1. Biomateriales metálicos para
implantes medicos y mecanismos de
impresión en 3D
Metallic Biomaterials for
Orthopedic Medical Devices and 3D
Printing
Introduction
State of Art
Capabilities
Conclusions
2. Electron Beam Melting /
Introduction
Introduction
State of Art
Projects
Capabilities
Conclusions
3. Introduction
Now a day’s cementless prosthesis become to be
popular, due the optimal characteristics of bone
ingrown fixation into the open cellular array in
interconnected pores. In practice, they are employed
on acetabula bone, columnar cages or glenoid devices.
4. Conductivity in the material, pore size and pore
arrangement,
encourage
or
limit
the
dissemination, vascularization and nutrient
transport through the porous matrix to the newly
formed tissue.
5. The pores presented on the matrix represent the
greatest
influence
on
bone
growth
conditions, where the cell can enter into the pores
(pore range size 100 mm to 500 mm) and
proliferating creating new bone.
6. The Challenge of this kind of open cellular is
achieve a osteoinduction, osteoconduction and
osseointegration of the bone.
The main porpoise is getting a great fixation into the
tissue without employ a PMMA cement
fixation, that in a long term is unstable.
7. Problem
A major problem concerning metallic implants in
orthopedic surgery is the differences between the
bone Young’s modulus (10–30 GPa) and bulk
metallic materials (between 110 GPa for Ti and 230
Gpa for Co–Cr alloys).
Due to this mechanical mismatch, bone is
insufficiently loaded and becomes stress
shielded, which eventually leads to bone
resorption. It has been suggested that when bone
loss is excessive, it can compromise the long-term
clinical performance of the prosthesis
11. Additive Manufacturing /Arcam EBM
High Technology on biomaterials
Ti6Al4V and Co-Cr and Recovery
Powder Method
Complexity
Shapes Based
Computer systems
drawing
Advantages
Capability to
obtain dense
and porous
materials with a
wide range of
mechanical properties.
Purity
Process in vacuum
environment
24. Efforts to eliminate the gas voids in the EBM built samples have included standard
HIP routines for Ti–6Al–4V: Thermal treatments 15 Ksi pressure at 900 C for 2 h.
The present figure shows that while the voids can be largely eliminated by a single
standard HIP cycle, remnants sometimes persist.
26. Figure 8. Pore and strut
measurement in 2-D
Figure 7. (A) unit cells of designed Ti6Al4V, (B) Optical light microscopy images of the as
produced scaffolds, (C) SEM Images of the as produced Ti6Al4V scaffolds and (D) 3-D
Model from micro CT data sets of the as produced Ti6Al4V scaffolds.
27. (a)
(b)
Figure 9. The lattice structure of a 1,000 cell octahedron structure. (a) Model (b) actual
structure.
28. Figura 11. Struts o ligamentos que constituyen la estructura tridimensional de la malla o esponja.
32. Figura 12. Modelo de esponja CAD la cual posee diferentes densidades interna y externamente, así como una vista del
corte transversal de la pieza.
L.E. Murr, K.N. Amato, S.J. Li, Y.X. Tian, X.Y. Cheng, S.M. Gaytan, E. Martinez, P.W. Shindo, F. Medina, and R.B.
Wicker, “Microstructure and Mechanical Properties of Open-Cellular Biomaterials Prototypes for Total Knee Replacement
Implants Fabricated by Electron Beam Melting,” Journal of the Mechanical Behavior of Biomedical Materials, Volume
4, Issue 7, (2011) pages 1396-1411
33. Figure 13. The structure of trabecular metal (courtesy of Zimmer). See text
for details.
34. Figure 14. Fracture plane of Duocel open-cell foam. The numbers indicate the
consecutively failed struts and the stars indicate intergranular fracture.
35. Figure 15. (a) SE-image of a low density sample. (b) SE-image of a high density
sample. Note the scale in (a) and (b).
42. Mechanical Testing Tensile specimens were machined from cylindrical build components, as
illustrated in Figure 2, and tested in an INSTRON** 500 R tensile machine at a strain rate of 3 x
10-3 s-1, at room temperature ~293 K (20 °C)). Fracture surfaces for failed tensile specimens
were also examined using FE-SEM [7].
42
43. Tensile Strenght for dense Ti6Al4V
alloy based EBM
In order to evaluate the effect of sample orientation on the
mechanical properties, samples were built in three
different orientations: standing up, laying down flat, and
lying on the side. Figure 21 shows the build orientations
of the samples with respect to the start plate.
44.
45. In order to validate the Arcam EBM process as
an acceptable alternative to conventional
fabrication methods, the mechanical properties
of Ti-6Al-4V alloy samples fabricated using
the Arcam EBM process were compared to Ti6Al-4V samples fabricated by other methods
such as various casting, forging, and laser
deposition procedures.
51. Young’s modulus
A particularly novel application involves the manufacture of open-cellular structures with
pre-selected elastic modulus or stiffness (E) for aerospace structural components, even
complex heat exchangers, etc., and orthopaedic implants tailored to eliminate bone stress
shielding by reducing E for high-modulus metals (such as Co-base alloys where E=210
GPa) by more than an order of magnitude.
Gibson and Ashby and Gibson have demonstrated that open-cellular structures in general
are characterized by:
E = Eo(ρ/ρo)2
E: Young modulus
ρ: Porous material Density
ρ0: Dense material Density
E0 : Stiffness obteined by uniaxial compressive test
Inside a Co-alloy base mesh stiffness is close to ~ 3.4GPa
ρ =1.9 g/cm3
ρ0=8.3 g/cm3
52. Microbiological / In vitro Cell
Assessment employing Human
Osteoblast like cells
53. Pore size and interconnectivity of synthetic porous
biomaterials play a crucial role in bone formation.
• A minimum pore size of 100–150 mm.
• In some cases [2], (>300 mm) for enhanced bone
formation and the formation of capillaries.
Criteria for bone ingrowth:
• Cell Size
• Migration Requirements
• Nutritional transport.
59. Fig. 7. DLF Ti–6Al–4V in vitro, human osteoblasts after 14 days of culturing, live/dead stain of cells on non-porous
material (a) and cell culture plastic as control (b), live/dead stain of culture on porous substrate with a nominal pore
diameter of 500 mm (c) and 1000 mm (d), SEM images from the same specimens (e, f). Some of the pores were filled
with cells, which had grown along the pore rims in a circular-shaped manner.
60. Fig. 7. SEM picture of seeded cp titanium foam under static culture conditions after nine weeks (AB) and under
perfusion after three weeks incubation (CF) Osteoblast under static culture condition could only be found on the
outer seeded surface with SAOS cells: Broken scaffolds inside view of middle section C: SAOS cells seeded outer
surface side D : Human osteoblast seeded surface side E: Human osteoblasts broken scaffold inside middle view F:
SAOS cell, unseeded surface side.
61. (a) CAD model used for the EBM-fabrication of cp-Ti and
Ti6Al4V scaffolds. (b) A photograph showing the scaffolds
used in the present study. (c–h) SEM images showing the
surface topography of cp-Ti (c–e) and Ti6Al4V (f–h)
scaffolds at increasing magnifications; scale bar = 10 μm, 1
μm, and 100 nm, respectively.
62. SEM images showing hES-MPs morphology and
distribution across the cp-Ti (a–d) and Ti6Al4V
(e–h) scaffolds; scale bar =200 μm (a, b, d, and f)
and 1 μm (c and f).
63. Histological micrographs of cp-Ti (a–c) and Ti6Al4V (d–f)
constructs stained with toluidine blue; scale bar = 100 μm.
65. Fig. 1. Anteroposterior (right) and lateral (left) radiographs of a dog showing typical position and fit of the femoral
component.
66. Fig. 6. Digital photographs of stained (methylene blue/basic fuchsine) histological sections of 3DFT (A), BMSC 3DFT
(B), 3DFT+BCP(C) and BMSC 3DFT+BCP (D) after 12 weeks of implantation on lumbar transverse processes. Bone is
stained pink/red, Ti alloy black and BCP ceramic dark brown. The transverse process can be seen at the bottom of the
implants and Teflon plates are visible between the implants.
67. Samples After Assessment
Epifluorescent microscopy images of fluorochrome markers in 3DFL
(A), 3DF (B), 3DFH (C), 3DFDL (D) and 3DFG (E). In all images
the earliest label is green (3 weeks, calcein green), the middle label is
yellow (6 weeks, oxytetracyclin) and the final label is orange (9
weeks, xylenol orange). The dark blue areas indicate scaffold.
68. Transmitted light micrographs of a transverse section through a 52-week implant with small pore size. There are multiple regions
of intimate bone-strut contact and evidence of a vascular supply throughout the ingrown bone
69. Porous scaffold dowels of Ti6Al4V were prepared and
implanted into cancellous and cortical bone sites in
adult sheep. Cancellous implants were examined under
gap, line-to-line, and press-fit conditions, whereas lineto-line implantation was used in cortical sites. Cortical
shear strength increased significantly with time and
reached 26.1 8.6 MPa at 12 weeks, accompanied by a
concomitant increase in bone integration and
remodeling.
70.
71. Cancelous bone fill implanted in an adult sheep
A porous scaffold of Ti6Al4V (Regenerex; Biomet) was used in the manufacture of the implant dowels, having an average
67% porosity and pore size distribution between 100 and 600 μm.
(A and B), Methylene blue and fuchsin stain at 12 weeks at the cortical site. (A) Low-magnification overview of the exposed
implant cross-section. (B) Higher-magnification image of taken at implant center. Histologic analysis demonstrated complete
bone formation throughout the implant. De novo bone was in intimate contact with the implant, and no intervening fibrous
tissue was observed.
72. Tibia Prosthesis in rabbits
Survey (to the left) and high magnification (to the
right) scanning electron micrographs of implants (A),
(B), and (C), respectively. Typical ridges and valleys
due to machining are shown for implants (A) and (B).
For implant (C), a wavy surface texture with rounded
protrusions and multiple crevices
Survey (to the left) and high magnification (to the right) light microscopy
micrographs of tibia implants (A), (B), and (C), respectively. The bone is
in close contact with the implants and, in the case of implant (C), the
bone follows the irregularities of the implant surface.
73. Measurement method for bone ingrowth depth and direct
bone–implant contact. The arrow represents the maximum
bone ingrowth depth of this quadrant. Direct bone–implant
contact was projected onto a circle representing the circumference
of the implant in order to determine the percentage of direct bone–
implant contact
Specimens. On top the specimens for the in vivo experiment,
below the specimens for the friction test. A wave structure, B
cubic structure, C plasma spray coating and D sandblasted
surface. (bar 10 mm)
74. Qualitative analysis of bone ingrowth. HE-stained slices of the wave (a) and cubic structure (b) with extensive
bone ingrowth into the pores. Bone ingrowth on the titanium plasma sprayed (c) and sandblasted (d) control. (bar
1 mm)
76. Causes of Shoulder Joint
Dysfunction
Osteoporosis,
Osteoarthritis,
Rheumatoid Arthritis
Severe Trauma (Fracture)
Main Cause: The cartilage is thinner than it is supposed to be or the bones are too
weak.
As a result the bones rub together causing pain, swelling and/or loss of motion
of the joint. To improve the movement of the joint and to relieve the pain, a
prosthesis to replace the glenoid of the shoulder joint is an option.
76
77. In ball-and-socket joints the spherical of
hemispherical head of one bone articulates with
the cup-like socket of another. These joints are
multiaxial and the most freely moving synovial
joints. Moving is allowed in all axes and
planes, including rotation.
In the shoulder, the joint sacrifice stability to
provide the most freely moving joint of the body.
77
78. Glenoid section or component loosening is
the major problem of total shoulder
arthroplasty. It is possible that uncemented
components may be able to achieve superior
fixation relative to cemented components.
Numerous all-polyethylene or metalbacked glenoid components, with keel- or
peg-shaped backings, fixated either with or
without cement, have been introduced in an
attempt to reduce the high glenoid
component loosening rate in total shoulder
arthroplasty
78
79. Cemented glenoid components are limited by high
stresses in the cement layer that cause damage and
osteolysis,
whereas
cementless
metal-backed
components show problems with rapid polyethylene
wear, component dissociation and pull out of the
screws used for implant fixation. The glenoid
component design is a relevant task.
81. This studies could help us to develop a metallic
biomaterials shoulder implant, creating a porous
coating of the same material (Ti6Al4V or Co-Cr) with
enough stability and long term fixation, to support the
osseointegration.
In particular is necessary to know the thickness of the
porous film formed on the implant to be removed
easily the implant and at the same time reducing the risk
of infection.
The final target would be, design the implants models
and tools to install and remove them.
82. Thank you for your attention
Gracias por su atención
