Motion preservation after cervical total disc replacement surgery-fact or fiction?

Cervical disc replacement surgery aims to preserve cervical motion in younger patients who present with symptomatic degenerative cervical disc herniation and mobile facet joints. We aimed to determine the demographics, pre-operative range of motion, operative parameters, post-operative parameters, range of motion at 2-years post-operatively, in 27 patients who presented to our unit over a 6-year period who underwent cervical total disc replacement surgery. Materials and methods: We performed a retrospective chart review of 27 patients who presented to our unit with degenerative cervical disc disease, from 01 January 2014 – 31 December 2019, who underwent cervical disc replacement surgery. The data collected included patient age; gender; mechanism of injury; clinical presentation; cervical level/s involved; description and site of the disc herniation; length of preoperative symptomatology; pre-operative cervical range of motion; length of operative procedure; volume of intra-operative blood loss; amount of immediate post-operative radiculopathy pain assessed by the visual analogue scale; complications; length of hospital stay; and cervical range of motion at 2-year follow-up. Results: The mean age of our subjects was 45.5 (+/-6.5) years. Regarding gender 11/27 (41%) subjects were female and 16/27 (59%) subjects were male. In terms of number of levels 21/27 (78%) subjects had single level surgery and 6/27 (22%) subjects had double level surgery. Considering age categories, patients in the 4th decade demonstrated a statistically significant increase between their pre-operative segmental range of cervical flexion and their post-operative segmental range of cervical flexion (p = 0.02). Conclusion: Through the results of our study we report that in our 27 subjects cervical total disc replacement surgery was motion preserving in 100% of our subjects at a 2-year study end point. We further report that all our subjects demonstrated some degree of increase in their segmental ranges of motion in all planes, although this was largely insignificant.