股骨远端骨折三种内固定方法生物力学比较研究与临床应用

目的：对股骨远端骨折三种内固定方法定量生物力学评价,为临床选择有效的内固定方法提供理论依据。方法：取12具新鲜尸体股骨标本,制成股骨髁间骨折（AO分类的C1型）,采用股骨髁上交锁髓内钉,L形髁钢板,加压钢板三种内固定方法,进行实验应力分析,比较不同内固定方法的优劣,并以有限元理论分析进一步论证它的结果。结果：发现在受同等载荷条件下,髁上交锁髓内钉固定最佳,而采用加压钢板固定的股骨髁强刚度较差（P＜0．05）,临床手术47例,按Kolmert功能评定标准,优良率分别为：股骨髁上交锁髓内钉94．1％,L形髁钢板82．4％,加压钢板76．9％。结论：采和股骨髁上交锁骨内钉固定方法优于其它内固定方法,值得临床推广应用。     

股骨远端骨折的手术治疗

目的　评价不同内固定材料治疗股骨远端骨折的临床疗效。方法　应用L形髁钢板 ,动力加压钉板 ,股骨远端解剖钢板和逆行股骨髁上交锁髓内钉等 4种内固定材料治疗股骨远端骨折 53例 ,其中随访 1 2个月以上者 44例 (平均随访 1 7月 ) ,采用X线检查及膝关节KSS评分评估治疗结果。结果　本组 44例患者 ,6例骨折对位欠佳 ,5例出现内固定松动、断裂 ,其中 2例发生骨折不愈合 ,无一例发生感染。各内固定组的优良率分别是 ,L形髁钢板 71 4% ,动力加压钉板 1 0 0 % ,解剖钢板 88 9% ,逆行交锁钉 89 5 % ,各组间优良率无显著差异。结论　 4种内固定都能起到较好治疗效果 ,手术适应症选择得当和内固定材料的规范操作是关键。逆行股骨髁上交锁髓内钉适用于粉碎性骨折 ,解剖钢板适用于骨骺未闭合青少年骨折 ,动力加压钉板适用于“T”形和“Y”形骨折 ,L形髁钢板不作为治疗首选 ,可作为其他方法的补充选择     

股骨远端骨折3种内固定方法的生物力学研究比较

目的:对股骨远端骨折三种内固定方法进行定量生物力学比较,为临床选择有效的内固定方法提供理论依据。方法:取12具新鲜尸体股骨标本,制成股骨髁间骨折模型(AO分类的C1型),采用股骨交锁髓内钉(A)、"L"形髁钢板(B)、加压钢板(C)3种内固定方法,观察股骨髁上应变、位移、刚度、强度,对股骨远端3种内固定方法进行生物力学分析,并以有限元理论分析论证它的结果。结果:试验发现在受同等载荷条件下,髁上交锁髓内钉固定强度、刚度最佳,而采用"L"形髁钢板和加压钢板固定股骨髁强度、刚度较差。3组应力和髁间位移均有显著差异性(P0.05)。结论:采用股骨髁上交锁髓内钉固定方法优于其他内固定方法,具有操作简单、锁钉定位准确、固定牢靠等优点,是治疗股骨远端骨折较好的内固定方法。     

股骨远端骨折3种内固定方法疗效评价

目的探讨3种内固定方法治疗股骨远端骨折的临床疗效。方法对95例股骨远端骨折患者分别采用加压钢板（16例）、L形髁钢板（20例）、股骨髁上交锁髓内钉（59例）内固定。比较3组内固定的手术时间、术中出血量、术后引流量、骨折愈合时间。结果 95例均获随访,时间5个月~9年。手术时间：股骨交锁髓内钉组短于另两组（P〈0.05、P〈0.01）;术中出血量和术后引流量：股骨交锁髓内钉组均少于另两组（P〈0.01）;骨折愈合时间：股骨交锁髓内钉组（5.2±0.5）个月,L形髁钢板组（9±0.6）个月,加压钢板组（11.3±0.6）个月,差异有统计学意义（P〈0.01）。按Kolm ert功能评定标准,3组优良率分别为：股骨髁上交锁髓内钉组94.9%,L形髁钢板组80%,加压钢板组62.5%。结论采用股骨髁上交锁髓内钉固定方法疗效优于其他两种内固定方法,具有操作简单、出血少、创伤小、锁钉定位准确、固定牢靠、并发症少等优点,是治疗股骨远端骨折较好的内固定方法。     

