orthopaedics biomechanics laboratory implant testing ...representing complex patient anatomy. the...

Orthopaedics Biomechanics Laboratory

Implant Testing TechnologyImplant Testing Technology985360 Nebraska Medical Center - Scott Technology Center, Omaha, NE 68198-5360 Director: Hani Haider, PhD Tel: 402-5595607 E-mail: [email protected]

Department of Orthopaedic Surgeryand Rehabilitation

y = 14.556x - 0.1554R2 = 0.9998

y = 16.285x + 3.0592R2 = 0.996

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Displacement Control (AMTI)Force Control (Instron-Stanmore)Linear (Displacement Control (AMTI))Linear (Force Control (Instron-Stanmore))

Error bars represent 95% confidence limits

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Station 1: 203720 .

Station 2: 097240 .

Station 3: 264660 ..

Station 4: 097240 ..

Soak control averagestns. 1-4 (uncorrected)

Old design

New design

WEAR

→

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Station 1: 203720 .

Station 2: 097240 .

Station 3: 264660 ..

Station 4: 097240 ..

Soak control averagestns. 1-4 (uncorrected)

Old design

New design

WEAR

→ Research contract work at our lab from:

Astratech Inc/ SwedenBiomet Inc / IN

Encore Orthopedics Inc / TXSmith & Nephew Inc / IN

Depuy Johnson & Johnson Inc / INKyocera Inc. / Japan

Zimmer Inc / INAll are multinational orthopaedic

manufacturing companies

Knee implant wear studies

Our Studies published:J. CORR 2000, J. Biomech. 2000, WBC 2000, ISTA 2001,

ORS 2002, SOB 2002, Book Ch. Prof.Eng.Pub. 2003., ASTM 2005, ICMBT 2005, ORS 2006.

Special jigs and fixtures built in our lab.

This setup is almost unique in the world

To aid design of new implants with high flexion capability for

younger and more active patients.

American Standard method (ASTM F1223) has recently been revised based on our

results

Our Studies published:

ORS 2003, J. CORR 2003, ISTA 2003, J. Biomechanics 2005.

AP soft tissue restraint force

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J&J DePuyPFC ΣStratec CC

S&N GenesisII

ZimmerNexGen CRZimmer MBK

Sulzer SALMBK

PCL Action

AP linear displacement

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J&J DePuy PFC Σ Stratec CCS&N GenesisII Zimmer NexGen CRZimmer MBK Sulzer SAL MBK

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S&NGenesisIIZimmerNexGen CRZimmer MBK

Sulzer SALMBK

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Femur pushes tibia anteriorly

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J&J DePuy PFC ΣStratec CCS&N GenesisIIZimmer NexGen CRZimmer MBKSulzer SAL MBK


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tiss

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(N) An

teri

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ve)/P

oste

rior

(-ve


S&N GenesisII


Sulzer SALMBK

PCL Action


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2

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dis

plac

emen

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m)

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oste

rior(

-ve


IE (axial) rotation

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) E

xter

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ve)


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Ext

erna

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Sulzer SALMBK


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Produced state-of-the-art simulator to test Knee Replacement implants

Methodology now adopted as an International Standard Test Method (ISO 14243-1)

We have 3 of these knee simulators in our lab and are fast becoming the top lab internationally in knee testing.

Research evaluates new knee implant designs before clinical use, or produce reliable lab performance data for regulatory purposes and design improvement.

Kinematics (motion) of knee implants

Our studies published:

ORS 2000, ISTA 2001, ORS 2002, Japan Knee Soc. 2002, AAOS 2003,

ORS 2003, Ch. in Book 2003, J. CORR 2003, ASTM 2005.

Effect of surgical misalignment of knees

Our published studies:

ORS 2001, ISTA 2001, Japan Knee Soc. 2002, AAOS 2003.

Simulation & durability testing Simulation & durability testing of of OrthopaedicOrthopaedic Knee Replacement implantsKnee Replacement implants

Knee implant motionKnee implant motionLaboratory (inLaboratory (in--vitro) simulation and vitro) simulation and

testing (human walking activity)testing (human walking activity) Knee laxity studiesKnee laxity studies

8-Station Fatigue MachineForce or displacement computer controlled

Testing machine designTesting machine design

Design and prototype

manufacture of new innovative biomechanics test machines

Lower Limb Knee Simulator

Fluidic Muscle actuated Computer Controlled

Friction Measuring Machine (tribometer) Specially high dynamic range for orthopaedic and other biomaterials

Wear !

