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

Abstract

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 clinicoradiological 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 \ 0.01) and mean arm pain VAS score decreased from 79 to 41. X-rays and CT demonstrated, respectively, a 94.5 % and a 92 % fusion rate. Three patients complained of moderate and two of mild transient dysphagia (15.5 %). No device-related complications occurred and no fractures, secondary to four screws insertion in one vertebral body (i.e., swiss cheese effect), were detected in multilevel cases. In patients with extensive anterior osteophytes only a ''focal spondylectomy'' was required. Conclusion The Zero-P device is safe and efficient, even in multilevel cases. Dysphagia is minimal, extensive anterior osteophytectomy is unnecessary and technical hints may ease the surgical workflow. This is the largest series, with the longest follow-up, reported.

Does a Zero-Profile Anchored Cage Offer Additional Stabilization as Anterior Cervical Plate?

“…19 , 21 , 22 The AC, which supplements the advantages and disadvantages of the aforementioned CP and SC, is gradually becoming more widely used. [1][2][3][4][5][6] Vanek et al 1 conducted a minimal 2-year prospective comparative study on the Zero-P spacer. Compared with the CP, there were no differences between the 2 groups for neck disability index, Cobb coronal value, and the presence of dysphagia; although the Cobb sagittal values differed up to 6 weeks, no differences were reported beyond that point.…”

“…2 , 3 Because these shortcomings of the SC and anterior cervical plate (ACP) are being improved upon, the use of ACs is gradually increasing. [1][2][3][4][5] Most authors have indicated that radiological and clinical outcomes of ACs are similar to those of cages with plates (CPs) and have particularly emphasized the point about the decreased occurrence of postoperative dysphasia. [1][2][3][4][5][6] ACs maintained comparable stability with CPs in one biomechanical study, but ACs showed a higher range of motion in fl exion/extension 7 ; in contrast, other articles reported that ACs lack multilevel stability.…”

“…[1][2][3][4][5] Most authors have indicated that radiological and clinical outcomes of ACs are similar to those of cages with plates (CPs) and have particularly emphasized the point about the decreased occurrence of postoperative dysphasia. [1][2][3][4][5][6] ACs maintained comparable stability with CPs in one biomechanical study, but ACs showed a higher range of motion in fl exion/extension 7 ; in contrast, other articles reported that ACs lack multilevel stability. 8 In our study, using SCs in patients with single-level cervical disc disease for comparison, the degree of additional stability provided by the fi xation devices of an AC was determined on the basis of comparisons and analyses of the postoperative retention of cervical alignment and motion stabilization.…”

Single anterior cervical discectomy and fusion (ACDF) using self- locking stand-alone polyetheretherketone (PEEK) cage: evaluation of pain and health-related quality of life

“…Barbagallo et al mentioned that SF-36 and NDI showed a statistically significant improvement and mean arm pain VAS score deterioration on zero-profile cage-plate device. Fusion rate was estimated over 90% and dysphagia at 15.5% without any device-related complication (36). For pain and disability, NDI is said to be the most valid and responsive measure of improvement after surgery for neck and arm pain.…”

Anterior Surgical Treatment of Cervical Spondylotic Myelopathy

“…Recent advances including low profile, integrated interbody cages have been developed in order to obviate the need for anterior plating with the goal of reducing plate-related morbidity. A number of biomechanical studies have shown that an anchored cage design with integrated screws afforded biomechanical stability comparable to that of the standard interbody cage with anterior plate [5]. Though long term studies are limited, several integrated low profile designs have been shown to have decreased rates of dysphagia compared to standard anterior plating systems [23].…”