Resorbable plating system stabilizes tissue‐engineered intervertebral discs implanted ex vivo in canine cervical spines

Abstract

Total disc replacement using tissue‐engineered intervertebral discs (TE‐IVDs) may offer a biological alternative to treat radiculopathy caused by disc degeneration. A composite TE‐IVD was previously developed and evaluated in rat tail and beagle cervical spine models in vivo. Although cell viability and tissue integration into host tissue were promising, significant implant displacement occurred at multiple spinal levels. The goal of the present study was to assess the effects of a resorbable plating system on the stiffness of motion segments and stability of tissue‐engineered implants subjected to axial compression. Canine motion segments from levels C2/C3 to C5/C6 were assessed as intact (CTRL), after discectomy (Dx), with an implanted TE‐IVD only (PLATE−), and with a TE‐IVD combined with an attached resorbable plate (PLATE+). Segments under PLATE+ conditions fully restored separation between endplates and showed significantly higher compressive stiffness than segments under PLATE− conditions. Plated segments partially restored more than 25% of the CTRL motion segment stiffness. Plate attachment also prevented implant extrusion from the disc space at 50% compressive strain, and this effect was more significant in segments from levels C3/C4 when compared to segments from level C5/C6. These results suggest that stabilization of motion segments via resorbable plating assists TE‐IVD retention in the disc space while allowing the opportunity for implants to fully integrate into the host tissue and achieve optimal restoration of spine biomechanics.

Preclinical ex-vivo Testing of Anti-inflammatory Drugs in a Bovine Intervertebral Degenerative Disc Model

“…In order to overcome current treatment barriers and improve patient care, biological approaches on IVD regeneration have gained increasing interest. According to the state of IVD degeneration, staged therapeutic concepts have been developed such as biomolecular, cell therapy, as well as tissue engineering (TE)-based treatments (Li et al, 2014(Li et al, , 2015(Li et al, , 2017Pirvu et al, 2015;Mojica-Santiago et al, 2018;Pennicooke et al, 2018). In earlier stages of disc degeneration when viable cells are still present, the aim is to relieve pain and enhance the intradiscal metabolism by stopping the catabolic cascade of ECM breakdown and inflammation.…”

New horizons in spine research: Disc biology, tissue engineering, biomechanics, translational, and clinical research

“…To restore the motion and improve the stability of the spine motion segments using TE‐IVDs, Mojica Santiago et al, have tested the potential of the bio‐resorbable plates using fixation system of 85:15 polylactic‐co‐glycolic acid plates and screws (Rapidsorb, Depuy Synthes Co. Johnson & Johnson, West Chester, PA) using canine cervical spines. The findings by Mojica Santiago et al, show that the plated segments partially restored motion segment stiffness compared to controls . Also, attachment of the resorbable plates prevented extrusion of the implant from the disc space.…”

“…The findings by Mojica Santiago et al, show that the plated segments partially restored motion segment stiffness compared to controls. 13 Also, attachment of the resorbable plates prevented extrusion of the implant from the disc space. Hence, the potential of these plates to fully integrate into the host tissue provides hope for improving current approaches for disc arthroplasty.…”

Canine models of spine disorders

“…In an attempt to address these limitations, endplate models, 64,65 biomechanical injury models, 66 and discectomy models 45 72 These models may also have therapeutic relevance in that chemonucleolysis has been successfully used as a treatment option in select human and veterinary patients. 69,70,[72][73][74] Surgically and chemically induced models have also been used in CD breeds of dogs in order to include the spontaneous-disease components to methods for initiating and perpetuating insults.…”

“…These biomechanical data can then be cor- ing can be used to assess the compressive modulus, elasticity, creep, stress-relaxation, and permeability of the IVD in order to characterize its functional composition, integrity, and viscoelasticity. 53,64,[190][191][192][193][194][195]…”