Hip, spine and ankle Hip, spine and ankle implant testingimplant testing

State-of-the-art AMTI 12-station Hip

and Spine Simulator

Rapid Prototyping (RP) Rapid Prototyping (RP) & &

RP surgical modelingRP surgical modeling

Most tangible & realistic representation of a patient’s anatomy

…… physically in the hands of a surgeon!

to physical

3D model

From medical scanner

to surgical planning

to custom implant

manufacture

We have processed (in-house)

CT imaging data, and manufactured

(in-house)

rapid 3D anatomical prototypes

representing complex patient anatomy.

The models were used to aid planning of knee and hip surgery in our

hospital.

Orthopaedics Biomechanics Laboratory

Advanced Surgical TechnologiesAdvanced Surgical Technologies985360 Nebraska Medical Center - Scott Technology Center, Omaha, NE 68198-5360 Director: Hani Haider, PhD Tel: 402-5595607 E-mail: [email protected]


Diagnostics & adaptive

action

Our ultimate goalIn-vivo diagnostics for early detection of:

implant wearmisalignmentloosening

and self-adapting implants

Smart Instrumented ImplantsSmart Instrumented ImplantsWe demonstrated the feasibility of using piezoelectric ceramics to generate electrical energy within Total Knee Replacement (TKR) implants

Future promise: Smart ImplantsOn-board microprocessor:

Process measurementsStore results Communicate them non-invasively (by radio) to the surgeon/therapist during follow-up visits.

Pilot study conducted with the help of UNL.

Our preliminary results published in: ORS 2003, ISTA 2003, ORS 2004, AAOS 2004,J. Mechatronics ASME/IEEE 2005 (two papers)

Philosophy of Minimally invasive surgery:

Smaller surgical access - small scar

Little bone removal – conservative, leaves options open

Less soft tissue trauma

Faster recovery time - one day operation possible

Suitable for the younger, more active patient

Our Studies published:6 presentations have been made on

this work in: ISTA 2005, ICMBT 2005 and ORS 2006.

Finite Element Finite Element AnalysisAnalysis

&&MinimallyMinimally--invasive invasive

implant design implant design

Our preliminary results of this work have been published in 17 papers in:

• International Society for technology in Arthroplasty (ISTA)

• American Academy of Orthopaedic Surgeons (AAOS)

• International Society for Computer Aided Orthopedic Surgery, (CAOS)

• Orthopaedic Research Societies of Canada, U.S.A., Japan and Europe

• International Conference on Mechanics of Biomaterials & Tissues (ICMBT)

• Orthopaedic Research Society

This work has won the HAP Paul Award

As the best research paper “… on new development in the field of

orthopaedic arthroplasty” at the International Society for technology in

Arthroplasty, Kyoto, Japan, 2005.

NebraskaNebraska’’s ins in--house developed house developed Navigation System for Knee SurgeryNavigation System for Knee Surgery

The use of JIGS for cutting bones to fit the implant can be avoided…

…by creating a virtual 3D environment system with meaningful feedback to the surgeon

for cutting freehand by

navigation


Biomechanics Laboratory The laboratory occupies 5500 square feet in the Scott Technology Center in Omaha, Nebraska. It is within 10-minute drive of the University of Nebraska Medical Center Department of Orthopaedic Surgery and Rehabilitation.

The lab is directed by Dr. Hani Haider (Associate Professor – faculty member), assisted by one Masters qualified Mechanical Engineer, another Masters qualified Biomedical Engineer/Computer Scientist, three full-time Engineering Research Technicians and one administrative assistant/secretary. All, including the director Dr. Hani Haider, have their main offices within the laboratory.

Surrounding the Biomechanics Lab central section are the Implant wear simulator laboratory, ancillary service room housing the pneumatic air-compressors, hydraulic pumps, chillers and other plant infrastructure powering the wear and biomechanics fatigue testing machines. In the same suite, are the faculty and researcher offices and desks, a computer-aided orthopaedics surgery, biomechanics-cadaveric and clinical orthopaedics research lab, a 30-40 person conference room with full multimedia audio-visual, data and teleconferencing facilities, and a mini workshop for test jig and fixture manufacture/finishing – see full machine-workshop in an adjacent building described later below).

Office

Clinical Orthopaedics

Research Laboratory

Desks

for 4 technicians

Biomechanics Laboratory

Wear simulator(s) laboratory

Machine shop

Faculty offices

Researcher offices

Nano-Biotechnology

Laboratory

Office

Clinical Orthopaedics

Research Laboratory

Desks

for 4 technicians

Desks

for 4 technicians

Biomechanics Laboratory

Wear simulator(s) laboratory

Machine shop

Faculty offices

Researcher offices

Nano-Biotechnology

Laboratory

Conference Room

The lab has over 25 PC computers and Unix workstations all interconnected with a local area network and the University campus wide network and each has access to the Internet. Over 15 PCs are interfaced to the test machinery and instrumentation for control, data-logging, and acquisition, and the same network connectivity. There are over 10 separate telephone voice lines. The following are the major items of Biomechanics research equipment housed in this laboratory.

