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The Orthopaedic Industry in 2007 - A Review
Author: OP News
JANUARY
NHS Private Centres To Take Over Orthopaedic Procedures
A controversial start to the year, with the NHS announcing that Primary care trusts in Cumbria and Lancashire were to carry out an eight-week consultation with Clinical Assessment Treatment and Support centres to carry out diagnostics and minor treatment to cut waiting lists.
The centres are run by private firms, but would be paid by the NHS, leading to complaints from the BMA that it may fragment the NHS. Mike Farrar, chief executive of NHS North West, said: “The centres are not a replacement for hospital services, rather they will let the hospitals concentrate more on what they do best - treating those who need immediate care. But Dr Jonathan Fielden, chairman of the BMA’s consultants committee, said: “These proposals could represent a significant threat to local NHS hospitals. When work goes to the private sector, they lose income.
Biomet Announce Merger - And It’s Not Smith & Nephew
After months of speculation, troubled Biomet finally announced details of a merger with a private equity consortium worth $10.9bn. The merger was announced just a week after rumours that Smith & Nephew would table an $11bn bid for the company.
Daniel P. Hann, Interim President and CEO of Biomet, said, “As an independent, private company with the strong backing of private equity partners who recognise our potential for growth and support our dedication to providing our patients the best in innovative, high quality medical products, we will be in an even stronger position to deliver on our commitment to them and their doctors, as well as our team members and the communities in which we operate.”
Alcohol May Protect Against Arthritis
If you’re a mouse. A study by Gothenburg University gave mice injections of collagen to induce rheumatoid arthritis (RA), then either untreated water or water with 10% pure alcohol. RA was found to develop significantly slower in the mice given alcohol, and had less severe symptoms once the disease did start to progress.
It’s thought the alcohol may boost production of testosterone, which restricts the release of cytokines that cause inflammation. But Professor Andrzej Tarkowski, who led the research, said: “We can’t translate these results to find out the therapeutic dose in humans. Professor Alan Silman, medical director at the Arthritis Research Campaign said: “It is possible that in this mouse model, alcohol may have had some effect in relation to arthritis. However it is doubtful whether this would have much influence in the human situation.”
The Great Debate – Early Intervention in the Hip and Knee was held in the IMAX Theatre at the heart of the Science Museum in South Kensington, London. The meeting, which was sponsored and organised by Finsbury Orthopaedics, was designed to encourage an atmosphere that would allow the 33-strong faculty to explore the technologies that enable them to manage the early symptoms of osteo-arthritis in the hip and knee and proved very popular - enough for a second to be announced for 2008.
Men Just As Likely As Women To Suffer Second Fracture
For years, women have been warned of the high risk of refractures, but it seems that men are the ones at the highest risk, according to a study. “After a first fracture, the risk of a subsequent fracture in women is doubled, but for men, it is increased three- to four-fold, so that the absolute risk of a subsequent fracture is the same for women and men,” said the study’s author, Jacqueline Center, a senior research officer at the Garvan Institute of Medical Research in Sydney, Australia.
Women’s refracture risk after one fracture similar to a woman 10 years older who had never experienced fracture, the researchers say. For men, the refracture rate was similar to a man 20 years older. So a 60 year-old man who fractures a bone has the same risk of another fracture as an 80 year-old, according to the study.FEBRUARY
Researchers Warn Of Osteoporosis Risk For Men
Another bad news story for men - physicians were warned by a Canadian researcher that they cannot continue to overlook osteoporosis problems in men. Dr. Aliya Khan said her paper, which supplements clinical practice guidelines for the diagnosis and management of osteoporosis, was intended to make physicians aware of the fact that they can no longer overlook diagnosing osteoporosis in their male patients. “The problem is that when men sustain fractures they are more likely to die or suffer a disability.”
Arthroscopy is ‘Failing Rotator Cuff Disease’
A U.S. surgeon claimed that using arthroscopy to treat rotator cuff disease is failing in a lot of operations. Jon Warner, director of The Harvard Shoulder Service in Massachusetts spoke of the “elephant in the room that no one wants to talk about.” at the AAOS meeting, that was held in in San Diego. “A large portion of my practice is fixing failed surgeries.”
“I am increasingly concerned that the demand, from patients, for arthroscopic surgery is driving this trend. Not all cases are suited for this type of surgery. There is an epidemic of rotator cuff problems with ‘baby boomers.’ They want arthroscopic surgery on an outpatient basis so they can get back to work the next day. As surgeons, we want to meet our patients’ requests. It’s a challenging situation.”
The NHS are paying too much for drugs, an Office of Fair Trading (OFT) report said. The OFT said that the Department of Health (DoH), which buys £7bn of drugs a year, was not getting the best prices from companies and recommended an overhaul of the Pharmaceutical Price Regulation Scheme (PPRS).
The two-year study identified several drugs where prices were up to ten times more costly than other drugs offering similar benefits. Value-based pricing would give companies stronger incentives to invest in drugs for medical conditions where there is greatest need.
But the director-general of the Association of British Pharmaceutical Industry, Dr Richard Barker, said the UK paid less per head for medicine than most major European countries and warned that drug firms need to feel valued in the UK “to keep research and development here.”
