Carbon fiber-reinforced PEEK implants in oncologic spine surgery: a multicenter experience on implications for postoperative patient management.

Objective: Carbon fiber-reinforced polyetheretherketone (CFRP) implants have been used safely in treating spinal oncological disease and promise improved imaging follow-up and radiotherapy planning. However, data on the implant's routine use in the clinical setting with implications for postoperative management are scarce. The aim of this observational study was to provide real-world insight into the current use of CFRP instrumentations in spinal oncological disease and to define their actual relevance for postoperative imaging follow-up and adjuvant treatment planning.

Methods: Datasets of patients treated between 2015 and 2022 with CFRP instrumentations due to spinal oncological disease were collected in a multicentric registry at four participating tertiary spine centers in Germany and Austria. Data on each patient's epidemiology, clinical status, surgery, adjuvant therapy, and outcome was collected retrospectively. Data management was performed using a multicentric REDCap database, and data were reviewed and analyzed descriptively.

Results: A total of 457 patients were enrolled. Most patients received decompression and instrumentation (n = 308 [67%]), with additional cage implantation in 33% (n = 149). In most cases, image-guided navigated screw implantation was performed (n = 321 [70%]). The postoperative complication rate was 13% (n = 61), mostly due to surgical site infections (n = 32 [7%]). Postoperative MRI was performed in 19% (n = 87), with MRI findings prompting revision surgery in 3% (n = 15). In total, 61% of all patients (n = 278) received adjuvant radiotherapy. In those patients, MRI was performed in 6% (18 cases) for procedure planning, while this was mostly based on preinterventional CT (n = 205 [74%]). Of all patients, 27% (n = 124) received routine MRI during follow-up, where relevant local tumor recurrence was detected in 35% (n = 44) at a median follow-up of 6 months.

Conclusions: Low overall complication and low surgical revision rates were reported. Because of the possibility of higher quality MRI follow-up due to CFRP implants, complications or relevant tumor recurrence during follow-up were detected safely and at a high rate in cases where MRI was performed. However, consequent MRI follow-up was not homogeneously performed, and adjuvant radiotherapy was handled rather heterogeneously. These findings lead to the conclusion that until homogeneous adjuvant follow-up and treatment standards are established, the potential benefits available through the use of CFRP implants are not exhausted, and the decision for the use of CFRP implants in comparison to standard titanium implants remains case-to-case based.