An unusual presentation of congenital infantile myofibromatosis arising from the interspinous ligament

The authors describe an extremely rare presentation of congenital infantile myofibromatosis. A full-term newborn boy presented with a thumb-sized subcutaneous mass on the mid-spinal line between the 2nd and 3rd lumbar spinous processes. A solid tumor arising from the interspinous ligament was resected. Microscopic and immunohistochemical studies revealed myofibromatosis. Accepted: 12 November 1997     

介绍一种新型脊柱动态内固定系统

传统腰椎融合固定术后存在许多不可避免的缺陷,可造成邻近节段的退行性变或加剧已存在的脊柱退行性变。而动态内固定系统的植入在不牺牲脊柱即刻稳定性的前提下将其动态固定,术后可分散坚固内固定的负荷传导,避免应力遮挡。但目前使用的各种棘突间动态内固定物,尚存在有的未能保留脊柱在各方向上弹性活动等诸多缺陷,均难以保证很低的并发症与很好的远期效果。设计一种新型脊柱动态内固定系统,既能适应脊柱的多向活动,又能设计保留棘上韧带。从设计理念而言,更能满足人体脊柱的正常活动。该棘间多向动态稳定器,可安于棘突根部,实现棘间、棘-板间弹性承载并能多向活动,从而有望克服现有技术的诸多不足并降低其价格,以促进临床的广泛应用。     

前路撑开矫正后凸畸形可能加重后凸的力学原因分析

目的探讨前路撑开方法有时达不到矫形目的的力学原因。方法利用经典牛顿力学的研究方法对撑开过程中脊柱的受力情况进行分析。结果后方韧带所能承受的屈服点应力强度Fo和后凸角度是影响矫形效果的两个最重要因素。结论在前路撑开复位时后凸角较大的情况和小儿的后凸畸形较容易发生畸形矫正失败,操作需要特别注意。我们设想于需要放置撑开器的节段棘突之间先安置一个牢固的连接装置,以增加矫形成功的可能性。     

Self-rated evaluation of outcome of the implantation of interspinous process distraction (X-Stop) for neurogenic claudication

The treatment of lumbar spinal stenosis is either conservative or surgical decompression. Recently, an interspinous decompression device (X-Stop) has been developed as an alternative. Patients treated with an X-Stop between 2003 and 2006 are subject of this study. The SF-36 Health Survey and Zürich Questionnaires are used. The data of pre- and post-operative self-rated questionnaires are collected and analysed by independent investigators. The data were statistically analysed. A good outcome was defined when the mean score at the ZQ for satisfaction was at maximal 2.0, and the mean improvement of the severity score was at least 0.5, and also for vitality score. For relations between outcome and gender, smoking, BMI, orthopaedic co-morbidity, number of implanted X-Stops were sought. The change in SF-36 scales was related to the outcome. Sixty-five patients did undergo implantation of an X-Stop. The mean age was 64.4 ± 10.0 years (range: 37.0–85.0 years). 31.1% Of the patients had a good outcome. A good outcome was not related to smoking, BMI, number of implanted X-Stops. However, a good outcome was related to the absence of orthopaedic co-morbidity or male gender. Patients with a good outcome had significantly a better improvement of the scales of the SF-36 concerning physical pain or impairment. The X-Stop does improve the clinical situation. However, a good outcome is achieved less often than previously reported. Probable explanations are discussed.     

Imaging characteristics of “dynamic” versus “static” spondylolisthesis: analysis using magnetic resonance imaging and flexion/extension films

Background contextTraditionally, the “dynamic” and “static” types of spondylolisthesis have been lumped into a single group in the literature. The goal of this study was to define the radiographic characteristics of “dynamic” and “static” spondylolisthesis with the use of magnetic resonance imaging (MRI) and flexion/extension radiographs.PurposeDescribe the characteristic findings present on MRI and flexion/extension radiographs that are associated with dynamic versus static spondylolisthesis.Study designRetrospective radiographic/imaging study.MethodsFrom 2009 to 2011, patients who underwent elective primary posterior spinal fusion for the diagnosis of spondylolisthesis had their plain films assessed for the degree of spondylolisthesis and were designated “dynamic” or “static,” as defined by historical measures. Axial and sagittal T2 MRIs were evaluated for associated facet fluid (FF), facet cysts, interspinous fluid (ISF), and facet hypertrophy. These finding were then statistically evaluated for associations between dynamic and static spondylolisthesis on flexion/extension radiographs and characteristic MRI findings.ResultsNinety patients were included in the study with 114 levels examined for spondylolisthesis. Patients with greater than 3 mm of instability on flexion/extension films were more likely to have FF (p=.018) and ISF (p<.001). Of the patients who had a greater than 3 mm of instability, 39.5% did not demonstrate spondylolisthesis on the sagittal MRI reconstruction. If ISF was present on MRI, there was a positive predictive value of 69.0% that there would be greater than 3 mm instability on flexion/extension films. Absence of FF on MRI had a positive predictive value of 75.6% for instability less than 3 mm on flexion/extension films. In the presence of ISF on MRI, the likelihood ratio of finding more than 3 mm of instability on flexion/extension films was 3.68. The presence of FF on MRI had a likelihood ratio of 1.43 for instability. A total of 36.8% of all spondylolisthesis reduced when supine on MRI.ConclusionsThe presence of FF and/or ISF is associated with instability greater than 3 mm in flexion/extension radiographs.     