Full Knee Wear Simulators

3 separate Instron-Stanmore Knee Simulators with full computer control and data logging (each simulator has 4 separate test stations)

The lab houses three separate state-of-the-art force-control Instron-Stanmore Knee Simulators. Each is a 4-station Total Knee Replacement joint simulation and wear testing under the force control method ISO 14243-1. The simulators can drive separate stations on an 8-station Fatigue testing machine (shown later below) to work as active (loaded) soak controls. These three test knee simulators at Nebraska have been upgraded with over 20-30 design and control software improvements over the original versions. All these upgrades were performed by the same engineer (Dr. Hani Haider) who led the production of the original Instron-Stanmore versions in England between 1997-2000.

Pin

Pin-on-disk wear testing machines

AMTI Orthopod Pin-on-Disk wear testing machine (flexible programmable motions and loads for orthopaedic joint couples)

Linear reciprocating Pin-on-Disk wear testing machine

(for hard on hard orthopaedic joint couples)

Specimen Lapping machine

Polishing machine

Friction measuring machine with high dynamic friction and stress range (Manufactured in the Biomechanics Lab at UNMC for orthopaedic implant research utilizing

frictionless air-bearing technology)

AMTI Hip Implant Wear Simulator

General Biomechanics Testing Systems Advanced four-axis computer controlled MTS Bionix fatigue testing machine, with highly customised knee and ankle constraint/laxity measurement systems, and specialised multi-axis control configurations. The fixtures shown opposite have been built with 6-degrees of freedom for knee and ankle, tests (all instrumented with sensors) with adjustability for posterior sloped installation and various contact angle and laxity/constraint and joint fatigue studies. Together with the two MTS single axis Mini-Bionix the machines, and an electro-mechanical Model 1000 Instron testing machine (not shown here), an 8-axis fatigue testing machine, and the many standard and custom made jigs and holders, this assortment facilitates a large number, and a very wide range of biomechanical testing needs.

Two MTS mini-Bionix single-axis testing machines

New 8-station biomechanics programmable fatigue testing machine

(Recently manufactured in-house, each station can run in time-variable uni-axial force or

displacement control)

In-house manufacture of jigs and fixtures Our Rapid Manufacturing Machine Workshop is in a separate building only 200 yards away from our Biomechanics Lab. Our laboratory technicians have full access to this manufacturing facility.

CNC Lathe and CNC Mill (Computer Numerically Controlled)

Rapid Prototyping Machine

Wire Electro Discharge Machining Center (EDM)

Welding Equipment(Conventional, inert gas, stainless steel

and Alum alloys etc)

Abrasive Water Jet Cutting Machine

Wire Electro Discharge Machining Center (EDM)

Dr. Hani Haider studied in England for his first degree and PhD in Mechanical Engineering. He was first appointed Lecturer in the University of Sheffield, from 1988 to 1996, with research in fluid dynamics, mechatronics, robotics and information technology. In 1997, he joined the faculty of University College London at the well known Centre of Biomedical Engineering in Stanmore. He was the principal mechanical and software engineer who produced the Instron-Stanmore Knee Simulator and the International Standards Organization (ISO) method for simulation and wear testing of knee replacement systems. He was invited to join the faculty of the University of Nebraska Medical Center in March 2000 as an Associate Professor at the Department of Orthopaedic

Surgery and Rehabilitation. His main mission was to make its Orthopaedics Biomechanics Laboratory a leading facility known internationally for implant technology. Dr. Haider has received over 25 research grants and contracts, mostly from the orthopaedic companies in the USA, and from Europe and Japan. He has presented over 100 papers in peer reviewed journals and international conferences in engineering and orthopedics biomechanics. He had won various academic prizes in his university years, then the “The KLINGER International Research Prize”/Austria for innovative engineering research work. In 2005, he won the HAP Paul Award by the International Society for Technology in Arthroplasty for “…the most innovative research paper on orthopaedics joint replacement technology”. In 2006, he won two awards from the University of Nebraska Medical Center for Special and Outstanding Professional Achievement. Dr. Haider is a Member of the United Kingdom’s Engineering Council, and its Institution of Mechanical Engineers, and various American professional societies. He co-chairs the committee for Knee Implant Wear Testing of ASTM International, and chairs the ASTM Total Ankle Specification/Testing standard committee. He also chairs the International Standards Organization (ISO) Review Workgroup of Knee Wear standards.

orthopaedics biomechanics laboratory implant testing ...representing complex patient anatomy. the...

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