Prognostic effect of increased postoperative MRI T2WI high signal intensity in degenerative cervical myelopathy

BACKGROUND CONTEXTHigh cord signals (HCS) are common in patients undergoing surgery for degenerative cervical myelopathy (DCM). Few studies have investigated the prognostic effects of postoperative HCS changes.PURPOSETo investigate whether different changes in the postoperative magnetic resonance imaging (MRI) T2-weighted images (T2WIs) signal intensity ratio (SIR) is related to patient outcomes, predictors of unsatisfactory recovery, and the factors associated with changes in postoperative SIR.STUDY DESIGNA retrospective chart review at a single institution.PATIENT SAMPLEThe study population included all consecutive patients who showed HCS in preoperative MRI T2WIs and underwent double-door laminoplasty for DCM from December 2017 to December 2020.OUTCOME MEASURESPatient self-reported measures included the Japanese Orthopedic Association (JOA) score, 36-Item Short Form Survey (SF-36) physical component score, and SF-36 mental component score. Imaging measures included SIR, length of HCS, and canal narrowing ratio (CNR).METHODSWe reviewed patient records and analyzed the statistical associations of MRI T2WI measures with the JOA score, SF-36 physical, and mental component scores.RESULTSFifty-three patients were categorized into three groups based on the postoperative HCS changes, identified from MRI T2WI before and after surgery: reduced (Group A, N=26); unchanged (Group B, N=12); and increased (Group C, N=15). The neurological recovery rates 12 months after surgery were 67.72%±17.45% in Group A, 51.53%±16.00% in Group B, and 13.35%±21.35% in Group C (p<.001). Significant differences across the three groups were found in symptom duration, postoperative SIR and length of HCS, pre- and postoperative CNR, recovery rate, JOA, SF-36 scores, with patients in Group C having the worst outcomes. Longer DCM symptom duration, greater preoperative CNR, and increased postoperative HCS were prognostic factors for a recovery rate<50%. Preoperative CNR, with an optimal threshold of 57.303%, was an independent risk factor for increased postoperative HCS.CONCLUSIONSLess than one-third of DCM patients with preoperative HCS exhibited an increase in HCS after double-door laminoplasty and reported worse outcomes at the 12-month follow-up when compared to patients with decreased or unchanged postoperative HCS.     

Does the asymmetry and extension function of the preoperative cervical paraspinal extensor predict postoperative cervical sagittal deformity in patients who undergo modified laminoplasty?

BACKGROUND CONTEXTA previous study found that the cross-sectional area (CSA) of the preoperative cervical paraspinal extensors (CPEs) was associated with loss of cervical lordosis after laminoplasty, while a recent study found that CPE asymmetry was associated with symptoms of degenerative cervical myelopathy. Whether preoperative CPE asymmetry can predict cervical sagittal deformity (CSD) after laminoplasty is unknown.PURPOSETo assess whether asymmetry, degree of degeneration, and extension function of the CPE can be used as predictors of postoperative CSD in patients who undergo laminoplasty.STUDY DESIGNA retrospective study.PATIENT SAMPLEFrom January 2017 to December 2019, 55 patients with multilevel cord compression and myelopathic symptoms were enrolled.OUTCOME MEASURESThe visual analog scale (VAS), neck disability index (NDI), and modified Japanese Orthopedic Association (mJOA) were used to assess cervical spinal function and quality of life.METHODSFrom January 2017 to December 2019, 55 patients undergoing modified laminoplasty were included. The following parameters were measured preoperatively and 24 months postoperatively on X-ray: (1) C0–C2 Cobb angle; (2) C2–C7 Cobb angle (CL); (3) T1 slope (T1S); (5) C2–C7 sagittal vertical axis (SVA); (6) T1S minus CL; (7) Preoperative extension function: Extension CL minus Neutral CL (EF). Preoperative global alignment parameters: (8) spino cranial angle, (9) C7-S1 sagittal vertical axis (C7 SVA), (10) pelvic incidence, (11) lumbar lordosis, (12) thoracic kyphosis. (13) Preoperative CPE parameters: Summation of bilateral total cross-sectional area (STCSA), summation of bilateral total cross-sectional area ratio (STCSAR), total cross-sectional area asymmetry, summation of bilateral functional cross-sectional area of muscle (SFCSA), summation of bilateral functional cross-sectional area of muscle ratio (FCSAR), and functional cross-sectional area of muscle asymmetry (FCSAA). The VAS, mJOA, and NDI were used to evaluate cervical spine function and quality of life. Patients were divided into the CSD group and the non-deformed group (N-CSD) group postoperatively, and the parameters between the two groups were compared. The Pearson correlation coefficient was used to evaluate the relationship between the parameters, and multiple regression analysis and ROC curve analysis were used to determine the predictors and key values.RESULTSCompared with functional scores, mJOA in the CSD group was significantly lower than that in the N-CSD group, while NDI and VAS were significantly higher. Postoperative CL was significantly correlated with EF, SFCSA/STCSA (C3–C6), SFCSAR (C4 and C6), STCSAR (C6), and FSCAA (C6). T1S minus CL was significantly correlated with EF, SFCSA/STCSA (C3–4 and C6), SFCSAR (C4 and C6), STCSAR (C6) and FSCAA (C6). C2–7 SVA was significantly correlated with EF, SFCSAR (C4 and C6), STCSAR (C6), and FSCAA (C6). Multiple regression analysis showed that FCSAA (C6), SFCSAR (C6), SFCSAR (C4), and EF were significant predictors of postoperative CSD. ROC curve analysis showed that the optimal cutoff points were 18.405, 2.95, 4.47, and 11.96.CONCLUSIONSThe present study found that preoperative extension dysfunction of CPEs, asymmetry at the C6 level cervical extensors, and cervical extensor CSAs without fatty infiltration at the C4 and C6 levels were associated with cervical sagittal imbalance after modified laminoplasty. These factors can be considered when future spine surgeons formulate surgical plans.     

