Biphasic calcium phosphate with submicron surface topography in an <i>Ovine</i> model of instrumented posterolateral spinal fusion.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31463454.
- Also identified by DOI 10.1002/jsp2.1039 and PMC identifier 6686792.
- Licence recorded as CC BY-NC-ND.
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Abstract
As spinal fusions require large volumes of bone graft, different bone graft substitutes are being investigated as alternatives. A subclass of calcium phosphate materials with submicron surface topography has been shown to be a highly effective bone graft substitute. In this work, a commercially available biphasic calcium phosphate (BCP) with submicron surface topography (MagnetOs; Kuros Biosciences BV) was evaluated in an <i>Ovine</i> model of instrumented posterolateral fusion. The material was implanted stand-alone, either as granules (BCP<sub>granules</sub>) or as granules embedded within a fast-resorbing polymeric carrier (BCP<sub>putty</sub>) and compared to autograft bone (AG). Twenty-five adult, female Merino sheep underwent posterolateral fusion at L2-3 and L4-5 levels with instrumentation. After 6, 12, and 26 weeks, outcomes were evaluated by manual palpation, range of motion (ROM) testing, micro-computed tomography, histology and histomorphometry. Fusion assessment by manual palpation 12 weeks after implantation revealed 100% fusion rates in all treatment groups. The three treatment groups showed a significant decrease in lateral bending at the fusion levels at 12 weeks (<i>P</i> < 0.05) and 26 weeks (<i>P</i> < 0.001) compared to the 6 week time-point. Flexion-extension and axial rotation were also reduced over time, but statistical significance was only reached in flexion-extension for AG and BCP<sub>putty</sub> between the 6 and 26 week time-points (<i>P</i> < 0.05). No significant differences in ROM were observed between the treatment groups at any of the time-points investigated. Histological assessment at 12 weeks showed fusion rates of 75%, 92%, and 83% for AG, BCP<sub>granules</sub> and BCP<sub>putty</sub>, respectively. The fusion rates were further increased 26 weeks postimplantation. Similar trends of bone growth were observed by histomorphometry. The fusion mass consisted of at least 55% bone for all treatment groups 26 weeks after implantation. These results suggest that this BCP with submicron surface topography, in granules or putty form, is a promising alternative to autograft for spinal fusion.