Porous titanium‐nickel for intervertebral fusion in a sheep model: Part 1. Histomorphometric and radiological analysis¹

Abstract

Porous titanium-nickel (PTN) implants represent an alternative to traditional intervertebral fusion cages. Indeed, PTN materials possess interconnecting pores with cell capillarity properties that may promote bone ingrowth and intervertebral fusion without the need for bone grafting. In this study, a PTN intervertebral fusion device was compared to a conventional TiAlV cage packed with autologous bone in a sheep model. The two devices were implanted at two noncontiguous intervertebral lumbar sites for 3, 6, and 12 months. PTN osseointegration showed a time-dependent trend increasing from 21.4% to 37.6% (3-12 months), whereas TiAlV cages remained at the same level of bone ingrowth (22.7%-25.4%; 3-12 months). Furthermore, PTN bone apposition (10.9%-24.2%; 3-12 months) was significantly higher than that of TiAlV implants (1.1%-5.1%; 3-12 months; p < 0.001, ANOVA). Radiological fusion scores increased with postsurgery time regardless of material type, but were consistently superior for PTN (12.5-18.5; 3-12 months) than for TiAlV cages (2.0-15.0; 3-12 months; p < 0.001, ANOVA). Implant materials were not significantly different according to the radiological interbody index based on preoperative disc height: Interbody index began at 132.6% (PTN) and 123.5% (TiAlV) immediately after surgery, then declined to 80.8% (PTN) and 91.0% (TiAlV) after 12 months. Nevertheless, ungrafted PTN constituted an excellent substrate for osteogenic cell integration and represents a new osteoconductive biomaterial with improved fusion characteristics in comparison to conventional TiAlV cages.

Selective leaching and surface properties of TiNiFe shape-memory alloys

“…1 Most TiNi SMAs further exhibit a low cytotoxicity and a good biocompatibility [2][3][4] and thus they are also suitable for biomedical applications, such as laparoscopic surgery, stents, shape-memory microvalves, and osteosynthesis devices. [5][6][7] It was reported that substituting Fe for Ni in TiNi SMAs induces the formation of the R-phase during the martensitic transformation and leads to some advanced mechanical properties superior to those of typical TiNi SMAs.…”

Direct visualization and quantification of bone growth into porous titanium implants using micro computed tomography

“…Conventional histological or metallographic two-dimensional (2D) sectioning techniques have been used predominantly to quantify bone growth into porous coatings using light microscopy (LM) and/or backscattered scanning electron microscopy (BSEM) [8]. Post-processing of acquired images routinely includes digital image analysis to determine the porosity, pore size and ratio of bone area to porous area (% ingrowth) [9]. While standard 2D histology techniques are effective, sample preparation is laborious, time consuming and results in the destruction of the specimen.…”

The spinal cord dura mater reaction to nitinol and titanium alloy particles: a 1-year study in rabbits

“…The biocompatibility and biofunctionality of the porous nitinol IFD, Actipore TM PLFx for the treatment of symptomatic disc degeneration were evaluated in a sheep model for a long period of time [4]. The corrosion resistance [37], as well as the mechanical tests [43,44], was evaluated successfully.…”