MARCH
Stem Cell Research ‘Being Held Back’ - Study
Scientific, ethical, social and financial hurdles were besetting the commercialisation of stem cells, according to a study. “Embryonic stem cell research has been mired in controversy with opposition from several ethical and social quarters besides which the science surrounding embryonic stem cells is itself in a very nascent stage,” said analysts Frost & Sullivan.
“In addition, owing to the high cost of development, these therapies are expected to be very expensive, and procuring reimbursement could be an uphill task.”
Smith & Nephew Become Fourth Largest Orthopaedic Player Through Plus Acquisition
With the potential Biomet deal coming to nothing, Smith & Nephew wasted no time in establishing itself as a top four orthopaedic player as it snapped up Plus Orthopedics for $889m and increased its reconstruction market share to 12%. The acquisition of Plus meant that the UK Company’s market share jumped by an all-important 3%, leapfrogging Biomet, and further decreasing any possibility of a takeover itself. The deal also doubled Smith & Nephew’s share of the European orthopaedic market.
APRIL
Three New Diabetes Genes Found
Scientists found several new genes that appear to increase the risk for developing type 2 diabetes, increasing the amount suspected to 10.
Dr. Kari Stefansson, CEO of deCODE Genetics, conducted a survey in Iceland comparing the frequencies of several hundred thousand common genetic variants in healthy people against those who have the disease. They found the CDKAL1 gene was associated with type 2 diabetes. “It affects the secretion of insulin,” Stefansson said.
Those with two copies of the risk variant faced a 50% increased risk of developing the disease when compared with people with only a single copy of the gene variant. About 25% of the population has this variant.
People with two copies of the gene variant produce about 20% less insulin in response to rising blood sugar than those with only one copy or non-carriers. This suggests that the variant increases the risk for type 2 diabetes by reducing insulin production.
Stryker Recognised in Company List
The Sunday Times named Stryker as the 44th ‘Best Mid-Size Company To Work For’ in the UK for 2007. It is the first year that the medical device company has entered the listing and has found itself ranked in the top 100.
Director of Human Resources at Stryker, Louis Efron said: “Stryker is about its people and that is why we are so proud of this listing. The company prides itself on a high service ethic, innovation and accountability - all elements which are embraced by every individual and the reason why we are leaders in the healthcare industry. Stryker’s strength lies in its recognition of the value of its people.”
Precise CAOS To Improve Hip Replacement Surgery
A state-of-the-art measuring techniques, similar to those used in aerospace, may be used to improve success rates for hip replacement surgery. The prototype hip replacement ‘phantom’ provides a precisely measured coordinate system and magnetic ball and socket joint to calibrate and to measure the clinically relevant performance of CAOS tracking instruments used in delicate operations to install artificial hip joints. The National Institute of Standards and Technology submited its CAOS phantom to surgeons for review with clinical trials expected in the future.
MAY
Internet Surgery Becomes Reality
You’ll never have to leave your desk - Robotic surgery can now be driven by surgeons across the Internet.
A team of scientists showed that the surgeon and robot can be linked via a 4,000 mile Internet connection, or by satellite, raising the possibility of a surgeon’s expertise being made available to patients lying in surgical theatres thousands of miles away.
The surgical trials showed that the delays were much greater when they used the satellite link than using the Internet, but after a short period of practice, the surgeon got used to this and there were no measurable differences in the quality of the surgery using the two forms of communication.
“This is an exciting next step forward in developing telesurgery, which holds the promise of many new efficient and cost-effective ways of providing advanced healthcare services,” said project leader Reiza Rayman.
First Gene Associated With Idiopathic Scoliosis Is Identified
Researchers identified the first gene associated with idiopathic scoliosis (I.S.), the most common spinal deformity in children.
The medical breakthrough was a result of a 10-year study of 53 large families, totaling 130 individuals with a confirmed I.S. diagnosis. As a result, the team identified the first gene associated with I.S. - CHD7 - allowing the medical community to form hypotheses to explain what causes the condition, and providing tools for future studies.
“This is the most definitive link between genetics and scoliosis that has been reported so far,” said Dr. Wise, director of molecular genetics at TSRHC.
First Presented Case Of Rare Disease
Authors have presented the first case report of Castleman disease after a large tumor grew alongside the spine through the neural foramen, located in the thoracic spine.
The tumor was removed surgically and a small piece of tissue was taken for pathologic exam, where it was found to be the rare disease, named after Dr. Castleman who first described the condition in 1956.
The rare tumor is made up of plasma cells in the lymph fluid from the immune system. Only four cases of the spine have ever been reported.
JUNE
Titanium Nails ‘Unstable’ In Children
Two studies proved that stainless steel nails were safer to treat broken bones in children than titanium nails. The authors of the first study reviewed children with unstable tibial diaphyseal fractures over a seven year period. There was a high rate of delayed healing and nonunions, surprising as children are more likely to have an uneventful course of healing.
The second study looked at using stainless steel elastic nails to support unstable femoral shaft fractures in children. The authors reported that the stainless steel nail worked well in both types of fractures. The authors concluded that stainless steel nails are stiffer and stronger than titanium nails; they work well for older children and teenagers who are too large for closed reduction and a full hip spica casting. And they can also be used for unstable fractures.
