股骨髁间窝的影像学测量及其临床意义

目的:观测股骨髁间窝的形态及大小,以及与前交叉韧带损伤、性别、身高、体重的关系.方法:采用屈膝45.后前位投照法对62个正常人膝关节行股骨髁间窝穿通位摄片.在肌腱沟水平测量股骨髁间窝宽度及股骨髁宽并计算股骨髁间窝宽度指数.结果:正常髁间窝形状呈倒“U”形.62个髁间窝宽为(18.9±4.8)mm,男为(19.8±3.8)mm,女为(18.3±5.3)mm,(t=1.29,P＞ 0.05).髁间窝指数平均为0.24±0.05.髁间窝指数与身高(r=-0.11)、体重(r=-0.13)、年龄(r=-0.28)不相关.结论:屈膝45.髁间窝穿通位像可完整显示髁间窝的形态与宽度.该测量可为临床上股骨髁间窝相关疾病的诊断和治疗提供放射学基础.术前对髁间窝进行影像学测量有着重要临床意义.     

股骨髁间窝的应用解剖及其临床研究

目的 探讨如何完善髌韧带中1／3重建前叉韧带术式，防止重建韧带撞 现象的发生。方法 测量42例和73例正常干、湿性股骨髁间窝标本的横径、纵径及其相关值；通过对湿性膝关节标本股骨髁间窝与前交叉韧带和重建韧带解剖关系的观测，确定膝关节伸展时髁间窝与韧带发生撞击的部位，在髌韧带中1／3重建前叉韧带的模拟和临床手术中， 切除股骨髁间窝前外侧壁及顶部部分骨质，加宽加深髁间窝，保持重建韧带与其有5mm间距。结果 临床应用19例中随访1年以上者11例，无1例出现重建韧带撞击现象，膝关节稳定性恢复良好。结论 股骨髁间窝扩大成形能有效地防止髁间窝对髌韧带的撞击，保证其顺利地替代前叉韧带的功能。     

前交叉韧带重建术中胫骨骨道定位的应用解剖研究

[目的]探究前交叉韧带(anterior cruciate ligament,ACL)于胫骨止点处的解剖形态以及测量髁间窝顶线与胫骨平台交汇点至后交叉韧带前缘的距离对胫骨骨道定位的解剖学意义,为ACL重建术提供理论依据。[方法]选取新鲜成人膝关节标本8例,仔细剔除关节周围肌肉、后关节囊等结构,保留前后交叉韧带及两侧侧副韧带,保证膝关节正常屈伸范围。在屈伸膝关节时按照ACL纤维张力区将其分为前内束和后外束,在胫骨附着处将ACL切断制备ACL损伤模型。用测量工具和Phontoshop软件获取ACL基本解剖参数以及髁间窝顶线与胫骨平台的交汇点、ACL前缘、ACL胫骨止点的中心点分别至后交叉韧带前缘的距离。[结果]ACL平均体部直径为(11.21±0.76)mm,ACL在胫骨止点处的平均最大横径为(11.34±0.79)mm,平均最大前后径为(16.54±0.82)mm。前内束和后外束在胫骨止点处的平均面积分别为(113.35±29.65)mm~2和(83.29±16.99)mm~2。髁间窝顶线与胫骨平台的交汇点、ACL前缘以及ACL胫骨止点的中心点至后交叉韧带前缘的距离分别为(12.13±0.96)mm,(21.14±0.83)mm和(8.82±0.77)mm。[结论]利用胫骨平台骨道定位ACL在股骨的解剖止点现实可行,在ACL重建术中具有重要意义。     

