四肢关节专用低场强MRI评估对膝关节损伤的诊断价值

目的：分析四肢关节专用低场强MRI诊断膝关节损伤的临床应用价值。 方法：于2004-12/2005-10解放军总医院全军骨科研究所收治经手术、关节镜检查或临床证实的膝关节损伤患者40例（43个膝关节）。应用Atorscan0.2T永磁型四肢关节专用低场强磁共振机,对膝关节损伤的MRI表现进行分析。 结果：四肢关节专用低场强MRI对半月板、前交叉韧带、骨挫伤等均可作出正确诊断。 结论：四肢关节专用低场强MRI对膝关节损伤的综合诊断具有重要意义,是膝关节损伤较理想的一种非创伤性检查方法。     

肌腱玻璃化法冷冻保存的体外实验

目的:目前临床上常用低温冷冻法来保存同种异体肌腱,但操作较复杂费时,并且所保存的肌腱活性较低而限制其应用。采用已筛选的玻璃化法冷冻保存鸡屈趾深肌腱,并将复温后的玻璃化肌腱进行体外检测,探索其作为肌腱移植材料的可行性。方法:实验于2003-11/2005-02在解放军总医院骨科研究所完成。①实验材料及分组:来亨鸡16只,雄性,体质量2.5kg左右,随机分为2组,玻璃化组为玻璃化肌腱,新鲜肌腱组为新鲜肌腱,每组8只。②实验过程:切取来亨鸡屈趾深肌腱,置入玻璃化液内快速投入液氮保存2周制备玻璃化肌腱。③实验评估:将2组肌腱在体外进行大体、组织学及超微结构观察,羟脯氨酸含量测定,生物力学性能检测,并对两组肌腱进行细胞培养与鉴定。结果:①玻璃化组肌腱的大体、组织学及超微结构与新鲜肌腱组相似,其细胞及细胞外结构得以良好保存。②应用碱解法测定玻璃化肌腱内的羟脯氨酸含量为69.27mg/g,与新鲜肌腱组间差异无统计学意义。③玻璃化组肌腱破裂强度为165.58MPa,弹性模量1.41GPa,与新鲜肌腱组的力学性能差异无统计学意义。④将玻璃化组肌腱进行细胞培养,细胞第8天自组织块长出,第21天后传代,培养3代后出现明显的退化现象,其生物学特性与新鲜肌腱组相似。⑤将两组肌腱培养的细胞分别进行免疫组织化学染色,经鉴定均为肌腱细胞。结论:玻璃化法保存的肌腱具有良好的细胞活性、细胞外结构及力学性能,其生物学及生物力学特性无明显变异。     

The rate of hepatic artery complications is higher in pediatric liver transplant recipients with metabolic liver diseases than with biliary atresia

Background

Liver transplantation (LT) is an excellent treatment option for patients with biliary atresia (BA) who fail portoenterostomy surgery. LT is also increasingly performed in patients with metabolic liver diseases. This study compared the outcomes in pediatric patients who underwent LT for metabolic liver diseases and BA.

Fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography as a tool to localize an insulinoma or beta-cell hyperplasia in adult patients

CONTEXT AND OBJECTIVE: Fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET) is a promising method in localizing neuroendocrine tumors. Recently, it has been shown to differentiate focal forms of congenital hyperinsulinism of infancy. The current study was set up to determine the potential of 18F-DOPA PET in identifying the insulin-secreting tumors or beta-cell hyperplasia of the pancreas in adults. PATIENTS AND METHODS: We prospectively studied 10 patients with confirmed hyperinsulinemic hypoglycemia and presumed insulin-secreting tumor using 18F-DOPA PET. Anatomical imaging was performed with computed tomography (CT) and magnetic resonance imaging (MRI). All patients were operated on, and histological verification was available in each case. Semiquantitative PET findings in the pancreas using standardized uptake values were compared to standardized uptake values of seven consecutive patients with nonpancreatic neuroendocrine tumors. RESULTS: By visual inspection of 18F-DOPA PET images, it was possible in nine of 10 patients to localize the pancreatic lesion, subsequently confirmed by histological analysis. 18F-DOPA uptake was enhanced in six of seven solid insulinomas and in the malignant insulinoma and its hepatic metastasis. Two patients with beta-cell hyperplasia showed increased focal uptake of 18F-DOPA in the affected areas. As compared to CT or MRI, 18F-DOPA PET was more sensitive in localizing diseased pancreatic tissue. CONCLUSION: 18F-DOPA PET was useful in most patients with insulinoma and negative CT, MRI, and ultrasound results. In agreement with previous findings in infants, preoperative 18F-DOPA imaging seems to be a method of choice for the detection of beta-cell hyperplasia in adults. It should be considered for the detection of insulinoma or beta-cell hyperplasia in patients with confirmed hyperinsulinemic hypoglycemias when other diagnostic work-up is negative.     

