Healing pattern classification for thoracolumbar burst fractures after posterior short-segment fixation
- 作者列表："Changxiang Liang","Guihua Liu","Guoyan Liang","Xiaoqing Zheng","Dong Yin","Dan Xiao","Shixing Zeng","Honghua Cai","Yunbing Chang
Abstract Background Thoracolumbar burst fractures can be treated with posterior short-segment fixation. However, no classification can help to estimate whether the healed vertebral body will have sufficient stability after implant removal. We aimed to develop a Healing Pattern Classification (HPC) to evaluate the stability of the healed vertebra based on cavity size and location. Methods Fifty-two thoracolumbar burst fracture patients treated with posterior short-segmental fixation without fusion and followed up for an average of 3.2 years were retrospectively studied. The HPC was divided into 4 types: type I - no cavity; type II - a small cavity with or without the violation of one endplate; type III - a large cavity with or without the violation of one endplate; and type IV - a burst cavity with the violation of both endplates or the lateral cortical shell. The intraobserver and interobserver intraclass correlation coefficients (ICCs) of the HPC were assessed. The demographic characteristics and clinical outcomes of the cohort were compared between the stable group (types I and II) and the unstable group (types III and IV). Logistic regression was conducted to evaluate risk factors for unstable healing. Results The intraobserver and interobserver ICCs of the HPC were 0.86 (95% CI = 0.74–0.90) and 0.77 (95% CI = 0.59–0.86), respectively. While the unstable healing group (types III and IV) accounted for 59.6% of the patients, most of these patients were asymptomatic. The preoperative Load Sharing Classification (LSC) comminution score may predict the occurrence of unstable healing (OR = 8.4, 95% CI = 2.4–29.7). Conclusions A reliable classification for assessing the stability of a healed vertebra was developed. With type I and II healing, the vertebra is considered stable, and the implant can be removed. With type III healing, the vertebra may have healing potential, but the implant should not be removed unless type II healing is achieved. With type IV healing, the vertebra is considered extremely unstable, and instrumentation should be maintained. Assessing the LSC comminution score preoperatively may help to predict unstable healing after surgery.
文摘背景胸腰椎爆裂性骨折可采用后路短节段固定治疗。然而，没有分类可以帮助估计愈合后的椎体在取出植入物后是否会有足够的稳定性。我们旨在开发一种愈合模式分类 (HPC)，根据空洞大小和位置评估愈合椎体的稳定性。方法对 52 例胸腰椎爆裂性骨折患者行后路短节段固定不融合治疗，平均随访 3.2 年。将 HPC 分为 4 种类型: I 型-无腔; II 型-有或无违反一个终板的小腔; 类型 III-大腔，有或没有违反一个终板;和 IV 型-一个破裂腔，违反两个终板或外侧皮质外壳。评估 HPC 的观察者内和观察者间组内相关系数 (ICCs)。比较稳定组 (ⅰ 型和 ⅱ 型) 和不稳定组 (ⅲ 型和 ⅳ 型) 队列的人口学特征和临床结局。进行 Logistic 回归评估不稳定愈合的危险因素。结果 HPC 的观察者内和观察者间 ICCs 分别为 0.86 (95% ci = 0.74-0.90) 和 0.77 (95% ci = 0.59-0.86)。而不稳定愈合组 (ⅲ 型和 ⅳ 型) 占 59.6%，这些患者大多无症状。术前负荷分担分级 (LSC) 粉碎评分可预测不稳定愈合的发生 (or = 8.4，95% ci = 2.4-29.7)。结论建立了一种可靠的评估愈合椎体稳定性的分类方法。随着 I 型和 II 型愈合，椎骨被认为是稳定的，植入物可以被移除。随着 III 型愈合，椎骨可能具有愈合潜力，但除非实现 II 型愈合，否则不应移除植入物。IV 型愈合时，椎骨被认为极不稳定，应保持器械。术前评估 LSC 粉碎评分可能有助于预测术后愈合不稳定。
METHODS::A major challenge in translating findings from genome-wide association studies (GWAS) to biological mechanisms is pinpointing functional variants because only a very small percentage of variants associated with a given trait actually impact the trait. We used an extensive epigenetics, transcriptomics, and genetics analysis of the TBX15/WARS2 neighbourhood to prioritize this region's best-candidate causal variants for the genetic risk of osteoporosis (estimated bone density, eBMD) and obesity (waist-hip ratio or waist circumference adjusted for body mass index). TBX15 encodes a transcription factor that is important in bone development and adipose biology. Manual curation of 692 GWAS-derived variants gave eight