The prevalence of intervertebral disc degeneration in the cervical, thoracic, and lumbar spine in asymptomatic cats.

Objective: To investigate the prevalence and severity of intervertebral disc (IVD) degeneration (IVDD) throughout the spine of young, middle-aged, and old asymptomatic cats; identify differences between the cervical, thoracic, and lumbar spine; and investigate the influence of sex and neuter status on the prevalence of feline IVDD.

Methods: 60 cadavers were collected from asymptomatic cats and subdivided into 3 age groups: young (≥ 1 to < 6 years), middle aged (≥ 6 to < 12 years), and old (≥ 12 years). T2 weighted sagittal MRI studies of the spine were obtained.

Targeted screening of inflammatory mediators in spontaneous degenerative disc disease in dogs reveals an upregulation of the tumor necrosis superfamily.

Background: The regulation of inflammatory mediators in the degenerating intervertebral disc (IVD) and corresponding ligamentum flavum (LF) is a topic of emerging interest. The study aimed to investigate the expression of a broad array of inflammatory mediators in the degenerated LF and IVD using a dog model of spontaneous degenerative disc disease (DDD) to determine potential treatment targets.

Methods: LF and IVD tissues were collected from 22 normal dogs (Pfirrmann grades I and II) and 18 dogs affected by DDD (Pfirrmann grades III and IV).

Ex vivo comparison of lateral plate repairs of experimental oblique ilial fractures in cats.

Objective: To determine the biomechanical behavior of different plate systems used for oblique ilial fracture fixation in cats.

Study Design: Ex vivo biomechanical study.

Sample Population: Fifty fresh-frozen feline hemipelvises.

Evaluation of the Dynamic Morphometry of the Caudal Cervical Intervertebral Disc Spaces of Small Dogs and Cats.

The objective of this study was to provide a morphometric description of the caudal cervical intervertebral disc (IVD) spaces of small-breed dogs and cats. Specimens consisting of C4 through C7 from five small-breed dogs and six cats were positioned in neutral, flexion, extension, and lateral bending positions; and CT images were acquired. Height and width of the cranial and caudal vertebral endplates (VEPs), angle between the VEPs (IVD wedge angle), and craniocaudal distance (IVD width) between VEPs for the four loading positions were measured and compared for three segments (C4-C5, C5-C6, and C6-C7).

Evaluation of agreement and correlation of results obtained with MRI-based and macroscopic observation-based grading schemes when used to assess intervertebral disk degeneration in cats.

Objective: To evaluate agreement in results obtained with an MRI-based grading scheme and a macroscopic observation-based grading scheme when used to assess intervertebral disk (IVD) degeneration in cats.

Sample: 241 MRI and 143 macroscopic images of singular IVDs in 44 client-owned cats (40 cadaveric and 4 live).

Procedures: Singular images of IVDs were obtained of live cats admitted for treatment of suspected neurologic disease (MRI images of IVDs) and of cadavers of cats euthanized for reasons unrelated to spinal disease (MRI and macroscopic images of IVDs) at the Small Animal Hospital, Vetsuisse Faculty, Zurich, Switzerland, between January 12, 2015, and October 19, 2015.

Safety and Accuracy of Minimally Invasive Long Bone Fracture Repair Using a 2.5-mm Interlocking Nail: A Cadaveric Feline Study.

Objectives:  The Targon Vet System (TVS) is a 2.5-mm interlocking nail that can be applied minimally invasively. The purpose of this study was to test if the TVS could be safely applied percutaneously to different feline long bones without fluoroscopic guidance.

Ex vivo computed tomography evaluation of loading position on morphometry of the caudal cervical intervertebral disk spaces of dogs.

OBJECTIVE To provide an objective, quantitative morphometric description of the caudal cervical intervertebral disk (IVD) spaces of dogs. SAMPLE Vertebral specimens consisting of C4 through C7 from 5 medium-sized dogs. PROCEDURES CT images were obtained with the specimens positioned in neutral, flexion, extension, and lateral bending positions.

