Thromboelastography in elective total hip arthroplasty

BACKGROUNDHypercoagulability plays an important role in predisposing patients to venous thromboembolism (VTE) after total hip arthroplasty (THA). We used thromboelastography (TEG) to examine the coagulation status of patients undergoing THA.AIMTo examine coagulation as measured by TEG in patients undergoing THA who received standard VTE chemoprophylaxis with enoxaparin. METHODSAfter ethical approval, we performed a retrospective analysis of data collected in patients undergoing primary elective THA. We analyzed TEG data on samples performed before skin incision, intraoperatively and for 5 d postoperatively. Conventional coagulation tests were performed preoperatively and on postoperative day 5. RESULTSTwenty patients undergoing general anesthesia and 32 patients undergoing spinal anesthesia (SA) were included. TEG demonstrated a progressively hypercoagulable state postoperatively, characterized by elevated maximum amplitude. TEG also demonstrated transient intraoperative hypercoagulability in patients receiving SA. In contrast, conventional coagulation tests were normal in all patients, pre- and postoperatively, except for an increase in plasma fibrinogen day 5 postoperatively. CONCLUSIONDespite VTE prophylaxis, patients following total hip replacement remain in a hypercoagulable state as measured by both TEG and conventional tests. This group may benefit from more optimal anticoagulation and/or additional perioperative hemostatic monitoring, via TEG or otherwise.     

Predictors of lower extremity arterial injury after total knee or total hip arthroplasty

OBJECTIVE: Lower extremity arterial injury is a rare complication following total knee (TKA) or total hip arthroplasty (THA). To date, no multi-institutional study has identified preoperative factors that may portend increased risk for these injuries. We queried a large clinical database for the incidence and predictors of arterial injury and/or compromise following lower extremity arthroplasty. METHODS: Prospectively collected preoperative and postoperative data by the National Surgical Quality Improvement Program (NSQIP) of the Veterans Affairs Medical Centers were analyzed. All patients from 1996 to 2003 in the NSQIP database who underwent TKA or THA were identified via CPT codes. NSQIP defined, 30-day, postoperative outcomes were analyzed. Data were compared using bivariable analysis, as well as limited multivariable logistic regression. RESULTS: A total of 41,633 arthroplasties (24,029 TKA, 2077 redo-TKA, 13,494 THA, 2033 redo-THA) were identified in the NSQIP database. A total of 34 (0.08%) lower extremity arterial injuries were recognized (0.08% TKA, 0.19% redo-TKA, 0.04% THA, 0.20% redo-THA). Eighteen injuries were repaired on the same day of surgery (seven intraop, 11 postop), eight between postoperative days 1 and 5, and 8 between days 6 and 30. Only two patients underwent lower extremity amputation (overall limb loss rate of 5.9% of patients who had arterial injury). Statistically significant predictors of lower extremity arterial injury identified on logistic regression analysis included redo procedure (odds ratio [OR] 2.7, 95% confidence interval [CI] 1.2-6.0, P = .013) and African American race (OR 2.5, 95% CI 1.2-5.3, P = .02). CONCLUSION: Lower extremity arterial injury was exceedingly rare after total knee or total hip arthroplasty. There is an increased incidence in African American patients and those undergoing redo arthroplasty. Among patients who sustain vascular injury, excellent limb salvage rates can be achieved with close postoperative surveillance to achieve early detection and repair of injuries.     

Time-driven activity-based cost of outpatient total hip and knee arthroplasty in different set-ups

Background and purpose — Length of stay (LOS) following total hip and knee arthroplasty (THA and TKA) has been reduced over the years due to fast-track. Short stays of 2 days in fast-track departments in Denmark have resulted in low total costs of around US$2,550. Outpatient THA and TKA is gaining popularity, albeit in a limited and selected group of patients; however, the financial benefit of outpatient arthroplasty remains unknown. We present baseline detailed economic calculations of outpatient THA and TKA in 2 different settings: one from the hospital and another from the ambulatory surgery department.