前内侧入路解剖重建单束前交叉韧带的临床评估

目的评估关节镜下经前内侧入路解剖重建单束前交叉韧带(ACL)的位置、形态及临床效果。方法对25例ACL断裂患者在关节镜下经前内侧入路应用解剖重建技术行单束ACL重建术,移植物应用自体腘绳肌腱。术后行X线、MRI检查,了解骨道情况,观察移植物形态及张力,并与11例健侧膝关节的正常ACL进行对比。应用Lysholm评分系统评估膝关节功能。结果术后X线片显示股骨隧道内口位于髁间窝顶与股骨后缘皮质线交叉点前缘,胫骨隧道内口位于髁间窝顶后方。MRI显示所有重建ACL张力良好,ACL上倾角为50.82°±4.57°,胫骨平台止点至前缘距离与平台纵径比值为0.50±0.04,两项与对照组比较差异均无统计学意义(P0.05)。患者均获得随访,时间为13~44个月。Lysholm评分术后为92.20分±4.29分,明显高于术前的64.76分±7.16分(P0.01)。结论关节镜下经前内侧入路解剖重建ACL的位置及形态接近解剖结构,早中期临床效果满意。     

前交叉韧带

前交叉韧带（ anterior cruciate ligament, ACL）实质部是既有弹性又有刚性的致密结缔组织,位于关节内,却被滑膜包绕,是关节内滑膜外结构。韧带起于股骨外侧髁后内侧一个半圆形的区域内,向前内下走行,穿过髁间窝止于胫骨前部到髁间棘之间。长度约30～38mm,宽度约10～12mm。     

关节镜下双股半腱肌腱转移重建后交叉韧带

目的:报告关节镜下双股半腱肌腱转移重建后交叉韧带及分析影响其手术效果因素.方法:采用开口螺旋肌腱剥离器,保留肌腱远侧附着点,在近侧腱肌交界处切断半腱肌腱,对折两股编织转移镜下重建后交叉韧带.隧道内口侧可吸收挤压螺钉固定,股骨隧道外口加强固定.结果:手术28例,平均随访33个月,按照日本骨科协会制定的膝关节疗效评定标准,优良率为85.7%.结论:(1)关节镜下双股半腱肌腱转移重建后交叉韧带,较B-PT-B通过隧道时柔顺通畅;(2)隧道内口可吸收钉挤压固定,愈后内口消失,避免韧带撞击内口使之逐渐扩大引起重建韧带松驰.(3)隧道内外口的坚强固定,使重建后交叉韧带有足够刚强度.     

关节镜下双股半腱肌腱转移重建后交叉韧带

目的:报告关节镜下双股半腱肌腱转移重建后交叉韧带及分析影响其手术效果因素。方法:采用开口螺旋肌腱剥离器,保留肌腱远侧附着点,在近侧腱肌交界处切断半腱肌腱,对折两股编织转移镜下重建后交叉韧带。隧道内口侧可吸收挤压螺钉固定,股骨隧道外口加强固定。结果:手术28例,平均随访33个月,按照日本骨科协会制定的膝关节疗效评定标准,优良率为85.7％。结论:(1)关节镜下双股半腱肌腱转移重建后交叉韧带,较B-PT-B通过隧道时柔顺通畅;(2)隧道内口可吸收钉挤压固定,愈后内口消失,避免韧带撞击内口使之逐渐扩大引起重建韧带松驰。(3)隧道内外口的坚强固定,使重建后交叉韧带有足够刚强度。     

关节镜下双股半腱肌腱转移重建后交叉韧带

目的：报告关节镜下双股半腱肌腱转移重建后交叉韧带及分析影响其手术效果因素。方法：采用开口螺旋肌腱剥离器，保留肌腱远侧附着点，在近侧腱肌交界处切断半腱肌腱，对折两股编织转移镜下重建后交叉韧带。隧道内口侧可吸收挤压螺钉固定，股骨隧道外口加强固定。结果：手术28例，平均随访33个月，按照日本骨科协会制定的膝关节疗效评定标准，优良率为85．7％。结论：(1)关节镜下双股半腱肌腱转移重建后交叉韧带，较B-PT-B通过隧道时柔顺通畅；(2)隧道内口可吸收钉挤压固定，愈后内口消失，避免韧带撞击内口使之逐渐扩大引起重建韧带松驰。(3)隧道内外口的坚强固定，使重建后交叉韧带有足够刚强度。     

