Comparison of PEEK vs 3D printed titanium cage for ACDF- Is there any difference in subsidence?

Author(s): Dr. Harshadkumar A. Patel, MD, Francine Zeng, MD, Dr. Hardeep Singh, MD, Dr. Scott S. Mallozzi, MD, Mark Cote, P.T, Dr. Isaac L. Moss, MD

Objectives:

To compare the subsidence between PEEK vs new 3D printed titanium cage(3DTC) for ACDF surgery.

Design:

Retrospective cohort study Setting: Single academic spine center.

Methods/Outcome Measures:

All patients underwent a standard ACDF surgery with respective PEEK and 3DTC interbodies. Cage subsidence was measured as the change in adjusted intervertebral height (aIVH) in immediate post-operative and subsequent follow-up neutral radiographs at 6 months and ≥1-year visits. Severe subsidence was defined as ≥3 mm of aIVH loss on follow up. Basic demographic information and post-operative complications were also measured. Mixed effects linear models were constructed to evaluate difference in subsidence. A total of 26 patients (44 levels) in the PEEK group and 31 patients (48 levels) in the 3DTC group were available for review at minimum 6 months follow up.

Results:

There was no difference in demographic variables, including Charleston co-morbidity index, BMI and smoking status between groups. The overall average subsidence was 1.17 mm (95% CI : 0.82 – 1.51, p<0.001) at 6 months and 1.42 mm (95% CI: 1.07- 1.78, p<0.001) at 1-year follow up. The 3DTC group had significantly lower subsidence compared to the PEEK group at 6 months (0.84 mm vs 1.59 mm, p <0.05) and at 1 year (0.85 mm vs 1.92 mm, p<0.05). Severe subsidence rates were 9.37% for 3DTC group versus 19.04% for the PEEK group at 1 year.(P>0.05)

Conclusions:

3DTC leads to overall minor, but significant reduction in subsidence compared to PEEK cages in ACDF surgery. 3DTC has comparable severe subsidence rate to PEEK cage