Patients and methods — Data from 6 patients (1 TKA, 1 uncemented THA, 1 cemented THA in each department) were collected prospectively using the Time Driven Activity Based Costing method (TDABC). Time consumed by different staff members involved in patient treatment in the perioperative period of outpatient THA and TKA was calculated in 2 different settings: one in the orthopedic department and one in the ambulatory surgery department.

Results — LOS was around 11?h in the orthopedic department and around 7?h in the ambulatory surgery department, respectively. TDABC revealed minor differences in the operative settings between departments and similar expenses occurred during the short stay of US$777 and US$746, respectively. Adding the preoperative preparation and postoperative follow-up resulted in total cost of US$951 and US$942 for the ward and the ambulatory surgery department, respectively.

Interpretation — Outpatient THA and TKA in hospital and ambulatory surgery departments results in similar cost using the TDABC method. Compared with the cost associated with 2-day stays, outpatient procedures are around two-thirds cheaper provided no increase occurs in complications or readmissions.     

Evaluation of the safety and efficacy of the perioperative administration of rofecoxib for total knee arthroplasty.

Nonsteroidal anti-inflammatory drugs (NSAIDs) frequently are discontinued before elective total knee arthroplasty (TKA) because of the increased incidence of perioperative bleeding. Rofecoxib, a selective cyclooxygenase 2 inhibitor, does not interfere with the coagulation system and may be a safer NSAID for patients undergoing TKA. In this study, 100 patients undergoing elective TKA discontinued their use of NSAIDs 10 days before surgery and were assigned randomly to receive either placebo (n = 50) or rofecoxib (n = 50), 25 mg daily for 5 consecutive days starting 3 days before surgery. The administration of rofecoxib resulted in improved preoperative pain scores and no significant increase in the incidence of perioperative bleeding or international normalized ratio compared with placebo. Rofecoxib does not need to be discontinued before elective TKA.     

Perioperative risk factors for deep vein thrombosis after total hip arthroplasty or total knee arthroplasty

Study ObjectiveTo determine the perioperative frequency of deep vein thrombosis (DVT) after lower limb joint prosthesis surgery using Doppler ultrasonography (US).DesignProspective cohort study.SettingOperating room and hospital ward.Patients144 consecutive ASA physical status 1 and 2 patients who underwent elective total hip arthroplasty (THA; n=64) or total knee arthroplasty (TKA; n = 80).InterventionsPatients were allocated to two groups, those who developed DVT (DVT group) postoperatively and those who did not (no-DVT group). To examine the perioperative risk factors for DVT after THA or TKA, comparative analysis of the two groups was done.MeasurementsDoppler US was performed on all patients from the bilateral femoral to lower limb to detect the existence of DVT postoperatively.Main ResultsDVT was detected in 61 patients (42%), including three proximal DVT patients (2%). Preoperative elevated plasma D-dimer value [P = 0.0131, odds ratio (OR) 1.54, 95% CI 1.10-2.17] and history of hyperlipidemia (P = 0.0453, OR 6.92, 95% CI 1.04-46.00] were significant risk factors for the onset of DVT. A preoperative plasma D-dimer cutoff value as a diagnostic test was obtained as 0.85 μg/mL.ConclusionsA high preoperative plasma D-dimer value and/or history of hyperlipidemia were risk factors for DVT after THA or TKA.     

