Anterior bone loss: A common phenomenon which should be considered as bone remodeling process existed not only in patients underwent cervical disk replacement but also those with anterior cervical diskectomy and fusion

ObjectiveAnterior bone loss (ABL) was considered as a non-progressive process secondary only to motion-preserving implant and has been noticed recently in cervical disk replacement (CDR) let alone patients with anterior cervical diskectomy and fusion (ACDF). Our purpose is to reveal this unnoticed phenomenon in ACDF and further explore its clinical and radiological outcomes.MethodsA total of 77 patients underwent ACDF with a minimum follow-up of at least one year were retrospectively reviewed. The average follow-up time was 22.51 +/- 16.31 months. There were 50 patients in group A with ABL, while there were 27 patients in group B without ABL. ABL was measured and classified into four grades according to Kieser's methods. Clinical evaluation, radiological parameters and fusion rate were recorded.ResultsThe incidence of bone ABL was 64.9% of Zero-P and 55.2% of endplates. The incidence of upper and lower endplates was 61% and 49%, respectively, and such difference was not significant. Mild ABL occurred in 22%, moderate ABL in 38% and severe ABL of 40% patients underwent ACDF with ABL. ABL would not affect both clinical outcomes and fusion rate. However, ABL would result in a higher incidence of subsidence.ConclusionABL should be considered as a common phenomenon that both CDR and ACDF owned a non-progressive process which confined in one year. ABL would result in a higher incidence of subsidence. Luckily, this phenomenon does not have an effect on postoperative clinical and fusion rate.

Automated summary

This study aimed to reveal the common non-progressive bone loss phenomenon in anterior cervical diskectomy and fusion (ACDF) and explore its clinical and radiological outcomes. Retrospective analysis showed that 64.9% of Zero-P fusion implants and 55.2% of endplates had bone loss, which did not affect postoperative clinical outcomes and fusion rate but resulted in a higher incidence of subsidence.