Biomechanical properties of plate constructs for feline ilial fracture gap stabilization.

Objective: To determine the biomechanical properties of plating techniques for comminuted feline ilial fractures.

Study Design: Ex vivo study on 40 paired feline hemipelves.

Sample Population: Forty paired fresh-frozen hemipelves that had been collected from 20 cats aged 2-6 years and weighing 4.

The Myth of Fibroid Degeneration in the Canine Intervertebral Disc: A Histopathological Comparison of Intervertebral Disc Degeneration in Chondrodystrophic and Nonchondrodystrophic Dogs.

Since the seminal work by Hans-Jörgen Hansen in 1952, it has been assumed that intervertebral disc (IVD) degeneration in chondrodystrophic (CD) dogs involves chondroid metaplasia of the nucleus pulposus, whereas in nonchondrodystrophic (NCD) dogs, fibrous metaplasia occurs. However, more recent studies suggest that IVD degeneration in NCD and CD dogs is more similar than originally thought. Therefore, the aim of this study was to compare the histopathology of IVD degeneration in CD and NCD dogs.

Bone Marrow-Derived Mesenchymal Stem Cells as Autologous Therapy in Dogs with Naturally Occurring Intervertebral Disc Disease: Feasibility, Safety, and Preliminary Results.

The intradiscal application of mesenchymal stem cells (MSCs) is considered a promising strategy for intervertebral disc (IVD) regeneration. Although many studies have been published, the feasibility and regenerative effects of intradiscal MSC application have not been evaluated in an animal model suffering from naturally occurring degenerative disc disease. Six German Shepherd Dogs suffering from naturally occurring degenerative IVD disease were included.

Effect of coculturing canine notochordal, nucleus pulposus and mesenchymal stromal cells for intervertebral disc regeneration.

Introduction: Early degenerative changes in the nucleus pulposus (NP) are observed after the disappearance of notochordal cells (NCs). Thus, it has been suggested that NCs play an important role in maintaining the NP and may have a regenerative potential on other cells of the NP. As the number of resident NP cells (NPCs) decreases in a degenerating disc, mesenchymal stromal (stem) cells (MSCs) may be used for cell supplementation.

Increased osmolarity and cell clustering preserve canine notochordal cell phenotype in culture.

Degeneration of the intervertebral disc (IVD) is associated with a loss of notochordal cells (NCs) from the nucleus pulposus (NP) and their replacement by chondrocyte-like cells. NCs are known to maintain extracellular matrix quality and stimulate the chondrocyte-like NP cells, making NCs attractive for designing new tissue engineering approaches for IVD regeneration. However, optimal conditions, such as osmolarity and other characteristics of the culture media, for long-term culture of NCs are not known.

Gene expression profiling of early intervertebral disc degeneration reveals a down-regulation of canonical Wnt signaling and caveolin-1 expression: implications for development of regenerative strategies.

Introduction: Early degeneration of the intervertebral disc (IVD) involves a change in cellular differentiation from notochordal cells (NCs) in the nucleus pulposus (NP) to chondrocyte-like cells (CLCs). The purpose of this study was to investigate the gene expression profiles involved in this process using NP tissue from non-chondrodystrophic and chondrodystrophic dogs, a species with naturally occurring IVD degeneration.

Methods: Dual channel DNA microarrays were used to compare 1) healthy NP tissue containing only NCs (NC-rich), 2) NP tissue with a mixed population of NCs and CLCs (Mixed), and 3) NP tissue containing solely CLCs (CLC-rich) in both non-chondrodystrophic and chondrodystrophic dogs.

Intervertebral disc degeneration in the dog. Part 1: Anatomy and physiology of the intervertebral disc and characteristics of intervertebral disc degeneration.

Intervertebral disc (IVD) degeneration is common in dogs and can give rise to a number of diseases, such as IVD herniation, cervical spondylomyelopathy, and degenerative lumbosacral stenosis. Although there have been many reports and reviews on the clinical aspects of canine IVD disease, few reports have discussed and reviewed the process of IVD degeneration. In this first part of a two-part review, the anatomy, physiology, histopathology, and biochemical and biomechanical characteristics of the healthy and degenerated IVD are described.

