全髋关节置换术(THA)中不同颈干角股骨假体对股骨近端解剖重建的影响

目的研究全髋关节置换术(THA)中不同颈干角股骨假体对股骨近端解剖重建的影响。方法回顾性分析2014年1月—2015年1月大连大学附属中山医院骨科接受全髋关节置换术治疗的80例患者,根据在手术过程中使用不同颈干角股骨假体将患者分为两组,每组40例;其中研究组采用颈干角为135°的股骨柄,对照组采用颈干角为127°的股骨柄。检测并记录两组患者的术后术侧股骨偏心距相对于健侧的变化值(x FO)、该变化值与健侧股骨偏心的比值(sd FO)指标值、股骨头旋转中心高度、全局偏心距以及术前、术后(1、3、6、12个月)双下肢长度差和Harris评分,并对其结果进行比较分析。结果研究组患者的x FO、sd FO指标值分别为(1.8±4.6)、(8.9±12.6),明显低于对照组(5.9±4.8)、(20.4±17.5),差异具有统计学意义(P0.05)。研究组患者的股骨头旋转中心高度以及全局偏心距分别为(4566.5±32.6)和(65.5±11.4)mm,而对照组患者分别为(4579.5±37.6)、(69.4±12.6)mm,两组比较差异无统计学意义(P0.05)。术后1、3、6、12个月,两组患者的双下肢长度差、Harris评分与术前比较均有明显改善,差异具有统计学意义(P0.05),而两组患者的Harris评分差异无统计学意义(P0.05);研究组患者术后未出现任何不适现象,术后6个月,对照组患者出现3例大转子疼痛现象,两组比较差异具有统计学意义(P0.05)。结论 127°和135°的颈干角股骨假体应用在全髋关节置换术(THA)中均可以取得良好的早期功能恢复,135°的颈干角股骨假体可以更好地重建股骨近端解剖。     

髋关节表面置换术假体柄的不同安放角度与其术后骨折风险相关性的有限元分析

目的应用有限元分析方法,分析不同股骨假体柄安放角度对髋关节表面置换术后股骨头颈部拉/压应力分布的影响,预测骨折发生的可能性,为临床髋关节表面置换选取最适股骨假体柄安放角度提供生物力学依据。方法采用16层螺旋CT采集正常成人髋关节数据,建立安放角度为120°、125°、130°、135°、140°、145°的髋关节表面置换术后三维有限元分析模型,对所有模型施加关节及肌肉载荷,观察不同模型间股骨头颈结构中的中性层位置、拉/压应力区范围,并统计超过屈服应力的节点比例。结果髋关节表面置换术后,随股骨假体柄安放角度增加,中性层的位置发生变化,拉应力区范围逐渐减少。当股骨金属假体柄安放角为135°～145°时,这种变化趋势不明显,并且股骨金属假体下松质骨及股骨颈皮质骨没有超过屈服应力的节点存在,股骨颈松质骨内超过屈服应力的节点比例数均未超过0.3%;随着假体柄安放角度的减小,股骨头颈部皮质骨、松质骨均存在超过屈服应力的节点,且该节点比例明显增加。结论骨质正常时进行髋关节表面置换术,股骨假体柄安放角度在135°～145°间可降低骨折的危险性,140°为其最适安放角度。     

不同股骨假体植入角度的髋关节表面置换术后股骨近端力学的有限元研究

目的探讨不同股骨假体植入角度对髋关节表面置换术后股骨近端力学变化的影响,为临床髋关节表面置换术股骨假体植入角度选择提供生物力学依据。方法采用16层螺旋CT扫描正常成人髋关节数据,建立植入角度为120°、125°、130°、135°、140°、145°的髋关节表面置换术后三维有限元分析模型,对所有模型施加人体缓慢行走时的载荷及约束,观察不同模型间股骨近端不同结构应力分布的变化。结果髋关节表面置换术后应力集中部位位于股骨金属假体-股骨骨质交界面处。随着股骨金属假体植入角度的增加,有效应力峰值呈逐渐减小趋势,135°～145°应力总体变化趋势不明显。结论骨质正常时,髋关节表面置换术的股骨金属假体植入适宜角度为135°～145°。     

S-ROM组配式股骨柄在股骨翻修术中的应用

人工全髋关节置换术(toral hip ar-throplasty,THA)后行股骨假体翻修时,取除股骨假体及骨水泥后,股骨髓腔内没有足够的松质骨,采用骨水泥固定假体方式常不能获得满意的固定效果,因此,存在使用非骨水泥型的生物学固定的股骨假体进行翻修的倾向.     

