Range of motion of thoracic spine in sagittal plane

Study design

Imaging study of thoracic spine.

Objective

The purpose of this study was to investigate dynamic alignment and range of motion (ROM) at all segmental levels of thoracic spine.

Summary of background data

Thoracic spine is considered to have restricted ROM because of restriction by the rib cage. However, angular movements of thoracic spine can induce thoracic compressive myelopathy in some patients. Although few previous studies have reported segmental ROM with regard to sagittal plane, these were based on cadaver specimens. No study has reported normal functional ROM of thoracic spine.

Methods

Fifty patients with cervical or lumbar spinal disease but neither thoracic spinal disease nor compression fracture were enrolled prospectively in this study (34 males, 16 females; mean age 55.4 ± 14.7 years; range 27–81 years). After preoperative myelography, multidetector-row computed tomography scanning was performed at passive maximum flexion and extension position. Total and segmental thoracic kyphotic angles were measured and ROM calculated.

Results

Total kyphotic angle (T1/L1) was 40.2° ± 11.4° and 8.5° ± 12.8° in flexion and extension, respectively (P < 0.0001). The apex of the kyphotic angle was at T6/7 in flexion. Total ROM (T1/L1) was 31.7° ± 11.3°. Segmental ROM decreased from T1/2 to T4/5 but increased gradually from T4/5 to T12/L1. Maximum ROM was at T12/L1 (4.2° ± 2.1°) and minimum at T4/5 (0.9° ± 3.0°).

Conclusions

Thoracic spine showed ROM in sagittal plane, despite being considered a stable region. These findings offer useful information in the diagnosis and selection of surgical intervention in thoracic spinal disease.     

全膝关节置换术对膝关节重度屈曲畸形的疗效系统评价

目的探讨全膝关节置换术对重度屈曲畸形的临床治疗效果。方法跟踪随访于2010年12月至2013年12月在本组进行TKA手术的38例重度屈曲畸形患者,以主动关节活动度、徒手肌力检查、Muller膝关节稳定性评分和美国特种外科医院评价系统为临床指标,比较手术前及随访终末时的变化来衡量手术的疗效。结果术后主动关节活动度、徒手肌力检测、稳定性指标上明显大于术前,与术前比较差异具有统计学意义（P〈0.05）。38例均得到随访,随访时间4个月~2.5年,平均1年。术前HSS评分-5~34分,平均22.6分;术后61~89分,平均77.4分,差别有统计学意义（P〈0.05）。术后优良率达到63.16%。结论 TKA手术对膝关节重度屈曲畸形获得满意效果,是临床治疗的有效方法。     

A time‐motion study of cardiovascular disease risk factor screening integrated into HIV clinic visits in Swaziland

Introduction

Screening of modifiable cardiovascular disease (CVD) risk factors is recommended but not routinely provided for HIV‐infected patients, especially in low‐resource settings. Potential concerns include limited staff time and low patient acceptability, but little empirical data exists. As part of a pilot study of screening in a large urban HIV clinic in Swaziland, we conducted a time‐motion study to assess the impact of screening on patient flow and HIV service delivery and exit interviews to assess patient acceptability.

Methods

A convenience sample of patients ≥40 years of age attending routine HIV clinic visits was screened for hypertension, diabetes, hyperlipidemia and tobacco smoking. We observed HIV visits with and without screening and measured time spent on HIV and CVD risk factor screening activities. We compared screened and unscreened patients on total visit time and time spent receiving HIV services using Wilcoxon rank‐sum tests. A separate convenience sample of screened patients participated in exit interviews to assess their satisfaction with screening.

Results

We observed 172 patient visits (122 with CVD risk factor screening and 50 without). Screening increased total visit time from a median (range) of 4 minutes (2 to 11) to 15 minutes (9 to 30) (p < 0.01). Time spent on HIV care was not affected: 4 (2 to 10) versus 4 (2 to 11) (p = 0.57). We recruited 126 patients for exit interviews, all of whom indicated that they would recommend screening to others.

Conclusion

Provision of CVD risk factor screening more than tripled the length of routine HIV clinic visits but did not reduce the time spent on HIV services. Programme managers need to take longer visit duration into account in order to effectively integrate CVD risk factor screening and counselling into HIV programmes.