Smith & Nephew Chief Executive Retires
Sir Christopher O’Donnell retired as Chief Executive and as a director of Smith & Nephew after 19 years at the company. Sir Christopher joined the company in 1988 and had been Chief Executive since 1997.
He was responsible for the streamlining of the company from nine to the current four divisions, as well as increasing turnover by 50%. David Illingworth, 53, who had been Chief Operating Officer of Smith & Nephew since February 2006 was promoted to Chief Executive.
This followed Ray Elliott’s retirement as President and CEO of Zimmer. Elliott, 57, who served nearly 25 years as a company president was replaced by David. Dvorak, who has been named as President and Chief Executive Officer of the Company and has also been appointed to the Company’s Board of Directors.
JULY
Orthopaedic Patients Wait Longest On NHS
The DoH published the latest waiting lists and patients requiring orthopaedic procedures wait longer than any other patients to be treated on the NHS.
Just 25% of trauma and orthopaedic patients were treated within the 18 week target set by the UK Government’s NHS Improvement Plan, coming bottom of the league table.
“There is an urgent need to improve NHS treatment for orthopaedic patients. These results are extremely worrying.” said Medical Technology Group (MTG) spokesperson, John Davis.
Loose Implant Detector Is Developed
A more efficient way of detecting loosened artificial hip implants was developed. Engineers at the University of Bath developed a diagnostic test, which measures the frequency of sound produced when the femur bone in the leg is vibrated.
The new method is far more sensitive than the traditional method of x-rays to detect the loosening of implants, and it can also diagnose if there are any much smaller gaps around the implanted joint.
Dr James Cunningham, of the University of Bath’s Department of Mechanical Engineering, said”This finding is important because surgeons need to know if the pain the patient is feeling comes from a loose joint needing surgery, or from another cause,” said Dr Cunningham.
Sandvik Acquires Doncasters Medical Technologies
Doncasters sold its Medical Technologies (DMT) division to Sandvik Materials Technology, who strengthened their position in the medical device market segment.
DMT’s core business as a contract manufacturer of orthopaedic products, combined with Sandvik’s materials technology, manufacturing and development capabilities made a unique player and supplier to the medical market.
Peter Gossas, President of Sandvik said: “We are now able to work with customers in the very early stages of the product development cycle and can assist in the design, materials selection, engineering and prototyping of new medical devices. We can also offer customers the opportunity of outsourcing more manufacturing operations rather than expanding or investing in their own in-house capacity.”
AUGUST
S+N Recall Hip Implant
Smith & Nephew withdrew 185 of its Birmingham Hip Resurfacing Systems after a packaging error led to incorrect size implants being used on patients.
Two patients in the U.S. were implanted with the wrong-sized device and it is expected that other cases may come to light during the recall process. The Hip implants were incorrectly packaged by a subcontractor and, as a result, different sizes of acetabular cup were mixed together. All hospitals and surgeons who had received these implants - across a number of countries including the UK - were notified, as were the Medicines & Healthcare Products Regulatory Agency and the FDA.
Biomet Accuse Zimmer Of ‘Distributor Interference’ As Lawsuit Beckons
Biomet initiated legal proceedings against Zimmer, former Biomet distributors and a former Biomet executive who resigned from Biomet in January 2007 and now currently works for Zimmer.
The lawsuit alleged that Zimmer y attempted to create an unfair market advantage by interfering with Biomet’s contractual relations with distributors and attempting to buy the assets of most of its distributors throughout the U.S.
Jeff Binder, Biomet’s President and CEO said: “In Biomet’s view, Zimmer’s offers are thinly veiled attempts to induce our distributors to violate their agreements with us and induce sales representatives to convert our customers to Zimmer. In furtherance of its attempts to disrupt our business, Zimmer has even purchased Biomet surgical instruments. Given that Zimmer has absolutely no use for these instruments, we believe the acquisition of the instruments was an attempt to disrupt service to our customers.”
DJO Agree To ReAble Therapeutics Acquisition
DJO agreed to a $1.6bn takeover by ReAble Therapeutics. The Board of Directors of DJO unanimously approved the transaction, which completed later in the year.
Ken Davidson, CEO of ReAble said: “DJO and ReAble have established strong positions in the orthopedic and rehabilitation markets. We are delighted to be joining them together. The resources of the combined company will allow us to develop even better and more innovative products, and to take care of more of the needs of more patients and caregivers than ever before. The strategic fit, both in the U.S. and overseas, is absolutely compelling.”
Vitamin C May Prevent CRPS
Researchers found that high doses of Vitamin C after a wrist fracture, for 50 days, may prevent Complex Regional Pain Syndrome (CRPS).
Previous studies have suggested that the body’s reaction in CRPS can be similar to that of a burn, which vitamin C helps reduced the amount of fluid needed as well as swelling. The researchers also found that when patients complained of discomfort from their casts, this could predict the development of CRPS.
SEPTEMBER
Study Discovers Way To Speed Up Bone-Forming Cell Growth
Research showed that bone-forming cells grow faster and produce more calcium on anodized titanium covered in carbon nanotubes compared with plain anodized titanium and the non-anodized version currently used in orthopaedic implants. The study uncovered a new material that can be used to make more successful implants and also shows promise for an all-new device: a ‘smart’ implant that can sense and report on bone growth.
