Turkish Neurosurgery 2025 , Vol 35 , Num 2
Spine and Peripheral Nerves - Impact of Rod Material and Spinopelvic Parameters on Distal Junctional Failure Following Lumbar Fusion: A Comparative Study of Semirigid PEEK and Rigid Titanium Alloy Rods
Numan KARAARSLAN1,Hidayet Safak CINE1,Ece UYSAL2,Bilgehan POTOGLU3,Mehmet Ali KAHRAMAN1,Emre HERDAN1,Mohammed ALADDAM1,Okkes Celil GOKCEK4,Abdullah Talha SIMSEK1,Ercan BOSNAK5,Mahmut DEMIRKOL1
1Istanbul Medeniyet University, Prof. Dr. Suleyman Yalcin City Hospital, Department of Neurosurgery, Istanbul, Türkiye
2Acibadem Healthcare Group, Acibadem Altunizade Hospital, Department of Neurosurgery, Istanbul, Türkiye
3Agri Training and Research Hospital, Department of Neurosurgery, Agri, Türkiye
4Tuzla Gispir Hospital, Department of Neurosurgery, Istanbul, Türkiye
5Medicalpark Gebze Hospital, Department of Neurosurgery, Istanbul, Türkiye
DOI : 10.5137/1019-5149.JTN.47917-24.4 AIM: To investigate the incidence of distal junctional failure (DJF) in patients undergoing posterior lumbar fusion with either semirigid polyether ether ketone (PEEK) or rigid titanium alloy rods, focusing on the impact of preoperative and postoperative spinopelvic parameters on DJF development.

MATERIAL and METHODS: A retrospective analysis was conducted on patients who underwent short-segment posterior transpedicular stabilization with semirigid PEEK or rigid titanium ally rods between 2015 and 2021. Preoperative and postoperative pelvic parameters, including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), PI-LL mismatch, and lower instrumented vertebra (LIV) were evaluated.

RESULTS: The total cohort consisted of 61 patients with a mean age of 55.85 ± 11.97 years. DJF occurred in 18.03% of patients in the PEEK group (6.67%) compared to the rigid rod group (29.03%) (p<0.05). Postoperative PI-LL mismatch was a critical factor in DJF development (p<0.05). Among patients with a preoperative PI-LL mismatch greater than 10°, non-DJF patients achieved a correction of -55.50°. Postoperative reductions in LL were also associated with an increased risk of DJF (p<0.05). In the PEEK group, DJF patients experienced -19.35° reduction in LL, whereas -11.02° in the rigid rod group.

CONCLUSION: PEEK rods were associated with a lower incidence of DJF compared to rigid titanium rods. Postoperative PI-LL mismatch and changes in lumbar lordosis and PI-LL mismatch are key predictors to prevent DJF. Keywords : Distal junctional failure, Lumbar fusion, PEEK rods, Rigid titanium rods, Spinopelvic parameters

Corresponding author : Numan KARAARSLAN, numankaraarslan@yahoo.com