基于MRI二维影像下股骨髁间窝的三维可视化研究

目的通过MRI二维影像对股骨髁间窝进行三维重建及测量,探讨虚拟股骨髁间窝成形术的可行性。方法 2009年9月-12月募集健康志愿者30名,男、女各15名,年龄20～30岁,身高150～185 cm,体重45～74 kg。排除膝关节疾病和手术史。根据性别不同将研究对象分为男性组和女性组,并将同性别的膝关节分为左膝及右膝2个亚组。对30名志愿者行双膝关节MRI扫描,将MRI二维图像导入交互式医学影像控制系统Mimics10.01,并对膝关节进行三维重建,通过三维图像测量获取髁间窝相关解剖学数据:髁间窝宽度(notch width,NW),内、外股骨髁宽度(condylar width,CW),髁间窝指数(notch width index,NWI)。收集2010年1月-3月收治的前交叉韧带(anteriorcruciate ligament,ACL)损伤患者膝关节三维图像,筛选出4例髁间窝狭窄(NWI≤0.2)的患者,在患者膝关节三维图像上虚拟髁间窝成形术,计算截骨厚度,并在ACL重建术中实施,评估移植物与髁间窝的撞击情况。结果男性组与女性组双侧股骨髁间窝三维模型的NW、CW比较差异均有统计学意义(P<0.05),NWI比较差异无统计学意义(P>0.05)。男性组内及女性组内左、右膝股骨髁间窝三维模型的NW、CW、NWI比较差异均无统计学意义(P>0.05)。在ACL重建术中,根据术前测量结果行髁间窝成形术后患者的NWI达正常值(NWI>0.22),韧带重建后关节镜观察以及术后3个月随访时行基于MRI二维图像的数字化三维重建膝关节模型并测量发现重建韧带与髁间窝无撞击。结论计算机三维重建模型与实体的髁间窝形态有较高相似度,NWI可较好地反映髁间窝狭窄程度;计算机虚拟髁间窝成形术可为ACL重建提供术前参考,以避免术后移植物与髁间窝的撞击。     

膝关节前交叉韧带前内束和后外束股骨止点位置的解剖研究

目的探讨膝关节前交叉韧带（ACL）前内束及后外束股骨止点的解剖位置,找到确定ACL前内束和后外束股骨止点的简单可行的方法,为双束重建ACL手术中的股骨骨道定位提供理论支持。方法解剖18个新鲜膝关节标本（25～45岁）的股骨端前内束和后外束的足迹,以标定前内束和后外束股骨止点中心点的位置。在屈膝90°位,测量ACL前内束及后外束股骨止点中心点距股骨髁间窝外侧壁前方、后方和下方软骨缘的距离。再对测量数据进行评估和对比。结果 ACL后外束股骨止点中心点距离股骨前方软骨缘（8.55±1.33）mm,距离股骨后方软骨缘（8.65±1.54）mm,二者间无统计学差异（t=-0.191,P〉0.05）;而ACL后外束股骨止点中心点距离股骨下方软骨缘（5.11±0.79）mm。ACL前内束股骨止点中心点距离股骨前方软骨缘（14.95±2.06）mm,距离股骨后方软骨缘（6.08±0.88）mm,二者间有统计学差异（t=16.633,P〈0.01）;而ACL前内束股骨止点中心点距离股骨下方软骨缘（9.10±1.55）mm。结论膝关节屈膝90°时,ACL后外束的股骨止点中心点位于股骨髁间窝外侧壁距离下方软骨缘5mm的高度,并处在与前方和后方软骨缘几乎等距的位置。而ACL前内束的股骨止点中心点位于股骨髁间窝外侧壁距离下方软骨缘9mm的高度,并处在前后连线大约后1/3的位置。在ACL双束重建的手术中,应用本研究的结果能够简单、快捷地确定ACL前内束和后外束股骨骨道位置。     

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 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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.     

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.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.