Posted on | April 22, 2012 | No Comments
How One Device Could Change Spine Surgery: Q&A With Sean Hensler of the Hensler Bone Press (Laura Miller @ Beckers)
Sean Hensler, PA-C, inventor of the Hensler Bone Press and founder of Hensler Surgical Products, discusses the bone press and how it will revolutionize orthopedic and spine procedures in the future. Mr. Hensler served as a physician assistant in more than 1,500 neurosurgical cases, where he developed the idea and design for the bone press.
Sean Hensler: In nearly every spinal fusion case, bone is drilled away. This bone is generally attempted to be collected, but many surgical teams literally dump it on the table and keep going. There is significant, precious bone within the blood and saline mixture. Most of the time, this bone is discarded, given the effort and time required to separate the bone slurry as well as the consistency of the bone after manual separation. Within moments, the blood starts to clot and the bone is difficult to retrieve. Some people try to salvage the bone by various crude methods, such as pressing a towel on it, but you actually lose the bone given it’s adherence to the towel. This also takes the scrub technician away from the surgery and surgeon while this process is taking place. This method is poor at best in attempting to retrieve the autologous bone.I was frustrated by the waste of this bone. I wanted to develop a device that proficiently separates the bone from blood, eliminates the potential for contamination and allows surgeons to collect and separate the bone without disrupting the surgery.
Q: How does the process work?
SH: The surgeon and/or assistant collects bone and fluid that is being drilled away. Many surgeons call this bone dust or shavings. After the container is full, you can pass that off to the nurse or scrub technician, whom then hands the first assist an empty container to resume collection. On the surgical table, attach the press head and suction and press down manually to deploy the press head to the bottom of the container. Once depressed to the bottom, simply tilt the container to suction the blood and fluid away quickly and easily. It takes less than 30 seconds. Simply stage the compressed semi-dry autologous bone on a non-adherent pad. Once another container is full, you simply swap containers and repeat the process until this portion of the case is complete. The bone is ready for use whenever the surgeon desires.
Q: How do you know there isn’t cell death?
SH: I had a clinical pathologist analyze the bone after the press to ensure there wasn’t any osteoblast cell death. Cell viability is key. There is the possibility that you could kill the cells while separating it from the blood with increased pressure, but that didn’t occur with this device. There was complete cell viability. One reason why we are able to keep the cells viable is because of the container’s design and press head engineering. We didn’t want a narrow container because it could increase the pressure on the bone. It’s important for this device to work well, but just as important if not more so, not incur any harm to the cells.
Q: Why don’t most surgeons use this or a similar process already to save bone?
SH: Most surgeons say it isn’t worth the trouble to collect the bone in the operating room, so they bring in the synthetics. I’ve seen 2 cc of synthetic go for $500 to $1,000. To purchase my device, it will be under $350 per device, and if you purchase more there is a cost savings. The device is disposable with each use, which means there isn’t the risk of cross contamination. The device produces compressed, viable bone for the surgery and allows for little to no interruption of the case. These are strong factors to promote case flow and cost savings.
Q: What is the estimated cost savings from using this device?
SH: You can usually collect a significant amount of bone this way, although it varies with every operation. The testing that took place with my device was a minimally invasive lumbar hemi-laminectomy. This bone was drilled away and we collected around 3.5 cc, which in the synthetic market, can range from $400 to $1,200 worth of bone. This is clearly enough bone to pack an implant, such as a TLIF. With bilateral one level or multi-level fusions, corpectomies or partial corpectomies, or straightforward lumbar laminectomies with on lay fusion, the bone should be sufficient, in most cases, to eliminate the need for synthetics. Not only is the bone enough, it is already compressed and ready to use to optimize fusion for each patient as they will get nearly all their own back from the surgery which is being drilled away.
I really want to try to save as much as I can and help surgeons achieve a better outcome for their patients. Patients’ own bone is osteoconductive and osteoinductive unlike synthetics, which is simply a scaffolding and will not fuse on it’s own. Why wouldn’t the patient want to have every bit of their own bone back for their fusion case? This device affords this to occur.
Q: What is the biggest benefit of using the device?
SH: The biggest benefit is that it improves patient outcomes because they get their own bone back from their surgery. It’s not going to interrupt the surgery and there’s no chance of cross contamination or hassle with re-sterilization. The container is 80 cc’s full, with graduations to 60 cc. The current 40 cc collection container is often filled and dumped four times per lumbar fusion and twice per cervical fusion, but of course this varies per case.
Q: What roadblocks did you hit when you were developing the device?
SH: There were several roadblocks we overcame during development. First, we put significant engineering into the press head; we developed 10 to 12 different press heads. Some had rings, some were without rings, and we had to figure out what worked best. We tested from 50 micron mesh to 300 micron mesh. We definitely had some fails, but the final press head that we had separated the bone nicely.
We didn’t have challenges with the collection container, but it did take some engineering to have the ribs line up to ensure the device was closed correctly.
Q: Where do you see this device heading in the future?
SH: I think it’s really going to change a lot of thinking and cut the cost of surgeries significantly. It should also promote better patient outcomes and make the surgery smoother. Beyond just spine surgery, this device could be used with orthopedic surgeries, joint surgeries, deformities or trauma — really with any time surgeons are drilling down bone for fusions, this device would be beneficial for the surgeon, but most importantly, the patient undergoing the fusion procedure.