant difference in median survival between the groups (short fusion group = 29 months vs. long fusion group = 26 months, P = 0.533). Mortality rates were also similar between groups during the follow-up period. The short fusion group had a higher rate of surgical complications (45% vs. 12.5%, P = 0.021) and more frequent postoperative complications (55% vs. 29.2%, P=0.125), although the difference was not statistically significant. Conclusion This study found no significant difference in survival rates between short and long fixation in elderly patients undergoing surgery for single-level spinal metastasis. In spinal metastasis surgery, extending the fixation range may be considered if necessary.