Alcoholism and fracture healing. A radiological study in the rat

Conventional, SPF, and germ-free Wistar rats of both sexes served as laboratory animals. The 2-month-old animals were alcoholized over a period of 1 year using 5%-20% ethanol. The femurs were then osteotomized and treated surgically. Every 2 weeks the course of healing was controlled radiologically. The findings on the process of healing are presented in this work.     

Magnetic resonance imaging with gadolinium DTPA enhancement in patients with acute head injury

Gadolinium-enhanced magnetic resonance (MR) imaging in patients with acute head injury was conducted to study if contrast extravasation was associated with development of hemorrhagic lesions. A series of 60 head-injured patients were admitted to our emergency unit. Computerized tomography (CT) scans and skull x-ray films were taken as rapidly as possible after hospitalization. Injury severity on admission was evaluated using the Glasgow Coma Scale (GCS) score, motor score, and pupillary examination, while overall outcome was assessed with the Glasgow Outcome Scale (GOS) 3 months after injury. Of all patients admitted, MR imaging with gadolinium enhancement was performed in 18 patients who were at high risk of developing hemorrhagic lesion within 6 h after injury. In these patients we investigated whether contrast extravasation was associated with development of hemorrhagic lesions. All 18 patients presented abnormal findings on their admission CT scans. Admission GCS score in those patients who underwent MR imaging with gadolinium enhancement was 13 or more in 12 patients, 9-12 in four patients, and 8 or less in two patients. Fourteen of 18 patients showed contrast extravasation, corresponding with an evolution of lesion size. Nine of 14 patients who demonstrated extravasation of the contrast medium required surgical treatment. The results of the current study suggest that extravasation of contrast medium indicates a continuance of posttraumatic bleeding. Thus, MR imaging with gadolinium enhancement in acutely head-injured patients may constitute a reasonable strategy for predicting the development of hemorrhagic lesions.     

Scaphoid and capitate fracture with concurrent scapholunate dissociation

Combined fracture of the scaphoid and capitate bones with concurrent scapholunate dissociation, but without severe dislocation, is a rare lesion which results in significant carpal instability and requires operative treatment. We report a case of this unusual injury and its functional result after 20 months.     

Preoperative magnetic resonance staging of rectal cancer with an endorectal coil and dynamic gadolinium enhancement

BACKGROUND: The aim of the study was to assess the value of endorectal coil magnetic resonance imaging (MRI) with gadolinium enhancement in the preoperative staging of rectal cancer. METHODS: In addition to standard evaluation, patients with rectal lesions were assessed by MRI obtained with a pelvic phased-array coil in combination with an endorectal coil. RESULTS: The study group comprised 29 patients with rectal cancer staged with an endorectal coil who had surgery without preoperative adjuvant therapy. In addition to standard T1- and T2-weighted images, dynamic contrast-enhanced images were acquired in all patients. Considerable interobserver variation was noted, particularly for pathological tumour stage pT1 or pT2 (kappa = 0.36). Compared with pathological findings, endorectal MRI correctly staged nine patients, overstaged 16 and understaged four. Whilst lymph node metastases were accurately detected in 70 per cent of patients, the positive predictive value was only 58 per cent. CONCLUSION: MR staging of rectal cancer with an endorectal coil and gadolinium enhancement is inaccurate for early tumours (stage T1 or T2) and is associated with a considerable degree of interobserver variation for individual scan sequences.     

