The case for osteobiologics in degenerative spine surgery
BY PROF HANS JÖRG MEISEL AND DR ZORICA BUSER
The new AO Spine Guideline for Using Osteobiologics in Spine Degeneration (AO-GO) focuses on anterior cervical discectomy and fusion surgeries (ACDF). It formulates precisely defined, clinically relevant, and internationally applicable recommendations for osteobiologics and their use. The Global Spine Journal Special Issue aims to fill the many knowledge gaps in this exciting field.
Osteobiologics—engineered materials that promote bone fusion—are critical for the success of spine surgeries. However, although they can lead to improved bone fusion at an earlier stage with fewer post-operative complications and fewer revisions, osteobiologics are often overlooked in the operating theater in favor of hardware. Many surgeons remain unaware of their vast potential. Selecting the optimal osteobiologic for each clinical scenario—including cost considerations—is also challenging.
The imbalance between osteobiologics and hardware has various reasons. Firstly, more industry representatives visit clinics to talk about hardware, and surgeons themselves are often involved in hardware development. Secondly, hardware is much more tangible: it can be manipulated in real time, and with near-instant results. Osteobiologics, on the other hand, are abstract: it takes months before we see results.
The convoluted market is another hurdle, as is the fact that osteobiologics research is often preclinical, poor-quality, and with little consideration for comorbidities and risk. For instance, it remains unclear how to select the appropriate product for smokers or osteoporosis patients.
The case for better regulation of osteobiologics
Consequently, many surgeons are reluctant to explore alternatives to the hardware they know and trust. Patients also frequently struggle: they are unable to find unbiased, concise, evidence-based information on osteobiologics. In addition, there is a cost angle: many expensive products lack strong evidence of efficacy. Hospitals therefore frequently question the decision to apply osteobiologics.
While the regulation of osteobiologics varies internationally, many regulators rely on preclinical research only for the approval of new products that are relatively similar to what is already on the market. As a result, manufacturers frequently frame their products as the "gold-standard", adding to the complexity.
The regulatory agencies will play an important role with osteobiologics, as they did with bone fillers: historically, bone fillers were little regulated, and a plethora of products was available. Today, bone fillers are governed by the European Union's Medical Device Regulation—clinical trials are required to demonstrate their safety and efficacy. For most classes of osteobiologics, this safeguard is still lacking.
Promoting greater understanding
The AO-GO Guidelines are an attempt to systematically assess the available evidence on osteobiologics and to provide updates to the wider community. They were developed by an international team of surgeons and researchers with expertise in degenerative spine diseases and can help us overcome many of the barriers we have outlined.
The Guidelines make evidence-based clinical recommendations that support osteobiologic use in practice. Although still limited to osteobiologic use in degenerative cervical spine conditions and ACDF procedures, the hope is that they will soon include other areas such as the lumbar region.
Because of their international perspective, the AO-GO Guidelines have global relevance. As osteobiologics vary in price and availability across regions, this is an important aspect. For example, as the pool of available evidence grows, the Guidelines will help clarify why some products are more costly, allowing surgeons to base their choice on cost-to-benefit considerations.
The Guidelines will also enhance future research involving osteobiologics in ACDF by clarifying which osteobiologics have a foundation of knowledge and which ones require further research.
The future of osteobiologics
We are confident that the AO-GO Guidelines will make working with osteobiologics more straightforward in all regions of the spine. It will we become clearer on which osteobiologic to use in each clinical scenario and promote evidence-based pairings of osteobiologics and hardware. The Guidelines can be combined with other classification systems to foster a holistic, evidence-based understanding of best-practice with osteobiologics. Ultimately, by promoting a more considered approach to osteobiologics, we can realize their full potential and benefit patients.
Additional links:
The AO-GO study was conducted by the AO Spine Knowledge Forum Degenerative.
The full guest article was published in the AO Spine Guest Blog under the title ‘Addressing the disparity between hardware and osteobiologics in degenerative spine surgery’.
About the Authors