The researchers hope the material will create a new class of implants that can sense bone growth then send that information to an external device. Rather than using X-ray or a bone scan, surgeons could monitor the output and determine whether to inject growth hormones or intervene to avoid additional surgery.
Cricketer Opens JRI’s New Manufacturing Facility
International cricket star Darren Gough officially unveiled JRI’s new £6m manufacturing facility in Sheffield.
The event saw around 230 attendees, including the Lord Mayor of Sheffield - Councillor Arthur Dunworth, the Master Cutler - Alan Reid, NHS Trust Heads and surgeons and nurses, taken on a tour of the new cutting-edge facility.
Brian Jones, the Managing Director of JRI, said: “We’re delighted key representatives from Sheffield and the healthcare industry gathered with our staff to mark this milestone for JRI. At the new facility we plan to increase production by further improving efficiency and growing as a team; with seven new employees already adding to the current 78 members of staff.”
Researchers: Bone Structure Based on ‘Special Sugars’
Researchers discovered that the structure of human bones is vastly different than previously believed. Researchers discovered that the characteristic toughness and stiffness of bone is predominantly due to the presence of specialised sugars, not proteins, as had been previous believed.
Dr David Reid, from the Duer Group, Department of Chemistry at the University of Cambridge said: “We believe our findings will alter some fundamental preconceptions of bone biology. On a practical level they unveil novel targets for drug discovery for bone and joint diseases, new biomarkers for diagnosis, and new strategies for developing synthetic materials that could be used in orthopaedics.
OCTOBER
Two New Arthritis Genes Found
Researchers have discovered two genes linked to ankylosing spondylitis, a form of arthritis in which some or all of the spine’s vertebrae fuse together.
Principal investigator, Lon Cardon and colleagues in the Wellcome Trust Case Control Consortium and The Australo-Anglo-American Spondylitis Consortium reported their findings that revealed the two genes linked to ankylosing spondylitis: ARTS1 and IL23R, both of which influence immune function. With HLA-B27, three genes are now known be involved in the disease. “We already knew that IL23R is involved in inflammation, but no one had ever thought it was involved in ankylosing spondylitis,” said Matthew Brown, M.D., a clinical researcher from the Wellcome Trust Centre for Human Genetics at the University of Oxford, who co-led the study with Cardon.
A treatment for Crohn’s disease that inhibits the activity of this gene already is undergoing human trials, Brown said, and the drug also looks very promising as a potential treatment for ankylosing spondylitis.
Surgeons identified one type of implant involved with squeaking most often: the Trident by Stryker.
In a small number of patients having a total hip replacement with ceramic-on-Surgeons reviewed studies done so far and found that the extended rim on the socket side of the Trident implant seemed to be causing pinching of the femoral head and neck. But it is still unknown what causes the hip to squeak - X-ray studies using fluoroscopy have helped identify some problems, whilst squeaking implants removed from patients have also been studied.
‘Big Five’ Ordered To Come Clean On Kickbacks
Four of the ‘big five’ orthopaedic companies agreed to pay a total of $311m and submit to five years of ethics monitoring by the U.S. government after they were accused of paying surgeons to get them to use their products.
Zimmer agreed to pay $170m, Johnson & Johnson (Depuy) will pay $84.7m, whilst Smith & Nephew will pay $28.9m and Biomet $26.9m. Stryker was not fined but will still enter into five years of monitoring. All five companies, which control 95% of the market for implants, were accused of paying tens or hundreds of thousands of dollars to individual surgeons as ‘kickbacks’, as well as treating them with trips away and other perks. Whilst the four companies agreed to pay the financial penalties imposed, none of them admitted wrongdoing, saying that it needed to pay surgeons for their expertise, as they often give important advice and test new products.
NOVEMBER
Surgery Halted In Hospital After Rise Post-op Infections
Surgery in an orthopaedic unit was suspended following an increase in infections in post-operation patients. All planned orthopaedic surgery at the Southern General Hospital in Glasgow was suspended after six patients contracted various bugs over the last five months. The orthopaedic unit at the Southern normally has amongst the lowest post-surgery infection rates in Scotland.
“In the period from May 2003 to December 2006, of approximately 1,900 patients to have undergone primary knee or hip replacements, seven developed deep surgical site infections,” said a statement from the health board.
Big Five’ Paid Surgeons $200m In ‘Fees’ For 2007
The furore surrounding the kickbacks just won’t go away, after disclosures given to U.S. prosecutors showed that the ‘big five’ have paid out more than $200m so far this year to doctors and hospitals.
The payments to doctors and hospitals ranged from a few dollars to individual doctors to about $3.9m to Mayo Clinic. The money includes royalties for inventions and payments for teaching classes. Zimmer paid the most to doctors - $85.8m , according to the disclosure. DePuy paid $48.8m, Stryker $27.8m, Biomet $19.6m and Smith & Nephew $19.3m.
DePuy said in a statement that the payments are “critical to advancing patient care and keeping the orthopaedic community appropriately educated and trained on new products and surgical techniques.” The other chose not to comment.
