title: Bryan cervical disc prostheses: preservation of function over time.
abstract: Preserving the function of cervical disc prostheses, even over the short term, is a matter of concern among surgeons. Our case series highlights our results and protocol for increasing the probability of continued device function. Twenty-five consecutive patients with a mean (+/-SEM) age of 44.3+/-8.3 years underwent 29 cervical total disc arthroplasties for disc herniations. Three patients underwent primary bilevel arthroplasty, and one patient underwent a second arthroplasty for another herniation 2 years after the first. Prosthesis ranges of motion were measured using dynamic plain X-ray studies and compared to the ranges of motion of adjacent segments. At follow-up, all prostheses were in the correct location and without subsidence. All displayed firm secondary stability. One segment had fused. Twenty-eight of 29 devices were mobile an average of 9.5 degrees +/-4.7 degrees (range 3 degrees to 20 degrees ) (for all 29 devices the average movement angle was 9.2 degrees +/-5 degrees ; range 0 degrees to 20 degrees ), 25 upper adjacent segments were mobile an average of 10.9 degrees +/-4.5 degrees (range 2 degrees to 20 degrees ) (excluding the fused prosthesis: 11 degrees +/-4.6 degrees ) and 15 lower adjacent segments were mobile an average of 9.8 degrees +/-6 degrees (range 1 degrees to 21 degrees ). With our protocol, 28 of 29 cervical disc prostheses in 25 consecutive patients were mobile after an average of 22.3+/-9.4 months. Prosthesis motion was physiological and very similar to that of the healthy adjacent segments. Long-term studies including larger numbers of patients are required to validate our initial observations.
authors.affiliation: Hirslanden Group, Klinik Beau-Site, Schänzlihalde 11, CH-3000 Bern 25, Switzerland. aerzte.beau-site@hirslanden.ch
authors.forename: Markus
authors.initials: M
authors.lastname: Wenger
authors.forename: Petrus van
authors.initials: Pv
authors.lastname: Hoonacker
authors.forename: Benoit
authors.initials: B
authors.lastname: Zachee
authors.forename: Robert
authors.initials: R
authors.lastname: Lange
authors.forename: Thomas-Marc
authors.initials: TM
authors.lastname: Markwalder
mesh_terms: D000328:Adult; D000368:Aged; D019643:Arthroplasty, Replacement / Q000295:instrumentation* / Q000379:methods; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000601:surgery*; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D019919:Prosthesis Implantation; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods