BIOLOXdelta The Fourth Generation of Ceramics - Scientific Information and Performance Data
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CeramTec Medical Products BIOLOX®delta The Fourth Generation of Ceramics Scientific Information and Performance Data
Key Issues in Hip Arthroplasty Osteolysis Although total hip arthroplasty is one of the most successful of all surgical procedures, a number of open questions relating to implant design and materials remain. According to the Swedish Register (2012), osteolysis and aseptic loosening are responsible for 68.2 percent of all revisions. The bearing materials used and the volume, size, and biological effects of wear particles play a decisive role in the development of these conditions. The second most frequent complication is dislocation created by prosthetic impingement and insufficient joint stability. Instability Component impingement can result in a limited range of motion (ROM). In addition to exact implant positioning, the technical ROM achieved after implantation plays a crucial role. While large ball head and cup-liner diameters increase ROM, they are associated (in the case of PE, XPE and MoM) with an increased volume of wear particles. In a metal-on-metal articulation this can result in an elevated level of metal ions released into the surrounding tissues. Both mechanisms have been the subject of intense scientific discussion. Hypersensitivity The incidence of hypersensitivity and allergic reactions to metals is increasing in the world’s industrialized countries. The possible onset of hypersensitive reactions in patients treated with metal-on-metal bearings cannot be completely ruled out in advance. Metal allergies detected post surgery represent an additional burden for patients and insurers. It has therefore become even more important to use implant materials that exhibit a biologically compatible behavior in the body. 2 Tribology and Arthroplasty
Key Issues in Hip Arthroplasty
Synovial Fluid Lubrication
There remains a limited understanding of the actual processes governing the tribological
performance of artificial joints. Unlike natural cartilage, even modern material combina-
tions do not allow for a permanent lubrication film to separate the two surfaces. For that
reason wear-resistant materials with optimal surface characteristics play a key role in deter-
mining the tribological outcome of arthroplasty.
Taper Corrosion
Corrosion at the head-neck taper has recently been found to be an important factor for
the outcomes of THA, and its severity is multi-factorial. There is increasing evidence that in
addition to wear reduction, ceramic femoral ball heads are also crucial in mitigating metal
taper corrosion on the stem side, while experiencing no corrosion themselves.
Tribology and Arthroplasty 3
4
Proven High Performance Ceramics
BIOLOX®delta
More than 40 years of experience in ceramic hip replacements together with more
than 10 million BIOLOX® implanted components confirms CeramTec as a world
leader in this technology.
Surgeons all over the world put their faith in CeramTec’s pink-colored BIOLOX® delta
ceramic. This colour gives surgeons the certainty that they are using implants of the
highest quality and reliability for their patients – from CeramTec.
BIOLOX® delta is the only ceramic with 10 years of successful clinical experience.
About 95 percent of all ceramic implants for hip arthroplasty are manufactured by
CeramTec. BIOLOX®delta ceramic components have been implanted in over 4 million
cases.
Ceramic components made of BIOLOX® owe their superi-
or properties to a unique material composition, the most
modern production techniques and a multi-stage, compre-
hensive system of quality control.
Comprehensive quality control –
3D measurement of ball heads
Competence in Ceramics 5
Proven High Performance Ceramics Extreme Hardness The purest raw materials and a manufacturing process that has been refined over decades ensure the highest degree of material uniformity, mechanical prop- erties and perhaps most importantly, hardness. This results in excellent wear resistance. Exacting Sphericity The femoral ball heads have a maximum variance from the ideal sphere of only 5 micrometers, whilst the inserts have a maximum variance of 7 microme- ters. This ensures that the articulation design produces the least amount of wear possible (testing accurancy
Text: CeraNews 2/2010 – Usbeck 7
Superiority in Extreme Conditions
Foreign particles that are
harder than the bearing sur- Polyethylene Ceramic
face lead to high levels of
wear (left).
Surfaces made of high per-
formance ceramics remain
largely unchanged (right).
Metal Ceramic
Source: CeramTec GmbH Source: CeramTec GmbH
Scratched surfaces increase
abrasion in cup liners made
of PE, XPE and metal (left).
Only an unscratched, smooth
surface of the sort achieved
in BIOLOX® ceramics enables
optimal wetting, outstand-
ing lubrication and minimal
wear (right).
Source: CeramTec GmbH Source: CeramTec GmbH
Hydrogen bonds with ceram-
ic surfaces ensure excellent
wettability and the forma-
tion of an effective lubricat-
ing film.
Source: CeramTec GmbH
8 Text: CeraNews
Material 2/2010
Properties
– Usbeck
Molecular Bonding
Loose Metal Structure
The molecular structures of metal alloys and ceramic materials are fundamentally dif-
ferent. In the case of a metal bond, the electrons orbit the atomic nuclei in an irregular
manner and with relatively low bonding strength. As a result of this, metal ions contin-
uously exit this molecular structure and are absorbed by the surrounding tissues. This
occurrence can result in many different chemical and biological reactions.
Stable Ceramic Structure
In ceramic molecules, the electrons follow exact orbital paths. The electrons’ bonding
strength is very high, making the molecules themselves extremely stable. This prevents
ion formation and chemical reactions within the body.
Metal bonding:
irregular electron orbitals
permit the formation of ions
(left).
Ceramic bonding:
tight electron orbitals rule out
ion formation and chemical
reactions (right).
Atomic nucleus
Electron
Source: CeramTec GmbH Source: CeramTec GmbH
Material Properties 9
Hardness and Toughness Combined
The extremely stable ceramic bond virtually rules out any possibility of plastic defor-
mation. While this permits the desired degree of extreme hardness, it also leads to a
relatively high degree of brittleness. However, by optimising the ceramic composition
one can achieve both extreme hardness and strength. Such composite models exist in
nature and in modern technology.
Damascene steel combines hard
and ductile alloys to form a high-
ly firm and resistant material.
Source: stienenDamast, Mönchengladbach, Germany Source: J.D. Verhoeven, A.H. Pendray, W.E. Dauksch, Journal of Metals,
vol. 50, No. 9, p. 60 (1998)
The protective pearl shell com-
bines hardness and strength. It
consists of hard-brittle aragonite
and very elastic layers of protein
and chitin.
Source: CeramTec GmbH Source: CeramTec GmbH
10 Material Properties11
The MULTIGEN PLUS Ceramic
Knee (Limacorporate, top)
The BPK-S Ceramic Knee
(Peter Brehm GmbH,
middle, bottom)
12 Text: CeraNews 2/2010 – UsbeckIntelligent Reinforcement Mechanisms
A Fundamental Difference
Material sciences make a distinction between fracture strength and fracture tough-
ness. Fracture strength is the maximum mechanical stress a material can withstand
without fracturing. Fracture toughness is the resistance of a material to the propa
gation of cracks. Ceramic materials that have been in use for a number of years,
such as BIOLOX®forte, already have a very high fracture strength.
BIOLOX® delta additionally exhibits an extremely high fracture toughness. It has a
much higher capacity than other ceramic materials to resist the onset of cracking
and to arrest the propagation of cracks. This property is based on two strengthening
mechanisms.
Strength under Peak Stress
The highest degree of material stress in hard-on-hard bearings occurs in small dia
meters. Here, the strength of BIOLOX® delta offers an extra benefit: the well proven
aluminum oxide (more than 80 percent by volume) ensures uncompromising hard-
ness. Additional ceramic reinforcement elements ensure the material’s high resis-
tance against fracture and crack propagation.
Material Properties 13Optimized Microstructure
The microstructure of
BIOLOX®delta: platelets with
crack-stopping function (1), alu-
minum-oxide particle (2), zirconi-
um-oxide particle (3).
Significantly smaller grain size 3
and higher uniformity (compared
to BIOLOX®forte, left) make even
smoother surfaces possible and
enhance the material properties. 1 2
2 µm 2 µm
Source: CeramTec GmbH Source: CeramTec GmbH
The principle of conversion re-
inforcement: zirconium oxide
particles act like airbags by ab-
Crack propagation Crack propagation
sorbing impacting forces (left).
The principle of platelet rein-
forcement: platelet-shaped
crystals block the propagation Aluminum Platelet
of cracks and thereby increase oxide
overall strength (right).
Zirconium
oxide
Source: CeramTec GmbH Source: CeramTec GmbH
Airbag Function Counteracting Crack Formation
The first strengthening mechanism is de
rived The second strengthening mechanism is the
from the dispersion of tetragonal zirconium oxide result of in situ formation of platelet-shaped
particles in the microstructure. These particles, crystals in the oxide mixture. These platelets
which are homogenously distributed throughout prevent cracking and crack propagation by neu-
the stable aluminum oxide matrix, produce local tralizing the crack energy. As a result of these
pressure peaks in the area of cracks and thereby strengthening mechanisms, BIOLOX®delta al-
counteract their propagation. lows implant designers to create component
geometries that were not possible with previous
ceramic materials.
14 Material PropertiesText: CeraNews 2/2010 – Usbeck 15
Long-lasting Strength
Improved Properties
The burst strength test assesses ceramic components by exposing them to axial loading
until the point of material failure. Ball heads made of BIOLOX® delta (28mm) resist loads
of more than 80 kN when tested. Larger ball heads show an even higher burst strength.
The burst strength of BIOLOX® delta is considerably higher than that of conventional
aluminum oxide ceramics. Furthermore, tests on standard material
samples show that the bending strength of BIOLOX® delta is not
adversely affected by repeated autoclaving. While hydrothermal
instability can occur in objects made of pure zirconium oxide, such 8t
instability does not arise due to the alumina matrix present in
BIOLOX® delta. This has been confirmed by extensive testing.
Burst stress to ball head – loads
of up to ten tons are introduced
Enhanced Biomechanical Properties via the cone.
The advantages of ceramic materials are especially apparent in large diameters
(≥ 32mm). Simulator studies show that the rates of wear remain low despite the signifi-
cantly larger friction surfaces, i.e. significantly lower than those of other materials. With
ceramic components, surgeons are no longer forced to compromise wear rates and di-
ameter, and can instead choose the best option for their patients.
Better Tribology
Dramatically reduced wear, enhanced range of motion and increased resistance to dislo-
cation make this bearing the number one choice when it comes to functional improve-
ment, durability and safety. In contrast to bearings with conventional and highly cross-
linked polyethylene, the rate of wear does not increase for ceramic-on-ceramic bearings
in the case of larger diameters. Given that BIOLOX® delta shows even lower rates of wear
in the simulator than BIOLOX®forte, one can expect superiority to all other materials for
bearings with large diameters.
16 Material PropertiesBurst strength (kN) Burst strength comparison:
Burst strength (kN)
Burst strength is the point
100 100 at which the component
breaks. This corresponds to a
force of more than 8 tons in
80 80
the case of a ball head made
of BIOLOX®delta (left).
60 60 BIOLOX®delta is resistant
to hydrothermal aging.
10 hours of autoclaving
40 40 corresponds to 40 years
of in vivo ageing (right).
20 20
Number of tests (7 ball heads)
0 0
1 2 3 4 5 6 7 Pristine 10 autoclave hours
Negative Positive
Volume wear rate (mm3 per million cycles) Volume wear rate (mm3 per million cycles) Negative effect of increased
metal head size (left) hip
joint simulator – highly
crosslinked polyethylene,
12 12
long-term wear rate after
10 million cycles
10 10
Positive effect of alumina
ceramic ball head compared
8 8
to metal femoral ball head
(right) hip joint simulator –
6 6 highly crosslinked polyeth-
ylene, long-term wear rate
4 4 after 10 million cycles
Source: Fisher J, University of Leeds (UK),
2 2
2006
28 mm 36 mm 0 36mm 36mm
0
Metal femoral Metal femoral Metal femoral Alumina ceramic
ball head on XPE ball head on XPE ball head on XPE femoral ball head on XPE
Material Properties 17More Options New Geometries The superior material properties of BIOLOX® delta permit component geometries that were not possible with previous ceramics. Cup liners with thinner wall thickness are still able to offer in- creased stability and safety as they allow the use of ceramic-on-ceramic bearings in larger diame- ters. In contrast to metal and polyethylene, ceramic bearings with larger diameters show no sig- nificantly increased rates of wear. Precise Lubrication Clearance A further advantage of thin-walled ceramic components is the material’s high stiffness. This en- sures that the precisely adjusted lubrication clearance between the components, which is neces- sary for the formation of a lubricating film, is not compromised by any deformation in the thin- walled elements. Sizes and Material Combinations The composition of BIOLOX® ball heads and cup liners permit any bearing combination of BIOLOX®forte and BIOLOX® delta. Ball heads made of both materials can also be combined with cup liners made of polyethylene and highly crosslinked polyethylene. BIOLOX® ball heads may only be used in combination with femoral stems and stem tapers specifically designed for this combination by the implant manufacturer in cooperation with CeramTec. Important: Please keep in mind that there is no international standard defining the design of the stem taper or their nomenclature. For this reason any reference to stem tapers such as 12/14, 10/12 etc. does not necessarily mean that their design is identical. From the tribological point of view, BIOLOX®forte and BIOLOX®delta ball heads can be used in combination with BIOLOX®forte or BIOLOX®delta inserts or with polyethylene or crosslinked polyethylene inserts specifically designed and approved/cleared by the Authorities for this application. Other combinations of articulating materials are not permissible. Regulatory guidelines as well as the instructions for use of the implant manufacturers in this regard must always be followed. BIOLOX® inserts may only be used in combination with acetabular shells specifically designed for this combination by the implant manufacturer in cooperation with CeramTec. From the tribological point of view, BIOLOX®forte and BIOLOX®delta inserts can be used in combination with BIOLOX®forte or BIOLOX®delta ball heads specifically designed and approved/cleared by the Authorities for this application. Other combinations of articulation materials are not permissible.Regulatory guidelines as well as the instructions for use of the implant manufacturers in this regard must always be followed. Biolox®forte inserts are produced only on request. 18 The strengths of BIOLOX®delta
19
20 Text: CeraNews 2/2010 – Usbeck
Application Diversity
Optimized Revision
BIOLOX®OPTION offers a suitable solution for the rare case of ceramic component
fracture. The ceramic revision femoral ball head (BIOLOX®OPTION) helps to signifi-
cantly reduce the rate of wear-related osteolysis following revision hip arthroplasty.
In the case of an acetabular cup revision, the surgeon has the option to use a CoP,
CoXPE or CoC bearing when a firmly fixed stem remains in situ.* Thus, a bearing
couple can be implanted which exhibits a greater degree of wear resistance than
the bearing couple used for primary hip arthroplasty.
Knee Arthroplasty
The geometry of bearings used in knee arthroplasty is significantly more complex
than that of the hip joint. The improved material properties of BIOLOX® delta have
made it possible to manufacture safe ceramic components for such geometries.
These knee implants are currently being introduced in clinical use.
Shoulder Arthroplasty
Polyethylene wear, loosening, metal allergy and infection are among the greatest
problems in shoulder arthroplasty which makes the use of BIOLOX® ceramic mate-
rials a logical choice. Introducing BIOLOX® ceramics into shoulder arthroplasty will
extend the clinical applications of these materials.
* The stem taper deformations are described in IFU BIOLOX®OPTION.
The strengths of BIOLOX®delta 21Further Applications
Our customers from the medical devices industry are constantly enquiring about new
capabilities and uses of bioceramics. The most urgent requests are for wear debris
reduction, improving imaging, preventing microbial contamination and providing
options for patients with hypersensitivity to metals. Bioinert ceramic components
offer proven and potential approaches to solving these problems, and are the focal
point of our research and development. The goal of CeramTec Medical Engineering is
to create ceramic products for new medical treatment options in areas such as spine,
small joints, and dental products.
The Strengths of BIOLOX®delta
• Excellent biological behaviour*
• Significantly low taper corrosion*
• No metal ion release*
• No known pathogenic reaction of particles*
• Resistant to third-body wear*
• Excellent wettability*
• Crack stopping function and increased
fracture toughness*
*References available on the file at CeramTec GmbH on request
22 The strengths of BIOLOX®delta23
Literature:
Affatato S, Modena E, Toni A, Taddei P. Retrieval analysis of three generations of BIOLOX® femo- Pan T, Zhao ZL, FU DL, WANG HL, GUO B. The early clinical efficiency and experience in ap-
ral heads: Spectroscopic and SEM characterisation. J Mech Behav Biomed Mater 2012;13C:118- plication of Delta ceramic-on-ceramic total hip arthroplasty. Journal of Clinical Orthopedics
128.:118-28. 2011;02/2011.
Benazzo F, Rossi S, Piovani L, Russo C. Ten years of experience with ceramic-ceramic bearing Raman R, Johnson G, Sharma H, Gopal S, Shaw C. Big balls - the ceramic experience. In: JBJS
in Total Hip Arthroplasty. In: The Journal of Bone and Joint Surgery (Proceedings) 93-B ed, (Proceedings) 93-B ed, 2011:222-c.
2011:154-d. Raman R, Johnson G, Sharma H, Gopal S, Shaw C, Singh J. Functional and clincal outcome of
Cai P, Hu Y, Xie J. Large-diameter Delta Ceramic-on-ceramic Versus Common-sized Ceram- cementless primary arthroplasty of the hip using large diameter ceramic bearing couples. In: JBJS
ic-on-polyethylene Bearings in THA. Orthopedics 2012;35:e1307-e1313. (Procceedings) 93-B ed, 2011:220-b.
Hamadouche M, Zaoui A, El Hage S, Letienne M, Boucher F, Mathieu M, Courpied JP. The in Stafford GH, Islam SU, Witt JD. Early to mid-term results of ceramic-on-ceramic total hip replace-
vitro and in vivo Safety of 22.2 mm Alumina Matrix Composite Ceramic Femoral Ball Heads. ment: ANALYSIS OF BEARING-SURFACE-RELATED COMPLICATIONS. Journal of Bone and Joint
A Prospective Evaluation. In: Cobb J, ed. Modern Trends in THR Bearings: Material and clinical Surgery - British Volume 2011;93-B:1017-20.
performance: Springer, 2010:157. Walter WL, Esposito C, Roques A, Walter WK, Zicat B, Tuke M, Walsh WR. Implant Retrieval Analy-
Hamilton WG, McAuley JP, Dennis DA, Murphy JA, Blumenfeld TJ, Politi J. THA with Delta ceramic sis of Biolox Forte vs. Biolox Delta Ceramic Femoral Heads: 2 Years Results [abstract]. AAOS 2011
on ceramic: results of a multicenter investigational device exemption trial. Clin Orthop Relat Res Proceedings 2011;Poster No. 045:491.
2010;468:358-66. Whittingham-Jones P, Mann B, Coward P, Hart AJ, Skinner JA. Fracture of a ceramic component
Lombardi AV, Jr., Berend KR, Seng BE, Clarke IC, Adams JB. Delta Ceramic-on-Alumina Ceramic in total hip replacement. Journal of Bone & Joint Surgery, British Volume 2012;94-B:570-3.
Articulation in Primary THA: Prospective, Randomized FDA-IDE Study and Retrieval Analysis. Clin Dower B, Grobler G, Nortje M, Reid C. Deltamotion [abstract]. Bone & Joint Journal Orthopaedic
Orthop Relat Res 2009. Proceedings Supplement 2013;95-B:54.
Maurer-Ertle W, Friesenbichler J, Liegl-Atzwanger B, Kuerzl G, Windhager R, Leithner A. Nonin- Jack CM, Molloy DO, Walter WL, Zicat BA, Walter WK. The use of ceramic-on-ceramic bearings in
flammatory Pseudotumor Simulating Venous Thrombosis After Metal-on-Metal Hip Resurfacing. isolated revision of the acetabular component. Bone Joint J 2013;95-B:333-8.
Orthopedics 2011 2011;34:678.
Meftah M, Ebrahimpour PB, He C, Ranawat AS, Ranawat CS. Preliminary clinical and ra-
diographic results of large ceramic heads on highly cross-linked polyethylene. Orthopedics
2011;34:e133-e137.
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contained in this document is of a general nature and does not represent medical advice or recommendations. Since this information does not constitute any diagnostic or therapeutic statement
with regard to any individual medical case, individual examination and advising of the respective patient are absolutely necessary and are not replaced by this document in whole or in part. The
information contained in this document was gathered and compiled by medical experts and qualified CeramTec employees to the best of their knowledge. The greatest care was taken to ensure the
accuracy and ease of understanding of the information used and presented. CeramTec does not assume any liability, however, for the up-to-dateness, accuracy, completeness or quality of the infor-
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