Acute arterial complications associated with total hip and knee arthroplasty

OBJECTIVE: To our knowledge, ours is the largest single-center experience with diagnosis and management of acute arterial hemorrhagic and limb-threatening ischemic complications associated with total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: Between 1989 and 2002, 23,199 TKA procedures (13,618 total, 11,953 primary, 1665 revision) and THR procedures (9581 total, 7812 primary, 1769 revision) were performed at the orthopedic service of Pennsylvania Hospital, Philadelphia. Arterial injuries were grouped according to type (ischemia, bleeding, pseudoaneurysm, ischemia plus bleeding) and time of recognition of injury (0-5 days after orthoplasty). RESULTS: Acute arterial complications developed in 32 patients (0.13%), associated with 24 TKA procedures (0.17%) and 8 THA procedures (0.08%; P =.0609). There were no deaths, and limb salvage was achieved in all patients. Arterial injury was detected by the orthopedic service on the same day (SD group) as performance of joint replacement in 18 patients (56%), but was not recognized until the first to fifth postoperative day (PO group) in 14 patients (44%). Arterial complications included acute lower-limb ischemia only in 18 patients SD group, 9; PO group, 9), bleeding only in 4 patients (SD group), arterial transection resulting in both ischemia and bleeding in 5 patients (SD group), and arterial pseudoaneurysm in 5 patients (PO group). Of the 18 patients with acute ischemia only, preoperative arteriography was performed in 12 patients (67%), and 6 patients (33%) were brought directly to the operating room because of advanced ischemia. Revascularization procedures in these 18 patients included bypass to the infrapopliteal artery (n = 7), popliteal artery (n = 5), or common femoral artery (n = 1); in only 5 patients (28%) was thrombectomy alone successful. These 18 patients tended to require fasciotomy (4 of 9 vs 2 of 9; P =.6199) and have foot drop (3 of 9 vs 1 of 9; P =.5765) more frequently when ischemia was recognized after the day of surgery. Bleeding was managed with arteriorrhaphy. Arterial transection was treated with end-to-end anastomosis (n = 3), interposition grafting (n = 1), and below-knee popliteal bypass (n = 1). Popliteal artery pseudoaneurysm was treated with percutaneous methods (n = 3) or surgery (n = 2). CONCLUSION: In this series, risk for arterial injury associated with THA and TKA was remarkably low. Nonetheless, even at a high-volume orthopedic hospital, acute arterial injury was not recognized on the day of surgery in about half of patients. Judicious use of preoperative arteriography and aggressive revascularization are critical to achieving limb salvage. Simple arterial thrombectomy to treat ischemic complications of THA and TKA is rarely sufficient.     

Abnormal Coagulation as a Risk Factor for Postoperative Complications After Primary and Revision Total Hip and Total Knee Arthroplasty

BackgroundPatients undergoing total joint arthroplasty (TJA) have an increased likelihood of having an abnormal coagulation profile compared with the general population. Coagulation abnormalities are often screened for before surgery and considered during perioperative planning. This study assesses a preoperative abnormal coagulation profile as a risk factor for postoperative complications after total hip arthroplasty (THA), revision THA (rTHA), total knee arthroplasty (TKA), and revision TKA (rTKA) and then examines specific coagulopathies to determine their influence on complication rates.MethodsPatients who underwent THA, rTHA, TKA, or rTKA from 2011 to 2017 were identified in the American College of Surgeons National Surgical Quality Improvement Program database and then assessed for preoperative abnormal coagulation profiles. Various postoperative complications were analyzed for each cohort, and two separate multivariate regression analyses were used to assess the relationship between abnormal coagulation and postoperative complications.Results403,566 THA, rTHA, TKA, or rTKA cases were identified, and 40,466 (10.0%) of patients were found to have an abnormal coagulation profile. Patients with preoperative coagulation abnormalities had higher likelihoods of postoperative complications after primary TJA than in revision TJA. An international normalized ratio>1.2 was associated with the most types of postoperative complications, followed by a bleeding disorder diagnosis. A partial thromboplastin time>35 seconds was associated with only one type of postoperative complication, while a platelet count <150,000 per μL was associated with postoperative complications only after TKA.ConclusionTJA in patients with abnormal coagulation profiles may result in adverse outcomes. These patients may benefit from preoperative intervention. Prophylactic care needs to be personalized to the specific coagulation abnormalities present.     