环状与线状分子结构钆螯合物增强MRI评价前列腺增生的对照研究

目的分析MRI对比剂环状分子结构钆螯合物钆特酸葡胺对前列腺增生的增强效果。方法回顾性分析75例前列腺增生多期动态增强(DEC)和延迟期增强MRI表现,分为观察组[Gatedotera(钆特酸葡胺)组,20例]、对照组1[Magnevist(钆喷酸葡胺)组,15例]、对照组2[Consun(钆喷酸葡胺)组,16例]和对照组3[Omniscan(钆双胺)组,24例]。比较各组间前列腺增生结节基础信号强度、最大信号强度、增强幅度、达峰时间、DEC曲线上升斜率。以闭孔内肌信号强度、图像噪声为参考,比较延迟期增生结节实质强化程度、实质CNR、包膜强化程度、包膜CNR及包膜显示清晰度的差异。结果各组间达峰时间差异有统计学意义(F=3.812,P=0.014),观察组达峰时间明显短于对照组2(P=0.021),对照组2达峰时间明显长于对照组1(P=0.011)及对照组3(P=0.023);包膜强化程度及包膜CNR差异均有统计学意义(P均0.05),观察组包膜强化程度明显高于对照组2(P=0.005)及对照组3(P=0.047),包膜CNR明显高于对照组1(P=0.016)、对照组2(P0.001)及对照组3(P0.001);且各组间MR增强扫描延迟期包膜显示清晰度差异有统计学意义(χ~2=127.86,P0.010)。其余指标各组间总体及两两比较差异均无统计学意义(P均0.05)。结论环状分子结构钆螯合物MRI对比剂增强效果与线状分子结构钆螯合物对比剂相仿,且显示包膜效果更优。     

骨折愈合的应力适应性研究──功能活动时兔胫骨断端应力状态的动态观察

设计了生物适应性很强的力学控制装置──滑动机械加载控制器，对骨折断端没有应力遮挡，把肌肉动力与肢体负重力作为执行力学加载的源动力，通过压力传感器、多导传感放大器动态记录生理活动状态下断端受力情况及愈合过程中断端的应力状态。结果表明，同一时期内骨折断端压力随肌肉收缩及步态发生变化，不同愈合时间断端压力均值随时间的增加而逐渐增加，而滑动机械加载控制器上承载由术后当日平均２．４ｋｇ逐渐变小至术后五周平均０．７８ｋｇ。同时，通过解剖显微镜进行断端骨痂显微观察，显示断端完全由外骨痂包绕，从而认为骨折断端压力变化是肢体功能恢复，断端骨痂承受载荷的表现，提示临床骨折固定后应适时地进行功能锻炼，肌肉收缩、患肢负重可为断端提供最好的力学环境──生理应力状态。     

骨折愈合的应力适应性研究

设计了生物适应性很强的力学控制装置──滑动机械加载控制器,对骨折断端没有应力遮挡,把肌肉动力与肢体负重力作为执行力学加载的源动力,通过压力传感器、多导传感放大器动态记录生理活动状态下断端受力情况及愈合过程中断端的应力状态。结果表明,同一时期内骨折断端压力随肌肉收缩及步态发生变化,不同愈合时间断端压力均值随时间的增加而逐渐增加,而滑动机械加载控制器上承载由术后当日平均2.4kg逐渐变小至术后五周平均0.78kg.同时,通过解剖显微镜进行断端骨痂显微观察,显示断端完全由外骨痂包绕,从而认为骨折断端压力变化是肢体功能恢复,断端骨痂承受载荷的表现,提示临床骨折固定后应适时地进行功能锻炼,肌肉收缩、患肢负重可为断端提供最好的力学环境──生理应力状态。     

Improved myocardial scar visualization with fast free-breathing motion-compensated black-blood T1-rho-prepared late gadolinium enhancement MRI

