Bonding of alkali- and heat-treated tantalum implants to bone

Abstract

Alkali- and heat-treated tantalum (Ta) has been shown to bond to bone. The purpose of this study was to investigate the effects of chemical treatments on the bone-bonding ability of tantalum implants in rabbit tibiae. Miyazaki et al. reported in vitro that alkali- and heat-treated tantalum had an apatite forming ability in an acellular simulated body fluid (SBF). In this study, smooth-surfaced rectangular plates (15 x 10 x 2 mm) of pure tantalum and treated tantalum were prepared. The plates were implanted transcortically into the proximal metaphyses of bilateral rabbit tibiae, alkali- and heat-treated plates for one limb and untreated plates for the contralateral limb, which served as a paired control. Bone bonding at the bone/implant interface was evaluated by tensile testing and undecalcified histological examination, at 8 and 16 weeks after implantation. The treated implants showed weak bonding to bone at 8 weeks, and exhibited significantly higher tensile failure loads compared with untreated tantalum implants at 16 weeks. The untreated implants showed almost no bonding, even at 16 weeks. Histological examination by Giemsa surface staining, contact microradiography (CMR), and scanning electron microscopy (SEM) revealed that treated tantalum implants bonded directly to bone tissue. In contrast, the untreated tantalum implants had a intervening fibrous tissue layer between the bone and the plate and did not bond to bone at 8 and 16 weeks. It is clear from these results that alkali and heat treatment induce the bone-bonding ability of tantalum. This new bioactive tantalum should be an effective material for weight-bearing and bone-bonding orthopedic devices.

Can Porous Tantalum Be Used to Achieve Ankle and Subtalar Arthrodesis?: A Pilot Study

“…Its compressive strength and elastic modulus are similar to normal bone, which theoretically reduces stress shielding and stress concentration [3][4][5]56]. Tantalum is biocompatible and its mechanical properties have been studied extensively [2,25,34,56]. Owing to its biocompatibility, tantalum has been used safely in patients for years for pacemaker electrodes, cranioplasty plates, and as radiopaque markers [29,30].…”

Numerical studies on alternative therapies for femoral head necrosis

“…This study revealed that the tantalum implant is superior to the fibular grafting technology in all these aspects. The bio-compatibility of tantalum implants was determined to be good and safe to use in vivo (Kato et al 2000).…”

Biointegration of Prosthetic Devices

“…This treated tantalum metal also forms the bonelike apatite on its surface in SBF and in the living body, and bonds to the living bone, as shown in Figure 24.13 (Kato et al 2000 ). Based on the mechanism of apatite formation on CaO · SiO 2 -based glasses in the section on " Ceramics for Bone Substitutes " and on NaOH -and heat -treated titanium metals in this section, a release of calcium and/or sodium ions, as well as a negatively charged functional group, seems to be important for apatite nucleation.…”