Fusion and Subsidence in Cervical Disc Replacements - A Retrospective Cohort Study

Description

In this presentation, Louis Hainsworth discusses his team's research on cervical disk replacements, focusing on the outcomes of fusion and subsidence in patients. He begins by outlining the two primary treatment options following anterior decompression for cervical spine issues: fusion and disk replacement. While acknowledging the higher upfront costs of disk replacements, Hainsworth emphasizes their potential for greater mobility and preventing adjacent level disease.



His study incorporates data from 99 consecutive disk replacement operations performed between 2015 and 2019, using the Mobi-C disk replacement device. Patients were assessed at multiple follow-up points (three months, six months, one year, and two years) with X-rays taken in flexion and extension to measure movement and assess for fusion, defined as less than 2 degrees of movement between the disk levels.



Hainsworth details the significant loss to follow-up in his data, particularly impacting two-year results due to the COVID pandemic. Out of the cases examined, about 24% showed at least one level fused after two years, with fusion rates higher in patients receiving more extensive (multi-level) replacements. Importantly, there were no reports of subsidence in any cases studied.



The presentation concludes with a discussion on the implications of the findings, suggesting that while one and two level replacements remain relatively mobile, there may be merit in considering the outcomes of multi-level procedures and their long-term effects. Hainsworth acknowledges the need for further studies to explore potential predictors of fusion outcomes and the impact of adjacent level symptoms. The presentation ends with an engaging exchange between Hainsworth and audience members about the practical implications, challenges, and future directions of disk replacement procedures in cervical spine surgeries.

DOI: 10.1302/3114-221757

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