     

Functional Safe Zone Is Superior to the Lewinnek Safe Zone for Total Hip Arthroplasty: Why the Lewinnek Safe Zone Is Not Always Predictive of Stability

Background

The Lewinnek “safe zone” is not always predictive of stability after total hip arthroplasty (THA). Recent studies have focused on functional hip motion as observed on lateral spine-pelvis-hip x-rays. The purpose of this study was to assess the correlation between the Lewinnek safe zone and the functional safe zone based on hip and pelvic motion in the sagittal plane.

Surgical management of left ventricular outflow tract obstruction in a specialized hypertrophic obstructive cardiomyopathy center

ObjectivesThis study evaluates operative approach and contemporary surgical outcomes in the management of left ventricular outflow tract obstruction by a single surgeon at a high-volume, specialized hypertrophic cardiomyopathy center.MethodsThis is a retrospective review of 1559 consecutive operations for left ventricular outflow tract obstruction from 2005 to 2015. Demographic profiles, echocardiogram-derived ventricular morphology and hemodynamics, operative data, and in-hospital outcomes were analyzed.ResultsOf the 1559 operations, 586 were isolated septal myectomies, 522 were myectomies with mitral valve or subvalvular apparatus intervention, 422 were myectomies with another concomitant procedure, and 29 were isolated mitral valve interventions without myectomy. Common mitral valve interventions included anterior leaflet shortening (16%), chordae tendineae resection (9.8%), papillary muscle resection (7.2%), and papillary muscle reorientation (7.5%). Ninety-two patients underwent mitral valve replacement, 42 for left ventricular outflow tract obstruction and 50 for intrinsic mitral valve pathology. Patients undergoing mitral interventions had thinner septums (18 ± 0.4 mm vs 22 ± 0.5 mm, P < .001) and less myocardium removed (6.2 ± 3.5 g vs 8.8 ± 3.8 g, P < .001) than patients without a mitral intervention. Prevalence of in-hospital permanent pacemaker insertion was 4.2% (n = 1334) for complete heart block and 1.1% (n = 464) for isolated septal myectomy with normal preoperative conduction. Overall, there were 2 postoperative ventricular septal defects (0.13%) and none for isolated myectomies. Operative mortality was 0.38%.ConclusionsSeptal myectomy can be performed safely with excellent outcomes when the procedure is performed by a highly experienced surgeon in a high-volume, specialized center. A mitral valve intervention is a useful adjunct in patients with moderate hypertrophy.     

应用体素内不相干运动扩散加权成像评价早期慢性移植肾肾病

目的：探讨应用体素内不相干运动扩散加权成像(intravoxel incoherent motion diffusion weighted imaging,IVIM-DWI)技术无创性评价早期慢性移植肾肾病(chronic allograft nephropathy,CAN)的可行性及临床应用价值。方法：收集符合本研究纳入标准的住院患者23例,其中经病理诊断为早期CAN的患者12例(CAN组),移植肾肾功能长期稳定的志愿者11例(对照组)。采用多b值DWI序列对移植肾进行磁共振扫描,利用IVIM2b_new软件获取移植肾的IVIM-DWI各定量参数伪彩图及测量肾实质的IVIM-DWI各定量参数值,包括真实扩散系数(D)、灌注相关扩散系数(D*)和灌注分数(f)。采用独立样本t检验对CAN组和对照组的IVIM各定量参数值进行比较,对差异具有统计学意义的指标进行ROC分析,并计算曲线下面积。结果：CAN组的定量参数D值低于对照组,差异具有统计学意义(P<0.05),两组间D*及f值的差异无统计学意义(P>0.05)。D值鉴别早期CAN的敏感度和特异度分别为58.3%和90.9%,曲线下面积为0.784。 结论：IVIM-DWI的定量参数D能在一定程度上无创性评价早期CAN。IVIM-DWI技术有望成为一种筛查早期CAN的简单有效的无创手段,以协助早期诊断与动态监测CAN。     