The Power Of The Prototype
Author: Bob Bruce, Sales and Marketing Director of Sandvik Medical Solutions
The spine is a challenging area for surgeons as there is very little space to manoeuvre during surgery and, as always, there is a constant pressure to minimise the time a patient spends under anaesthesia.
It is not surprising, therefore, that there is continual innovation and evolution in the design of implants and instruments.
The commercial challenge facing OEMs is how to get these designs from idea to finished product, both cost effectively and quickly.
Prototyping is essential to achieving this as it translates the OEM’s clinical design into a product that can be manufactured affordably; and ensures that every step of the manufacturing process can be controlled and documented, which is crucial for securing regulatory approval.
Obviously, before making any commitment to production, the OEMs need to be certain the design will actually work. Developing an initial prototype will highlight any issues in the design itself and these can then be addressed. But having a working prototype does not mean the product can be manufactured cost effectively.
This is where the skill and expertise of the manufacturer comes in. Sandvik aims to be a strong strategic partner to OEMs, working in close collaboration to address the complex challenges of manufacturing instruments and implants.
Long experience in prototyping
Kenny Cleveland, General Manager at Sandvik Medical Solutions’ (formerly Doncasters Medical Technologies) Alabama Operations, has been manufacturing orthopedic devices since 1992.
Kenny started the operation in Alabama in 1985 working in the aerospace and medical sectors, responsible for developing, amongst other things, some of the parts on the Space Station. For the past three years the business has concentrated solely on the medical sector, deepening its expertise. The aim for Kenny and his team is to bring value to their customers. OEMs’ engineers utilise Computer aided design (CAD) systems which contain finite element analysis and 3-D modeling to create increasingly complex designs. However, this very complexity may result in a product that is expensive to produce. Kenny’s team looks at these designs from the OEMs and works closely with their engineer to build “manufacturability” into the final product. The goal is to focus on the final production requirements to reduce manufacturing cost and improve time to market, without any compromise to the efficacy of the product.
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| Clockwise from top left: Machine operator running an EDM wire machine ; Kenny Cleveland and the Sandvik plant |
“One area we can make a difference is in knowing how to balance tolerances,” explained Kenny. “Every aspect of the design has upper and lower limits on tolerances and we use our judgement to assess the impact of moving towards the upper or lower end. Slight shifts within the tolerance levels can have a major impact on the fit, function and operating mechanisms of the final instrument and whether or not the manufacture of a product is affordable.”
“We also look at the specified materials. For example an OEM asked us to manufacture a retractor which does the job of spreading the tissue and muscle apart giving the surgeon access to the spine. We discussed the possibility of changing the material from a 300 series stainless to a 17-4ph stainless. The consequence was that the heat treatable material provided better functionality of the component when assembled. A longer life span for the instrument in the field was also projected.
“Another example relates to a torque measuring device. The device had to be able to repeat measurements precisely every time. To deliver this we examined the design, considered the materials and recommended a manufacturing process.
“We work closely with OEMs and approach each project from a manufacturing perspective to make suggestions that typically include balancing tolerances and adding or removing features such as radii or chamfers. The earlier in the development process this interaction takes place then the greater the positive impact our suggestions may have.”
The other key area in which the prototyping process is vital is in ensuring the right quality levels. Manufacturing to the higher regulatory classifications requires complete traceability throughout the manufacturing process. The Sandvik team’s previous experience of the aerospace sector underpinned a culture throughout the manufacturing facility that made it straightforward to implement the required, internationally recognised ISO 13485:2003 quality system.
Kenny explained: “The aerospace sector also places extremely high demands on suppliers. Even the tiniest component on the Space Station must be traceable right through its entire production process.
“We have brought forward the disciplines we developed in this sector to our work with spinal implants and instruments. All our prototypes and production processes are developed under the direction of the international quality standard.”
Recognizing the OEM’s need for qualified manufacturing assistance when developing new products, Sandvik´s Alabama Operations launched its stand alone prototype cell in late 2005. As a result, Sandvik can react to the urgent needs of a quick turn around, capture adjustments made during the manufacturing process and handle the demands of full launch quantities, financially as well as in terms of volume.
Kenny continued: “Customers always receive full feedback on the prototypes. We red line their original drawings to identify changes that improve manufacturability and return a copy of these drawings to the lead development engineer, who decides which changes and updates to include prior to releasing final production orders. This valuable service is just one example of our commitment to helping our customers meet their manufacturing goals.”
Prototyping at Sandvik Medical Solutions
Sandvik Medical Solutions provides three different levels for prototype development.
At every level, Sandvik concentrates on its customers’ commercial pressures and their need to minimise time-to-market. The company works as a strategic partner to OEMs, enabling a close technical collaboration focused on achieving the ultimate goal of a user friendly, commercially acceptable device.
The first level of prototype addresses the earliest stage of product development, sometimes referred to as ‘proof of concept’. This is the point where the OEM’s development engineer has the product concept in mind and has finished the solid model design.
“We can receive this model design from the customer electronically, transfer it to our CAD/CAM system for programming then input it directly into our CNC machine tools, and deliver a finished product as per the model surfaces,” explained Kenny. “Typically, there are just a few ‘critical’ dimensions to maintain in order to prove the ‘proof of concept’. Depending on complexity, this type of prototype requires the shortest lead time, generally about two to three weeks.”