采用锥形股骨柄生物学固定对高龄患者行全髋置换术后的骨改建及临床疗效

目的 探讨采用锥形股骨柄假体生物学固定对高龄患者行全髋关节置换术(total hip arthroplsty,THA)后的假体周围骨改建及中期临床疗效.方法 随机选取2003年1月-2005年1月采用锥形股骨柄假体生物学固定行THA的高龄患者(70～90岁)30例(34髋).对术后及随访X线片的影像学资料、术后及随访中采用双能X线骨密度仪(DEXA)测量的手术前、后假体周围骨密度资料进行分析,临床疗效采用Harris标准评定,并以Kaplan-Meier法评价股骨假体的使用寿命.结果 4例死于肺癌,余26例(30髋)获5～7年(平均6年)随访.术后X线片测量显示12髋1年内假体下沉＜1.5 mm,无假体松动.增生性骨反应见于Gruen 2,3,4,5,6,11,12区;吸收性骨反应见于1,7区.DEXA检查显示骨密度增加在2,3,4,5区,骨密度减少主要发生在1,6,7区.术后6个月内,2,5区的骨密度增加速度最快(P＜0.05),2年后各区骨密度改变趋于稳定(P＞0.05).术后1年内的假体周围总骨密度减少较多(P＜0.05),手术2年后的假体周围总骨密度基本无改变(P＞0.05),只是骨量从股骨近端到远端呈区域性重新分布.髋关节功能Harris评分从术前38.56±8.21提高至最近随访时的86.32±6.01,假体6年存留率达100%.结论采用锥形股骨柄假体生物学固定对高龄患者行THA后的假体周围具有良好的骨改建模式,且中期临床效果良好.     

老年人股骨颈骨折股骨头置换术中短柄假体的有限元分析

目的针对老年人股骨颈骨折后假体置换术,使用有限元分析的方法对股骨短柄假体与常规股骨假体的生物力学特性进行对比。方法利用薄层CT资料建立股骨三维有限元模型,利用我院股骨中空多孔股骨假体相关参数建立两种髋关节股骨假体三维有限元模型;应用Ansys 5.7有限元分析软件考察两种假体植入后的应力分布,并进行比较。结果短柄假体所受最大mises应力较常规股骨假体明显减小;力学传导模式仍为远端应力集中,最大mises应力仍出现在张力侧。结论老年人股骨颈骨折关节置换术中短柄假体力学特性优越。     

全髋关节假体安装参数的优化组合

目的 研究满足日常生活活动范围条件下,全髋关节假体安装参数优化组合及髋臼安装角度安全范围.方法 建立人工全髋关节三维可视化计算机模型,将髋关节屈曲≥110°、屈曲90°内旋≥30°、后伸≥30°、外旋≥40°定义为日常生活活动范围一般标准;将屈曲≥120°、屈曲90°内旋≥45°、后伸≥30°、外旋≥40°定义为严格标准,头颈直径比变化范围为2～2.92,假体颈前倾角变化范围为0°～30°,髋臼假体外展角变化范围为10°～60°,髋臼前倾角变化范围为0°～70°,计算满足上述两种活动标准,臼杯外展角每变化5°,相应的髋臼假体前倾角,颈干角设定为135°.髋臼前倾角和外展角组合的安全范围定义为满足上述活动范围而没有杯颈撞击的面积.应用SAS6.12统计软件对数据进行分析.结果 髋臼角度安全范围随着头颈比增大而增大;严格标准下的安全范围比一般标准的小.颈干角135°、一般标准活动度,髋臼前倾角平均值与外展角的和加0.816倍颈前倾角等于84.76°;严格标准活动度,髋臼前倾角平均值与外展角的和加0.873倍颈前倾角等于92.04°.结论 大的头颈直径比明显增大髋臼角安全范围的面积.髋关节活动范围要求越高,髋臼角安全范围就越小,但可以通过增大头颈比来纠正.一般标准和严格标准活动度,髋臼前倾角平均值与外展角的和(Y)与颈前倾角(X)的组合分别可通过公式进行估计:Y1=-0.816X1+84.76(R2=0.993),Y2=-0.873X2 +92.04(R2=0.999).     

