title: Biomechanical evaluation of a novel nucleus pulposus prosthesis in canine cadaveric spines.
abstract: Partial disc replacement is a new surgical technique aimed at restoring functionality to degenerated intervertebral discs (IVDs). The aim of the present study was to assess biomechanically the behaviour of a novel nucleus pulposus prosthesis (NPP) in situ and its ability to restore functionality to the canine IVD after nuclectomy alone or after combined dorsal laminectomy and nuclectomy. Nine canine T13-L5 specimens (L2L3 group) and 10 L5-Cd1 specimens (LS group) were tested biomechanically in the native state, after nuclectomy (L2L3 group) or after combined dorsal laminectomy and nuclectomy (LS group), and after insertion of the NPP. Range of motion (ROM), neutral zone (NZ), and neutral zone stiffness (NZS) were determined in flexion/extension, lateral bending, and axial rotation. Nuclectomy alone and combined dorsal laminectomy and nuclectomy caused significant instability in all motion directions. Implantation of the NPP resulted in significant restoration of the parameters (ROM, NZ, and NZS) towards the native state; however, fragmentation/herniation of the NPP occurred in 47% of the cases. In conclusion, the NPP has the ability to improve functionality of the nuclectomized canine IVD. The high rate of NPP failure requires modifications directed at the integrity of the NPP and its confinement to the nuclear cavity.
authors: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, 3508 TD Utrecht, The Netherlands. L.A.Smolders@uu.nl
authors: Lucas Adam
authors: LA
authors: Smolders
authors: Niklas
authors: N
authors: Bergknut
authors: Idsart
authors: I
authors: Kingma
authors: Albert Jan
authors: AJ
authors: van der Veen
authors: Theodoor Henri
authors: TH
authors: Smit
authors: Levinus Hendrik
authors: LH
authors: Koole
authors: Herman Anthonie Willem
authors: HA
authors: Hazewinkel
authors: Björn Petrus
authors: BP
authors: Meij
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002102:Cadaver; D004283:Dog Diseases / Q000601:surgery*; D004285:Dogs; D005260:Female; D055959:Intervertebral Disc Degeneration / Q000601:surgery / Q000662:veterinary*; D007796:Laminectomy / Q000662:veterinary; D008159:Lumbar Vertebrae / Q000601:surgery*; D019919:Prosthesis Implantation / Q000379:methods / Q000662:veterinary*; D016059:Range of Motion, Articular; D013904:Thoracic Vertebrae / Q000601:surgery*; D016896:Treatment Outcome