No abstract

Based on a working fluid consisting of a poorly water-soluble drug and a pharmaceutical polymer in an organic solvent, electrospinning has been widely exploited to create a variety of amorphous solid dispersions However, there have been very few reports about how to prepare the working fluid in a reasonable manner. In this study, an investigation was conducted to determine the influences of ultrasonic fluid pretreatment on the quality of resultant ASDs fabricated from the working fluids. SEM results demonstrated that nanofiber-based amorphous solid dispersions from the treated fluids treated amorphous solid dispersions exhibited better quality than the traditional nanofibers from untreated fluids in the following aspects: 1) a straighter linear morphology; 2) a smooth surface; and 3) a more evener diameter distribution. The fabrication mechanism associated with the influences of ultrasonic treatments of working fluids on the resultant nanofibers’ quality is suggested. Although XRD and ATR–FTIR experiments clearly verified that the drug ketoprofen was homogeneously distributed all over the TASDs and the traditional nanofibers in an amorphous state regardless of the ultrasonic treatments, the in vitro dissolution tests clearly demonstrated that the TASDs had a better sustained drug release performance than the traditional nanofibers in terms of the initial release rate and the sustained release time periods.

Background Restoration of sagittal balance is a crucial consideration in posterior lumbar interbody fusion (PLIF) surgery and adverse postoperative outcomes are associated with inadequate restoration of sagittal alignment. However, there remains a shortage of substantial evidence regarding the effect of rod curvature on both sagittal spinopelvic radiographic parameters and clinical outcomes. Method A retrospective case–control study was conducted in this study. Patient demographics (age, gender, height, weight and BMI), surgical characteristics (number of fused levels, surgical time, blood loss and hospital stay) and radiographic parameters (lumbar lordosis [LL], sacral slope [SS], pelvic incidence [PI], pelvic tilt [PT], PI-LL, Cobb angle of fused segments [Cobb], rod curvature [RC], Posterior tangent angle of fused segments [PTA] and RC-PTA) were analyzed. Results Patients in the abnormal group had older mean age and suffered more blood loss than those in the normal group. In addition, RC and RC-PTA were significantly lower in the abnormal group compared to the normal group. Multivariate regression analysis revealed that lower age (OR = 0.94; 95% CI: 0.89–0.99; P = 0.0187), lower PTA (OR = 0.91; 95% CI: 0.85–0.96; P = 0.0015) and higher RC (OR = 1.35; 95% CI: 1.20–1.51; P < 0.0001) were related to higher odds of better surgical outcomes. The receiver operating characteristic curve analysis showed that the ROC curve (AUC) for predicting outcomes of surgery by RC classifier was 0.851 (0.769–0.932). Conclusions In patients who underwent PLIF surgery for lumbar spinal stenosis, those who had a satisfactory postoperative outcome tended to be younger, had lower blood loss, and higher values of RC and RC-PTA compared to those who had poor recovery and required revision surgery. Additionally, RC was found to be a reliable predictor of postoperative outcomes.

Objective Previous studies have neither explored the usage of cross‐links nor investigated the optimal position of the cross‐links in posterior lumbar interbody fusion (PLIF). This study evaluates biomechanical properties of cross‐links in terms of different fixation segments and optimal position in single‐ and multi‐segment posterior lumbar interbody fusion. Methods Two finite element (FE) models of instrumented lumbosacral spine with single‐(L4/5) and multi‐segment (L3‐S1) PLIF surgery were simulated. On the basis of the two models, the benefits of the usage of cross‐links were assessed and compared with the status of no application of cross‐links. Moreover, the effects of position of cross‐links on multi‐segment PLIF surgery were studied in Upper, Middle, and Lower positions. Results No significant difference was found in the range of motion (ROM), intersegmental rotational angle (IRA) of adjacent segments, and intradiscal pressure (IDP) regardless of the usage of cross‐links in the single‐segment PLIF surgery, while the cross‐link increased the maximum von Mises stress in the fixation (MSF) under the axial rotation (53.65 MPa vs 41.42 MPa). In the multi‐segment PLIF surgery, the usage of cross‐links showed anti‐rotational advantages indicated by ROM (Without Cross‐link 2.35o, Upper, 2.24o; Middle, 2.26o; Lower, 2.30o) and IRA (Without Cross‐link 1.19o, Upper, 1.08o; Middle, 1.09o; Lower, 1.13o). The greatest values of MSF were found in without cross‐link case under the flexion, lateral bending, and axial rotation (37.48, 62.61, and 86.73 MPa). The application of cross‐links at the Middle and Lower positions had lower values of MSF (48.79 and 69.62 MPa) under the lateral bending and axial rotation, respectively. Conclusion The application of cross‐links was not beneficial for the single‐segment PLIF, while it was found highly advantageous for the multi‐segment PLIF. Moreover, the usage of cross‐links at the Middle or Lower positions resulted in a better biomechanical stability.