3D-printed titanium cages without bone graft outperform PEEK cages with autograft in an animal model.

BACKGROUND CONTEXT

Modernization of 3D printing has allowed for the production of porous titanium interbody cages (3D-pTi) which purportedly optimize implant characteristics and increase osseointegration; however, this remains largely unstudied in vivo.

PURPOSE

To compare osseointegration of three-dimensional (3D) titanium cages without bone graft and Polyether-ether-ketone (PEEK) interbody cages with autologous iliac crest bone graft (AICBG).

STUDY DESIGN

Animal study utilizing an ovine in vivo model of lumbar fusion.

METHODS

Interbody cages of PEEK or 3D-pTi supplied by Spineart SA (Geneva, Switzerland) were implanted in seven living sheep at L2-L3 and L4-L5, leaving the intervening disc space untreated. Both implant materials were used in each sheep and randomized to the aforementioned disc spaces. Computed tomography (CT) was obtained at 4 weeks and 8 weeks. MicroCT and histological sections were obtained to evaluate osseointegration.

RESULTS

MicroCT demonstrated osseous in-growth of native cancellous bone in the trabecular architecture of the 3D-pTi interbody cages and no interaction between the PEEK cages with the surrounding native bone. Qualitative histology revealed robust osseointegration in 3D-pTi implants and negligible osseointegration with localized fibrosis in PEEK implants. Evidence of intramembranous and endochondral ossification was apparent with the 3D-pTi cages. Quantitative histometric bone implant contact demonstrated significantly more contact in the 3D-pTi implants versus PEEK (p<.001); region of interest calculations also demonstrated significantly greater osseous and cartilaginous interdigitation at the implant-native bone interface with the 3D-pTi cages (p=.008 and p=.015, respectively).

CONCLUSIONS

3D-pTi interbody cages without bone graft outperform PEEK interbody cages with AICBG in terms of osseointegration at 4 and 8 weeks postoperatively in an ovine lumbar fusion model.

CLINICAL SIGNIFICANCE

3D-pTi interbody cages demonstrated early and robust osseointegration without any bone graft or additive osteoinductive agents. This may yield early stability in anterior lumbar arthrodesis and potentially bolster the rate of successful fusion. This could be of particular advantage in patients with spinal neoplasms needing post-ablative arthrodesis, where local autograft use would be ill advised.

Informations de copyright

Copyright © 2021 Elsevier Inc. All rights reserved.

Déclaration de conflit d'intérêts

Declarations of competing interests This study received grant funding through Spineart SA (Geneva, Switzerland). Spineart SA is the manufacturer of the tested implant devices in which this study sought to evaluate. The results from this manuscript were presented in abstract form at 35th Annual Meeting of the North American Spine Society on 1 September 2020. The manuscript has not been previously published nor is it under review in any other journal. No known or perceived conflicts of interest exist amongst any of the authors regarding the material presented within this manuscript, with the exception of Dr. Joseph Laratta, MD who reports the following in the interest of full disclosure: consulting roles with Stryker/K2M, NuVasive, 4Webb, Spineart, Evolution Spine, and Gerson Lehrman Group; receives royalties from Spineart, Evolution Spine, has intellectual property with Combination biologic and ICBG/BMAC system; receives grants from Medtronic, NuVasive, Stryker/K2M, Orthopaedic Science Research Foundation; receives travel and accommodations from American Institute of Minimally Invasive Surgery, NuVasive, Stryker/K2M, Spineart, Fisher Owen Fund; serves on the editorial board of Spine, Global Spine Journal, and Journal of Spine Surgery.