MagnetOs Preclinical Study

Efficacy of a synthetic calcium phosphate with submicron surface topography as autograft extender in lapine posterolateral spinal fusion.

Abstract: Posterolateral spinal fusion (PLF) is a common procedure in orthopedic surgery that is performed to fuse adjacent vertebrae to reduce symptoms related to spinal conditions. In the current study, a novel synthetic calcium phosphate with submicron surface topography was evaluated as an autograft extender in a validated rabbit model of PLF. Fifty-nine skeletally mature New Zealand white rabbits were divided into three groups and underwent single-level intertransverse process PLF at L4-5 using (1) autologous bone graft (ABG) alone or in a 1:1 combination with (2) calcium phosphate granules (ABG/BCPgranules), or (3) granules embedded in a fast-resorbing polymeric carrier (ABG/BCPputty). After 6, 9, and 12 weeks, animals were sacrificed and spinal fusion was assessed by manual palpation, Radiographs, micro-CT, mechanical testing (12 weeks only), histology, and histomorphometry. Based on all endpoints, all groups showed a gradual progression in bone formation and maturation during time, leading to solid fusion masses between the transverse processes after 12 weeks. Fusion assessments by manual palpation, radiography and histology were consistent and demonstrated equivalent fusion rates between groups, with high bilateral fusion rates after 12 weeks. Mechanical tests after 12 weeks indicated substantially lower range of motion for all groups, compared to non-operated controls. By histology and histomorphometry, the gradual formation and maturation of bone in the fusion mass was confirmed for each graft type. With these results, we describe the equivalent performance between autograft and a novel calcium phosphate material as an autograft extender in a rabbit model of PLF using an extensive range of evaluation techniques.

Citation: van Dijk LA, Barbieri D, Barrère-de Groot F, Yuan H, Oliver R, Christou C, Walsh WR, de Bruijn JD. Efficacy of a synthetic calcium phosphate with submicron surface topography as autograft extender in lapine posterolateral spinal fusion. J Biomed Mater Res B Appl Biomater. 2019;107(6):2080-2090. DOI: 10.1002/jbm.b.34301. Epub. 2019 Jan 7. PMID: 30614621; PMCID: PMC6690075.

Disclaimer: Results from in vitro or in vivo laboratory testing may not be predictive of clinical experience in humans. Please refer to the Instructions for Use for a full list of indications, contraindications, precautions and warnings. For important safety and intended use information please visit kurosbio.com/eifu. MagnetOs is not cleared by the FDA or TGA as an osteoinductive bone graft.

PROMO/MAG/GL/001-19/R00