Anterior Cervical Fixation: BMP

Bone Morphogenetic Protein

The new technologies still require some bone material to be placed in the center to provide scaffolding for bone growth. Synthetic materials also lacked the endogenous bone growth enhancing proteins found in autografts and therefore their fusion rates were lower. (11) Realizing the importance of proteins in bone fusions, scientists isolated the protein promoters of fusion known as bone morphogenetic proteins (BMP).

The first product using a bioengineered bone morphogenetic protein was INFUSE™ (Medtronic Sofamor Danek, Memphis, TN). INFUSE™ was approved by the Food and Drug Administration (FDA) for use with titanium interbody implants in the lumbar spine.

Figure 5. INFUSE™ (Bone Morphogenetic Protein)

INFUSE™ has been used extensively in the lumbar spine with titanium interbody devices without any autograft or allograft. Fusion rates have been close to 100%. (12) The use of INFUSE™ in the cervical spine has not undergone FDA evaluation and is therefore an "off-label" use. We have used INFUSE™ in conjunction with PEEK interbody spacers in the cervical spine with very good results.

Figure 6. Combination of PEEK and INFUSE™ .

Preliminary results are promising and INFUSE™ may be especially appropriate in people undergoing multiple level fusions and people who are less likely to fuse because of concomitant medical problems. The combination of PEEK and INFUSE™ hopefully avoids the problems associated with autograft harvest, reduces disk height collapse, avoids the use of limited supply bone bank bone, and has a very high fusion rate.

Figure 7. Lateral X-ray of a two-level anterior cervical discectomy with PEEK and INFUSE™ after 2 months showing excellent fusion.

Figure 8. CT after a two-level anterior cervical fusion with PEEK and INFUSE™ demonstrating bone formation within and around the PEEK interbody spacer.