Postthrombotic syndrome after asymptomatic deep vein thrombosis following total knee and hip arthroplasty

Lower extremity deep vein thrombosis (DVT) is relatively common after total knee arthroplasty (TKA) and total hip arthroplasty (THA). In this study, we sought to identify whether post-thrombotic syndrome is a significant risk in patients with asymptomatic DVT after TKA and THA. Included in the study were 186 patients (203 lower extremities) who had undergone routine lower extremity venography after TKA or THA between 1989 and 1993. Patients were contacted a minimum of 7 years after surgery. Postoperative varicose veins occurred in 8% of limbs without DVT compared with 12% of limbs with DVT. Hyperpigmentation occurred in 13% of limbs without DVT and in 16% and 18% of limbs with proximal and distal DVT, respectively. Swelling occurred in 6% of limbs without DVT, in 8% of limbs with proximal DVT, and in 12% of limbs with distal DVT. None of these differences was statistically significant, and there were no differences for proximal versus distal DVT. There was no significant increase in risk for postthrombotic syndrome after asymptomatic proximal or distal DVT after TKA or THA.     

Total joint replacement: A multiple risk factor analysis of physical activity level 1–2 years postoperatively

Background and purpose — The effect of total joint arthroplasty (TJA) on physical activity is not fully understood. We investigated the change in physical activity after TJA and patient factors associated with change.

Patients and methods — Using a total joint replacement registry, primary total hip arthroplasty (THA) patients (n = 5,678) and knee arthroplasty (TKA) patients (n = 11,084) between January 1, 2010 and December 31, 2012 were identified. Median age at THA was 68 and median age at TKA was 67. Change in self-reported physical activity (minutes per week) from before TJA (within 1 year of surgery) to after TJA (1–2 years) was the outcome of interest. Patient demographics and comorbidities were evaluated as risk factors. Multiple linear regression was used.

Results — Median physical activity before surgery was 50?min/week (IQR: 0–140) for THA patients and 58 (IQR: 3–143) for TKA patients. Median physical activity after surgery was 150?min/week (IQR: 60–280) for both THA patients and TKA patients. Following TJA, 50% of patients met CDC/WHO physical activity guideline criteria. Higher body mass index was associated with lower change in physical activity (THA: ?7.1?min/week; TKA: ?5.9?min/week). Females had lower change than males (THA: ?11?min/week; TKA: ?9.1?min/week). In TKA patients, renal failure was associated with lower change (?17?min/week), as were neurological disorders (?30?min/week).

Interpretation — Self-reported minutes of physical activity increased from before to after TJA, but 50% of TJA patients did not meet recommended physical activity guideline criteria. Higher body mass index, female sex, and specific comorbidities were found to be associated with low change in physical activity. Patient education on the benefits of physical activity should concentrate on these subgroups of patients.     

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.     

A pilot study of computed tomography-detected asymptomatic pulmonary filling defects after hip and knee arthroplasties

We asked what the incidence of asymptomatic filling defects is on routine multidetector computed tomography (MDCT) in primary hip (total hip arthroplasty [THA]) and knee arthroplasties (TKA) patients. We prospectively performed MDCT scans on the first postoperative day for THA (n = 21)/TKA (n = 27). Patients underwent routine postoperative care, and data were collected for symptoms such as tachycardia or shortness of breath. More patients undergoing TKA had positive computed tomography scans than those undergoing THA: 11 (41%) vs 1 (5%), respectively. All patients diagnosed with a filling defect were discharged from the hospital without treatment of symptomatic pulmonary embolism. Our study demonstrates a high rate of abnormal MDCT early after lower extremity arthroplasty, the clinical importance of which may be benign.     

