The spine journal : official journal of the North American Spine Society
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Osteoconductive porous ceramic bone graft materials supplemented with mesenchymal precursor cells (MPC) derived from autologous bone marrow aspirates have been shown to stimulate successful interbody and posterolateral spine fusion in preclinical models. Recent advances in immunomagnetic cell sorting have enabled purification and isolation of pluripotent stem cells from marrow aspirates and have expanded stem cell technology to allogeneic cell sources. Allogeneic MPC technology combined with appropriate synthetic biomaterial carriers could provide both the osteogenic and osteoconductive components needed for successful posterolateral spine fusion without the need for autologous bone harvest or expensive recombinant protein technology. ⋯ Adult allogeneic mesenchymal precursor cells delivered via a hydroxyapatite:tricalcium phosphate carrier were both safe and efficacious in this ovine spine fusion model. Results from this preclinical study support that allogeneic mesenchymal precursor cells produced fusion efficacy similar to that achieved using iliac crest autograft, thereby providing a safe and viable option to achieve successful posterolateral spine fusion.
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Carragee et al. reported an accelerated progression of lumbar intervertebral disc (IVD) degeneration after discography in a human trial. Local anesthetics and contrast agents have exhibited toxicity to cardiac, renal, and neuronal cells. We hypothesize that local anesthetics or contrast agents commonly injected into the disc space during discography may result in cytotoxicity in vitro. In this study, we compared the cytotoxicity of these agents, alone or in combination, using nucleus pulposus (NP) and annulus fibrosus (AF) cells in a three-dimensional (3D) culture system. ⋯ Cell death was observed when AF and NP cells were incubated in a dose- and time-dependent manner with local anesthetics and contrast agents commonly used for discography. Relative toxicity of these compounds was noted in the order of bupivacaine, lidocaine, iopamidol, and iohexol. Future studies of the effects of these agents in organ culture or animal models are indicated to predict what happens in vivo.
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Although the use of mesenchymal stem cells (MSC) with scaffolds for bone repair has been considered an effective method, the interactions between implanted materials and bone tissues have not been fully elucidated. At some specific sites, such as the vertebral body (VB) of the spine, the process of bone repair with implanted biomaterials is rarely reported. Recently, adipose tissue was found to be an alternative source of MSC besides bone marrow. However, the strategy of using adipose-derived stromal (ADS) cells with bioactive scaffold for the repair of spinal bone defects has seldom been studied. ⋯ Adipose-derived stromal cells maintained in culture on a scaffold and treated with osteogenic induction with growth factor ex vivo could be used to enhance bone repair in vivo.
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Comparative Study
Quantitative estimation of the high-intensity zone in the lumbar spine: comparison between the symptomatic and asymptomatic population.
The high-intensity zone (HIZ) on magnetic resonance imaging (MRI) has been studied for more than 20 years, but its diagnostic value in low back pain (LBP) is limited by the high incidence in asymptomatic subjects. Little effort has been made to improve the objective assessment of HIZ. ⋯ A series of quantitative measurements for HIZ was established and demonstrated excellent intra- and interobserver reliability. The signal intensity of HIZ was different in patients with or without LBP, and significant brighter signal was observed in symptomatic subjects.
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Meta Analysis
Effectiveness of local vancomycin powder to decrease surgical site infections: a meta-analysis.
Some surgeons use systemic vancomycin to prevent surgical site infections (SSIs), but patients who do not carry methicillin-resistant Staphylococcus aureus have an increased risk of SSIs when given vancomycin alone for intravenous prophylaxis. Applying vancomycin powder to the wound before closure could increase the local tissue vancomycin level without significant systemic levels. However, the effectiveness of local vancomycin powder application for preventing SSIs has not been established. ⋯ Local administration of vancomycin powder appears to protect against SSIs, deep incisional SSIs, and S. aureus SSIs after spinal operations. Large, high-quality studies should be performed to evaluate this intervention before it is used routinely.