Evaluating long-term construct stability in metastatic spine cancer patients with carbon fiber-reinforced polyetheretherketone instrumentation.

OBJECTIVE: Metastatic spine disease significantly impacts the oncological population, often requiring surgical intervention to address spinal instability. Traditional constructs, including titanium-based long-segment instrumentation and short-segment cement augmentation, have been the mainstay in managing these patients. Carbon fiber-reinforced polyetheretherketone (CFR-PEEK) hardware and shorter-segment instrumentation have demonstrated benefits of improved surveillance, earlier recurrence detection, and shorter operative time. This study evaluated the long-term experience of a single center with CFR-PEEK constructs in patients with metastatic spine disease. It also investigated the clinical durability of short-segment constructs and evaluated the necessity of cement augmentation in maintaining construct stability.

METHODS: This retrospective, single-center study included patients with metastatic disease to the spine who underwent surgical fixation using CFR-PEEK hardware between 2021 and 2024. Inclusion criteria required perioperative radiation therapy and a minimum of 6 months of radiographic follow-up. Patients were stratified into short-construct (n = 13) and long-construct (n = 7) groups based on the number of vertebral levels spanned. Subgroup analysis of cement-augmented versus nonaugmented short constructs was performed. Variables analyzed included preoperative scores (American Spinal Injury Association grade, Karnofsky Performance Scale score, Spine Instability Neoplastic Score, and epidural spinal cord compression grade), estimated blood loss, length of hospital stay, and postoperative outcomes. Radiographic failure and revision surgery rates were primary endpoints. Statistical analyses were conducted using nonparametric methods.

RESULTS: At 14 months of mean follow-up time, no radiographic failures or revision surgeries were observed within the 20 patients included in this study. Patients in the long-construct group had more vertebral levels involved (2.00 vs 1.15, p = 0.024), lower preoperative Karnofsky Performance Scale scores (58.57 vs 76.15, p = 0.01), and more frequent use of mixed constructs with titanium rods (p = 0.007). Short constructs demonstrated equivalent durability without the routine need for cement augmentation. Within the short-construct cohort, cement augmentation was associated with longer hospital stays (8.8 vs 3.63 days, p = 0.008) but did not reduce failure rates.

CONCLUSIONS: CFR-PEEK instrumentation demonstrates excellent durability and stability in metastatic spine disease, even in patients receiving perioperative radiation therapy. Short-segment instrumentation demonstrates comparable durability to long-segment constructs while reducing operative risks and hospitalization duration. While cement augmentation has traditionally been used to enhance construct strength, the findings in this study suggest that its routine use may not be necessary in short-segment constructs; however, larger studies are needed to better understand long-term outcomes, optimize construct selection, and identify factors influencing hardware failure in this high-risk population.