异体骨移植在全髋关节置换术后感染股骨翻修中的应用

目的 探讨异体骨植骨治疗髋关节置换术后感染股骨骨质缺损的有效性与可行性.方法 髋关节置换术后感染股骨侧骨质缺损患者20例,在二期翻修时采用异体植骨,其中16例股骨侧使用骨水泥固定假体结合打压植骨,4例股骨侧使用非骨水泥固定假体结合异体皮质骨支撑植骨.术后定期随访,根据X线片及Harris评分结果进行评价.结果 所有患者均获随访,平均随访时间20.3个月(4～61个月),X线片上无明显异体骨溶解征象,Harris评分从术前的平均34.2分提高到最后随访时的平均87.7分,患者满意率为90%,在最后随访时没有感染复发患者.结论 异体骨植骨治疗髋关节置换术后感染后股骨侧骨质缺损是有效且可行的.     

骨水泥叠加技术在髋关节置换术后股骨假体周围骨折中的应用

目的探讨骨水泥型假体人工髋关节置换术后发生股骨假体周围骨折的有效治疗方法。方法对2009年3月-2013年2月15例行骨水泥型假体人工髋关节置换术后发生股骨假体周围骨折患者均采取骨折复位内固定．骨水泥叠加技术固定假体;骨折发生时间为髋关节置换术后10d～3年,按Vancouver骨折分型：B2型11例,B3型4例。术后6个月对髋关节功能进行Harris评分,观察术后疗效。结果15例患者均获得随访,术后X线片检查骨折均愈合良好,假体稳定,位置安放合适;无感染、无内固定物及关节假体移位、断裂发生。髋关节功能Harris平均83分（76～87分）。结论骨水泥叠加技术是骨水泥型假体人工髋关节置换术后发生股骨假体周围骨折的有效治疗方法。     

计算机辅助髋关节囊韧带重建三维有限元分析及其生物力学意义

目的 从生物力学角度,采用三维有限元方法,探讨关节囊韧带重建对髋关节的稳定机制.方法 利用功能强大的有限元分析软件Unigraphics NX 2.0和SolidWorks 2006构建出包括坐股韧带重建的全髋关节置换术(total hip arthroplasty,THA)三维有限元模型,模拟坐位腿交叉动作载荷,获取假体脱位过程的角活动度和相应的阻力矩值.结果 所构建坐股韧带为多体连接非线性、大界面划移、高弹性的结构模型,客观反映坐股韧带真实解剖形态及其生物力学行为.增加坐股韧带重建的模型与仅有金属的模型相比,降低了撞击点和脱位点峰应力分别为17%和31%.峰阻力矩增加了57%,并提供了2.29倍的稳定性.结论 坐股韧带作为髋关节后方关节囊一个确切的解剖结构,对后方稳定装置的力学完整性起到重要的作用,髋关节成形术中应该重建髋关节囊韧带.     

Effect of joint position and ligament tension on the MR signal intensity of the cruciate ligaments of the knee

Six cadaveric lower extremities were imaged with T1-weighted spin-echo pulse sequences with the knees extended and flexed to 90°. Magnetic resonance signal intensities of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) were compared. Changing from extension to flexion resulted in decreased signal intensity in six of six ACLs and five of six PCLs. Two of the knees were then imaged with and without tension applied to the ACL. Both specimens showed a decrease in signal intensity with tension, followed by an increase in signal intensity with release of the tension. Finally, in three of the limbs the ACL was surgically reconstructed and then imaged with and without tension applied to the tension graft. Signal intensity decreased with tension and increased with release of the tension in all three specimens. Thus, joint position and changes in ligament tension affect the signal intensity of the ACL and PCL, generally resulting in a signal intensity decrease with tension.     

Percutaneous needle biopsy of the spine

The purpose of this review article is to provide a brief overview of the recent literature on the two main types of percutaneous biopsy methods done in the spinal column: fine needle aspiration biopsy (FNAB) and core needle biopsy (CNB). FNAB is the process of obtaining a sample of cells and bits of tissue for examination by applying suction through a fine needle attached to a syringe. Core needle biopsy involves extracting a cylindrical sample of tissue using a large, hollow needle. The decision for needle biopsy is a joint effort between the clinician, pathologist, radiologist, surgeon, and patient. Specific techniques and approaches with varying needle systems are described for each spinal region. Percutaneous image-guided spine biopsy is a safe and effective procedure. It is the procedure of choice in definitive diagnosis of pathologic lesions of the spine.     

