Discrepancy between cervical disc prostheses and anatomical cervical dimensions

Abstract

Objective: The aim of this study was to assess appropriateness of the sizes of available cervical discprostheses based on tomographic measurement of human cervical vertebrae.Methods: The anatomic dimensions of the C3eC7 segments were measured on 50 patients (age range26e47 years) with computerized tomography scan and compared with the sizes of the popular cervicaltotal disc prostheses (CTDP) at the market [Bryan (Medtronic), Prodisc-C (Synthes), Prestige LP (Medtronic), Discover (DePuy)]. The mediolateral and anteriorposterior diameters of the upper and lowerendplates were measured with a digital measuring system.Results: Overall, 43.7% of the largest implant footprints were smaller in the anterior-posterior diameterand 42.6% in the mediolateral diameter were smaller than cervical endplate measurements. Discrepancyof the level C5/C6 and C6/C7 was calculated as 56.2% at the anteroposterior diameter and 43.8% at thecenter of mediolateral diameter.Conclusion: Large disparity has been found between the sizes of devices and cervical anatomic data.Companies that produce CTDP should take care of the anatomical dimensions and generate differentsizes of CTDP. Spine surgeon should be familiar with the size mismatch in CTDP that may affect theclinical and radiological outcome of the surgery.© 2016 Publishing services by Elsevier B.V. on behalf of Turkish Association of Orthopaedics andTraumatology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).