Original ArticleUse of a Zero-Profile Device for Contiguous 2-Level Anterior Cervical Diskectomy and Fusion: Comparison with Cage with Plate Construct
Introduction
Anterior cervical diskectomy and fusion (ACDF) is generally been accepted as the gold standard surgical treatment for patients with cervical disk disease.1 It is important to reestablish stable load-bearing, maintain intervertebral disk height, and improve cervical lordosis for anterior cervical reconstruction and fusion. Anterior cervical cage with plate construct (CP) has been widely used in ACDF because it improves clinical outcomes, stability, fusion rate, and correction of lordosis.1, 2 Use of a plate construct may prevent graft dislocation and cage subsidence and confer segmental stability until bony fusion. However, it may also cause complications such as dysphasia, tracheoesophageal injury, or plate malposition.
Accordingly, application of a standalone cage has been used in conjunction with ACDF.3, 4, 5, 6 Although standalone cages have demonstrated clinical outcomes nearly equal to those of CP,7, 8, 9, 10 they have also been associated with a low-fusion rate, high subsidence rate, and difficulty maintaining cervical lordosis.6, 11
A new zero-profile, standalone device (Zero P; Synthes GmbH, Zuchwil, Switzerland) was recently developed to reduce the complications of traditional cervical plate construct while maintaining the benefits of interbody cages with plate construct. Zero P is composed of a radiolucent polyetheretherketone (PEEK) cage integrated with an anterior titanium plate containing 4 holes with screw treads that allow for fixation directly through the end plate. Zero P has a compact shape that allows for minimal volume between the anterior cervical body and soft tissue beneath the esophagus and trachea. Moreover, Zero P requires a smaller dissection compared with a traditional plate construct, which makes the device less prone to complications.
Recent reports documenting the use of Zero P for single-level and multilevel ACDF have shown a low incidence rate of complications, especially dysphasia, and competitive clinical and radiologic outcomes compared with CP.12, 13, 14, 15, 16, 17, 18 However, some clinicians still have questions whether Zero P is appropriate for multilevel ACDF because it has not been proven superior to CP for correction of cervical alignment and prevention of subsidence.19, 20 There are few reports regarding the efficacy of zero-profile devices for ACDF that focus on only 2 contiguous levels. The aim of this study is to compare zero-profile and CP devices for the treatment of contiguous 2-level ACDF.
Section snippets
Patient Population
Data were collected retrospectively for contiguous 2-level ACDF for degenerative cervical disk disease from December 2006 to February 2015 at a single institution. Patients suffering from symptoms of radiculopathy and/or myelopathy were included in the study. Radiologic findings corresponded to clinical manifestations and physical examinations.
Exclusion criteria were as follows: a history of previous cervical operation; follow-up period <6 months; radiologic parameters that could not be
Demographic and Surgical Data
The cases included 32 patients in the CP group and 31 patients in the Zero P group. Most operations occurred at C5/6, 6/7 in both groups and were not significantly different (P = 0.185). There was no significant difference between the 2 groups in terms of kyphotic changes (P = 0.936), which were evaluated preoperatively by lateral plain radiograph. The operation time for the Zero P group was significantly shorter than that of the CP group (P = 0.043). Demographic factors were not significantly
Discussion
During the past several decades, there has been a significant evolution in devices used for ACDF. Anterior cervical plating and cage insertion have been widely used. Cage insertion with plate construct has benefits for maintenance of mechanical stability, prevention of cage displacement, and increase of fusion rate.1 However, some reports have noted that plate construct for ACDF involves complications. In particular, the rate of complications may increase in ≥2-level ACDF.3, 4, 5, 6
To insert a
Conclusion
Use of a zero-profile device could be a useful option in contiguous 2-level ACDF. On the basis of our results, the most important aspect of Zero P usage is proper inserting position. An improvement in maintenance of the cervical angle and intervertebral disk height might be expected if the titanium alloy plate in Zero P is positioned well in the anterior vertebral line at the cortical corner of the cranial and caudal anterior cervical body at the disk level. To confirm this result, a long-term
References (28)
Esophageal perforation from anterior cervical screw migration
Surg Neurol
(2007)- et al.
Stand-alone interbody cage versus anterior cervical plate for treatment of cervical disc herniation: sequential changes in cage subsidence
J Clin Neurosci
(2008) - et al.
Do stand-alone interbody spacers with integrated screws provide adequate segmental stability for multilevel cervical arthrodesis?
Spine J
(2014) - et al.
Comparison of plate-cage construct and stand-alone anchored spacer in the surgical treatment of three-level cervical spondylotic myelopathy: a preliminary clinical study
Spine J
(2015) - et al.
Anterior approaches to fusion of the cervical spine: a metaanalysis of fusion rates
J Neurosurg Spine
(2007) - et al.
The efficacy of plate construct augmentation versus cage alone in anterior cervical fusion
Spine (Phila Pa 1976)
(2009) - et al.
Anterior cervical discectomy and fusion associated complications
Spine (Phila Pa 1976)
(2007) - et al.
The results of anterior interbody fusion of the cervical spine. Review of ninety-three consecutive cases
J Neurosurg
(1969) - et al.
The long-term clinical outcome of patients undergoing anterior cervical discectomy with and without intervertebral bone graft placement
Neurosurgery
(1998) - et al.
Polyetheretherketone cage filled with beta-tricalcium phosphate versus autogenous tricortical iliac bone graft in anterior cervical discectomy and fusion
Korean J Spine
(2011)
Comparison of fusion with cage alone and plate instrumentation in two-level cervical degenerative disease
J Korean Neurosurg Soc
Subsidence of the wing titanium cage after anterior cervical interbody fusion: 2-year follow-up study
J Neurosurg Spine
Complications associated with harvesting autogenous iliac bone graft
Am J Orthop (Belle Mead NJ)
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
Eur Spine J
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Anterior cervical discectomy and fusion: Techniques, complications, and future directives
2020, Seminars in Spine SurgeryCitation Excerpt :In recent years, stand-alone anchored spacers (SAAS) have been designed to integrate the functionality of an anterior cervical plate and cervical interbody spacer into a single device. While long-term outcomes data are not yet available, these implants (e.g. Zero-P, Perfect-C, Fidji, ROI-C) have shown promising results for one- and two-level ACDF.47–57 In a recent meta-analysis, patients who underwent ACDF with SAAS had less operative blood loss, an improved C2-C7 Cobb angle, lower incidence of postoperative dysphagia, and adjacent segment degeneration compared to their traditional cage-and-plate method counterparts.58
Conflict of interest statement: This study was supported by a grant from the Spine Health Wooridul Hospital. None of the authors of this paper has a financial or personal relationship with other people or organizations that could inappropriately influence or bias the content of the paper.