Part A: Failure Analysis - Assessment Criteria [200 marks]
1. Demonstrate a sound knowledge base in the relevant topic;
2. Demonstrate the ability to delineate the problem in the case study;
3. Demonstrate the ability to analyse (and critique) the potential failure modes, and propose the likely cause of failure and a strong justification/argument to back the assertion;
4. Demonstrate the ability to propose rectification or prevention strategies;
5. Demonstrate the ability to professionally present your report (including in-text citation and referencing).
Part B: Materials Selection - Assessment Criteria [200 marks]
1. Demonstrate a sound knowledge base in material selection methodology;
2. Demonstrate the ability to delineate the engineering requirements of the materials;
3. Demonstrate the ability to systematically apply material selection methods;
4. Demonstrate the ability to propose the best material(s), and a strong justification/argument to back the recommendation(s);
5. Demonstrate the ability to professionally present your report (including in-text citation and referencing).
NOTE: It is inadequate to provide an answer like ‘very hard steel’. Be specific in your material selection, and always support it with evidence (such as figures or material selection charts from materials handbook). You can find most of the information resources from the textbook, USQ Library Online or relevant library databases such as ASM Online. Use Harvard referen cing style; refer to USQ Library website for details. Limit the number of pages of your report submission to approx 30 pages excluding appendix.
CASE STUDY – JOINT REACTION
Reporter: Quentin McDermott Four Corners Broadcast: 16/05/2011
The Articular Surface Replacement hip or ASR created by DePuy and marketed by the Johnson and Johnson company was sold to doctors and patients as a giant step forward in joint replacement. Its creators boasted it would give greater mobility and help patients get back on their feet quicker. Now reporter Quentin McDermott investigates claims that the metals hips are disintegrating and making patients sick.
Australians spend over $7 billion a year on medical devices that are supposed to make their lives better. In most cases they do. Pacemakers, hip and knee replacements can transform a patient's life. But who tests these devices to make sure they are safe? Now some doctors and policy makers say our regulation and testing regime is failing us and they are calling for greater scrutiny being directed to this essential industry.
His name is Ron. He was an active, happy 76-year-old. In 2005 he had a total hip replacement. A short time after the operation the metal hip he received began to malfunction. A large lump, the size a grapefruit, developed on the side of his leg. After consultation with his specialist and being told little could be done, Ron asked for a second opinion. What he found shocked him and his new doctor.
Analysing the fluid drained from the lump on his leg the doctor found pieces of metal that could only have come from the metal prosthesis inside him. Five operations later Ron has no hip at all and can barely walk.
Catherine was forty three when she accepted her doctor's advice and agreed to have an ASR hip replacement. After the operation she began to feel ill. Desperate to find out what was making her feel sick, she asked her doctor to do pathology tests. What she found horrified her. The tests revealed she had -toxic- levels of cobalt in her system. The only possible source of the cobalt was the hip she'd been given.
Further investigation revealed the metal from the hip had damaged surrounding tissue in her upper leg and gave every indication her illness had been caused by massive levels of cobalt.
Ron and Catherine are not the only people to find there are serious problems with the DePuy ASR hip replacements. It's now estimated that the problems associated with this type of hip, which relies on metal to metal technology, could affect hundreds, even thousands of people across Australia.
The question is: how was this metal on metal technology approved? Who did the design and who tested it before it was used in human beings? As one patient with a faulty hip put it:
-...the patients are the guinea pigs yes, and then they use the result when they put them in a patient.-
The Four Corners program -Joint Reaction-, presented by Kerry O'Brien on Monday 16th May at
8.30pm on ABC 1. Extracted from http://www.abc.net.au/4corners/content/2011/s3215297.htm
The two investigative reports below present the scenario for the failure of the DePuy orthopaedic hip implant (these are part of the files to be downloaded and critiqued):
Expert Advisory Group report: soft tissue reactions associated with MoM hip replacements | MHRA UK | October 2010
An Expert Advisory Group (EAG) involving members of the British Hip Society (BHS), the British
Orthopaedic Association (BOA), the Medicines and Healthcare products Regulatory Agency (MHRA), and the National Joint Registry of England and Wales (NJR) was set up to: determine the incidence of this problem; and advise clinicians on any modifications to current practice which may be necessary to minimise the risk of this adverse reaction and optimise early detection. Download the report.
