低分子肝素和利伐沙班在髋膝关节置换中的应用

下肢深静脉栓塞是髋膝关节置换术后常见并发症,危险性大。目前对临床应用广泛的低分子肝素的有效性及安全性存在一定的争议,对其不良反应研究报道较少。大规模临床试验显示,逐渐应用于临床的利伐沙班作为一种新型口服抗凝药,具有较好的疗效及安全性。该文就低分子肝素和利伐沙班在预防髋膝关节置换术后下肢深静脉栓塞形成中的作用作一简要综述。     

低分子肝素使用时机对关节置换手术失血量和DVT发生率的影响

目的 探讨全髋和全膝置换手术使用低分子肝素预防深静脉血栓(deep vein thrombosis,DVT)的时机对手术失血量和术后DVT发生率的影响.方法 单侧初次关节置换262例中全髋关节置换179例,术前开始使用低分子肝素82例,术后开始使用97例;全膝关节置换83例,术前开始使用低分子肝素44例,术后开始使用39例.根据患者身高、体重及手术前后红细胞压积和输血量,计算两种给药时机的总失血量、隐性失血量及其占原血容量的比例,并比较DVT发生率.结果 (1)全髋关节置换患者术前开始使用低分子肝素组总失血量平均为1638ml,占原血容量的38.1%;术后开始使用低分子肝素组1425ml,占原血容量的34.2%.全膝关节置换患者术前使用低分子肝素组1569ml,占原血容量的37.4%;术后开始使用低分子肝素组1319ml,占原血容量的31.6%.全髋和全膝置换术前开始使用与术后开始使用低分子肝素比较总失血量与其占原血容量比例的差异均有统计学意义.(2)全髋关节置换DVT的发生率为16.2%,全膝关节置换为25.3%,差异无统计学意义.结论 术前使用低分子肝素可增加全髋和全膝关节置换手术的总失血量和隐性失血量,使用低分子肝素的时机对术后DVT的发生率无影响,术后再使用低分子肝素更安全.     

Low molecular weight heparin prophylaxis in total knee arthroplasty: the answer.

Venous thrombosis continues to be a major risk after total knee arthroplasty. Without prophylaxis, the prevalence of deep vein thrombosis is as high as 84%, with proximal occurrence as high as 20%. Of more concern is the occurrence of pulmonary embolism as high as 7%, with fatal pulmonary embolism as high as 0.7%. This high prevalence mandates that prophylaxis for thromboembolic disease be used for patients undergoing total knee arthroplasty. Low molecular weight heparin has been studied extensively and is safe and effective prophylaxis after total knee arthroplasty. Low molecular weight heparins have a predictable dose response, offer high bioavailability at low doses, and produce linear pharmacokinetics. It has a half-life of approximately 4.5 hours providing effective dosing every 12 to 24 hours with rapid antithrombotic action. Routine pharmacologic prophylaxis with low molecular weight heparin seems to be effective in decreasing the occurrence of venous thromboembolism. However, venographic prevalence of deep vein thrombosis among patients undergoing total knee arthroplasty and receiving prophylaxis remains substantial at 30.6%. Prophylaxis with low molecular weight heparin beyond hospitalization may be indicated with decreased hospital stays, although studies have not been convincing that extended outpatient prophylaxis for more then 7 to 10 days is necessary.     

利伐沙班与低分子肝素在预防人工全膝关节置换术后深静脉血栓形成的分析

[目的]观察利伐沙班与低分子肝素在预防人工全膝关节置换深静脉血栓的疗效性和安全性.[方法]回顾性分析2009年5月～2011年2月行人工全膝关节置换术的患者200例,将其分为两组,利伐沙班组100例,给予利伐沙班10mg/d口服,连续14d;低分子肝素组的100例,术后给予低分子肝素5000IU/d皮下注射,连续14d.术后14d行双下肢静脉彩超检查有无深静脉血栓形成,并观察两组用药期间有无肺动脉栓塞和严重出血事件的发生.[结果]利伐沙班组深静脉血栓形成的发生率5％,显著低于低分子肝素组的9％,两组均末发生肺动脉栓塞和严重出血事件.[结论]应用利伐沙班较低分子肝素更有效预防膝关节置换术后下肢深静脉血栓的形成,出现严重出血事件很少,二者均较安全.     