Comparison of general and spinal anesthesia and their influence on hemostatic markers in patients undergoing total hip arthroplasty

STUDY OBJECTIVE: To evaluate the profile of molecular hemostatic markers in patients receiving either spinal or balanced general anesthesia for total hip arthroplasty. DESIGN: Open, randomized, observational study. SETTING: Orthopedic unit and central laboratory of a university hospital. PATIENTS: 26 consenting ASA physical status II and III inpatients undergoing total hip arthroplasty with general balanced anesthesia (n = 10) or spinal (regional) anesthesia (n = 16). INTERVENTIONS: The time course of seven procoagulatory and fibrinolytic parameters was examined during and after surgery in both groups of patients (general and regional). Blood samples were drawn on the day before surgery, directly before induction of general anesthesia or regional anesthesia, respectively, intraoperatively (before bone manipulation), at the end of surgery, and on the mornings of postoperative days 1 and 5. MEASUREMENTS AND MAIN RESULTS: The coagulation samples were centrifuged within 1 hour of collection at 2,300 g for 15 minutes at 4 degrees C. Hemoglobin, hematocrit, platelets, fibrinogen, prothrombin time, thrombin time, activated partial thromboplastin time, antithrombin, and protein C were measured immediately on arrival at the laboratory. Specimens were then aliquoted and stored at -70 degrees C. Within 2 weeks, samples were thawed and prepared for the following assays: thrombin-antithrombin complexes (TAT complexes), D-dimers, plasminogen activator inhibitor type 1 (PAI-1), and plasminogen and plasmin inhibitor. Maximum activation of coagulation was not reached until 2 hours postoperatively and then slowly decreased until normal values were reached around the fifth postoperative day. Parameters displaying the greatest changes were antithrombin and D-dimers. No statistically significant differences were found between the two groups at the individual time points. CONCLUSION: Our initial hypothesis that the lesser risk of postoperative DVT in patients undergoing total hip arthroplasty in regional anesthesia is reflected in the course of the plasmatic molecular markers of hemostasis could not be verified. There were no significant differences in the timely course of the markers at any given time point.     

Total knee arthroplasty in morbidly obese patients treated with bariatric surgery: a comparative study

Our objective was to compare outcomes (anesthesia time, total operative time, tourniquet time, duration of hospital stay, 90-day complication rate, and transfusion rates) of patients with total knee arthroplasty (TKA) who underwent bariatric surgery before or after TKA. One hundred twenty-five patients were included: TKA before bariatric surgery (group 1; n = 39), TKA within 2 years of bariatric surgery (group 2; n = 25), and TKA more than 2 years after bariatric surgery (group 3; n = 61). Patients with TKA more than 2 years after bariatric surgery had shorter anesthesia and total operative and tourniquet times than other groups; differences were significant between groups. Ninety-day complication and transfusion rates approached but did not meet statistical significance. Ninety-day complication rates and duration of hospital stay did not differ significantly between the 3 groups. The level of evidence was level II (cohort study).     

老年患者全膝和全髋关节置换术围手术期血红蛋白及红细胞压积的转归

 目的 探讨非输血老年患者全膝和全髋关节置换术围手术期血红蛋白及红细胞压积的自然转归及其与性别、手术类型之间的关系。方法 2012年9月至2013年2月接受全膝关节或全髋关节置换术的60岁以上骨关节炎患者107例,男54例,女53例;年龄60~82岁,平均69.4岁。检测术前、手术日、术后第1~7天,3周、6周、3个月、6个月的血红蛋白和红细胞压积,分析其变化趋势。将不同性别和手术类别各个时点的血红蛋白和红细胞压积进行比较,评价性别和手术类别对血红蛋白和红细胞压积转归的影响。结果 所有患者血红蛋白和红细胞压积均于术后至第4天出现明显下降,最低点出现在术后第4天,术后1周至3周,血红蛋白和红细胞压积回升最快,在术后6周至3个月逐渐恢复到术前水平。在下降和恢复过程的各个时点,男性与女性患者的血红蛋白、红细胞压积差异无统计学意义。全髋关节置换组术后第4天内血红蛋白下降多于全膝关节置换组,全髋关节置换组手术日红细胞压积下降多于全膝关节置换组,差异均有统计学意义,其他时点两组血红蛋白和红细胞压积下降值的差异无统计学意义。结论 全膝和全髋关节置换术后血红蛋白和红细胞压积的最低点出现在术后第4天,术后6~12周恢复。性别因素对围手术期失血及恢复无明显影响。全髋关节置换术后血红蛋白和红细胞压积下降多于全膝关节置换。     

