By Thomas Melin and Sean Hensler
Most surgeons consider autologous bone graft to be the “gold Standard” for fusion procedures. Unfortunately, other products such as demineralised bone matrix, cancellous bone clips, bone morphogenetic protein (BMP) etc., are often used even though their efficacy is clearly inferior to autologous bone. The reasons are complex, but the most common issue is the inability to recover sufficient autologous bone at the time of surgery.
More than 15 years ago, in an effort to address this issue, I [Thomas Melin] began collecting the particles of bone (“bone dust”) created by the use of high speed drills for use as autologous bone graft. The fusion results were excellent but the collection process was very inefficient—both in terms of time and in terms of the quantity of autologous bone collected.
Seveal years ago, Robert Sean Hensler joined my practice and also experienced the challenges of collecting and separating suitable autologous bone graft material from “bone dust”. Realising that there must be a better way, he created the first renderings of a bone collection and separation device a little over two years ago. The combination of Mr Hensler’s concept and my clinical experience lead to further development. Ultimately, the device gained FDA approval and was recently released for use in the USA. It is marketed as the Hensler Bone Press.
To understand the benefits of the Hensler Bone Press, one must first visualise an operative case where bone is being drilled away such as a lumbar laminectomy. As the drill removes bone, a mixture of bone particles, blood and irrigation is formed. This is typically removed from the operative site and discarded as waste. The device saves and separates viable autologous bone graft from this mixture. In essence, it preserves and separates a very valuable commodity (autologous bone graft) from the true waste. It accomplishes this by means of a two-step process. In step one, a collection container is placed in the operating room suction line in close proximity to whatever type suction tip the surgeon chooses to use. As bone is drilled away at the operative site, suction is used to remove the bone dust, blood and irrigation, which is trapped in the collection container.
When full, the container is removed and replaced with a second collection container. The contents of the first container are processed in step two. In this step, the press head is engaged allowing the separation of blood and other fluids from the autologous bone. The processed bone is then removed from the container and saved for later usage. This renders the first container again ready for use during the collection phase. Obviously, this process can be repeated as many times as are necessary.
This device clearly demonstrates that “necessity is the mother of invention”. There was a need to preserve autologous bone graft created when bone was drilled away at the operative site. To fulfill this need, a collection and separation device was conceived. The Hensler Bone Press accomplishes this goal with great efficiency, yielding enough autologous bone graft to reduce or even eliminate the need for other products such as demineralised bone matrix or synthetics. This fact makes the device very cost effective, potentially saving hundreds to thousands of dollars on every case where it is used.
An additional benefit is the ease in which the device can be used during surgery. There is virtually no interruption or delay to the operative procedure. This fact clearly emphasises the benefit of individuals who will ultimately use the Hensler Bone Press also being responsible for its design.
Thomas Melin is assistant clinical professor, Department of Neurosurgery, University of North Carolina, senior partner and president, Coastal Neurosurgical Associates and Spine Center, Wilmington, USA. He is co-founder and managing member Hensler Surgical Products, LLC
Sean Hensler is a neurosurgical physician’s assistant, Coastal Neurosurgical Associates and Spine Center, Wilmington, USA, and co-founder and managing member, Hensler Surgical Products