髋臼发育不良髋臼缘生物力学测定

[目的]证实由于兔髋臼发育不良，股骨头被髋臼所覆盖的面积减少，股骨头的球状关节和髋臼的舟状关节负重面趋于集中，头臼关节不能耐受高度集中的强大的机械应力作用，最终导致髋关节脱位．[方法]本实验利用七V13型数据采集记录仪、X线片和组织病理切片对对照组和实验组髋关节进行力学测定和病理学观察一[结果]实验组髋臼缘软骨逐渐发生退变和变形，髋臼缘A、B、C、D4点位置，所受应力均有变化。对照组和实验组，t检验，P〈0．01。[结论]本实验对髋臼发育不良兔髋臼缘力学测定，可以推测人类先天性髋关节脱位的机理和原冈与髋臼发育不良有密切联系。先天性髋关节脱位患儿应早期发现，早期治疗，提高临床治疗效果。     

髋臼周围损伤对髋关节发育影响的实验研究

目的：探讨髋臼软骨及周围骨膜损伤对髋关节发育的影响。方法：4-5周龄白兔20只，切除其右饲髋关节部分髋臼软骨(A组)及臼缘上方骨膜(B组)，左侧作为对照。用X线、形态学及组织学方法观察髋关节发育状况。结果：右侧全部出现髋关节发育不良，半脱位发生率：A组80％，B组40％。对照侧发育正常。结论：髋臼软骨及臼缘上方骨膜破坏可导致髋关节发育不良和半脱位。     

髋臼发育不良动物模型的建立及其临床意义

目的探讨髋臼发育不良在先天性髋关节脱位发病过程中的意义。方法将１２只幼犬通过外科手术造成单侧髋关节脱位,术后３、４周通过大体标本、组织学及Ｘ线摄片,观察髋臼变化。结果术后３周幼犬实验性髋关节脱位侧即出现髋臼发育不良,髋臼上部呈斜坡状,髋臼浅,Ｘ线片上可见髋臼指数增大,由实验前平均１３２±１３度增大为平均２７８±１５度,组织学观察见髋臼软骨退行变化。结论髋臼发育不良为髋关节脱位的继发病变,不是髋关节脱位的原因;如果髋关节脱位或髋关节松驰得到及时治疗,髋臼发育不良可以恢复正常     

实验性髋臼发育不良的病理形态学研究

目的 :探讨造成髋关节发育不良的病理发病机制。方法 :将 18只幼兔的左髋关节屈曲膝关节伸直位石膏固定 4周 ,比较双侧髋关节的X线片及病理组织学变化。结果 :髋关节屈曲膝关节伸直位石膏固定 4周造成了髋关节发育不良的动物模型。髋臼变浅、股骨头变小、向外上方移位。X线片可见髋臼指数增大 ,由固定前的 (2 8.44± 3 .91)°增大为 (3 3 .17± 3 .65 )° ;臼头指数减小 ,由固定前的 (75 .2 0± 4.41) %减小为 (5 8.71± 8.2 1) %。组织学观察可见关节软骨退行性改变。结论 :髋关节屈曲膝关节持续伸直位状态 ,容易造成髋关节发育不良。随着时间的延长 ,病理变化加重。及早复位 ,髋关节可以恢复正常     

髋臼Y形软骨损伤对髋关节发育影响的实验研究

目的探讨“Y”形软骨损伤后骨骺早闭对髋关节发育的影响。方法选用10只4~5周龄大白兔,切除、破坏右侧髋臼部分“Y”形软骨,左侧髋关节不行处理,作为对照。X线动态观察双侧髋关节发育状况,术后12周处死动物,进行形态学及组织学观察。结果手术侧术后3周“Y”形软骨均出现骨骺早闭,髋臼内壁增厚、髋臼变浅;术后6~9周髋臼浅且形态不规则,4例出现半脱位;术后12周全部出现关节发育不良,50%的髋关节发生半脱位。形态学观察见髋臼变浅,内壁厚度增加,股骨头增大、变扁,关节软骨失去光泽,部分缺失。HE染色见髋臼及股骨头软骨层变薄,软骨细胞排列紊乱,骺板扭曲、变薄。对照侧各髋关节形态结构正常。手术侧各期臼头指数、相对髋臼指数及臼壁厚度与对照侧相比差异均有显著性意义(P<0.05)。手术侧术后12周臼头指数及相对髋臼指数与术后第2d相比差异有非常显著性意义(P<0.01)。结论“Y”形软骨损伤可导致骨桥形成、骨骺早闭,使髋臼内壁增厚、髋臼变浅,继而引发髋关节发育不良和半脱位。     