MR imaging of disorders of the brachial plexus

The authors evaluated 64 consecutive patients with suspected brachial plexus (BP) abnormalities of diverse cause with magnetic resonance (MR) imaging, using the body coil and a standardized protocol. Of the 43 patients for whom follow-up was available, 25 were suspected of having neoplastic involvement of the BP, nine had sustained injuries, and nine presented with BP symptoms of uncertain cause. MR imaging was 63% sensitive, 100% specific, and 77% accurate in demonstrating the abnormality in this diverse patient population. When patients with neoplastic and traumatic disorders were considered separately, sensitivity increased to 81%, accuracy to 88%, and specificity remained unchanged. In the patients with a clinical diagnosis of idiopathic or viral plexitis, the MR imaging findings were normal, serving to exclude other structural abnormalities. It is concluded that MR imaging is valuable in the assessment of a wide range of BP disorders.     

CT Arthrography and Virtual Arthroscopy in the Diagnosis of the Anterior Cruciate Ligament and Meniscal Abnormalities of the Knee Joint

Objective

To determine the diagnostic accuracy of CT arthrography and virtual arthroscopy in the diagnosis of anterior cruciate ligament and meniscus pathology.

Materials and Methods

Thirty-eight consecutive patients who underwent CT arthrography and arthroscopy of the knee were included in this study. The ages of the patients ranged from 19 to 52 years and all of the patients were male. Sagittal, coronal, transverse and oblique coronal multiplanar reconstruction images were reformatted from CT arthrography. Virtual arthroscopy was performed from 6 standard views using a volume rendering technique. Three radiologists analyzed the MPR images and two orthopedic surgeons analyzed the virtual arthroscopic images.

Results

The sensitivity and specificity of CT arthrography for the diagnosis of anterior cruciate ligament abnormalities were 87.5%-100% and 93.3-96.7%, respectively, and those for meniscus abnormalities were 91.7%-100% and 98.1%, respectively. The sensitivity and specificity of virtual arthroscopy for the diagnosis of anterior cruciate ligament abnormalities were 87.5% and 83.3-90%, respectively, and those for meniscus abnormalities were 83.3%-87.5% and 96.1-98.1%, respectively.

Conclusion

CT arthrography and virtual arthroscopy showed good diagnostic accuracy for anterior cruciate ligament and meniscal abnormalities.     

Trauma of the chest

Trauma to the chest may cause a wide range of injuries including fractures of the thoracic skeleton, contusion or laceration of pulmonary parenchyma, damage to the tracheobronchial tree, diaphragmatic rupture or cardiac contusion. Conditions affecting primarily extrathoracic sites may have indirect effects on the lungs causing adult respiratory distress syndrome or fat embolism. Laceration of the aorta is the typical and likewise most life threatening complication of massive blunt chest trauma necessitating immediate diagnosis and repair.Conventional radiography rather than cross-sectional imaging is the mainstay in diagnosing thoracic trauma. During the critical phase with often concomitant shock, pelvic and spinal injuries tailored radiographic views or even upright chest radiographs are impractical. The severely traumatized patient is usually radiographed in the supine position and suboptimal roentgenograms may have to be accepted for several reasons. It is well documented that many abnormalities detected on CT were not apparent on conventional radiographs, but CT is reserved for hemodynamical stable patients. Nevertheless certain situations like aortic rupture require further evaluation by CT and aortography.The value of conventional radiography, CT, MRI and aortography in chest trauma is reviewed and typical radiographic findings are presented.     

Three-dimensional MR visualization of the intracisternal course of the cranial nerves V-VIII by virtual cisternoscopy