The second level is usually found mid way through the development process. The OEMs have then refined the design using feedback from surgeons and the detailing and dimensions are nearly complete. Sandvik typically produces three to five copies of this level of prototypes. Some dimensional inspection (especially of critical features) is routed through the quality laboratory. Lead times tend to average three to five weeks, again depending on complexity.
The third level is usually the final step before full production and includes clinical trials as needed. Prints are about 95% complete; five to ten prototypes are typically produced and the full quality system is employed, simulating production level manufacturing. Prototypes at this stage have the longest lead times due to the requirement for the full production simulation – five to six weeks is usually achieved.
“At Sandvik, capturing the precise details throughout the manufacturing process is equally important for each of these three levels of prototype development,” continued Kenny.
Sandvik Medical Solutions is proficient in all volumes – from 10 to 500 – and specialises in complex assemblies for products containing as many as 35 different components. Its expertise in prototyping means it can turn challenging designs into working manufacturable products quickly.
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Left-Right: Quality Manager checking dimensions of a part on the comparator; spinal instruments
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At the forefront of new technologies
The company has always been at the forefront of new technologies, investing in in-house facilities as required. Chrome coating, for example, was introduced to the medical sector in the early nineties. This bio-compatible coating improves the wear resistance of the product, giving the instruments a longer life-span.
Sandvik Medical Solutions’ Alabama Operations was the first dedicated instrument manufacturing facility to invest in its own in-house Chrome coating process, receiving validation on biocompatibility tests including cytotoxicity, irritability and tissue sensitivity. The consequence is that customers can now benefit from a controlled process with shorter lead times and reduced costs.
Today, the business is working on a number of different projects including complete instrument set builds. This programme allows Sandvik to input its manufacturing expertise at an earlier stage of the development process and better support the quality inspection requirements while managing the manufacturing process itself and achieving the required launch date.
Sandvik has also been able to effectively reduce instrument lead times by up to 50% while reducing the customer’s monthly inventory. This has been done through creative manufacturing scheduling combined with accurate customer forecasts and long term agreements.
Instrument maintenance programmes and investment in machinery are underway, helping the operation achieve its ultimate aim of providing the services that the OEMs ask for.
Prototyping has become and will remain a crucial step in this process enabling OEMs to refine the designs to ensure their manufacturability. As an organization with a long and proven track record in the area of prototyping, contract manufacturing, and materials knowledge Sandvik is well placed to be a strategic partner to OEMs, helping them achieve their goals.
Spinal Tumour Surgery
Authors: Palaniappan Lakshmanan, MS (Orth), AFRCS
Newcastle General Hospital, Newcastle-Upon-Tyne
Sashin Ahuja, MS (Orth), FRCS, FRCS (Orth)
University Hospital of Wales & Llandough Hospital, Cardiff
Introduction
Skeletal metastasis is discovered at the time of death in 60% – 70% of patients with malignant tumours out of which 40% - 50% affect the spine13. Skeletal metastasis is the third commonest site of metastasis12. The spinal column is the most common site of skeletal metastases3. The majority of spinal secondaries come from primary cancers in the lungs, prostate, breast, kidney, thyroid and gastrointestinal tract. The cervical spine is usually involved in 10% of the metastasis while the lumbar spine is affected in 20%, and the thoracic spine is involved in the majority of the cases to the extent of 70% 5. Primary tumours of the spine form less than 2% of all spinal tumours, however, chordoma and osteoblastoma predominantly occur in the spinal column.
Surgical treatment in spinal tumours should aim at reducing pain, relieve compression of the neural elements, stabilise the spine mechanically, and achieve local control of the tumour. Enneking’s oncological principles of surgical margins for long bone tumours may not entirely apply for spine tumours because of complex paraspinal visceral and vascular anatomy and lack of reliable instrumentation for complex spine reconstruction. However, with improvement in techniques and technologies en bloc resection has become possible with removal of single or upto three vertebral bodies in spine tumours.
In this article, we will discuss the different factors to be considered during surgery and its indications, followed by the different methods available for reconstruction in special situations.
1. En bloc Resection/Curative Resection
This can be performed in aggressive benign primary tumours, primary malignant tumours and solitary spinal bony metastasis with “bony-only” metastases from different primary solid tumours from viscera with good prognosis. Local malignancies like chordomas, selected sarcomas like chondrosarcomas, pancoast tumours, osteoblastomas and giant cell tumours respond well with en bloc resection. If the margins are tumour-free radiotherapy may not be needed after en bloc resection. However in some sarcomas where the dura that is adhered to the tumour must be excised, a watertight duroplasty with autologous fascia with or without appropriate muscle flap coverage must be performed. The muscle flap coverage is recommended if radiotherapy is considered.
To perform an en bloc resection of the spinal tumour a detailed surgical planning is required. The Weinstein-Boriani-Biagini system of spine tumour staging described in 1977 offers a simple and standardised way to plan en bloc vertebrectomy. In this system, the transverse extent of the tumour is described with references to 12 radiating zones (as like the face of the clock), and the longitudinal extent is described into five concentric levels from outside to inside upto the level of the dura and spinal cord/neural elements1.
