RT Journal Article
SR Electronic
T1 The Anteroposterior Positioning of Viscoelastic Cervical Disc Prosthesis Does Not Alter the Outcomes
JF International Journal of Spine Surgery
JO Int J Spine Surg
FD International Society for the Advancement of Spine Surgery
SP 690
OP 697
DO 10.14444/8533
VO 17
IS 5
A1 Baptiste Boukebous
A1 Lorenzo Serfaty
A1 Oussema Abdelhedi
A1 Mohamed Zoghlami
A1 Cédric Maillot
A1 Jean-Yves Lazennec
A1 Marc-Antoine Rousseau
YR 2023
UL http://ijssurgery.com//content/17/5/690.abstract
AB Background While first-generation articulated disc prostheses had an ideal positioning schematically as posterior as possible because of their geometrically determined center of rotation, the dogma may change for viscoelastic implants, whose center of rotation is free. Our hypothesis was to assess whether the anteroposterior positioning (APP) of a viscoelastic implant may influence the clinical or radiological outcomes at follow-up.Methods Twenty-five patients (mean age 47 years) were evaluated, with an average follow-up of 25.9 months. The primary outcome was the implants’ APP on lateral radiographs. APP between 0% and 49% meant anterior centering, 50% perfect centering, and 51% to 100% posterior centering. The cohort was divided into 2 groups: anterior positioning and posterior positioning. Measurements were performed blindly to the functional outcomes. Visual analog scale for neck pain and radicular pain and the Neck Disability Index were assessed. Range of motion was measured at the last follow-up. The C2 to C7 Cobb angle and the spinocranial angle were also measured.Results The median crude offset from the vertebral endplate center was 0.4 mm (mean: 0.3 mm, Q1: −1.5 mm, Q3: 2 mm; range, −2.9 to 4 mm). The mean overall APP was 49%, 45.2% (95% CI, 43.2%–47.1%) in the anterior group, and 54.1% (95% CI, 51.4%–55.3%) in the posterior group. Fifteen patients were in the group anterior positioning and 10 in the group posterior positioning. The mean spinocranial angle was 79° preoperatively and 74° preoperatively (P = 0.04). Functional outcomes were significantly improved at the last follow-up (P < 10−4). There was no significant correlation between the APP, functional outcomes, and range of motion.Conclusion The APP of the CP-ESP viscoelastic disc arthroplasty does not significantly influence the clinical or radiological outcomes at follow-up. This study suggests that this type of implant tolerates greater variability in its implantation technique.Level of Evidence 4.