Limited Intervention in Adult Scoliosis-A Systematic Review.

BACKGROUND/OBJECTIVES: Adult scoliosis is traditionally treated with long-segment fusion, which provides strong radiographic correction and significant improvements in health-related quality of life but comes at a high morbidity cost. This systematic review seeks to examine the literature behind limited interventions in adult scoliosis patients and examine the best approaches to treatment. METHODS: This is a MEDLINE- and PubMed-based literature search that ultimately included 49 articles with a total of 21,836 subjects. RESULTS: Our search found that long-segment interventions had strong radiographic corrections but also resulted in high perioperative morbidity. Limited interventions were best suited to patients with compensated deformity, with decompression best for neurologic symptoms and fusion needed to treat neurological symptoms secondary to up-down stenosis and to provide stability across unstable segments. Decompression can consist of discectomy, laminotomy, and/or foraminotomy, all of which are shown to provide symptomatic relief of neurologic pain. Short-segment fusion has been shown to provide improvements in patient outcomes, albeit with higher rates of adjacent segment disease and concerns for correctional loss. Interbody devices can provide decompression without posterior element manipulation. Future directions include short-segment fusion in uncompensated deformity and dynamic stabilization constructs. CONCLUSIONS: Limited interventions can provide symptomatic relief to adult spine deformity patients, with indications mostly in patients with balanced deformities and neurological pain.

Ligament Augmentation With Mersilene Tape Reduces the Rates of Proximal Junctional Kyphosis and Failure in Adult Spinal Deformity.

OBJECTIVE: To investigate prevention of proximal junctional kyphosis (PJK) and failure (PJF) following adult spinal deformity (ASD) surgery utilizing a novel technique of posterior ligament augmentation with polyester fiber tether. METHODS: This study evaluated ASD adult patients who underwent posterior decompression and instrumented fusion from the thoracolumbar junction (T9-L1) to the pelvis from 2011-2017. Basic demographic data were obtained. Radiographic outcomes included proximal junctional angle (PJA), sagittal vertical axis, PJK, and PJF. The study population was divided into patients who had ASD surgery with and without ligamentous augmentation. RESULTS: A total of 43 subjects were evaluated, including 20 without and 23 with ligamentous augmentation. PJA increased over time for both groups. PJA was smaller for the augmented group, and rate of increase in PJA was slower in the augmented group (p < 0.0001). The rate of PJK was significantly higher in the nonaugmented group (p = 0.01). PJF was significantly less common in the augmented group (p = 0.003). Time to revision surgery was lower in the nonaugmented group (p = 0.003). CONCLUSION: Our novel ligament augmentation technique utilizing polyethylene tape is an effective technique to slow progression of the PJA and lower the risk for proximal junctional disease in ASD surgery.

Hydrodynamic modulation of embryonic stem cell differentiation by rotary orbital suspension culture.

Embryonic stem cells (ESCs) can differentiate into all somatic cell types, but the development of effective strategies to direct ESC fate is dependent upon defining environmental parameters capable of influencing cell phenotype. ESCs are commonly differentiated via cell aggregates referred to as embryoid bodies (EBs), but current culture methods, such as hanging drop and static suspension, yield relatively few or heterogeneous populations of EBs. Alternatively, rotary orbital suspension culture enhances EB formation efficiency, cell yield, and homogeneity without adversely affecting differentiation. Thus, the objective of this study was to systematically examine the effects of hydrodynamic conditions created by rotary orbital shaking on EB formation, structure, and differentiation. Mouse ESCs introduced to suspension culture at a range of rotary orbital speeds (20-60 rpm) exhibited variable EB formation sizes and yields due to differences in the kinetics of cell aggregation. Computational fluid dynamic analyses indicated that rotary orbital shaking generated relatively uniform and mild shear stresses (< or =2.5 dyn/cm(2)) within the regions EBs occupied in culture dishes, at each of the orbital speeds examined. The hydrodynamic conditions modulated EB structure, indicated by differences in the cellular organization and morphology of the spheroids. Compared to static culture, exposure to hydrodynamic conditions significantly altered the gene expression profile of EBs. Moreover, varying rotary orbital speeds differentially modulated the kinetic profile of gene expression and relative percentages of differentiated cell types. Overall, this study demonstrates that manipulation of hydrodynamic environments modulates ESC differentiation, thus providing a novel, scalable approach to integrate into the development of directed stem cell differentiation strategies.