If the tumour involves either only the vertebral body or only the posterior elements, then both pedicles are cut to achieve the en bloc resection If the tumour occupies one side of the vertebral body and the ipsilatereal pedicle and articular process, a sagittal split osteotomy is performed to achieve en bloc resection. However, if the tumour involves both pedicles, surgery is aimed at minimizing the surface area of the tumour in which case it becomes an intralesional dissection.
2. Spinal Instability
Surgery may also be performed for spinal instability produced by tumours which can be categorised as acute or chronic. Spinal instability is the degree of motion beyond which pain, neurological deficit or abnormal angulation occurs 9. Spinal instability caused by tumours is different from that caused by trauma. Acute instability involves the presence of kyphotic deformity and/or subluxation with spinal cord compression accompanied by pain and/or myelopathy. This usually needs surgical stabilisation. Chronic instability involves compression fractures of various degrees and are usually subtle and usually not associated with spinal cord compression or severe pain. This can usually be managed by non-operative measures, however, when it progresses to acute form, may need surgical stabilisation.
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| Case 1: Preoperative radiograph showing collapsed vertebral body due to metastasis |
3. Fusion Or No Fusion
Unlike in degenerative spines, fusion is not always the goal in spine tumour surgery. Pseudoarthrosis is defined as failure of attempted fusion one year after surgery. Many patients with spinal metastasis may not live long to assess fusion. However, it is still an issue in primary malignant spinal tumours and long-term survivors It has been shown in the literature that the rate of pseudoarthrosis increases with lumbar lesions, primary tumours or patients who received a radiation of more than 4000 rads postsurgery.
Spinal Reconstruction Surgery
There are essentially two approaches for reconstructing the spine after tumour excision.
a. Anterior reconstruction
In spinal tumours traditionally after spondylectomy, the gap is filled with methyl methacrylate (MMA). It has its advantages, viz, cheap, easily available, and resistant to tumour invasion and radiotherapy. A variety of grafts, both auto- and allografts are also used for this purpose, however, fusion is a concern especially if postoperative radiotherapy is employed. For patients with more than 6 months of life expectancy, allografts or cage may be used. Stackable carbon fibre or titanium cages are frequently used in anterior reconstruction. During the last few years several artificial materials and implants have been developed to replace the vertebral body and include titanium cages, ceramic, ceramic/glass, and carbon fibre spacers.
b. Posterior instrumentation
This is often accomplished by screw (pedicles and lateral masses) and this is preferable than hooks in spinal reconstruction for tumours. The posterior constructs are under high stress at the proximal and distal end of the spine especially if it is associated with kyphotic deformity. Reduction of the deformity in such cases may be obtained by using cross-rod bending technique. Wires and hooks through either the kyphotic or lordotic deformity should be avoided. Posterior constructs can be used to reduce kyphosis by placing it in compression or to produce kyphosis by placing it in distraction. Care should be taken not to end the level of the construct in segments where there is tumour involvement, junctional zones (cervicothoracic, thoracolumbar), spondylolisthesis, spinal stenosis or significant degenerative changes.
c. Anterior or Posterior reconstruction
When considering spinal reconstruction in spinal tumours, failure has been reported in anterior or posterior reconstruction alone. Hence, a combined approach with both anterior and posterior or a staged approach with posterior fixation after an anterior reconstruction is used in most cases. Oda et al demonstrated superior fixation biomechanically with a combined anterior-posterior reconstruction than an anterior or a posterior reconstruction alone in thoracolumbar total vertebrectomy7.
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| Case 2: Preoperative radiograph showing collapse of vertebral body |
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| Case 2: Sagittal CT scan showing the involved vertebral body |
Special Considerations
Cervical Spine Reconstruction
As most of the metastatic lesions involve the vertebral body, anterior cervical corpectomy followed by reconstruction and stabilisation is an effective way of surgical management in most cases. PMMA assisted reconstruction is useful in patients with limited life expectancy. Dislodgement of the PMMA used to be a problem, however recent techniques of using Steinman pins and filling the resection cavity with PMMA11, and using various rod and hook systems seems to overcome the problem. To prevent the dura getting affected by the exothermic reaction, a gel foam or a fat pad may be used. In conjunction with PMMA to augment the fixation some authors 8 have described the use of a ceramic prosthesis. Further, the construct failure can also be reduced by the addition of anterior cervical locking plate and screws2,6. Coaxial double-lumen PMMA reconstruction using the chest tubes have been described that yield excellent clinical results especially when combined with anterior plating and/or posterior instrumentation6. To fill the vertebrectomy defect, a titanium mesh cage can be used as a cylindrical interbody reconstruction device that can be filled with auto- or allograft or even PMMA. A titanium Telescopic Plate Spacer (TPS) can be used as a hybrid interbody spacer to reconstruct either one- or two-level corpectomy defects and simultaneously achieve maximum kyphosis correction4. The TPS provides immediate stability allowing early mobilization without the need for external orthosis.
