For the treatment of degenerative disc disease (DDD), the Tritanium posterior lumbar cage (Stryker) is an effective alternative to polyetheretherketone (PEEK) cages, with higher fusion rates, lower subsidence and lower indirect costs. This is according to new research published in Spine Surgery and Related Research by Byron Stephens (Vanderbilt University Medical Center, Nashville, USA) et al.
However, speaking to Spinal News International, Stephens said: “These data should be interpreted with caution. I would not interpret these data to suggest that titanium porous ingrowth titanium implants are superior to PEEK. Rather, they are an option that does not seem to be inferior to PEEK.”
The study sought to assess the efficacy of the device in the treatment of DDD at one or two contiguous levels from L2 to S1.
Nearest-neighbour 1:1 matched control transforaminal lumbar interbody fusion with PEEK vs. Tritanium posterior lumbar cage interbody fusion patients were identified using propensity scoring from patients that underwent elective surgery for DDDs.
Line graphs were generated to compare the trajectories of improvement in patient-reported outcomes (PROs) from baseline to three and 12 months postoperatively. The nominal data were compared via the χ2 test, while the continuous data were compared via Student’s t-test.
A total of 228 patients who underwent elective lumbar interbody fusion surgery for DDDs and had completed 12-month follow-up were included in the study. The completion rate for 12-month follow-up rate was recorded at 81%. The mean age for the 135 female and 93 male patients was 63.52 ± 9.39 years.
In light of the propensity score matching, there was no significant statistical difference in the baseline PRO scores between the two groups. On average, patients in both groups improved regarding the PROs from baseline to three- and 12-month scores in a statistically significant manner.
There was no difference between the PEEK cohort and the Tritanium cohort regarding either the three- or 12-month EQ-5D quality of life scores (p=0.288 and p=0.450), numeric rating scale for leg pain (p=0.619 and p=0.965), and numeric rating scale for low back pain (p=0.549 and p=0.743); however, the Tritanium interbody cage group had better Oswestry Disability Index (ODI) scores compared to the control group of the PEEK interbody cage at both three and 12 months (p=0.013 and p=0.048).
In addition, the study found that a lower proportion of patients were discharged to facility in the Tritanium interbody cage group compared to the PEEK group (9% vs. 20% [p=0.014]). However, there was no statistical difference in the readmissions or return to operating room for the two cohorts.
Of the 228 patients, 200 had radiological follow-up within the first year of the lumbar interbody fusion surgery. On review of the radiological images and electronic medical records, intact fusion of the surgical levels with no complications was seen in 90% of the Tritanium cohort, whereas a statistically significant lower proportion of patients had intact fusion in the control group of the PEEK interbody cage (73%, p=0.003). The images revealed around 40% incidences of subsidence of the cages in the PEEK cohort, while only 23.5% incidences of subsidence of the cage were identified in the Tritanium cohort (p=0.010).
Finally, there was shown to be no statistical difference in the return to work for the two groups, and 90% (n=64) of the preoperatively employed patients (n=71) returned to work at three months postoperatively. The direct cost of surgery and episode of care had no statistical difference (p=0.950); however, the indirect costs for healthcare resource utilisations were higher for the PEEK group than for the Tritanium group (p=0.006).