Screw-Integrated vs Traditional Cervical Cages in ACDF for Degenerative Disc Disease

Overview

This study is a prospective, comparative clinical trial conducted at Assiut University Hospitals to evaluate the effectiveness of two different interbody fusion devices in patients with Cervical Degenerative Disc Disease (CDDD). The primary objective is to compare cervical cages with integrated screws against traditional stand-alone cervical cages during single or double-level Anterior Cervical Discectomy and Fusion (ACDF). While ACDF is the gold standard for CDDD, traditional cages can sometimes lead to complications like subsidence or incomplete fusion; integrated screw designs aim to provide immediate stability and reduce these risks. Investigators will assess 40 patients over a 12-month follow-up period, focusing on primary outcomes of radiological interbody fusion using the Daniel Riew grading system. Secondary outcomes include the maintenance of cervical alignment (Ishihara Index), change in segmental angles (Cobb's method), disc height restoration, and clinical improvements in pain and function measured by the Visual Analog Scale (VAS) and Neck Disability Index (NDI). The study's rationale is to provide clearer evidence on whether screw-integrated cages offer superior radiological and clinical outcomes to help guide future surgical preferences

Cervical degenerative disc disease (CDDD) is a common degenerative spinal disorder and a well-recognized cause of neck pain, cervical radiculopathy, and myelopathy. In patients who fail to respond to conservative treatment, anterior cervical discectomy and fusion (ACDF) is considered the gold standard surgical procedure for single-level disease, as originally described and validated in several classical and long-term studies. The main objectives of ACDF include adequate neural decompression, restoration of disc height, maintenance of cervical alignment, and achievement of solid interbody fusion. Various interbody fusion devices have been developed to improve fusion outcomes. The traditional standalone cervical cage has demonstrated acceptable clinical results; however, several authors have reported potential complications such as cage subsidence, segmental kyphosis, and delayed or incomplete fusion. To overcome these limitations, cervical cages with integrated screw fixation and zero-profile devices have been introduced to provide immediate segmental stability and reduce micromotion at the fusion site, as supported by biomechanical and clinical evidence. Available data from the literature show inconsistent results regarding the superiority of screw-integrated cages compared to traditional cages in single-level ACDF. While some studies reported improved radiological stability, better maintenance of cervical lordosis, and higher fusion rates with screw-fixed cages, other studies demonstrated comparable clinical and radiological outcomes between both techniques. Currently, the choice of fusion device is largely based on surgeon preference rather than definitive evidence. Therefore, the rationale of this research is to conduct a comparative evaluation of cervical cages with screws versus traditional cervical cages in ACDF, aiming to clarify their impact on fusion, alignment, and clinical outcomes