髁上交锁钉治疗股骨远端骨折的生物力学与临床

目的：总结股骨髁上交锁髓内钉治疗股骨远端骨折的效果。方法：取12具新鲜尸体股骨标本,制成股骨髁间骨折（AO分类的C1型）,采用股骨髁上交锁髓内钉,L形髁钢板,加压钢板三种内固定方法,进行实验应力分析,比较没内固定方法的优劣,并以有限元理论分析进一步论证它的结果,应用股骨髁上交锁髓内钉治疗20例患（21个股骨）,骨折按AO／ASIF分类;A1 1例,A2 1例,A3 4例,B2 1例,C1 2例,C3 7例,结果：在受同等载荷条件下,髁上交锁髓内钉固定方法最佳,而采用髁钢板,加压钢板固定的股骨髁强刚度较差（P＜0．05）,采用股骨髁上交锁髓内钉平均手术时间100min,平均出血量400mL,平均随访11个月,骨折愈合时间4－10月（平均5．3月）,按Kolmert功能评定标准,优良18 例（90％）,一般1例,差1例,结论：股骨髁上交锁髓内钉可有效治疗股骨远端骨折,具有操作简便,出血少,锁钉定位准确,固定牢靠,并发症少等优点。     

股骨远端骨折手术治疗体会

目的探讨不同的手术策略治疗股骨远端骨折的临床效果。方法对100例股骨远端骨折患者,分别使用股骨远端解剖钢板、动力髁钢板、逆行股骨髁上交锁髓内钉、L形髁钢板进行治疗。比较治疗的优良率。结果股骨远端解剖钢板治疗优良率89.47%。逆行股骨髁上交锁髓内钉优良率90.48%。L形髁钢板优良率68.97%。动力髁钢板优良率93.55%。总优良85例(85.00%)。结论四种方式均有较好的效果,应根据不同骨折类型选择正确的固定方式和固定材料。     

股骨远端粉碎性骨折的内固定治疗

目的探讨不同内固定器材治疗股骨远端粉碎性骨折的临床疗效。方法应用L形钢板、动力加压髁钢板、股骨远端解剖钢板和逆行股骨髁上交锁髓内钉等4种材料治疗股骨远端粉碎性骨折。结果32例随访12~34个月,无感染病例,1例发生断钉致骨折延迟愈合。结论4种内固定都能起到较好治疗效果,手术规范操作是关键。     

应用不同内固定方法治疗股骨远端骨折的疗效分析

目的比较分析应用不同内固定方法治疗股骨远端骨折的疗效。方法对86例成人股骨远端骨折应用切开复位分别L形钢板(30例)、动力髁螺钉(Dynamic Condylar Screw，DCS)(22例)、髁上交锁髓内钉(36例)固定的方法进行治疗，术后随访1a以上，对其骨折愈合时间、膝关节活动度、短缩及畸形、步态等四项指标进行评价。结果3种固定方法优良率分别为33％(10／30)、36％(8／22)、83％(30／36)。L形钢板与动力髁钢板相比，无显差异，两与髁上交锁髓内钉相比，后明显优于前两。结论髁上交锁髓内钉内固定是目前治疗股骨远端骨折的最好方法，愈合率高，关节功能恢复好。     

股骨髁间骨折三种内固定方法生物力学实验研究与临床应用

目的　为临床选择有效的内固定方法提供实验依据。方法　取 9具新鲜尸体股骨标本 ,制成股骨髁间骨折 (AO分类的C1型 ) ,采用L形髁钢板 +螺栓、L形髁钢板、加压钢板 +螺栓三种内固定方法 ,进行实验应力分析 ,比较不同内固定方法的优劣 ,并以有限元理论分析进一步论证它的结果。结果　L形髁钢板 +螺栓内固定优于L形髁钢板、加压钢板 +螺栓固定 ,应力和髁间位移均具有显著差异 (P <0 0 1)。临床手术 5 2例中 43例平均随访 2 5个月 ,膝关节功能优良率分别为 :L形髁钢板+螺栓 95 % ,L形髁钢板 84 6 % ,加压钢板 +螺栓 81 8%。结论　L形髁钢板 +螺栓联合固定是治疗股骨髁间骨折较好的内固定方法。     

股骨远端骨折几种不同固定方法疗效分析

目的比效分析应用几种不同固定方法治疗股骨远端骨折的疗效。方法对70例成人股骨远端骨折切开复位分别应用股骨远端钢板(18例)、外固定架(20例)、髁上交锁髓内钉(32例)固定的方法进行治疗,术后随访1年以上,对其骨折愈合时间、膝关节活动度、短缩及畸形、步态等四项指标进行评价。结果3种固定方法优良率分别为39%(7/18)、35%(7/20)、88%(28/32)。股骨远端钢板与外固定架相比,无显著差异,二者与髁上交锁髓内钉相比,后者明显优于前二者。结论髁上交锁髓内钉固定是目前治疗股骨远端骨折的最好方法,愈合率高,关节功能恢复好。     

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.     

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.     

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.     

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.