Zero-P: a new zero-profile cage-plate device for single and multilevel ACDF. A single Institution series with four years maximum follow-up and review of the literature on zero-profile devices

Purpose To analyze the prospectively collected data in a series of patients treated with single- or multilevel ACDF with a stand-alone, zero-profile device, focusing on clinico-radiological outcome, complications and technical hints, and to review the literature on such new devices. Methods Eighty-five patients harboring symptomatic DDD underwent ACDF with the Zero-P cage-plate: 29 at 1-level and 56 at 2–4 levels (total 162 devices). In the multilevel group, 9 patients received a combination of Zero-P and stand-alone cages (hybrid implants). This study focuses on 32 patients with follow-up ranging from 20 to 48 months. NDI, SF-36 and arm pain VAS scores were registered preoperatively and at follow-up visits. Dysphagia was assessed using the Bazaz score. Imaging included X-rays, CT and MRI, also to assess the presence of vertebral body fractures in multilevel cases. Paired Student t test was used for statistical analysis. Results SF-36 and NDI showed a statistically significant improvement ( p