Tuesday, February 2, 2010

501 Pedicle Screws and Counting

My Abacus does not have enough of beads on its wires to count this high.

On February 2nd, AlphaTec Spine announced that it had received CE Mark approval for the commercial sale of this device in the European Union. The powers to be at AlphaTec claim that this device is innovative because it is intended to significantly increase the pullout and holding strength of this screw.

Obviously, the marketing spin on this device is that it was designed with the intent of addressing a need for patients that have the "Aging Spine." The reality is that this is an expandable screw that locks the screw into the neck of the pedicle. Hmmmmm, sounds familar to another platform that surfaced a few years ago by a company named Expandable Orthopedics.

So here's our question to our readers, Is this truly an innovative device, and will it effect the clinical outcomes for lumbar fusions? Or, is this another attempt to market a product that really won't make a difference? Our staff has not heard of any surgeons complaining about screw pullout, what have our readers heard. This is your opportunity to bring your opinions to the public. You know what they say, Is it new? Is it True? And, Will it make a difference?

15 comments:

  1. The question I have regarding these screws is how do you get them out during a revision case? Can you or do you just have a corpectomy system available, instead?

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  2. Pull-out strength is a highly subjective characteristic of a screw. In my years of development and testing, there are factors besides the geometry of the screw that can boost results in a screw pull-out testing. First it is sometimes common practice that test medium consideration can and will be adjusted to suit the needs of the product. This adjusting can be hidden by vague report writing.

    Comparing pull-out strength on screws is a delicate science only due to the fact each company has what is the best method for them, and sometimes stack the results against a competitors.

    The bigger questions we all need to be asking ourselves is when is testing and discussion going to be fair and balanced. Testing and reporting will never be fair and balanced only due to the fact each company says it has the best and want the results to stand by it.

    However the deeper question is do implant companies actually care about a patient or is it one big pissing contest at the end of the day.

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  3. ...not to mention 173 spine startups and counting listed alphabetically on OrthoStreams.com.

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  4. Take a field trip to your local Home Depot/Lowes and glance at all the possible "INNOVATIONS" in the hardware/fastener section!!!!

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  5. I am under the impression that improved fixation is needed for patients with osteoporosis. Screw loosening in bone is probably the bigger issue, as compared to pull-out. Pull-out tests are relatively simple and pull-out tests could be an indicator of overall better fixation.

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  6. How often do we hear of screw loosening? In addition, many of the newer screws have exceptional "pull-out" strength. Is this a real problem, or is this a solution to a problem that doesn't really exist?

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  7. Asking about the rate of screw loosening or pull-out is a great question. Other good questions: What is the revision rate for pedicle screws? What percentage can be attributed to fixation failure of the screw? How many patients that would otherwise be candidates for fusion with pedicle screws are turned away because of poor bone quality? I don't have the answers - just asking.

    If newer screws have exeptional pull-out, what has changed in the design in recent years?

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  8. Pull-out is not a real problem in most cases. When dealing with fixation screws. Pull-out and loosening are often attributed to improper selection and implantation.

    There are limited factors that influence pull-out and loosening characteristics. However testing methods can influence results.

    The biggest issue with screws is still breaking at the necks of the heads and overall construct strength.

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  9. Bad bone is bad bone. Metal wears through bone. Putting pressure on bad bone with an expandable screw is going to change the mode of failure, not so much the rate of failure. For bad bone a better solution is to strengthen the vertebra as a whole. That is what one tries to do with screw augmentation. PMMA or some other injectable self setting material, maybe even calcium phosphate cements, although these have some mechanical limitations.

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  10. Our spine practice saw them at NAS but did not have time to view their preso. As someone else commented the booth was full of people waiting to get information and we had a plane to catch. They have a website www.baxano.com for doctors and administrators that wish to get info and have been responsive.

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  11. Most technology has a place. This will have a place with Oseopenic and Oseoporotic patients. Also revision surgery will be assisted significantly by weak pedicles not bearing the brunt of larger width screws that have the potential to damage the integrity of the pedicle.

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  12. Far be it from me to suggest, but depth, trajectory and intimal bone conact are probably THE biggest determinants of screw pullout, regardless of bone quality or screw geometry.

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  13. just use better biologics, get a solid anterior column fusion (old osteoporotic patients arent getting big scoli surgeries anyways). harware fails (fracture, pullout, "windshield wipering") when the race between bony fusion and harware failure is lost. Many poor ped. screw placers use 5.0-5.5 screws. Use a modern dual minor design of a decent diameter and length and youre set. If the pts dexa score is that bad then instrumented fusion via ped. screws might not be the best option. Give them an XLIF with spinous process fixation, they'll fuse.

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  14. An expandable screw can allow for less inventory (one size fits all)-good for the company, distributor.

    To the patient, and his/her bone howeve, metal is still metal. Poor bone will react (resorb,break, fuse) and behave the same to a 5.5mm screw that is fixed as it will to a 5.5mm screw that was "expanded" to this "perfect size."

    The product is a screw and ends up being a screw---pedicle screws have not had much pull out issues, bones on the other hand have issues that will not change.

    Product is a Non-Event in the continuum of healthcare.

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  15. Just deposited $6000 to their account. Can I ask them for the refund of my money. They charged me $23500 as their standard surgery bill. Pls advice

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