Craniocervical instability in patients with Ehlers-Danlos syndrome: controversies in diagnosis and management

Ehlers-Danlos syndrome (EDS) is a rare hereditary condition that can result in ligamentous laxity and hypermobility of the cervical spine. A subset of patients can develop clinical instability of the craniocervical junction associated with pain and neurological dysfunction, potentially warranting treatment with occipitocervical fixation (OCF). Surgical decision-making in patients with EDS can be complicated by difficulty distinguishing from hypermobility inherent in the disease and true pathological instability necessitating intervention. Here we comprehensively review the available medical literature to critically appraise the evidence behind various proposed definitions of instability in the EDS population, and summarize the available outcomes data after OCF. Several radiographic parameters have been used, including the clivo-axial angle, basion-axial interval, and pB-C2 measurement. Despite increasing recognition of EDS by spine surgeons, there remains a paucity of data supporting proposed radiographic parameters for spinal instability among EDS patients. Furthermore, there is a lack of high-quality evidence concerning the efficacy of surgical treatments for chronic debilitating pain prevalent in this population. More standardized clinical measures and rigorous study methodologies are needed to elucidate the role of surgical intervention in this complex patient population.     

Surgical management of spinal liposarcoma: a case series of 7 patients and literature review

European Spine Journal - Liposarcoma, one of the most common soft tissue sarcomas originates from primitive mesenchymal cells. But spinal involvement of either primary or metastatic liposarcoma is...     

Intravenous delivery of microRNA-133b along with Argonaute-2 enhances spinal cord recovery following cervical contusion in mice

Background contextAcute spinal cord injury (SCI) is a devastating condition for which spine decompression and stabilization of injury remains the only therapy available in the clinical setup. However, fibrous scar formation during the healing process significantly impairs full recovery. MicroRNAs (miRs) are small noncoding RNAs that regulate gene expression by binding to target mRNA(s) and initiating translational repression or mRNA degradation. It has been reported that microRNA-133b (miR133b) is highly expressed in regenerating neurons following a SCI in zebrafish, and lentiviral delivery of miR133b at the time of SCI in mice resulted in improved functional recovery.PurposeThe aim of this study was to investigate whether intravenous delivery of miR133b enhances spinal cord recovery when administered 24 hours following a cervical contusion injury in mice.Study designThis is an experimental animal study of acute SCI, investigating the effect of miR133b on spinal cord recovery by targeting scar lesion formation. The approach involved setting an acute SCI in mice, which was followed 24 hours later by intravenous co-delivery of miR133b and Argonaute 2 (Ago2), a protein involved in miRNA stabilization. Readouts of the impact of this intervention included analysis of RNA and protein expression at the lesion site, in particular with regard to markers of scar tissue formation, and determination of motor function recovery by the grip strength meter task.MethodsC57BL6 female mice between 6 and 8 weeks of age were tested. The injury model employed was a unilateral moderate contusion at the cervical fifth level. Twenty-four hours following the injury, the authors co-delivered miR133b, or scrambled miRNA as negative control, along with Ago2 for 3 consecutive days, one dose per day via tail-vein injection. They first investigated the level of miR133b in the spinal cord and in spinal cord lesion after a single dose of injection. Next, they determined the efficacy of miR133b and/or Ago2 delivery in regulating gene and protein expression at the lesion site. Finally, they established the role of miR133b and/or Ago2 in enhancing forelimb gripping recovery as assessed by the grip strength meter task for 8 weeks post-SCI.ResultsIntravenous delivery of miR133b and/or Ago2 targeted the microenvironment at the lesion site and prevented the increased expression of certain extracellular matrix proteins (ECM), in particular collagen type 1 alpha 1 and tenascin N, which are known to have a key role in scar formation. It also reduced microglia and/or macrophage recruitment to the lesion site. Functional recovery in mice treated with miR133b and/or Ago2 started around 2 weeks postinjury and continued to improve over time, whereas mice in the control group displayed significantly poorer recovery.ConclusionsOur data indicate therapeutic activity of intravenous miR133b and/or Ago2 treatment, possibly via decreasing ECM protein expression and macrophage recruitment at the lesion site, thereby minimizing detrimental fibrous scar formation.Clinical significanceThere is an urgent medical need for better treatments of SCIs. Based on our findings in a preclinical model, the miR133b and/or Ago2 system specifically targets fibrous scar formation, a barrier in neuronal regrowth, by remodeling ECM molecules at the injury site. Prevention of scar formation is critical to improved outcomes of treatment. Of note, delivery of miR133b and/or Ago2 was initiated 24 hours after traumatic impact, thus indicating a fairly long window of opportunity providing more time and flexibility for therapeutic intervention. Intravenous miR133b may become a beneficial therapeutic strategy to treat patients with acute SCI.     