Purpose:
A post-processing protocol for 3D visualization of the cranial nerves V-VIII along their intracisternal course is presented. Material and Methods:
Six healthy volunteers underwent MR imaging (1.5 T) to obtain high-resolution heavily T2-weighted data sets (3DFT CISS) with isotropic voxels (0.5 mm³). The data sets were post-processed by using volume rendering software in order to visualize the intracisternal courses of the cranial nerves V-VIII as well as their root entry zones. The data acquisition and post-processing protocol was then applied in 14 patients with a suspected neural compression syndrome according to the clinical findings as well as cross-sectional images and evaluated with respect to image quality and diagnostic value by two neuroradiologists, using a five-point scale. Results:
Virtual cisternoscopy allowed a comprehensive intracisternal 3D visualization of the affected cranial nerves in 12/14 patients. The mean post-processing time amounted to 13.1/5.6/13.7 min for the cranial nerves V/VI/VII and VIII. The mean score for image quality was 4.2, that for diagnostic value 4.1. 2D and/or 3D reference images were indispensable for appreciating the spatial information provided by virtual cisternoscopy. Conclusion:
The data acquisition and post-processing protocol presented here allows comprehensive and standardized intracisternal 3D visualization of the cranial nerves V-VIII in a routine setting as a complementary imaging procedure.     

Some borderlands of the cervical spine

The complexity of the structure of the cervical spine as well superimposition by the parts of adjacent vertebrae, as well as other structures may cause some abnormalities to be overlooked. Among those abnormalities are, the short sagittal diameter, neoplasm in the cancellous part of the vertebral bodies, spurs in the apophyseal joints, trauma, infection and others.     

Localized proton MR spectroscopy of the brain in children

Small-voxel (3.0–8.0 cm³), magnetic resonance (MR) imaging–guided proton MR spectroscopy was performed in 54 patients (aged 6 days to 19 years) with intracranial masses (n = 16), neurodegenerative disorders (n = 34), and other neurologic diseases (n = 4) and in 23 age-matched control subjects without brain disease. A combined short TE (18 msec) stimulatedecho acquisition mode (STEAM) and long TE (135 and/or 270 msec) spin-echo point-resolved spatially localized spectroscopy (PRESS) protocol, using designed radio-frequency pulses, was performed at 1.5 T. STEAM spectra revealed short T2 and/or strongly coupled metabolites; prominent resonances were obtained from N-acetyl aspartate (NAA), choline-containing compounds (Cho), and total creatine (tCr). Lactate was well resolved with the long TE PRESS sequence. Intracranial tumors were readily differentiated from cerebrospinal fluid (CSF) collections. All tumors showed low NAA, high Cho, and reduced tCr levels. Neurodegenerative disorders showed low or absent NAA levels and enhanced mobile lipid, glutamate and glutamine, and inositol levels, consistent with neuronal loss, gliosis, demyelination, and amino acid neuro-toxicity. Preliminary experience indicates that proton MR spectroscopy can contribute in the evaluation of central nervous system abnormalities of infants and children.     

MR imaging characteristics of noncancerous lesions of the prostate.

Radical prostatectomy specimens from 53 men with clinical stage A or B prostate cancer were retrospectively reviewed and compared with correlative axial T2-weighted magnetic resonance (MR) images obtained just before surgery. Non-cancerous lesions were evaluated for signal intensity and location. Focal high-signal-intensity areas (n = 72) were present in 81% of patients. The 26% of lesions seen in the central gland all correlated with cystic atrophy. Of the 53 lesions seen in the peripheral prostate, 47 (89%) were cystic atrophy without associated cancer, four (7.5%) cystic atrophy with cancer, and two (3.8%) focal inflammation. Focal low-signal-intensity areas (n = 42) were present in 60% of patients. Of the 31% of lesions in the central prostate, one-fifth correlated with benign prostatic hyperplasia (BPH) and four-fifths with fibrous tissue. Of the 69% of peripheral lesions, 83% corresponded to fibrous tissue, 10% to BPH, and 7% to normal tissue. Mixed lesions (n = 42) were present in 64% of patients; 86% of these were located centrally and 14% peripherally. All mixed central lesions were BPH; the peripheral lesions were areas of combined cystic atrophy and fibrosis. BPH of low or mixed signal intensity can extend into the peripheral prostate and mimic cancer. High-intensity cystic atrophy associated with cancer can mimic normal tissue.     

MRI of the post-discectomy lumbar spine

Laminectomy and discectomy are common procedures in the management of symptomatic lumbar disc herniation. Complications of such surgery include recurrent/residual disc herniation, epidural scar formation, discitis, arachnoiditis and pseudo-meningocele. Gadolinium-enhanced MRI is the technique of choice for investigating recurrent symptoms following discectomy. This article reviews the normal early and late post-laminectomy MR appearances, as well as the pathological findings associated with the above-mentioned complications.