Empty polyetheretherketone (PEEK) cages in anterior cervical diskectomy and fusion (ACDF) show slow radiographic fusion that reduces clinical improvement: results from the prospective multicenter “PIERCE-PEEK” study

Abstract

BackgroundAnterior cervical diskectomy and fusion (ACDF) is a well-established surgical treatment for radiculopathy and myelopathy. Previous studies showed that empty PEEK cages have lower radiographic fusion rates, but the clinical relevance remains unclear. This paper’s aim is to provide high-quality evidence on the outcomes of ACDF with empty PEEK cages and on the relevance of radiographic fusion for clinical outcomes.MethodsThis large prospective multicenter clinical trial performed single-level ACDF with empty PEEK cages on patients with cervical radiculopathy or myelopathy. The main clinical outcomes were VAS (0–10) for pain and NDI (0–100) for functioning. Radiographic fusion was evaluated by two investigators for three different aspects.ResultsThe median (range) improvement of the VAS pain score was: 3 (1–6) at 6 months, 3 (2–8) at 12 months, and 4 (2–8) at 18 months. The median (range) improvement of the NDI score was: 12 (2–34) at 6 months, 18 (4–46) at 12 months, and 22 (2–44) at 18 months. Complete radiographic fusion was reached by 126 patients (43%) at 6 months, 214 patients (73%) at 12 months, and 241 patients (83%) at 18 months. Radiographic fusion was a highly significant (p < 0.001) predictor of the improvement of VAS and NDI scores.ConclusionThis study provides strong evidence that ACDF is effective treatment, but the overall rate of radiographic fusion with empty PEEK cages is slow and insufficient. Lack of complete radiographic fusion leads to less improvement of pain and disability. We recommend against using empty uncoated pure PEEK cages in ACDF.Trial registration ISRCTN42774128. Retrospectively registered 14 April 2009.

Structural Allograft Versus PEEK Implants in Anterior Cervical Discectomy and Fusion: A Systematic Review

“…We required minimum radiographic follow-up of 2 years for inclusion in our review ( Table 3). The 1 high-quality study excluded because of a lack of 2-year radiographic follow-up was the PIERCE-PEEK Study (Prospective International Multicenter Evaluation of Radiological and Clinical Effects of Stand-Alone PEEK Intervertebral Spacers for ACDF) by Suess et al 9 The authors followed a cohort of 356 patients who underwent ACDF with PEEK interbody devices without any osteopromotive fillers and without additional anterior instrumentation. Complete radiographic fusion occurred for 43% of patients at 6 months, 73% of patients at 12 months, and 83% of patients at 18 months.…”

Allograft Structural Interbody Spacers Compared to PEEK Cages in Cervical Fusion: Benchtop and Clinical Evidence

“…The authors note the low fusion rates of empty PEEK cages, but stated that the lack of fusion did not affect clinical outcomes. Similarly, Suess et al evaluated the clinical and radiographic outcomes of 292 patients who received empty PEEK cages for single-level ACDF procedures [56]. PEEK demonstrated radiographic fusion in 126 patients (43%) at 6 months, 214 patients (73%) at 12 months, and 241 patients (83%) at 18 months.…”

The outcomes of stand alone polyetheretherketone cages in anterior cervical discectomy and fusion

“…1 Post-operative radiographs of a 46-year-old female who underwent anterior cervical discectomy and fusion with PEEK cages filled with bone marrow aspirate. Surgical indication was right arm radiculopathy that failed non-surgical treatment recent prospective multicenter study on 292 patients by Suess et al [18] indicated poor performance of empty standalone PEEK cages. They found that these cages had slow radiographic fusion rates with an 83% complete fusion at 18 months, which translated into poor clinical outcomes.…”

“…A change by 2. Regarding empty PEEK cages, Suess et al [18] reported in an RCT a mean change of 4 (interquartile range 3-6 if fused or 3-4 if not fused) following ACDF at 18 months. The rest of the studies on empty PEEK cages were case series.…”

“…Park et al [24], Farrokhi et al [12], and Kapetanakis et al [22] defined fusion by the presence of motion and bone bridging on radiographs. Suess et al [18] defined fusion with three parameters consisting of bony bridging, absence of radiolucency at the implant-vertebrae interface, and the lack of motion on dynamic x-rays. Cho et al [14] utilized radiographs to assess fusion without any further details on how fusion was objectively measured.…”