Scoliosis and interspinous decompression with the X-STOP: prospective minimum 1-year outcomes in lumbar spinal stenosis

Background context

The X-STOP interspinous decompression device, as a treatment for neurogenic intermittent claudication (NIC) because of lumbar spinal stenosis (LSS), has been shown to be superior to nonoperative control treatment. Current Food and Drug Administration labeling limits X-STOP use to NIC patients with a maximum of 25° concomitant lumbar scoliosis. This value was arrived at arbitrarily by the device developers and is untested.

Purpose

To determine X-STOP utility for NIC in patients with concomitant lumbar scoliosis.

Study design

A prospective, single institution, clinical outcome study comparing patients with scoliosis with patients without scoliosis who underwent X-STOP interspinous decompression for NIC because of LSS.

Patient sample

A cohort of 179 consecutive patients, 63 with scoliosis (Cobb angle 11° or more) and 116 without scoliosis, with symptoms attributable to NIC treated between January 2006 and May 2007, were included in the study.

Outcome measures

All patients completed self-reported preoperative and minimum 1-year postoperative outcome forms. Functional measures included Oswestry Disability Index (ODI), visual analog scale (VAS) pain score, and maximum walking and standing times in minutes. Three questions measured patient satisfaction: How satisfied were you with the procedure (very satisfied, somewhat satisfied, somewhat dissatisfied, or very dissatisfied); Would you have the procedure again? (yes or no); Would you recommend the procedure to a friend? (yes or no).

Methods

Before analysis, the 179 consecutive X-STOP patients were divided into three groups: Group 1 (controls without scoliosis, n=116); Group 2 (low scoliosis: 11–25°, n=41), and Group 3 (high scoliosis: 26° or more, n=22). The three groups were not statistically different for any preoperative functional scores. Groups were analyzed for pre- to postoperative functional change and level of satisfaction. Segmental scoliosis at the treated level was also analyzed.

Results

Fifty-six percent of Group 1 and Group 2 patients, but only 18% of Group 3 patients, achieved the success criterion of an ODI improvement of 15 or more points (Group 3 the outlier, p=.004). The satisfaction rate was Group 1, 76%; Group 2, 78%; Group 3, 59% (Group 3 the outlier, p=.0001). On average, all three groups improved for each outcome: Group 1 (ODI 17.3, VAS 2.0, standing time 39 minutes, and walking time 43 minutes), Group 2 (ODI 20.0, VAS 1.9, standing time 65 minutes, and walking time 64 minutes), Group 3 (ODI 7.2, VAS 0.9, standing time 18 minutes, and walking time 16 minutes). There was no statistical relationship between any outcome and segmental scoliosis.

Conclusions

The outcome success rate for the X-STOP procedure to treat NIC is lower in patients with overall lumbar scoliosis more than 25° but is unaltered by segmental scoliosis at the affected level. Although patients and surgeons must be aware that the presence of more than 25° of scoliosis portends less favorable results with X-STOP implantation for NIC because of LSS, success in these patients is not precluded, and selection of treatment must be put into the context of individual patient risk and other treatment options.     

腰椎棘突间稳定器(Wallis)早期疗效分析

目的评价棘突间动力稳定器(Wallis)治疗腰椎退行性疾病的即时(出院前)和短期效果,探讨其适应证选择和手术技巧。方法2008年7月～2009年7月,36例腰椎退行性疾病患者共植入Wallis38套(L2/31套,L3/44套,L4/533套)。其中腰椎间盘脱出症(中央型)8例,腰椎盘脱出伴突出2例,腰椎间盘突出症伴黄韧带增厚10例,腰椎间盘突出症伴侧隐窝狭窄8例,单节退变性椎管狭窄症4例,Topping off4例。采用北美脊柱学会(North American Spine Society,NASS)问卷评价出院前患者及随访患者对手术的满意度,同时测量手术前后椎间盘终板间高度。结果手术时间30～90min,平均60min;术中出血量10～100ml,平均50ml。出院前NASS问卷显示,32例患者(88.9%)认为腰部坚实有力,术前酸乏症状消失或明显减轻。术前终板间高度降低的37个椎间盘中有31个(84%)获得1～3mm的改善。36例患者均获随访,随访时间1～12个月,平均7个月。随访期间NASS问卷总满意度为92.5%,未出现Wallis引起的并发症。结论Wallis的即时和近期疗效满意,是治疗腰椎退变性疾病的有效方法。     

Structural Fire Performance of Concrete-Filled Built-Up Cold-Formed Steel Columns

Concrete-filled composite columns are widely used in the construction industry, exploiting the benefits of combining steel and concrete, providing, for instance, high load-bearing capacities and enhanced fire resistance. These solutions are extensively used in high-rise buildings and/or when high fire resistance performance requirements are imposed. In this exploratory research, a new type of concrete-filled composite column is investigated using fire resistance tests. Promoting the use of cold-formed steel products and developing innovative solutions for low-rise buildings with lower passive fire protection requirements led to the solutions presented in this research. Hence, a set of fire-resistance tests were undertaken on concrete-filled closed built-up cold-formed steel columns, where single cold-formed steel shapes are combined and fastened to create a box-shaped cross-section. The experimental results were then compared with the corresponding bare steel solutions to assess, in detail, the observed enhancements. Additionally, the effect of restraint on thermal elongation was assessed.