Novel spinal instrumentation to enhance osteogenesis and fusion: a preliminary study

Abstract

<jats:sec> <jats:title>OBJECTIVE</jats:title> <jats:p>Instrumented spinal fusion continues to exhibit high failure rates in patients undergoing multilevel lumbar fusion or pseudarthrosis revision; with Grade II or higher spondylolisthesis; or in those possessing risk factors such as obesity, tobacco use, or metabolic disorders. Direct current (DC) electrical stimulation of bone growth represents a unique surgical adjunct in vertebral fusion procedures, yet existing spinal fusion stimulators are not optimized to enhance interbody fusion. To develop an advanced method of applying DC electrical stimulation to promote interbody fusion, a novel osteogenic spinal system capable of routing DC through rigid instrumentation and into the vertebral bodies was fabricated. A pilot study was designed to assess the feasibility of osteogenic instrumentation and compare the ability of osteogenic instrumentation to promote successful interbody fusion in vivo to standard spinal instrumentation with autograft.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>Instrumented, single-level, posterior lumbar interbody fusion (PLIF) with autologous graft was performed at L4–5 in adult Toggenburg/Alpine goats, using both osteogenic spinal instrumentation (plus electrical stimulation) and standard spinal instrumentation (no electrical stimulation). At terminal time points (3 months, 6 months), animals were killed and lumbar spines were explanted for radiographic analysis using a SOMATOM Dual Source Definition CT Scanner and high-resolution Microcat II CT Scanner. Trabecular continuity, radiodensity within the fusion mass, and regional bone formation were examined to determine successful spinal fusion.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>Quantitative analysis of average bone density in pedicle screw beds confirmed that electroactive pedicle screws used in the osteogenic spinal system focally enhanced bone density in instrumented vertebral bodies. Qualitative and quantitative analysis of high-resolution CT scans of explanted lumbar spines further demonstrated that the osteogenic spinal system induced solid bony fusion across the L4–5 disc space as early as 6 weeks postoperatively. In comparison, inactive spinal instrumentation with autograft was unable to promote successful interbody fusion by 6 months postoperatively.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>Results of this study demonstrate that novel osteogenic spinal instrumentation supports interbody fusion through the focal delivery of DC electrical stimulation. With further technical development and scientific/clinical validation, osteogenic spinal instrumentation may offer a unique alternative to biological scaffolds and pharmaceutical adjuncts used in spinal fusion procedures.</jats:p></jats:sec>

The effect of electrical stimulation therapies on spinal fusion: a cross-disciplinary systematic review and meta-analysis of the preclinical and clinical data

“…The remaining study routed electrical current through pedicle screws and rods. 67 The reported fusion rates ranged between 70% and 100% for the treatment group and between 0% and 73% for controls (Supplemental Fig. 2A).…”

Preparation of Coralline Hydroxyapatite Implant with Recombinant Human Bone Morphogenetic Protein‐2‐Loaded Chitosan Nanospheres and Its Osteogenic Efficacy

“…Johnson (2011) found that oxysterols had the ability to promote osteogenesis, protect lipogenesis, and induce spinal fusion 6 . In recent years, spinal instrumentation has been developed to enhance osteogenesis and fusion 7 . However, despite the studies that have been produced, osteogenesis after spinal fusion remains a clinical challenge and new methods are still needed to enhance the efficacy of osteogenesis after spinal fusion.…”