Outcomes of single-level cervical disc arthroplasty versus anterior cervical discectomy and fusion

Several studies have established the short-term safety and efficacy of cervical disc arthroplasty (CDA) as compared to anterior cervical discectomy and fusion (ACDF). However, few single-center comparative trials have been performed, and current studies do not contain large numbers of patients. We retrospectively reviewed all patients from a single military tertiary medical center between August 2008 to August 2012 who underwent single-level CDA or single-level ACDF and compared their clinical outcomes and complications. A total of 259 consecutive patients were included in the study, 171 patients in the CDA group with an average follow-up of 9.8 (±9.9) months and 88 patients in the ACDF group with an average follow-up of 11.8 (±9.6) months. Relief of pre-operative symptoms was 90.1% in the CDA group and 86.4% in the ACDF group with rates of return to full pre-operative activity of 93.0% and 88.6%, respectively. Patients who underwent CDA had a higher rate of persistent posterior neck pain (15.8% versus 12.5%), and patients who underwent ACDF were at risk for symptomatic pseudarthrosis at a rate of 3.4%. Reoperation rates were higher in the ACDF group (5.7% versus 3.5%). To our knowledge, this review is the largest, non-funded, comparison study between single-level CDA and single-level ACDF. This study demonstrates that CDA is a safe and reliable alternative to ACDF in the treatment of cervical radiculopathy and myelopathy resulting from spondylosis and acute disc herniation.     

Prognostic Factors of Patients with Spinal Chondrosarcoma: A Retrospective Analysis of 98 Consecutive Patients in a Single Center

Purpose

Chondrosarcoma (CHS) in the spine is relatively rare and minimal information has been published in the literature regarding this subject. The objective of our study was to discuss the factors that may affect outcomes of patients with spinal CHS.

Methods

Univariate and multivariate analyses were performed to identify prognostic factors for recurrence, distant metastasis, and survival of spinal CHS. T test, χ ² test and rank sum test were used to analyze a single factor for recurrence and metastasis, while survival rate was estimated using the Kaplan–Meier method. Factors with p values of ≤0.1 were subjected to multivariate analyses by binary logistic regression analyses or Cox regression analyses. p Values of ≤0.05 were considered statistically significant.

Results

A total of 98 patients with spinal CHS were included in the study. The mean follow-up period was 49.7 months (range 6–178). Recurrence was detected in 42 patients after initial surgery in our center, while distant metastasis and death occurred in 24 and 32 cases, respectively. The statistical analyses suggested that pathology grade III was closely related with distant metastasis which was an independent prognostic factor for overall survival. Total en bloc spondylectomy could significantly decrease the risk of recurrence, distant metastasis, and death of patients with spinal CHS.

Conclusions

Total en bloc spondylectomy could significantly decrease the risk of recurrence and distant metastasis, and meanwhile improve overall survival of spinal CHS. Distant metastasis which was closely associated with pathology grade III was an adverse prognostic factor for overall survival of spinal CHS.     

Individualized endovascular treatment of high-grade traumatic vertebral artery injury

Background

Traumatic vertebral artery injury (TVAI) is associated with craniocervical trauma that can lead to potentially fatal posterior circulation stroke. It presents a clinical challenge since it is hard to detect and there are no widely accepted guidelines on diagnosis and management. High-grade TVAI is more difficult to treat and no consensus has been reached yet.

Methods

We performed a single-center, long-term, therapeutic study involving 272 patients with craniocervical injury, eleven of which were diagnosed with high-grade TVAI. Individualized endovascular treatments were performed on these patients based upon the hemodynamic and morphological characteristics of the injured vertebral artery. Postoperative angiography was conducted at 2 weeks, 3 months and 6 months, and then annually after intervention.

