Short-Segment Cement-Augmented Fixation in Open Separation Surgery for Metastatic Epidural Spinal Cord Compression: Two-Year Follow-up Results

Introduction: Advances in spine oncology have transformed surgical goals for metastatic spinal disease, moving away from extensive multi-segment fusion surgeries to more focused interventions. Cement-augmentation of fenestrated screws has facilitated shorter fusion constructs (e.g., one level above and below index level), addressing biomechanical challenges with reduced morbidity. This study aimed to assess the long-term outcomes of such short-segment constructs.

Methods: A retrospective review from 2018 to 2020 at a tertiary cancer center included patients over 18 years undergoing spine surgery for metastatic disease with short segment constructs. Data collected encompassed index level, deformity presence, radiation treatment, hardware details, preoperative clinical status, and operative specifics, with a focus on long-term radiographic outcomes.

Results: Out of the 137 patients meeting inclusion criteria, 94 individuals (68.6%) underwent open surgery, while 43 (31.4%) received percutaneous short-segment fixations. The distribution across open index levels revealed 50 in the thoracic region (53.2%), 32 in lumbar (34.0%), 4 in cervical (4.26%), and 8 in junctional (8.51%). Division within percutaneous saw 17 in the thoracic region (39.5%), 17 in lumbar (39.5%), and 9 in junctional (20.1%). Open surgery exhibited a mean 28.8° kyphosis, slightly higher than the percutaneous average of 26.7°. Five instances of hardware failure were identified, with 4/5 occurring in the percutaneous group and 1/5 in the open group. Among percutaneous, three occurred at junctional levels and one was observed at a semirigid level. The open-fixation failure took place at a junctional level. All failures occurred in cement-augmented constructs. Overall rate of hardware failure rate was 3.6%.

Conclusion : Short-segment cement-augmented fixation is a viable technique in managing metastatic spine disease. Long-term failure rates were similar to our previous six-month follow-up results and in-line with failure rates for longer constructs. Given the preponderance of failures at junctional levels, further investigations should look closely at this region and its biomechanical stresses.