strong candidates for causal SNPs that modulate TBX15 transcription in subcutaneous adipose tissue (SAT) or osteoblasts, which highly and specifically express this gene. None of these SNPs were prioritized by Bayesian fine-mapping. The eight regulatory causal SNPs were in enhancer or promoter chromatin seen preferentially in SAT or osteoblasts at TBX15 intron-1 or upstream. They overlap strongly predicted, allele-specific transcription factor binding sites. Our analysis suggests that these SNPs act independently of two missense SNPs in TBX15. Remarkably, five of the regulatory SNPs were associated with eBMD and obesity and had the same trait-increasing allele for both. We found that WARS2 obesity-related SNPs can be ascribed to high linkage disequilibrium with TBX15 intron-1 SNPs. Our findings from GWAS index, proxy, and imputed SNPs suggest that a few SNPs, including three in a 0.7-kb cluster, act as causal regulatory variants to fine-tune TBX15 expression and, thereby, affect both obesity and osteoporosis risk.
METHODS:PURPOSE:Systemic mastocytosis (SM) is characterized by the expansion of clonal mast cells that infiltrate various organ systems. The extent of organ infiltration and subsequent organ damage distinguishes between indolent SM (ISM) defined by a nearly normal life expectancy and advanced SM (AdvSM) defined by poor prognosis. In ISM, measurement of the bone mineral density (BMD) frequently reveals osteoporosis. In contrast, the clinical implication of an increased BMD and osteosclerosis remains unclear. METHODS:BMD was evaluated in 61 patients with mastocytosis (ISM, n = 29, 48%; AdvSM, n = 32, 52%). We correlated the prevalence of osteoporosis, increased BMD and osteosclerosis with clinical parameters, disease variant and prognosis. RESULTS:Osteoporosis was detected in 11/29 (38%) patients with ISM but only in 2/32 (6%) patients with AdvSM (p = 0.004). An increased BMD was detected in 1/29 (3%) patients with ISM and 24/32 (75%) patients with AdvSM (p < 0.001) while osteosclerosis was only detected in AdvSM patients (16/32, 50%). AdvSM patients with increased BMD had higher levels of bone marrow mast cell infiltration, higher serum tryptase and alkaline phosphatase levels compared to ISM as well as higher number of high-molecular risk mutations (p < 0.05). In addition, we found that the prognosis of AdvSM patients with increased BMD is inferior compared to those without increased BMD (median overall survival 3.6 years versus not reached, p = 0.031). CONCLUSIONS:Osteoporosis is a common feature in ISM but not in AdvSM. An increased BMD is frequently present in AdvSM but not in ISM and is associated with more advanced disease and inferior outcome.
METHODS::We present salmon calcitonin (SCT) loaded Hydroxyapatite nanoparticles (HAP-NPs) for sublingual osteoporosis therapy. Surface stabilized HAP-NPs were prepared by aqueous precipitation. SCT was loaded by ionic complexation, as confirmed by FTIR. SCT-HAP-NPs exhibited high loading efficiency (~85%), average size (~100nm), and zeta potential (~-25 mv). Stability of SCT was established by circular dichroism spectroscopy and HPLC analysis. Confocal laser scanning microscopy confirmed deep penetration of SCT-HAP-NPs into the mucosa with >4-fold enhancement in permeability relative to SCT solution. Sublingual SCT-HAP-NPs revealed relative bioavailability of ~15% compared to the subcutaneous injection in rabbits (200iu). Significant and comparable improvement in serum biomarkers with increase in bone mass and mechanical strength and decreased bone erosion compared to subcutaneous SCT was confirmed in ovariectomized (OVX) osteoporosis rat model. Such comparable pharmacodynamic effect at the same dose suggested targeted bone delivery and promise of sublingual SCT-HAP-NPs as a non-invasive alternative to the injection.