Tantalum is a good bone graft substitute in tibial tubercle advancement

Advanced surface modification techniques for titanium implants: a review of osteogenic and antibacterial strategies

Titanium (Ti) implants are widely used in orthopedic and dental applications due to their excellent mechanical strength, corrosion resistance, and biocompatibility. However, their limited osteointegration and susceptibility to bacterial infections remain major clinical challenges. Recent advancements in surface modification techniques have significantly improved the osteogenic and antibacterial properties of Ti implants. This review summarizes key strategies, including ion doping, hydroxyapatite (HAp) coatings, nanostructured surfaces, and graphene-based modifications. Zinc (Zn)-doped coatings increase osteoblast proliferation by 25%, enhance cell adhesion by 40%, and inhibit Staphylococcus aureus by 24%. Magnesium (Mg)-doped Ti surfaces enhance osteoblast differentiation, with 38% increased alkaline phosphatase (ALP) activity and a 4.5-fold increase in cell proliferation. Copper (Cu)-doped coatings achieve 99.45% antibacterial efficacy against S. aureus and 98.65% against Escherichia coli (E. coli). Zn-substituted HAp promotes mineralized nodule formation by 4.5-fold and exhibits 16.25% bacterial inhibition against E. coli. Graphene-based coatings stimulate bone marrow stem cells (BMSCs) and provide light-responsive surface potentials for enhanced osteogenesis. Despite these advancements, challenges remain in optimizing ion release kinetics and long-term stability. Future research should focus on multi-functional coatings that integrate osteogenic, antibacterial, and immunomodulatory properties to enhance clinical performance and patient outcomes.

Radiopaque and Biocompatible PMMA Bone Cement Triggered by Nano Tantalum Carbide and Its Osteogenic Performance

Poly(methyl methacrylate) (PMMA) bone cements have been widely used in orthopedics; thanks to their excellent mechanical properties, biocompatibility, and chemical stability. Barium sulfate and zirconia are usually added into PMMA bone cement to enhance the X-ray radiopacity, while the mechanical strength, radiopacity, and biocompatibility are not well improved. In this study, an insoluble and corrosion-resistant ceramic, tantalum carbide (TaC), was added into the PMMA bone cement as radiopacifies, significantly improving the mechanical, radiopaque, biocompatibility, and osteogenic performance of bone cement. The TaC-PMMA bone cement with varied TaC contents exhibits compressive strength over 100 MPa, higher than that of the commercial 30% BaSO4-PMMA bone cement. Intriguingly, when the TaC content reaches 20%, the radiopacity is equivalent to the commercial bone cement with 30% of BaSO4 in PMMA. The cytotoxicity and osteogenic performance indicate that the incorporation of TaC not only enhances the osteogenic properties of PMMA but also does not reduce cell viability. This study suggests that TaC could be a superior and multifunctional radio-pacifier for PMMA bone cement, offering a promising avenue for improving patient outcomes in orthopedic applications.

Use of Osteobiologics for Fracture Management: The When, What, and How

Osteobiologics are defined as a group of natural and synthetic materials used to augment bone healing. The selection of the most appropriate osteobiologic from the growing list of available options can be a challenging task. In selecting a material, surgeons should weigh a variety of considerations, including the indication for their use (the when), the most suitable substance (the what), and the correct mode of application (the how). This summary reviews these considerations and seeks to provide the surgeon with a basis for informed clinical evidence-based decision-making in their choice of a successful option.

The Synergy of Topographical Micropatterning and Ta|TaCu Bilayered Thin Film on Titanium Implants Enables Dual-Functions of Enhanced Osteogenesis and Anti-Infection

Poor osteogenesis and implant-associated infection are the two leading causes of failure for dental and orthopedic implants. Surface design with enhanced osteogenesis often fails in antibacterial activity, or vice versa. Herein, a surface design strategy, which overcomes this trade-off via the synergistic effects of topographical micropatterning and a bilayered nanostructured metallic thin film is presented. A specific microgrooved pattern is fabricated on the titanium surface, followed by sequential deposition of a nanostructured copper (Cu)-containing tantalum (Ta) (TaCu) layer and a pure Ta cap layer. The microgrooved patterns coupled with the nanorough Ta cap layer shows strong contact guidance to preosteoblasts and significantly enhances the osteogenic differentiation in vitro, while the controlled local sustained release of Cu ions is responsible for high antibacterial activity. Importantly, rat calvarial defect models in vivo further confirm that the synergy of microgrooved patterns and the Ta|TaCu bilayered thin film on titanium surface could effectively promote bone regeneration. The present effective and versatile surface design strategy provides significant insight into intelligent surface engineering that can control biological response at the site of healing in dental and orthopedic implants.

Biocompatible Porous Tantalum Metal Plates in the Treatment of Tibial Fracture

Fractures of the tibia represent a common class of injuries in orthopedics. The blood supply to the tibia is poor due to the small subcutaneous muscle tissues inside. Consequently, the tibia is prone to delayed fracture healing and nonunion of the fracture after surgery. In this case, we used porous tantalum metal plate to treat nonunion of a tibial fracture and achieved satisfactory therapeutic effects. For the first time in the field, we used 3D printing technology to fabricate porous tantalum metal plates for the treatment of tibial fractures. The resulting porous tantalum metal exhibited excellent mechanical and biological properties, and improved the therapeutic effects for the treatment of a tibial fracture nonunion. Porous tantalum metal plates have great application potential as a new implant material for internal fixation.

