Vd Chaklin Ural Scientific And Research Institute Of Traumatology And Orthopaedics

Yekaterinburg, Russia

Vd Chaklin Ural Scientific And Research Institute Of Traumatology And Orthopaedics

Yekaterinburg, Russia
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Rubshtein A.P.,RAS Institute of Metal Physics | Makarova E.B.,Vd Chaklin Ural Scientific And Research Institute Of Traumatology And Orthopaedics | Rinkevich A.B.,RAS Institute of Metal Physics | Medvedeva D.S.,RAS Institute of Metal Physics | And 2 more authors.
Materials Science and Engineering C | Year: 2015

The porous titanium implants were introduced into the condyles of tibias and femurs of sheep. New bone tissue fills the pore, and the porous titanium-new bone tissue composite is formed. The duration of composite formation was 4, 8, 24 and 52 weeks. The formed composites were extracted from the bone and subjected to a compression test. The Young's modulus was calculated using the measured stress-strain curve. The time dependence of the Young's modulus of the composite was obtained. After 4 weeks the new bone tissue that filled the pores does not affect the elastic properties of implants. After 24 and 52 weeks the Young's modulus increases by 21-34% and 62-136%, respectively. The numerical calculations of the elasticity of porous titanium-new bone tissue composite were conducted using a simple polydisperse model that is based on the consideration of heterogeneous structure as a continuous medium with spherical inclusions of different sizes. The kinetics of the change in the elasticity of the new bone tissue is presented via the intermediate characteristics, namely the relative ultimate tensile strength or proportion of mature bone tissue in the bone tissue. The calculated and experimentally measured values of the Young's modulus of the composite are in good agreement after 8 weeks of composite formation. The properties of the porous titanium-new bone tissue composites can only be predicted when data on the properties of new bone tissue are available after 8 weeks of contact between the implant and the native bone. © 2015 Elsevier B.V. All rights reserved.


Rubstein A.P.,RAS Institute of Metal Physics | Makarova E.B.,Vd Chaklin Ural Scientific And Research Institute Of Traumatology And Orthopaedics | Trakhtenberg I.S.,RAS Institute of Metal Physics | Kudryavtseva I.P.,Vd Chaklin Ural Scientific And Research Institute Of Traumatology And Orthopaedics | And 3 more authors.
Diamond and Related Materials | Year: 2012

High-porous implants capable of osteointegration are currently of great interest. Osseointegration is the establishment of bond strength between implant and host bone due to bone ingrowth into the porous structure. Ingrowth of bone tissue requires open interconnected pores and biocompatible surface, which is in direct contact with host tissues. Implants for orthopedics must have in addition a sufficient mechanical strength. In this work for in vivo experiments, cylindrical implants of 4.5 mm diameter made of porous titanium (PTi) produced by the original technology were used. To improve osseointegration, on the implant surface the diamond-like carbon (DLC) or nitrogen-containing carbon (CN 0.25) films were deposited using PVD technique. The PTi, PTi (DLC) and PTi (CN 0.25) implants saturated by adhesion fraction of autologous bone marrow were implanted in rabbit right tibia and femoral condyles. Tensile strength study of native compact bone (σ NB) and neogenic bone tissue (σ BTS) at the implant-host bone interface showed the following: after 4 weeks (σ BTS/ σ NB) = 0.39, 0.57 and 0.52, at 16 weeks (σ BTS/ σ NB) = 0.46, 0.70 and 0.58 for PTi, PTi (DLC) and PTi (CN 0.25), respectively. In all cases after 52 weeks the neogenic bone tissue strength at the interface did not differ from the native bone strength. Histological studies of tissue formed in the implant pores, showed that after 4 weeks a bone tissue of varying maturity was formed in the entire volume of implants: on the periphery of the implant it found bone trabecules ingrown from parent bed, and closer to the implant center a spongy immature bone tissue. In 16 weeks the integration of parent bed bone and newly formed bone trabecules was determined. This process was most inhered to PTi (DLC). After 52 weeks bone tissue integrated a 2/3 PTi (DLC) and 1/3 PTi (CN 0.25) diameter of the implant. Our studies showed that all implants are biocompatible and osseointegrate with the native host bone. The porous titanium with DLC is the most effective and can be recommended for use in clinical trial. © 2011 Elsevier B.V. All rights reserved.


Rubshtein A.P.,RAS Institute of Metal Physics | Trakhtenberg I.Sh.,RAS Institute of Metal Physics | Makarova E.B.,Vd Chaklin Ural Scientific And Research Institute Of Traumatology And Orthopaedics | Triphonova E.B.,Vd Chaklin Ural Scientific And Research Institute Of Traumatology And Orthopaedics | And 3 more authors.
Materials Science and Engineering C | Year: 2014

A porous material has been produced by pressing spongy titanium granules with subsequent vacuum sintering. The material with porosity of more than 30% has an open system of interconnecting pores. The Young's modulus and 0.2% proof strength have been measured for the samples having 20-55% porosity. If the porosity is between 30 and 45%, the mechanical properties are determined by irregular shape of pores, which is due to spongy titanium granules. The experiment in vivo was performed on adult rabbits. Before surgery the implants were saturated with adherent autologous bone marrow cells. The implants were introduced into the defects formed in the condyles of tibias and femurs. Investigations of osseointegration of implants having 40% porosity showed that the whole system of pores was filled with mature bone tissue in 16 weeks after surgery. Neogenic bone tissue has an uneven surface formed by lacunas and craters indicative of active resorption and subsequent rearrangement (SEM examination). The bone tissue is pierced by neoformed vessels. Irregular-shaped pores with tortuous walls and numerous lateral channels going through the granules provide necessary conditions for the formation of functional bone tissue in the implant volume and the periimplant region. © 2013 Elsevier B.V. All rights reserved.

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