The spine journal : official journal of the North American Spine Society
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Comparative Study
Comparison of the biomechanical effect of pedicle-based dynamic stabilization: a study using finite element analysis.
Recently, nonfusion pedicle-based dynamic stabilization systems (PBDSs) have been developed and used in the management of degenerative lumbar spinal diseases. Still effects on spinal kinematics and clinical effects are controversial. Little biomechanical information exists for providing biomechanical characteristics of pedicle-based dynamic stabilization according to the PBDS design before clinical implementation. ⋯ Implanted segments with PBDSs have limited ROM when compared with the intact spine. Center of rotation and stress distribution differed according to the design and materials used. These biomechanical effects produced a nonphysiological stress on the functional spinal unit when they were implanted. The biomechanical effects of current PBDSs should be carefully considered before clinical implementation.
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Besides their clinical impact, the economic impact of health care-related adverse events (AEs) is significant. Although a number of studies have attempted to estimate the economic impact of AEs, few have directly linked costs to clinician-reported event severity. ⋯ In this surgical spine cohort, AEs accounted for 16% of the total cost of in-hospital care. Higher severity AEs were progressively more costly on a per-case basis; however, the more frequent lower severity events (ie, Grade I and II) also had a substantial aggregate cost (43%). These results suggest that a strong business case exists for patient safety strategies focused not only on severe AEs but also on the reduction of lower severity events that may be more amenable to prevention efforts.
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The rates of pseudoarthrosis after a single-level spinal fusion have been reported up to 35%, and the agents that increase the rate of fusion have an important role in decreasing pseudoarthrosis after spinal fusion. Previous studies have analyzed the effects of local insulin application to an autograft in a rat segmental defect model. Defects treated with a time-released insulin implant had significantly more new bone formation and greater quality of bone compared with controls based on histology and histomorphometry. A time-released insulin implant may have similar effects when applied in a lumbar spinal fusion model. ⋯ This study demonstrates the potential role of a time-released insulin implant as a bone graft enhancer using a rat posterolateral intertransverse lumbar fusion model. The insulin-treatment group had significantly higher fusion rates based on the radiographs and manual palpation and had significantly higher levels of IGF-I and significantly more bone volume on micro-CT.