Cohere Research Update with Dr. Frank Phillips

In the wake of COVID-19, NuVasive has sought alternative ways to fulfill its commitment to surgeon education and professional development. To that end, NuVasive recently connected via Skype with Dr. Frank Phillips, Professor and Director, Section of Minimally Invasive Spine Surgery and Division of Spine Surgery, Rush University Medical Center, to discuss Cohere research updates.

NUVA: At the 2020 Annual Conference of the International Society for the Advancement of Spine Surgery (ISASS), you and co-authors presented an independent study of Cohere in a challenging ACDF patient population.1 Can you summarize your study design?

Dr. Frank Phillips: We presented a multi-center, retrospective cohort study consisting of:

  • Three participating centers with three fellowship-trained spine surgeon
  • 33 patients enrolled with a minimum of one-year follow-up
  • Three or more levels treated per patient with porous PEEK implants for ACDF

Clinical outcomes were measured using patient reported outcomes (NDI, VAS neck and VAS arm). Radiographic outcomes, including spinal alignment and graft subsidence, were assessed on preoperative, immediate postoperative and final neutral lateral radiographs for all patients. Fusion was assessed on final follow-up radiographs by two independent reviewers. 1

NUVA: What were the key findings of this study?

Dr. Frank Phillips: In regard to the key outcomes, we found that:

  • Patients exhibited significant improvement in all outcome metrics (NDI, VAS neck and VAS arm)
  • In terms of radiographic outcomes, we had one patient who had pseudarthrosis
  • That’s one patient out of a total of 33 patients having three-, four-, and five-level ACDFs, a 3% pseudarthrosis rate in this challenging patient population
  • We also found favorable and significant improvement in overall postoperative cervical lordosis, SVA fusion segment lordosis, T1 slope, as well as disc height

NUVA: Those are impressive outcomes! Can you help put those findings in context and comment on the significance of this study?

Dr. Frank Phillips: Historically the literature has reported pseudarthrosis rates with multilevel ACDFs can be very high to the point that many surgeons routinely back these constructs up with posterior instrumentation. A recent publication found that nearly half of all three- and four-level ACDF patients treated with allografts and plates had at least one level with radiographic non-union.2 Essentially, what our study suggests is that in multilevel three-, four-, and five-level ACDFs, we were able to achieve a 97% fusion rate using porous PEEK technology.1

NUVA: Dr. Phillips, thank you very much for shedding some light on your recent research with Cohere. Congratulations and best wishes on being named President of ISASS for 2020-21.


For more information on Cohere interbody devices and the porous PEEK technology, click here.


For complete important safety information, refer to the Cohere IFU found at


1. Basques B, Gomez G, Padovano A, et al. Outcomes with porous PEEK interbody cages for anterior cervical discectomy and fusion at three or more levels. International Society for the Advancement of Spine Surgery 2020 Annual Meeting. San Juan, Puerto Rico, USA.
2. Wewel JT, Kasliwal MK, Adogwa O, et al. Fusion rate following three- and four-level ACDF using allograft and segmental instrumentation: A radiographic study. J Clinic Neuroscience 2019;62:142-6.

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