A pragmatic single centre retrospective comparative review of complication profile between PEEK cages and Zero-P cage screw constructs.

Background: Anterior Decompression and Fusion (ACDF) is a common surgery recommended for symptomatic cervical degenerative disc disease after failed conservative care. There is no consensus on the choice of implants, and it varies between surgeons. This study aims to analyse the early complications following ACDF performed using a standalone cage versus a Zero-P (Cage Screw - (CS)) construct for patients with cervical degenerative disc disease.

Methods: A total of 162 patients underwent an ACDF between August 2016 and July 2018. There were 83 patients (111 cervical disc levels) with standalone cage (SA) and 79 patients (111 cervical disc levels) with cage-screw (CS) fixation. There was no difference between the groups in terms of age, gender, and levels of surgery. The follow-up ranged from 2 months to 24 months. Complications, both clinical and radiological, were assessed between the groups.

Results: Both the SA and Zero-P (CS) groups were subdivided into single and multilevel surgery. Complications encountered in the SA group were temporary swallowing problems 10, hoarseness of voice 3, cage migration 1, delayed union 1, Horner's syndrome 1, cage subsidence 2. In the CS group swallowing problems 4, hoarseness of voice 4, CSF leak 1, recurrent symptoms 1. The observed difference in the incidence of complications between the groups did not reach statistical significance. Univariate analysis between the groups did not show any difference in the improvement of cervical sagittal balance, fusion rate, subsidence, and complications encountered. Multivariate logistic regression analysis for complications showed no difference between the groups when assessed for smoking, gender, age, Charlson comorbidity index, levels of surgery, fusion status, Odom score, or the type of implant.

Conclusion: In this short-term study, the standalone (SA) cages showed no difference in their complication profile in comparison to a cage-screw construct for both single and multilevel ACDF. Standalone cages might be a cost-effective option without increased complication risks. Nevertheless, we propose a longer-term follow-up with a prospective randomized trial for further evaluation of this finding.