犬急性心肌梗死早期冠状动脉旁路移植术对左室壁运动的影响

目的 探讨犬急性心肌梗死早期冠状动脉旁路移植术对室壁运动的影响及其在唤醒冬眠心肌中的意义.方法 结扎犬冠状动脉前降支制备心肌梗死模型(30只).按手术日期随机分组,分别在心肌梗死后1、2、4、6周行冠状动脉旁路移植术作为实验组,其中第2周4只,其余每组6只;对每个实验组分别设立心肌梗死对照组(不进行冠状动脉旁路移植术),每组2只.实验组在冠状动脉旁路移植术前及冠状动脉旁路移植术8周后开胸利用多巴酚丁胺超声负荷试验结合组织多普勒成像技术标记冬眠心肌,并测定室壁运动记分;对照组在相同时间点同样的方法标记冬眠心肌并测定室壁运动记分.每只犬处死后分别测定心肌梗死面积.结果 每个实验组各存活4只,对照组均存活.1、2周实验组较4、6周实验组及对照组梗死区心肌室壁运动记分的变化明显减小(0.03±0.06,0.05 ±0.09,0.23 ±0.08,0.27±0.06,0.32 ±0.05,P＜0.05),所有实验组较对照组心肌室壁运动记分的变化明显减小(1.195±0.09,1.25±0.18,1.30±0.18,1.36 ±0.11,1.65 ±0.17,P＜0.05),所有实验组较对照组唤醒更多的冬眠心肌(0.27 ±0.12,0.22±0.04,0.31±0.09,0.23±0.03,0.03 ±0.04,P＜0.05).1、2周实验组较4、6周实验组及对照组心肌梗死范围明显减小[(20.75±2.63)％,(21.25±2.5)％,(27.25±1.71)％,(27.75±2.22)％,(26.50±0.71)％,(29.00±1.41)％,(27.00±1.41)％,(28.50±0.71)％,P＜0.05)].结论 犬急性心肌梗死早期冠状动脉旁路移植可以明显改善心肌室壁运动,唤醒更多的冬眠心肌,尤其2周内行冠状动脉旁路移植术可以最大限度地减少梗死心肌对室壁运动的影响,并可以减少心肌梗死范围.     

Compliant positioning of total hip components for optimal range of motion.

Impingement between femoral neck and endoprosthetic cup is one of the causes for dislocation in total hip arthroplasty (THA). Choosing a correct combined orientation of both components, the acetabular cup and femoral stem, in manual or computer-assisted implantation will yield a maximized, stable range of motion (ROM) and will reduce the risk for dislocation. A mathematical model of a THA was developed to determine the optimal combination of cup inclination, cup anteversion, and stem antetorsion for maximizing ROM and minimizing the risk for cup-neck impingement. Single and combined hip joint motions were tested. A radiographic definition was used for component orientation. Additional parameters, such as stem-neck (CCD) angle, head-neck ratio, and the design of the acetabular opening, were also considered. The model showed that a maximized and safe ROM requires compliant, well-defined combinations of cup inclination, cup anteversion, and stem antetorsion depending on the intended ROM. Radiographic cup anteversion and stem antetorsion were linearly correlated. Additional internal rotation reduced flexion, and additional external rotation reduced extension, abduction and adduction. The articulating hemispheric surface of acetabular cups should be oriented between 40 degrees and 45 degrees of radiographic inclination, between 20 degrees and 28 degrees of radiographic cup anteversion, and should be combined with stem antetorsion so that the sum of cup anteversion plus 0.7 times the stem antetorsion equals 37 degrees. Final component orientation must also consider cup containment, implant impingement with bone and soft tissue, and preoperative skeletal contractures or deformities to achieve the optimal compromise for each patient.     

Measurement of vessel wall strain using cine phase contrast MRI

PURPOSE: To determine the feasibility of using magnetic resonance imaging (MRI) to non-invasively measure strain in the aortic wall. MATERIALS AND METHODS: Cine phase contrast MRI was used to measure the velocity of the aortic wall and calculate changes in circumferential strain over the cardiac cycle. A deformable vessel phantom was used for initial testing and in vitro validation. Ultrasonic sonomicrometer crystals were attached to the vessel wall and used as a gold standard. RESULTS: In the in vitro validation, MRI-calculated wall displacements were within 0.02 mm of the sonomicrometer measurements when maximal displacement was 0.28 mm. The measured maximum strain in vitro was 0.02. The in vivo results were on the same order as prior results using ultrasound echo-tracking. CONCLUSION: Results of in vivo studies and measurement of cyclic strain in human thoracic and abdominal aortas demonstrate the feasibility of the technique.