Editorial: Metal on Metal: Is It Worth the Risk? | The Journal of Arthroplasty Vol. 25 No. 1 | 2010 There has been an explosion in the use of metal-on-metal bearings in the last 5 years throughout the world. This has mostly been driven by the use of metal bearings in resurfacing, although metal heads have also been used in conjunction with primary total hip arthroplasties. The move to metal heads has primarily been driven by a desire to use larger articulations to reduce dislocations, although smaller metal head combinations are also available and are used clinically. The questions to be addressed in this editorial are firstly to ask if metal bearings do confer a clinical advantage and secondly to look at the potential downside with the use of metal heads. Authors: Ross Crawford, DPhil, Chitranjan S. Ranawat, MD, Richard H. Rothman, MD, PhD. [PDF 96.73Kb]
Some further background information to provide context for the problem:
• Watch the YouTube videos provided on MEC3203 Studydesk as an introduction to the case study, or click on the link: http://www.abc.net.au/4corners/special_eds/20110516/hips/
• Some initial background reading on medical-device materials, failure analysis, materials selection, fatigue failures, wear failures:
o http://en.wikipedia.org/wiki/Failure_analysis o http://en.wikipedia.org/wiki/Materials_selection o http://en.wikipedia.org/wiki/Fatigue_(material) o http://en.wikipedia.org/wiki/Wear
o http://en.wikipedia.org/wiki/Hip_replacement
o ASM Failure Analysis Center & ASM Handbooks Online (via USQ Library link) http://resguide.usq.edu.au/index.php?type=ebooks&desc=1&route=subject86&ID=16&access=86
• Some initial background reading on DePuy implant failures:
o http://www.abc.net.au/4corners/content/2011/s3218155.htm o http://en.wikipedia.org/wiki/2010_DePuy_Hip_Recall
o http://www.abc.net.au/news/2011-05-16/patients-reveal-agony-of-toxic-hipimplants/2694656
o http://www.abc.net.au/news/2011-02-28/tasmanian-leads-hip-classaction/1960270
o http://www.abc.net.au/radionational/programs/healthreport/artificial-knee-gonewrong/2986700
o http://www.abc.net.au/radionational/programs/healthreport/hip-replacementdevice-withdrawn/3024148
Part A FAILURE ANALYSIS
Scenario for the -Failure Analysis- part of this assignment is in the form of a client brief in reviewing failures/literature documented in the past, critiquing investigative work done, and systematically investigating the failure to provide detailed insights into the case of DePuy orthopaedic hip implant failure:
1) Outline a brief background on the failure, operations, and its operating environment;
2) Provide an analysis of the potential causes of failure based on an extensive review of literature; 3) Review and critique one of the “failure reports” as prepared by the experts; comment specifically on whether the methodology is suitable and adequate based on your extensive review of literature; 4) Comment on whether additional information or additional investigation is required (eg sample testing); and
5) Recommend suitable solutions or rectification to the problem (based on certain assumptions).
Part B MATERIALS SELECTION
Johnson & Johnson, the maker of the DePuy Orthopaedic implants, has decided to engage you to redesign the materials specification for its hip replacement product range. In the light of recent publicised failures, the company has engaged your firm to identify an alternate material for the DePuy orthopaedic hip implant.
Scenario for the -Materials Selection- part of this assignment is in the form of a client brief:
1) Provide an outline and analysis of the performance requirements;
2) Evaluate and select an appropriate materials selection method;
3) Systematically justify your selection of materials for the equipment;
4) Comment on whether additional information or additional investigation is required; 5) Recommend suitable materials for the “orthopaedic hip implant” (based on certain assumptions).