Autologous Bone or "Bone in a Bottle"?

I am likely to be among the aging minority of my colleagues in advocating for the use of autologous cancellous bone in most spine fusions, joint arthrodesis, and treatments of delayed unions. While some will contend that my adovocacy is dated and clearly a perspective that involves some self-interest (I developed the Corex device, a percutaneous antologous bone harvesting tool, sold by Trinity Orthopedics as well as being ditributed by Medtronic).

I am unable to deny my age (34 years since finishing my residency) and while self-interest is not laudible like altruism, I would be glad to defend the proposition that autolgous cancellous bone remains the "gold standard" by which all other bone grafts and bone graft substitutes are judged. Orthopedists and spine surgeons not uncommonly proclaim with pride, that they have not harvested bone for many years if at all. Some even more unfortunately, were never properly (i.e. effectively and with minimal soft tissue and cortical disruption) trained on how to harvest bone from patients, because their residency and fellowship instructors were similarly inclined.

I attended a symposium at last year's NASS in Orlando on bone graft substitutes, and remarkably all of the panelists conceded that autolgous cancellous bone remained the "gold standard", yet none of them used autologous bone in their practices. The expressed reason being concern for graft site morbidity and a desire to avoid the surgical effort and time needed to harvest bone. There is nothing wrong with avoiding morbidity and reducing surgical time and surgeon effort, as long as the alternatives provide comparable outcome. Outcome (i.e. fusion or bone healing) is where the "rubber meets the road" and yet many surgeons cite their anecdotal personal experience as the basis for concluding that their version of "bone in the bottle" is equivalent to autologous cancellous bone.

The same NASS panelists (the ones that never used autolgous bone), had to admit that the data for non-autologous bone (other than BMP-2) is relatively meager or even absent. While the literature will often contain a few non-inferiority studies (almost exclusively sponsored by the purveyor of the specific "bone in the bottle"), it is a presumptious to assume that one or a few published non-inferiority studies in specific clincial circumstances equates equivalent efficacy in a myriad of applications. Cancellous atograft applications have been used, studied, and published for over one hundred years and virtually all of these studies were not subject to the potential conflict of interest associated with various studies involving bone graft substitutes.

NASS provided a summary statement on the use of bone graft substitutes after reviewing the literature and concluded that autologous cancellous bone should be used preferentially to all bone graft substitues in spine fusions, except where limitations on available bone graft volume requires supplimentation with a bone graft substitute. A number of studies have shown that if the surgeon avoids extensive soft tissue stripping and cortical stripping or destabilization, graft site morbidity can be minimized to a very acceptable level.

Many surgeons are relatively unaware of technology (such as Corex) which enables percutanous cancellous harvesting with trivial to absent donor site morbidity. Patients are frequently unaware of which side (e.g. anterior or psoterior crest or proximal tibia) was used for graftng unless they are able to the specific wound dressing associated with the graft harvest site. Literature substantiates this anecdotal observation, as published studies have shown that patients are unable to discern which side their graft was harvested from and when the bone was used in higher lumbar or thoracic fusions, the dondor site morbidity is considerably less than in lumbosacral procedures (suggesting that subjective donor site pain may simply be referred spinal pain).

All this said, I commend my colleagues to become more familiar with more recent autologus bone grafting literature and techniques and to consider the not only the therapeutic advantages for their patients but also the economics associated with autologous bone graft harvesting.

Jim Marino

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