PurposeClinical guidelines recommend the use of bright-blood late gadolinium enhancement (BR-LGE) for the detection and quantification of regional myocardial fibrosis and scar. This technique, however, may suffer from poor contrast at the blood-scar interface, particularly in patients with subendocardial myocardial infarction. The purpose of this study was to assess the clinical performance of a two-dimensional black-blood LGE (BL-LGE) sequence, which combines free-breathing T₁-rho-prepared single-shot acquisitions with an advanced non-rigid motion-compensated patch-based reconstruction.Materials and methodsExtended phase graph simulations and phantom experiments were performed to investigate the performance of the motion-correction algorithm and to assess the black-blood properties of the proposed sequence. Fifty-one patients (37 men, 14 women; mean age, 55 ± 15 [SD] years; age range: 19–81 years) with known or suspected cardiac disease prospectively underwent free-breathing T₁-rho-prepared BL-LGE imaging with inline non-rigid motion-compensated patch-based reconstruction at 1.5T. Conventional breath-held BR-LGE images were acquired for comparison purposes. Acquisition times were recorded. Two readers graded the image quality and relative contrasts were calculated. Presence, location, and extent of LGE were evaluated.ResultsBL-LGE images were acquired with full ventricular coverage in 115 ± 25 (SD) sec (range: 64–160 sec). Image quality was significantly higher on free-breathing BL-LGE imaging than on its breath-held BR-LGE counterpart (3.6 ± 0.7 [SD] [range: 2–4] vs. 3.9 ± 0.2 [SD] [range: 3–4]) (P <0.01) and was graded as diagnostic for 44/51 (86%) patients. The mean scar-to-myocardium and scar-to-blood relative contrasts were significantly higher on BL-LGE images (P < 0.01 for both). The extent of LGE was larger on BL-LGE (median, 5 segments [IQR: 2, 7 segments] vs. median, 4 segments [IQR: 1, 6 segments]) (P < 0.01), the method being particularly sensitive in segments with LGE involving the subendocardium or papillary muscles. In eight patients (16%), BL-LGE could ascertain or rule out a diagnosis otherwise inconclusive on BR-LGE.ConclusionFree-breathing T₁-rho-prepared BL-LGE imaging with inline motion compensated reconstruction offers a promising diagnostic technology for the non-invasive assessment of myocardial injuries.     

Calcitonin and fracture healing. An experimental study on rats

The effects of systemically administered calcitonin (CT) on fracture healing were analyzed in an experimental study on rats. The healing of a fracture was followed from 3 days up to 9 weeks postoperatively. Half of the rats in each age group were given daily CT 10 MRC-U/kg body wt s.c. Mechanical properties of the healing tibial fractures (tension strength) as well as various connective tissue components of the callus tissue were analyzed. No difference in the radiological or microscopical appearance of the fractures was detectable between the animals receiving CT and the controls. In the biochemical analysis matrix production as assessed from the concentrations of nitrogen, hexosamines, and hydroxyproline within the callus followed the usual lines of undistributed fracture union without any difference between the groups with and without CT. No differences could be detected in the mineralization of the callus between the specimens from animals receiving CT and those without. The tensile strength values of the fractures increased almost linearly up to 9 weeks. At 1 week the tensile strength values for fractures union in the animals without CT were approximately 50% higher, but later on no differences could be detected between the groups. These results indicate that although in the early phases of long-term CT therapy collagen synthesis may be impaired, there will be no effect on the net content of collagen or calcifying tissue in the callus or on the mechanical strength of healing fractures.     

Nonunion and pseudarthrosis of fracture healing. A histopathologic study of 95 human specimens

Forty-one human tissue specimens from fracture nonunions in extraarticular locations demonstrated a spectrum of clefts at the site of nonunion ranging from tiny microscopic spaces within the soft tissue of the nonunion to dominant clefts that completely separated the ends of the fracture. These latter specimens were examples of frank pseudarthrosis. The soft tissues lining the large clefts were often considerably eroded. Pseudarthrosis of fracture healing may be a late manifestation of more mobile nonunions that progressively tear apart. Fifty-four additional nonunion or pseudarthrosis specimens from former intraarticular fractures demonstrated the same sequence of changes occurring in 24 of the cases. However, 30 of the intraarticular fractures demonstrated no tissues of a fibrous nonunion, which could indicate that in such locations pseudarthrosis may exist from the date of the original fracture.     

Scaphoid fracture displacement with forearm rotation in a short-arm thumb spica cast.