利伐沙班与低相对分子质量肝素预防人工髋膝关节置换术后静脉血栓栓塞症的前瞻性随机对照研究

目的 通过比较利伐沙班与低相对分子质量肝素(LMWH)对静脉血栓栓塞症(VTE)的预防作用,评价两者预防人工全髋关节置换术(THA)和全膝关节置换术(TKA)后VTE的有效性与安全性.方法 2009年8月至2010年7月共收治84例行THA和TKA的患者,随机分为利伐沙班组和LMWH组,利伐沙班组48例,男13例,女35例;平均年龄63.9岁;THA 25例,其中1例行双侧置换术;TKA23例,其中10例行双侧置换术.LMWH组36例,男10例,女26例;平均年龄57.2岁;THA 16例,其中5例行双侧置换术;TKA 20例,其中6例行双侧置换术.THA患者术后第1～35天、TKA患者术后第1～14天,利伐沙班组给予利伐沙班10 mg,1次/d,口服;LMWH组给予LMWH 0.4 mL,1次/d,皮下注射. 结果两组患者围手术期失血量差异均无统计学意义(P＞0.05).所有患者术后获3个月随访.利伐沙班组深静脉血栓形成(DVT)发生率为20.8%(10/48),LMWH组DVT发生率为25.0%(9/36),两组比较差异无统计学意义(χ2=0.204,P=0.651).两组患者均未发生症状性肺栓塞. 结论利伐沙班能有效预防THA、TKA后下肢DVT的发生,同时具有良好的安全性,其疗效与LMWH相当,且不会增加出血等并发症.     

Thrombosis prophylaxis with low molecular weight heparin in total hip replacement

In a randomized prospective trial, the efficacy of low molecular weight heparin (LMWH) (Fragmin) and dextran 70 (Macrodex) in preventing deep vein thrombosis (DVT) in the legs was evaluated in 98 consecutive patients undergoing elective total hip replacement. The patients were randomly allocated to receive either 2500 anti-factor Xa units LMWH twice daily for 7 days, with the first dose given 2 h before surgery; or 500 ml dextran 70 twice during the day of operation, followed by a single infusion of 500 ml on the first and again on the third postoperative day. DVT was assessed by 125I-fibrinogen test for 2 weeks postoperatively, a positive test being followed by phlebography. DVT developed in 22 (45 per cent) of 49 patients receiving dextran 70 and in 10 (20 per cent) of 49 patients in the LMWH group (P less than 0.01). LMWH was thus statistically significantly better than dextran 70 in preventing DVT in the legs. It was not firmly established whether this benefit was also valid in the high ileofemoral region. Two patients with non-fatal pulmonary embolism were found in each group. Per- and postoperative blood loss and blood transfusion requirements were significantly lower in the LMWH group.     

Similar thromboprophylaxis with rivaroxaban and low molecular weight heparin but fewer hemorrhagic complications with combined intra-articular and intravenous tranexamic acid in total knee arthroplasty

European Journal of Orthopaedic Surgery & Traumatology - To evaluate the efficacy of the combined intravenous and intra-articular administration of tranexamic acid (TXA) to control the...     

The effect of total knee arthroplasty on body weight

This prospective study quantified the weight change in 20 consecutive patients undergoing total knee arthroplasty. Resected bone, soft tissues, and bone reamings were collected during surgery and weighed using a digital scale at the end of the procedure. Results were compared to the cumulative weights of the prosthesis, bone cement, patellar component, and polyethylene liner. Average weight of the resected bone and soft tissues was 167.71 g for men and 130.13 g for women. Mean weight of the implanted prosthesis and cement used was 509.92 g for men and 422.56 g for women. Men tended to receive a larger-sized prosthesis than women. Overall, the average weight gain as a result of knee arthroplasty was 345.54 g for men and 292.44 g for women. This translates to an insignificant increase in body weight.     