髋臼内下移小臼解剖位安放全髋关节置换术治疗成人髋臼发育不良伴骨性关节炎

目的评价髋臼内下移小臼解剖位安放全髋关节置换术治疗成人髋臼发育不良继发骨性关节炎的结果。方法采用髋臼内下移小臼解剖位安装的全髋关节置换术对42例48髋进行的人工全髋关节置换手术。其中40例42髋关节得到了平均46.6个月的完整随访,通过Harris评分及X线片评价临床效果。结果Harris评分的优良率达95.8%。X线片未见假体松动和骨溶解。结论髋臼内下移小臼解剖位安装的全髋关节置换是成人先天性髋臼发育不良骨性关节炎的有效治疗方法。     

髋臼发育不良患者髋臼盂唇内翻的影像学特征及临床意义

目的 通过临床研究报告青少年及成人髋臼发育不良患者髋臼盂唇内翻的影像学特征及临床意义.方法 2010年10月至2012年11月,对248例青少年及成人髋臼发育不良及髋关节半脱位患者行骨盆X线、髋关节核磁造影检查,发现12髋存在典型关节内盘状软骨样结构,均为女性,年龄9～36岁,平均17.8岁,左侧5髋,右侧7髋;并通过髋关节切开清理,得到大体标本及病理证实.结果 青少年及成人髋臼盂唇内翻的X线片特点是髋臼负重区短小,部分软骨下骨模糊、欠规则;直接核磁造影片上内翻盂唇呈线条样低信号衬于髋臼与股骨头之间.其病理结构为纤维软骨.青少年及成人髋臼盂唇内翻多见于女性、较严重髋关节发育不良或半脱位,较早出现髋关节疼痛.绝大部分患髋4字试验阳性,部分患侧髋关节前内侧撞击试验或后外侧撞击试验阳性.其预后及临床意义值得探讨.结论 典型青少年及成人髋臼盂唇内翻有明显的X线片和髋关节核磁特征,其临床特征、预后及意义需进一步研究.     

V形镍钛合金支架植入治疗犬髋臼发育不良的实验研究

目的 探讨Ｖ形镍钛合金（记忆合金）支架植入髋臼顶部后,对其髋臼发育不良的矫正及对其髋臼发育的影响。方法 选用髋臼发育不良的幼犬１０只,随机分为２组,在髋臼顶部距臼缘上０．５ｃｍ处用弧形骨刀做与髋臼弧度一致的截骨,其截骨深达Ｙ形软骨,将截骨后的骨瓣向下扳压,在骨瓣上方植入２￣３只Ｖ形镍钛合金支架,术后４、１２周行双髋关节Ｘ线摄片,进行大体及组织学观察。结果 术后１２周髋臼顶部由术前斜坡形恢复为弧形,     

机械应力对幼鼠髋臼发育影响的实验研究

目的阐明异常机械应力对髋臼发育和髋臼软骨生长板内软骨细胞增殖的影响,探讨髋臼发育不良的修复方法。方法将60只3周龄的雌性Wistar大鼠分成3组,每组20只,左侧髋关节为实验侧,右侧为对照侧。A组:在2周内反复将髋关节手法脱位后再复位;B组:膝关节伸直位钢针固定,制作髋臼发育不良的动物模型,2周后拔出钢针;C组:持续伸直位固定膝关节。三组动物分别于第5、7、9、12周时进行钼靶软X线、组织形态学及透射电镜观察。结果A组第5周时唇缘变钝,髋臼角比对侧增大约5°,软骨生长板内增殖层软骨细胞极向紊乱,SO染色无差异,圆韧带有淋巴细胞浸润,第7、9、12周时变化小,两侧无差异;B组第5周时髋臼角比对侧明显增大,第7周时唇缘变钝、内翻,纤维增生,柱状细胞极性紊乱,肥大细胞层增多,第9、12周时接近正常,12周时髋臼角为23.4°,髋臼入口最短径为5.0mm;C组髋臼角比对侧持续增大,没有任何改善倾向,第12周时唇缘内翻、扁平,无明显柱状细胞排列,细胞核变小,细胞器减少,空泡形成,髋臼角为71.3°,髋臼入口最短径为2.9mm。结论在髋臼发育旺盛期解除异常机械应力、恢复头臼同心,髋臼发育不良有治愈倾向。造成髋臼发育不良的直接原因是软骨生长板内增殖层软骨细胞代谢功能发生改变,骨化延迟。     

青壮年先天性髋关节发育不良影像学分析及截骨重建手术规律

目的对青壮年先天性髋关节发育不良(DDH)进行影像学分析,揭示其截骨重建手术规律。方法 27例(27髋)DDH行髋部截骨重建,术前依据X线、CT片着重分析髋臼、股骨头外形、股骨头骨质质量及髋关节重建关键点。结果髋关节发育不良表现为髋臼变形,股骨头正常;不完全脱位表现为股骨头、髋臼重度变形;低位脱位表现为髋臼浅、髋臼壁不全,股骨头伴髋臼变形并生成头赘;高位脱位表现为代偿骨赘形成臼顶、髋臼壁残缺;股骨头与髋臼对应面平直,宽大裸区骨质萎缩。结论髋关节发育不良者应行髋臼截骨,恢复原有髋关节;髋关节脱位应采用联合截骨,重建有效髋关节。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.