Biomechanical testing of a β-tricalcium phosphate wedge for advancement of the tibial tuberosity

Objectives: to evaluate in vitro the strength of different compositions of beta-tricalcium phosphate (β-TCP) wedges in comparison with titanium foam and cages. To study the response to cyclic loading of the strongest β-TCP wedge, titanium foam and titanium cage.

Methods: Compression test: Twenty-five tibiae were prepared for tibial tuberosity advancement using the modified Maquet technique. Five groups were defined depending on the material used to maintain the tibial tuberosity: Group 1 = titanium cage; Group 2 = wedges of porous titanium foam with 50% porosity (OrthoFoam®); Group 3 = blocks of biphasic synthetic bone (60% hydroxyapatite [HAP] and 40% _-TCP, porosity 80%); Group 4 = blocks of biphasic synthetic bone (60% HAP and 40% _-TCP, porosity 70%) and Group 5 = blocks of biphasic synthetic bone (65% HAP and 35% _-TCP, porosity 60%). Loads to failure were calculated for each implant. Cyclic study: Five additional tibiaes of group 1, 2 and 5 were fatigue tested from 100 to 500 N at a rate of 4 Hz for 200,000 cycles or until failure.

Results: Compression test: For the five groups, the mean load at failure was 1895 N, 1917 N, 178 N, 562 N and 1370 N respectively. Cyclical study: All samples in the three groups tested withstood 200,000 cycles without failure.

Clinical significance: The ideal implant to maintain tibial tuberosity advancement after the modified Maquet technique would be absorbable and allow osteoconduction and osteoinduction. As such, β-TCP wedges have many advantages and our study shows that they can withstand loads in the patellar tendon up to 500 N over 200,000 cycles in vitro and deserve more investigation.

Antibacterial activity, corrosion resistance and wear behavior of spark plasma sintered Ta-5Cu alloy for biomedical applications

Tantalum has been widely used in orthopedic and dental implants. However, the major barrier to the extended use of such medical devices is the possibility of bacterial adhesion to the implant surface which will cause implant-associated infections. To solve this problem, bulk Ta-5Cu alloy has been fabricated by a combination of mechanical alloying and spark plasma sintering. The effect of the addition of Cu on the hardness, antibacterial activity, cytocompatibility, corrosion resistance and wear performance was systematically investigated. The sintered Ta-5Cu alloy shows enhanced antibacterial activity against E. Coli due to the sustained release of Cu ions. However, the addition of Cu would produce slight cytotoxicity and decrease corrosion resistance of Ta. Furthermore, pin-on-disk wear tests show that Ta-5Cu alloy has a much lower coefficient of friction but a higher wear rate and shows a distinct wear mode from that of Ta upon sliding against stainless steel 440C. Wear-induced plastic deformation leads to elongation of Ta and Cu grains along the sliding direction and nanolayered structures were observed upon approaching the sliding surface. The presence of hard oxides also shows a profound effect on the plastic flow of the base material and results in localized vortex patterns. The obtained results are expected to provide deep insights into the development of novel Ta-Cu alloy for biomedical applications.

The Modified Maquet Procedure (MMP) in Dogs: Technical Development and Initial Clinical Experience

The literature about tibial tuberosity advancement surgery in dogs and humans informed the development of a version of the operation using a wedge-shaped implant of titanium foam. Computer-assisted drawing and stereolithography was used to create instruments and implants that were evaluated by cadaver surgery. A trial, involving 26 client-owned dogs with lameness due to cranial cruciate ligament failure, was started. Follow-up was done by clinical and radiographic examination after 4 wk and clinical examination again 6-11 mo after surgery. The titanium foam implant maintained tibial tuberosity advancement easily and effectively. The same major complication occurred in 2 of the first 6 cases before, a slightly modified technique was used to treat 20 dogs without complication. At mid-term follow-up (6-11 mo), 20/26 dogs (77%) had returned to full function, two dogs (7.7%) had acceptable function, two dogs (7.7%) could not be evaluated due to recent contra lateral modified Maquet procedure surgery, and two (7.7%) dogs had died for reasons unrelated to the study. This is the first clinical report of the use of titanium foam in veterinary orthopaedics. Modified Maquet procedure appears to be an effective treatment for lameness due to failure of the cranial cruciate ligament in dogs.

Proximal humeral nonunion treated with an intramedullary tantalum cylinder

Nonunion is uncommon after proximal humerus fracture surgery. There is no agreement about preferred method of treatment. Traditional approaches have included laterally based locking plates, autogenous grafting, and endosteal support to provide improved biomechanical stability. Open reduction and internal fixation (ORIF) of proximal humeral nonunion has been performed with various methods, including blade plates and bone grafting, as well as intramedullary support with autologous or allogenic grafts. Both malunion and nonunion have occurred after ORIF with locking plates. Endosteal support in the form of a fibular allograft incorporated into the locking plate construct can increase mechanical stability in selected cases. An ideal implant for proximal humeral nonunion provides medial column mechanical support and osteoconductive and osteoinductive properties. Porous intramedullary tantalum metal may play a role in nonunion surgery as an alternative to fibular allograft because of its versatility of use and salutary biological effects. It offers many material advantages for use in nonunion surgery. Tantalum is extensively porous (75%-80%), has a stiffness close to that of native bone, and offers the possibility of being a carrier for osteoinductive materials. It may also be suitable for patients who refuse allograft material. This article describes a 65-year-old woman with recalcitrant proximal humeral nonunion who was successfully treated with revision ORIF with intramedullary tantalum cylinder augmentation with a lateral-based locking plate and autogenous cancellous bone grafting. At 5-year follow-up, she had excellent motion and clinical and radiographic union.