低分子量肝素在血液透析中的应用

为探讨低分子量肝素在血液透析中的抗凝作用，选择血液透析患者６０例、１５００例次，分成两组。一组透析中使用肝素抗凝，另一组使用低分子量肝素（ＣＸ）抗凝，分别测量凝血时间、凝血酶原时间、活化部分凝血活酶时间及血小板，进行对照研究。结果发现，ＣＸ比肝素能更有效地抗凝，又能减少出血倾向，透析器复用次数明显增加，活化部分凝血活酶时间降低（Ｐ＜０．０１）。表明低分子量肝素特别适用于有出血倾向者，可代替肝素在血液透析中应用。     

The role of patellar resurfacing in total knee arthroplasty

The ideal treatment of the patella in primary total knee arthroplasty (TKA) for osteoarthritis (OA) remains unclear. Although data exist in the literature to support either resurfacing or not resurfacing the patella, evidence continues to emerge that unresurfaced patellas deteriorate with time. Recent prospective, randomized studies also favor patellar resurfacing over retaining the native patella, reporting reoperation rates to convert unresurfaced to resurfaced patellas exceeding those for complications after patellar resurfacing. In addition, the incidence of residual patellofemoral pain after secondary resurfacing is substantially higher than when patellofemoral resurfacing is done primarily. Patient selection criteria are critical in the decision-making process. Patellofemoral complications, the greatest argument against resurfacing, have been diminished with improved surgical techniques and implant design.     

The role of bladder catheterization in total knee arthroplasty

The use of a urinary bladder catheter in the perioperative period for patients undergoing total knee arthroplasty is controversial. In the current study, two bladder management protocols were studied. One group of patients had an indwelling catheter inserted into the bladder before total knee arthroplasty. The other group of patients was observed and treated for urinary retention as necessary. From 1993 to 1998, 652 patients undergoing primary, unilateral total knee arthroplasty were randomized by surgeon into two groups: one group underwent preoperative insertion of an indwelling bladder catheter (306 patients), and one group (346 patients) had a catheter inserted postoperatively as necessary. Sixty-six percent (229 of 346) of these patients required catheterization (203 had indwelling catheters and 26 had intermittent straight catheters). A urinary tract infection developed in five patients (1.6%) in whom a catheter was inserted preoperatively. A urinary tract infection developed in six patients (1.7%) in whom a catheter was inserted if necessary. Five of these urinary tract infections developed in patients with delayed indwelling bladder catheters. A urinary tract infection did not develop in any patient in whom a straight catheter was inserted. There was no significant difference in the length of stay in the hospital between the two groups. The group in whom a catheter always was inserted generated $491 greater cost for total knee arthroplasty than patients in whom a catheter was inserted if necessary.     

Antiproliferative effects of low molecular weight heparin

AIM: To investigate the effect of low molecular weight heparins (LMWH) on the inhibition of intimal hyperplasia (IH) developing in prosthetic vascular patch graft implanted into sheep carotid artery. METHODS: A gelatin sealed Dacron patch graft was implanted into the common carotid artery of sheep, which were then allocated to a control group (n = 10) or to one of four treatment groups (each group n = 10) receiving either a low dose (LD) or high dose (HD) of one of two LMWH (enoxaparin 1 or 2 mg/kg/day, dalteparin 100 or 200 units/kg/day) administered subcutaneously for 4 weeks. Anti-activated factor X and activated partial thromboplastin time were assayed from blood collected prior to and at 1 and 2 h after LMWH administration on days 3, 7, 14, 21 and 28. Animals were killed on day 28 after taking blood samples prior to, then at 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 h following the last injection. Grafts were collected for analysis and measurements of intimal thickness obtained under light microscopy from eight transverse sections of each grafted artery aided by computer image analysis. An IH index was calculated by dividing the area of IH (mm2) by the width of the graft (mm). RESULTS: Intimal hyperplasia index measurements (mean +/- SD) were: controls 0.574 +/- 0.077, LD enoxaparin 0.471 +/- 0.056, LD dalteparin 0.404 +/- 0.025, HD enoxaparin 0.398 +/- 0.068, HD dalteparin 0.332 +/- 0.048. The reductions in IH index compared to controls were significant (P < 0.05) for both LD and HD dalteparin and for HD enoxaparin. CONCLUSION: Both LMWH dalteparin and enoxaparin reduced the amount of IH formation with dalteparin showing a greater effect in the present animal study. The possibility that different LMWH might exert differing antiproliferative effects requires further investigation.     

