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Augmentation of regenerative osteogenesis represents a premier clinical need, as hundreds of thousands of patients are left with insufficient healing of bony defects related to a host of insults ranging from congenital abnormalities to traumatic injury to surgically-induced deficits. A synthetic material that closely mimics the composition and structure of the human osteogenic niche represents great potential to successfully address this high demand. In this study, a magnesium-doped hydroxyapatite/type I collagen scaffold was fabricated through a biologically-inspired mineralization process and designed to mimic human trabecular bone. The composition of the scaffold was fully characterized by XRD, FTIR, ICP and TGA, and compared to human bone. Also, the scaffold microstructure was evaluated by SEM, while its nano-structure and nano-mechanical properties were evaluated by AFM. Human bone marrow-derived mesenchymal stem cells were used to test the in vitro capability of the scaffold to promote osteogenic differentiation. The cell/scaffold constructs were cultured up to 7 days and the adhesion, organization and proliferation of the cells were evaluated. The ability of the scaffold to induce osteogenic differentiation of the cells was assessed over 3 weeks and the correlate gene expression for classic genes of osteogenesis was assessed. Finally, when tested in an ectopic model in rabbit, the scaffold produced a large volume of trabecular bone in only two weeks, that subsequently underwent maturation over time as expected, with increased mature cortical bone formation, supporting its ability to promote bone regeneration in clinically-relevant scenarios. Altogether, these results confirm a high level of structural mimicry by the scaffold to the composition and structure of human osteogenic niche that translated to faster and more efficient osteoinduction in vivo--features that suggest such a biomaterial may have great utility in future clinical applications where bone regeneration is required.

A high dose of 40 mg of rhBMP-2/CRM in lumbar spinal arthrodesis was associated with an increased risk of new cancer.

Lumbar microdecompression is a minimally invasive technique that appears to provide excellent functional outcomes.

Interbody cage devices, used to assist interbody fusion, are rapidly gaining popularity in the surgical management of chronic low back pain. This update provides a structural classification of commonly used devices and assesses them against a set of clearly defined surgical goals, including ability to correct the existing mechanical deformation, ability to provide mechanical stability, ability to provide a suitable environment for arthrodesis, and ability to limit "built-in" morbidity. In addition, the materials used in the devices are examined regarding their biomechanical, biologic, and radiographic characteristics.

In this study, poly(dl-lactide-co-glycolide)/porous silicon (PLGA/pSi) composite microspheres, synthesized by a solid-in-oil-in-water (S/O/W) emulsion method, are developed for the long-term controlled delivery of biomolecules for orthopedic tissue engineering applications. Confocal and fluorescent microscopy, together with material analysis, show that each composite microsphere contained multiple pSi particles embedded within the PLGA matrix. The release profiles of fluorescein isothiocyanate (FITC)-labeled bovine serum albumin (FITC-BSA), loaded inside the pSi within the PLGA matrix, indicate that both PLGA and pSi contribute to the control of the release rate of the payload. Protein stability studies show that PLGA/pSi composite can protect BSA from degradation during the long term release. We find that during the degradation of the composite material, the presence of the pSi particles neutralizes the acidic pH due to the PLGA degradation by-products, thus minimizing the risk of inducing inflammatory responses in the exposed cells while stimulating the mineralization in osteogenic growth media. Confocal studies show that the cellular uptake of the composite microspheres is avoided, while the fluorescent payload is detectable intracellularly after 7 days of co-incubation. In conclusion, the PLGA/pSi composite microspheres offer an additional level of controlled release and could be ideal candidates as drug delivery vehicles for orthopedic tissue engineering applications.

In this study, the use of AGF resulted in inferior rates of arthrodesis compared with autogenous bone graft alone. Although it is important to note there are several techniques available to produce AGF and that the concentration of AGF may differ between individuals, based on the authors' findings, they cannot recommend the use of AGF for this indication until further clinical studies, perhaps altering these variables, prove otherwise.

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