Percutaneous Pinning of Fifth Carpal–Metacarpal Fracture–Dislocations: An Alternative Pin Trajectory

Traditional management of unstable fourth and fifth carpal-metacarpal (CMC) fracture-dislocations (fx-dislocs) of the hand includes closed reduction and percutaneous pinning (CRPP) versus open reduction internal fixation (ORIF). Traditional trajectory of pin placement is toward the base of the hook of the hamate. Our case series of CMC fx-dislocs treated with this trajectory led to the development of ulnar deep motor branch symptoms (sxs). We attempt to propose an alternative trajectory that could lower the chance of iatrogenic injury. Five fresh frozen cadaveric specimens underwent percutaneous pinning of the fifth CMC joint using fluoroscopic guidance. Each cadaver was dissected, and the proximity of the deep motor branch of the ulnar nerve was measured in relation to a pin that penetrated the volar cortex. Our results confirm the close proximity of the deep motor branch of the ulnar nerve to the volar cortex of the hamate and demonstrate the potential for iatrogenic injury during CRPP of the fifth CMC fx-dislocs, especially with penetration of the volar cortex. By demonstrating the close proximity of the deep motor branch to the volar cortex of the hamate in cadavers, we highlight the potential for iatrogenic injury with CRPP of CMC fx-dislocs as seen in our case series. We recommend a more midaxial starting point on the proximal metacarpal with a trajectory aimed at the midbody of the hamate to prevent penetration of the hamate volar cortex and limit the chances of iatrogenic injury.     

Whole body positron emission tomography in follow-up of high risk melanoma

The aim of this study was to determine the clinical impact of whole body positron emission tomography (FDG PET) to detect clinically silent metastases in the follow-up of patients with high risk melanoma. FDG PET was performed to 30 asymptomatic melanoma patients (AJCC stage IIB-IIIC) 7-24 months after the primary surgery and sentinel node biopsy. FDG PET was able to detect six of seven recurrences, constituting 20% of all study patients. One patient presented with a negative FDG PET finding at the very first scanning, but was positive later in a repeated scan after manifestation of palpable mass in the axilla. The positive PET finding had an impact on treatment decisions in every case: three patients underwent surgical resection and four patients received chemotherapy or interferon. The mean follow-up time was 27 months (range, 12-48 months) and during that time the other 23 patients with true negative FDG PET were disease-free. One of the seven recurrences was in remission after surgical metastasectomy. In conclusion, whole body FDG PET is a valuable follow-up tool in high risk melanoma to diagnose recurrences and to select the patients, who are suitable for surgical metastasectomy.     

Losses of chromosomal arms 1p and 19q in the diagnosis of oligodendroglioma. A study of paraffin-embedded sections.

Comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), polymerase chain reaction-based microsatellite analysis, and p53 sequencing were performed in paraffin-embedded material from 18 oligodendrogliomas and histologically similar astrocytomas. The study was undertaken because of evidence that concurrent loss of both the 1p and 19q chromosome arms is a specific marker for oligodendrogliomas. Of the six lesions with a review diagnosis of oligodendroglioma, all had the predicted loss of 1p and 19q seen by CGH, FISH, and polymerase chain reaction. Other lesions, including some considered oligodendroglioma or mixed glioma by the submitting institution, did not. There were no p53 mutations in any of the six oligodendrogliomas, whereas 5 of the 10 remaining, successfully studied cases did have p53 mutations. The results suggest that CGH and FISH performed on current or archival tissue can aid in classification of infiltrating gliomas such as oligodendrogliomas and astrocytomas. The results of the p53 studies are consistent with findings of previous investigations that such mutations are less common in oligodendrogliomas than they are in astrocytomas.