Intervertebral disc degeneration in the dog. Part 2: chondrodystrophic and non-chondrodystrophic breeds.

Dogs can be grouped into two distinct types of breed based on the predisposition to chondrodystrophy, namely, non-chondrodystrophic (NCD) and chondrodystrophic (CD). In addition to a different process of endochondral ossification, NCD and CD breeds have different characteristics of intravertebral disc (IVD) degeneration and IVD degenerative diseases. The anatomy, physiology, histopathology, and biochemical and biomechanical characteristics of the healthy and degenerated IVD are discussed in the first part of this two-part review.

Pedicle screw-rod fixation of the canine lumbosacral junction.

Objective: To assess pedicle screw-rod fixation (PSRF) of the canine lumbosacral junction (LSJ) ex vivo and in vivo.

Study Design: Ex vivo cadaver study and in vivo pilot study.

Sample Population: Six canine cadaveric lumbosacral spinal specimens and 3 Greyhound dogs diagnosed with degenerative lumbosacral stenosis (DLSS).

Biomechanical assessment of the effects of decompressive surgery in non-chondrodystrophic and chondrodystrophic canine multisegmented lumbar spines.

Purpose: Dogs are often used as an animal model in spinal research, but consideration should be given to the breed used as chondrodystrophic (CD) dog breeds always develop IVD degeneration at an early age, whereas non-chondrodystrophic (NCD) dog breeds may develop IVD degeneration, but only later in life. The aim of this study was to provide a mechanical characterization of the NCD [non-degenerated intervertebral discs (IVDs), rich in notochordal cells] and CD (degenerated IVDs, rich in chondrocyte-like cells) canine spine before and after decompressive surgery (nucleotomy).

Methods: The biomechanical properties of multisegmented lumbar spine specimens (T13-L5 and L5-Cd1) from 2-year-old NCD dogs (healthy) and CD dogs (early degeneration) were investigated in flexion/extension (FE), lateral bending (LB), and axial rotation (AR), in the native state and after nucleotomy of L2-L3 or dorsal laminectomy and nucleotomy of L7-S1.

Canonical Wnt signaling in the notochordal cell is upregulated in early intervertebral disk degeneration.

The notochordal cell (NC) of the nucleus pulposus (NP) is considered a potential NP progenitor cell, and early intervertebral disk (IVD) degeneration involves replacement of NCs by chondrocyte-like cells (CLCs). Wnt/β-catenin signaling plays a crucial role in maintaining the notochordal fate during embryogenesis, but is also involved in tissue degeneration and regeneration. The canine species, which can be subdivided into non-chondrodystrophic and chondrodystrophic breeds, is characterized by differential maintenance of the NC: in non-chondrodystrophic dogs, the NC remains the predominant cell type during the majority of life, with IVD degeneration only occurring at old age; conversely, in chondrodystrophic dogs the NC is lost early in life, with concurrent degeneration of all IVDs.

Biomechanical evaluation of a novel nucleus pulposus prosthesis in canine cadaveric spines.

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.

The dog as an animal model for intervertebral disc degeneration?

Study Design: Prospective observational and analytic study.

Objective: To investigate whether spontaneous intervertebral disc degeneration (IVDD) occurring in both chondrodystrophic (CD) and nonchondrodystrophic dogs (NCD) can be used as a valid translational model for human IVDD research.

Summary Of Background Data: Different animal models are used in IVDD research, but in most of these models IVDD is induced manually or chemically rather than occurring spontaneously.

The performance of a hydrogel nucleus pulposus prosthesis in an ex vivo canine model.

A nucleus pulposus prosthesis (NPP) made of the hydrogel N-vinyl-2-pyrrolidinone copolymerized with 2-(4'-iodobenzoyl)-oxo-ethyl methacrylate has recently been developed. The special features of this NPP, i.e.