Results

Ten vertebral pseudoaneurysms and one arteriovenous fistula (AVF) were confirmed by postoperative angiography. All the participants’ neurological deficit symptoms disappeared or were significantly alleviated gradually, and no new symptoms were found after endovascular treatment. Follow-up angiography of the patients with pseudoaneurysms showed a normally shaped vertebral artery with no stenosis or aneurysms; the angiographic result of the patient with the AVF presented successful embolization in the proximal vertebral artery fistula with no progression or new stenosis. Their modified Rankin Scale (mRS) scores were also satisfactory.

Conclusions

Application of individualized endovascular therapy in high-grade TVAI is safe, technically feasible and clinically effective, but there is no comparison between endovascular management and other management approaches because randomized trials cannot be carried out currently.     

人黄韧带细胞骨化发生过程中的自噬

文题释义： 黄韧带骨化症：是由于脊柱黄韧带发生骨向分化而形成的一种韧带骨化疾病,常导致椎管狭窄,造成脊髓受压,并产生不可逆损害,出现肢体感觉障碍,严重的将导致瘫痪。目前对黄韧带骨化病因学研究取得了一定的进展,但其具体的发病机制仍未完全明确。 自噬：因外界或自身环境的改变,细胞器和胞内蛋白通过溶酶体进行分解消化并重新利用,从而达到适应外界环境、维持细胞内环境稳定的过程,是真核细胞特有一种表现形式。 MAPK信号通路：是生物体内重要的信号转导系统之一,它可以被物理应激、炎性细胞因子、生长因子以及细胞复合物等一系列细胞外信号或刺激激活,从而参与介导细胞生长、发育、分裂以及分化等多种生理及病理过程。在哺乳动物细胞中MAPK信号通路的主要信号分子包括ERK1/2、JNK以及P38等。 背景：黄韧带骨化发生的病理机制尚不清楚,临床上无有效的药物或非手术治疗的方法。目前研究发现,骨桥蛋白与自噬在成骨过程中均发挥重要作用,二者在黄韧带骨化中的作用尚不清楚。 目的：通过对骨桥蛋白和自噬在黄韧带骨化发生机制的研究,尝试找出药物治疗的潜在作用靶点。 方法：①黄韧带骨化病、胸椎骨折或单纯腰椎间盘突出症患者行后路全椎板切除减压获取黄韧带,将标本分为骨化组和非骨化组,每组各取8例标本,通过免疫组化染色观察骨桥蛋白、骨钙素及自噬指标Beclin-1、LC3、P62的表达;②通过组织块贴壁法进行黄韧带细胞的分离培养,并用不同质量浓度的骨桥蛋白干预不同时间来构建体外黄韧带细胞骨化模型;③非骨化组黄韧带细胞用不同浓度的自噬抑制剂3-甲基腺嘌呤干预后,再用100 μg/L骨桥蛋白诱导,应用Western blot检测骨化指标碱性磷酸酶、骨钙素的表达变化;④用100 μg/L骨桥蛋白干预非骨化黄韧带细胞,并在0,15,30,60,120 min终止骨化诱导过程,应用Western blot检测MAPK信号通路中重要分子ERK1/2、JNK、P38的磷酸化情况;⑤非骨化组黄韧带细胞用ERK1/2特异的磷酸化阻滞剂U0126阻断ERK1/2通路磷酸化后,再用100 μg/L骨桥蛋白诱导,应用Western blot检测碱性磷酸酶以及骨钙素的表达变化。 结果与结论：①骨化黄韧带和非骨化黄韧带组织骨钙素、骨桥蛋白的免疫组化均呈阳性表达;骨化黄韧带组织中Beclin-1呈阳性表达,而LC3及P62未见明显阳性结果;非黄韧带骨化组织中Beclin-1、LC3、P62均呈阳性表达;②与非骨化组比较,骨化组黄韧带细胞中碱性磷酸酶和骨钙素的表达增加;骨桥蛋白可诱导黄韧带骨化,骨桥蛋白的作用具有浓度相关性和时间相关性;③自噬强弱与骨化程度呈负相关,即自噬越明显,骨化作用越弱;④骨桥蛋白能使MAPK信号通路磷酸化,并具有一定的时间相关性;抑制MAPK磷酸化过程后,骨桥蛋白仍然能够诱导黄韧带细胞的骨化;⑤结果表明,黄韧带骨化发生过程中,信号通路上ERK1/2、骨桥蛋白、骨钙素、碱性磷酸酶分子的上下游关系为：ERK1/2→骨桥蛋白→骨钙素/碱性磷酸酶。 ORCID: 0000-0003-0008-9802(许国峰) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程