Maria Shepherd, Data Decision Group

The U.S. market for osteoconductive and osteoinductive implants is a market reflecting active development coupled with the expectation of continued significant transition. These materials are used in arthroplasty, fracture repair and spine fusion procedures. This market is estimated to have grown from $400 million in 2000 to $1.5 billion in 2007.¹

Despite issues with these materials, the bone graft and bone substitute market continues to be driven by:

• Surgeon need to increase fusion rates

• Spine procedure volume growth

• The arrival of growth factors

• New bone implant products

The market currently has five segments: allograft, demineralized bone matrix (DBM), bone graft substitutes, machined bone and recombinant human bone morphogenetic protein (rhBMP).

Spinal fusion procedures are advancing into a new era of bone biology.² ­New innovative technologies, such as stem cells and gene therapy are being investigated in animal studies.

Mesenchymal stem cells (MSCs) are of great interest because of their ability to self-renew. In animal models, bone marrow MSCs have demonstrated efficacy in spine fusion.

In the future, the use of autologous MSCs to treat spinal fusion may be an effective alternative to autogenous bone grafts. In several studies, it has been demonstrated that autologous MSC composites could improve bone regeneration and achieve osseous spinal fusion. Successful spinal fusion is largely mediated by endogenous osteoblasts; this means that MSC therapy may be particularly beneficial for elderly patients and those with reduced cellular stores.

Gene transfer technologies are in development for applications that require large amounts of a biologically active target gene protein. In spinal fusion, the genes coding for osteoinductive factors can be transferred to the local spine fusion environment. Transduced cells (those that have had genes transferred into them) can secrete the target protein extracellularly and deliver it to the spinal environment in physiologically appropriate doses for a sustained period of time, maximizing the osteoinductive potential of these growth factors.

According to Pearl Diver, overall spine fusion procedure growth may be disrupted by several new technologies on the horizon.

If these technologies impact the growth in spine fusion procedure volumes, this could remove a primary driver of growth in the bone and bone substitute market. In particular, a high percentage of DBM product sales are thought to be attributable to spine fusion, putting this product at higher risk.

The bone graft market is truly one in transition. Multiple factors will continue to impact this market. They include:

• The increase in the number of osteoinductive growth factors.

• Technologies like motion preservation and the impact they could have on fusion procedure rates.

• New technologies that treat the spine earlier in the disease state process may also decrease fusion procedure rates.

• Futures advances in gene therapy.

This is an exciting time to be in spine. New biologics and mechanical technologies that are in development are the tools that seek to close the gap on the treatment of back pain. There is still a long way to go, but with all the research going on in this area, advances are coming quickly.

References:

1. www.pearldiverinc.com

2. Mikyazaki et.al, Eur Spine J 2009 18:783-799 An update on bone substitutes for spinal fusion.

3. Gan, et. al. Spine 28: 1219-1224.

Maria Shepherd is president at Data Decision Group, a medical device and life sciences strategic marketing, market research and mergers and acquisitions support firm.