The role of femoral stem extension in total knee arthroplasty

Although stemmed femoral components often are used in revision total knee arthroplasty, no quantitative comparison of the relative stability of a femoral component with and without a stem has been performed previously. A radiostereophotogrammetric analysis was performed to determine the influence of stem extension on mechanical stability in a laboratory experiment. In addition, the contribution of impacted morselized bone graft used for reconstruction of bone defects to stability was determined. Ten fresh frozen distal femoral specimens, of which the bone mineral density was measured, were prepared to fit a cemented femoral component with an uncemented stem. A cyclic axial load of 750 N was applied to the medial part of the femoral component. The loading test was repeated after creation of a standard, unicondylar, uncontained medial bone defect, after reconstruction of the defect with impacted morselized bone graft, after disconnecting the stem from the component, and after removal of the morselized bone graft. A significant difference was found in rotation and translation of the femoral component with the stem and after its functional removal. The femoral component rotated significantly into varus and internal rotation, and the tip of the stem translated significantly laterally after disconnection of the stem. A linear correlation between bone mineral density in the femoral neck and the radiostereophotogrammetric motion data was absent, but a bone mineral density threshold level of 0.55 g/cm2 was present, below which stability decreased considerably. Morselized bone graft provided only a minor contribution to stability compared with a stem.     

The role of unicompartmental knee arthroplasty versus total knee arthroplasty in providing maximal performance and satisfaction

Unicondylar knee arthroplasty (UKA) and total knee arthroplasty (TKA) are both recommended for the treatment of medial compartment osteoarthritis in the varus knee. Some authors report favorable functional results and patient satisfaction from TKA on the basis of extensive, long-term success of knee arthroplasty. Others cite the arduous rehabilitation and bone loss associated with traditional knee arthroplasty, opting for UKA, especially in young, high-demand patients. This article reviews the elements of successful UKA. It emphasizes the advantages of UKA versus traditional knee arthroplasty and minimally invasive TKA.     

全髋关节置换术中小剂量肝素的应用研究

目的研究全髋关节置换术中使用小剂量肝素的有效性和安全性。方法在纽约特种外科医院的行全髋关节置换的患者共993例,从2006年1月到2010年5月。其中男473例,女529例,均排除了患有血小板减少症、出血体质以及不能行硬膜外麻醉的患者。手术采用硬膜外低压麻醉（平均动脉压维持在45～55mmHg）,行后外侧切口,尽量减少股静脉扭曲的时间,反复冲洗和吸引出股骨髓腔内容物。当处理髋臼侧的时候,下肢处于中立位置。处理股骨侧髓腔之前2—3min,静脉给予肝素（10—15U／kg）。结果此组患者平均手术时间83分钟（35～268min）,平均失血量183ml（50—1400m1）。术后随访3个月。本组患者共有13例发生血栓性疾病,占患者总数的1．3％。所有血栓患者中确诊为DVT的有10例,发生率为1％。没有一例患者发生切口血肿及主要出血并发症。随访期间没有一例患者死亡。结论全髋关节术中给予肝素血栓发生率低,术后无相关的出血并发生。     

Low-molecular-weight heparin and partial thromboplastin time-adjusted unfractionated heparin in thromboprophylaxis after total knee and total hip arthroplasty

Thromboprophylaxis with heparins after total hip arthroplasty (THA) and total knee arthroplasty (TKA) is well established. The aim of this study was to compare low-molecular-weight heparin (enoxaparin) with partial thromboplastin time (PTT)-adjusted, unfractionated heparin (heparin sodium). In a prospective study of THA and TKA 246 patients, physical examination and compression and duplex ultrasound were performed 1 day before and 7 and 14 days after surgery. One hundred thirty patients received 40 mg enoxaparin subcutaneously once per day. One hundred sixteen patients received 5,000 IU heparin sodium subcutaneously 3 times daily. As the PTT did not reach 40 seconds, the heparin sodium dosage was increased to 7,500 IU 3 times daily. The overall thrombosis rate was 4% (n = 10). In the enoxaparin group, the rate was 2.9% of the 70 THAs and 10% of the 60 TKAs. Thrombosis also occurred in the group that received heparin sodium: 1.8% of the THAs and 1.7% of the TKAs. For TKA, the difference between the 2 heparin groups was statistically significant. In the thromboprophylaxis of TKA, PTT-adjusted unfractionated heparins are superior to fixed doses of low-molecular-weight heparins.