Three-dimensional motion between the fragments of an experimental scaphoid waist fracture was measured during dynamic forearm pronation and supination in a short-arm thumb spica cast with and without applied tendon loads. Metal markers placed in each fragment were tracked using high-speed biplane radiographic image sequences and stereophotogrammetric analysis. Peak displacements (from the intact state) exceeded 1 mm in all specimens, with the largest movements occurring in the radial direction during pronation (mean: 2.1 mm unloaded, 2.5 mm loaded). Total range of displacement motion between fragments exceeded 3 mm (mean ulnar/radial direction: 3.4 mm unloaded, 4.1 mm loaded). Dorsal/palmar and proximal/distal displacements were minimal except at the extremes of forearm pronation/supination. Rotations between fragments were small (within +/- 6 degrees) and varied considerably across specimens. No significant differences were found between loaded and unloaded trials. Thus, in the absence of long-arm thumb spica casting to limit forearm rotation, significant motion between the fragments of a scaphoid waist fracture is likely.     

外用罂粟碱霜对扩张皮肤血流量及扩张皮瓣成活长度的影响

目的探讨外用罂粟碱霜对扩张皮肤的血流量及对扩张皮瓣成活长度的影响.方法以小型猪为实验动物,将罂粟碱霜用于组织扩张过程,分别与罂粟碱全身给药和囊内导入2种方式以及常规扩张进行对照,观察在扩张前后及给药前后扩张皮肤的组织血流量以及扩张皮瓣成活长度的差异.结果扩张注水前外用组皮肤血流量值较其它组明显较高(P＜0.05).在扩张后外用组较其它各组仍处于较高水平(P＜0.01);给药前外用组皮肤血流量值较其它2组高(P＜0.05);外用组在给药后,扩张皮肤的血流量值不断上升并最终高于其它各组,至240分钟时与其它各组明显差异(P＜0.05);术后10天外用组平均皮瓣成活长度为(13.67±1.28)cm,导入组为(11.07±0.88)cm;肌注组为(10.79±0.49)cm,对照组为(9.49±0.77)cm,外用组与其它各组之间差别均非常显著(P＜0.01);外用组扩张包膜组织中罂粟碱的平均含量为(3.5±1.2)μg/g,导入组和肌注组包膜组织中及各组动物血液中均检测不到罂粟碱含量.结论外用罂粟碱霜剂能够透过皮肤并有效地发挥扩张血管的作用,从而增加扩张皮肤的血流量,增加扩张皮瓣的成活长度.对于扩大组织扩张术的应用范围、减少并发症、提高手术效果有重要的应用价值.     

外用罂粟碱霜对扩张皮肤血流量及扩张皮瓣成活长度的影响

目的　探讨外用罂粟碱霜对扩张皮肤的血流量及对扩张皮瓣成活长度的影响。方法　以小型猪为实验动物 ,将罂粟碱霜用于组织扩张过程 ,分别与罂粟碱全身给药和囊内导入 2种方式以及常规扩张进行对照 ,观察在扩张前后及给药前后扩张皮肤的组织血流量以及扩张皮瓣成活长度的差异。结果　扩张注水前外用组皮肤血流量值较其它组明显较高 (P <0 .0 5)。在扩张后外用组较其它各组仍处于较高水平 (P <0 .0 1 ) ;给药前外用组皮肤血流量值较其它 2组高 (P <0 .0 5) ;外用组在给药后 ,扩张皮肤的血流量值不断上升并最终高于其它各组 ,至 2 4 0分钟时与其它各组明显差异 (P <0 .0 5) ;术后 1 0天外用组平均皮瓣成活长度为 (1 3 .67± 1 .2 8)cm ,导入组为 (1 1 .0 7± 0 .88)cm ;肌注组为 (1 0 .79± 0 .49)cm ,对照组为 (9.49± 0 .77)cm ,外用组与其它各组之间差别均非常显著 (P <0 .0 1 ) ;外用组扩张包膜组织中罂粟碱的平均含量为 (3 .5± 1 .2 ) μg/g,导入组和肌注组包膜组织中及各组动物血液中均检测不到罂粟碱含量。结论　外用罂粟碱霜剂能够透过皮肤并有效地发挥扩张血管的作用 ,从而增加扩张皮肤的血流量 ,增加扩张皮瓣的成活长度。对于扩大组织扩张术的应用范围、减少并发症、提高手术效果有重要的应用价     

A dynamic dual isotope radionuclear method of quantifying penile blood flow.

