Effectiveness of a Fully Impregnated Hydroxyapatite Polyetheretherketone Cage on Fusion in Anterior Cervical Spine Surgery.

Introduction Anterior cervical discectomy and fusion (ACDF) is the gold standard for the treatment of cervical spondylosis. However, new techniques, technologies, and improved implants have aided surgeons in reducing operative time with enhanced patient outcomes. Impregnated hydroxyapatite polyetheretherketone (HA PEEK) cages (Arena-C HA®, LESspine Inc. Malden, MA) are one such option that has aimed to increase the fusion rate. The authors herein aimed to assess the use of HA PEEK interbody cages by looking at outcomes, complications, and radiographic fusion.  Methods The medical records of 41 consecutive patients undergoing single-level ACDF with impregnated HA PEEK cages (group 1) were compared to the control group of 47 patients who had single-level ACDF without impregnated HA PEEK cages (group 2). Outcomes assessed included Visual Analog Scale (VAS) neck, Neck Disability Index (NDI) scores, radiographic fusion, and complication rates.  Results Of the 41 patients in group 1 (HA PEEK), 48% were female population with a mean age of 58.5+/- 1.7 years and BMI 29.7+/-1.2 kg/m2. Of the 47 patients in group 2 (non-HA PEEK), 53% were female with a mean age of 54.3+/- 1.2 years and BMI 27.8+/-0.8 kg/m2. Using t-test, there was a statistically significant intergroup difference in two-year VAS neck and NDI scores, p=0.007, and p=0.001, respectively. Radiographic fusion occurred as early as three months in the HA PEEK group.  Conclusions This study has demonstrated the equivalence of impregnated HA PEEK cages in single-level ACDF. Significant improvements were seen in VAS and NDI scores in the HA PEEK group. There was no incidence of heterotopic bone formation or reaction to HA PEEK cages. Additionally, a trend toward fusion was seen in HA PEEK patients as early as three to five months compared to seven to eight months for the ACDF group. We conclude that HA PEEK cages can be safely placed with excellent outcomes. However, further studies are required to look at added benefits.