Cervicothoracic Spine Reconstruction
Similar to the cervical spine reconstruction, anterior column reconstruction can be performed with PMMA cast held by vertical Steinmann pins or use of fibular allograft or iliac crest autograft or a mesh cage packed with autograft. Further, anterior cervical plates, Harms cage, expandable cages and metal spacers come into help for anterior reconstruction. Posterior reconstruction can be performed with iliac crest autograft and/or local autograft from laminectomy along with various posterior instrumentation like interspinous or facet wires, Luque rods and sublaminar wires, paediatric Cotrel-Dubousset hooks and rods, AO plates and lateral mass screws, pedicle screws, polyaxial screws, dual-diameter rods and interlocking connections.
Significant anatomical variations are common as the cervicothoracic junction represents a transition zone and also a change from a mobile cervical lordosis to a rigid thoracic kyphosis. Further, the lower cervical laminae are thinner and weaker compared to the upper thoracic vertebrae.
Additionally as the spinal canal at this level is narrow, this may limit the use of the hook/rod system for cervicothoracic spine stabilisation. While using lateral mass screws care should be taken to avoid vertebral artery and spinal nerves. As the cervicothoracic junction represent an area of inherent instability, it is advisable to produce a long construct for spinal stabilisation, by including at least three or four levels above and below the diseased area.
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| Case 2: Post-percutaneous vertebroplasty |
Percutaneous vertebroplasty
This is a newer technique where the collapsed vertebral body in myeloma (as in osteoporosis), is injected with acrylic cement using a needle to stabilise the painful compression vertebral fracture. It is believed that pain relief in such cases is obtained by mechanical support and stability provided by the bone cement to the vertebral body. Complication rate is 1%-3% when treating for osteoporotic vertebral fractures, while it is 7%-10% when treating malignant vertebral fractures. This technique stabilises and strengthens the vertebral body but does not restore the height or shape of the vertebral body.
Is Surgical Treatment Better Than Radiotherapy Alone In Spinal Metastases?
Patchell et al in their multicentre prospective randomised controlled trial comparing the efficacy of surgery to radiotherapy in patients with vertebral body metastatic disease and neurological deficit found that surgery followed by radiotherapy than radiotherapy alone produced superior outcome with significantly higher number of patients with surgery regaining their ability to walk and tended to maintain their newfound mobility longer than the nonoperative group. Further the need for corticosteroids and analgesics were decreased in the surgical group. Additionally, there was improvement in maintenance of urinary incontinence, muscle strength and neurological profile as determined by ASIA scores, improvement in functional ability as determined by Frankel grading and also survival time in the surgical group compared to the non-operative group with radiotherapy alone.
Conclusion
Surgical treatment plays an important role in the management of spinal tumours and continues to expand and improve as the population with spinal tumours also is growing in numbers with longer life expectancy. Instrument technology and biological innovations continue to improve, however stringent biomechanical testing and clinical studies are necessary to affirm their effectiveness before we apply in our clinical practice.
References
- Boriani S, Weinstein JN, Biagini R: Primary bone tumors of the spine. Terminology and surgical staging. Spine 22:1036–1044, 1997
- Caspar W, Pitzen T, Papavero L, et al: Anterior cervical plating for the treatment of neoplasms in the cervical vertebrae. J Neurosurg (Spine 1) 90:27–34, 1999
- Cohen DB: Tumors of the spine, in Koval KJ (ed): Orthopaedic Knowledge Update: 7. Rosemont, IL: American Academy of Orthopaedic Surgeons Publishers, 2002, pp 673–687
- Coumans JV, Marcheck CP, Henderson FC: Use of the telescopic plate spacer in treatment of cervical and cervicothoracic spine tumors. Neurosurgery 51:417–424, 2002
- Gokasalan ZL, York JE, Walsh GL, et al: Transthoracic vertebrectomy for metastatic spinal tumors. J Neurosurg 89:599–609, 1998
- Miller DJ, Lang FF, Walsh GL, et al: Coaxial double-lumen methylmethacrylate reconstruction in the anterior cervical and upper thoracic spine after tumor resection. J Neurosurg (Spine 2) 92:181–190, 2000
- Oda I, Cunningham BW, Abumi K, et al: The stability of reconstruction methods after thoracolumbar total spondylectomy. An in vitro investigation. Spine 24:1634–1638, 1999
- Ono K, Yonenobu K, Ebara S, et al: Prosthetic replacement surgery for cervical spine metastasis. Spine 13:817–822, 1988
- Panjabi MM, Thibodeau LL, Crisco JJ III, et al: What constitutes spinal instability? Clin Neurosurg 34:313–339, 1988
- Patchell RA, Tibbs PA, Regine WF, et al. Direct decompressive surgical resection in the treatment of spinal cord compression caused by metastatic cancer: A randomised trial. Lancet 366:643- 648, 2005
- Sundaresan N, Steinberger AA, Moore F, et al: Indications and results of combined anterior-posterior approaches for spine tumor surgery. J Neurosurg 85:438–446, 1996
- Vrionis FD, Small J. Surgical management of metastatic spinal neoplasms. Neurosurg Focus 15(5): E12, 2003
- Yao KC, Boriani S, Gokaslan ZL, et al: En bloc spondylectomy for spinal metastases: a review of techniques. Neurosurg Focus 15(5): E6, 2003
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