A new radionuclear method of quantifying arterial and venous blood flow of the penis is described. The technique is based on the simultaneous recording of the change in blood volume and venous outflow in the flaccid and erect states, which is produced pharmacologically. The change in penile blood volume is determined by measuring the change in the technetium-labeled red blood cell activity with time. Venous outflow is recorded with a xenon washout technique. The isotope data are used to compute arterial and venous flows with a complex computerized mathematical formula. Three basic blood flow patterns have been noted that distinguish normal patients from those with arterial insufficiency and venous leakage. The study is relatively easy and noninvasive to perform, and it appears to quantify penile blood flow accurately.     

Rodent models for the study of articular fracture healing.

The goal of this study was to document the healing time course and expression of ex vivo cell-based gene delivery in articular fracture models in the mouse and rat. Articular medial intercondylar femoral osteotomy was performed in the stifle (knee) joints of hairless immunocompetent mice and medial or lateral similar osteotomy was performed in athymic nude rats. Genetically modified cells expressing luciferase were delivered in a three-dimensional alginate matrix directly into the osteotomy site. Sensitivity of an in vivo imaging system to detect expression of luciferase was compared between rodents in this fracture model. Osteotomy healing was assessed using high-detail radiography, helical computed tomography (CT), high-field magnetic resonance imaging, and histology. The mouse model was less satisfactory because the small size of the murine femur made reliable assessment of fracture healing restricted to histopathology, and complications occurred in 11/24 mice (45.8%), most frequently transverse supracondylar femoral fracture postoperatively. Gene expression was inconsistently confirmed in mice in vivo for 11 days (p < .003). In rats, high-detail radiography and CT were used to assess osteotomy healing. Magnetic resonance imaging (4.7 T) in rats could produce three-dimensional images that would permit assessment of bone and cartilage, but was time-consuming and expensive. In rats, the only surgical complication, transverse femoral fracture, was reduced from 83.3% with the medial osteotomy to 0% with a lateral osteotomy. In vivo imaging confirmed gene expression in the alginate/cell constructs in rats for at least 4 days (p < .05). The nude rat model has the advantage of larger femora and the ability to implant xenograft cells. A lateral intercondylar osteotomy of the distal femur in the rat can be used to study the healing of articular fractures.     

成纤维细胞生长因子促进骨折愈合的作用及机制

FGF的生物学特性成纤维细胞生长因子（fibroblastgrowthfactor,FGF）最初从牛脑垂体提取液中分离获得,距今已有半个多世纪,但FGF与同源FGF特异结构与功能之间的相互作用直到最近１０～１５年才被确认犤１犦,不过FGF对中胚层细胞、神经外胚层细胞的促有丝分裂及促血管生成活性已经证实。FGF由酸性FGF（acidicfibroblastgrowthfactorm,aFGF）及碱性FGF（basicfi－brodlastgrowthfactor,bFGF）两种蛋白质组成,aFGF由１４０个氨基酸、bFGF由１５４个氨基酸组成,它们都具有不同的结构形式犤２犦。bFGF是FGF家族中的一个…     

A model for intramembranous ossification during fracture healing.

We have developed a method to study the molecular basis of intramembranous fracture healing. Unlike intramedullary rods that permit rotation of the fractured bone segments, our murine model relies on an external fixation device to provide stabilization. In this study we compare stabilized fracture callus tissues with callus tissues from non-stabilized fractures during the inflammatory, soft callus, hard callus, and remodeling stages of healing. Histological analyses indicate that stabilized fractures heal with virtually no evidence of cartilage whereas non-stabilized fractures produce abundant cartilage at the fracture site. Expression patterns of collagen type IIa (colIIa) and osteocalcin (oc) reveal that mesenchymal cells at the fracture site commit to either a chondrogenic or an osteogenic lineage during the earliest stages of healing. The mechanical environment influences this cell fate decision, since mesenchymal cells in a stabilized fracture express oc and fail to express colIIa. Future studies will use this murine model of intramembranous fracture healing to explore, at a molecular level, how the mechanical environment exerts its influence on healing of a fracture.