Early diagnosis of deep vein thrombosis in female patients who undergo total knee arthroplasty with measurement of P-selectin activation

BACKGROUND: Deep vein thrombosis (DVT) remains a leading cause of postoperative morbidity and mortality in patients who undergo total knee arthroplasty (TKA). Although patients with previous thrombotic episodes are inherently at a higher risk for subsequent episodes of DVT, it remains difficult to predict such an occurrence and to make a diagnosis in early stages. One potentially useful assay that can be used in the determination of changes of coagulation among patients who undergo arthroplasty is platelet activation. The goal of this study was to establish a predictive value for DVT with measurement of P-selectin levels that could help in planning appropriate perioperative management strategies for patients at high risk for DVT. METHODS: A total of 52 patients who underwent TKA with general anesthesia underwent contrast venography on the 5th postoperative day. Platelet activation before and after operation was measured with platelet surface expression of P-selectin with flow cytometry in these two groups of patients for TKA. None of the patients underwent any anticoagulation therapy. RESULTS: Nineteen of the 52 patients for TKA showed radiologic evidence of DVT, whereas 33 patients for TKA had no radiologic signs of DVT. There was no difference in platelet activation at baseline, which was 1 hour before induction of anesthesia, between the two groups (P >.05) as measured with P-selectin assays. Differences were noted between the two groups on the 5th day after operation, wherein P-selectin was expressed in only 2.72% +/- 0.9% (mean +/- standard deviation) of platelets in patients for TKA with healthy venogram results. This differed significantly from platelets in patients for TKA with DVT, who had P-selectin expression of 6.56% +/- 3.1% (mean +/- standard deviation; P <.01). Sensitivity for the diagnosis of DVT with P-selectin assay was calculated to be 74%, and specificity was found to be 94%. CONCLUSION: The findings showed that radiologically confirmed DVT in patients for TKA surgery with general anesthesia is associated with an elevated number of activated platelets. Perioperative assessment of P-selectin may predict the early onset of DVT in patients who undergo high risk surgical procedures like TKA. This laboratory assay may help prevent the occurrence of the fatal events caused by DVT with use of early therapeutic intervention, such as heparinization.     

Retrospective evaluation of inpatient celecoxib use after total hip and knee arthroplasty at a Veterans Affairs Medical Center

A retrospective cohort study (1.5 years) was performed to investigate the efficacy of celecoxib vs non-celecoxib use in patient who underwent total knee arthroplasty (TKA) and total hip arthroplasty (THA). Study time frame encompassed a pre and post period of a local policy decision opening access to short-term celecoxib use after TKA/THA. Primary end point was the amount of opioid use during their inpatient stay postprocedure. The TKA (n = 81) and THA (n = 60) groups were analyzed independently. Both celecoxib groups used significantly less opioids during their inpatient stay vs noncelecoxib groups, given in oral morphine milligram equivalents (TKA: 203 vs 337 mg, P = .002; THA: 214 vs 336 mg, P = .005). Other secondary outcome measures showed that the celecoxib groups also reported reduction in pain scores, total as needed (PRN) opioid doses, PRN opioid doses per day, average dose of PRN opioids, total PRN opioids, use of intravenous opioids, and rehabilitation facility admissions (in the TKA group only). Linear regression analysis showed a statistically significant inverse relationship between opioid consumption and age. Short-term celecoxib use after TKA/THA may lead to a reduction in overall opioid use and improved pain scores; however, further studies will be required to validate the results of this study.     

Outcomes of total hip and knee arthroplasty after cardiac transplantation

The outcomes of 18 primary or revision total hip (THA) and knee arthroplasties (TKA) in 9 patients with cardiac transplants were reviewed. Primary total joint arthroplasties were performed for osteonecrosis (5 hips) or osteoarthritis (5 hips, 4 knees). There were no infections in any of these patients. Final Harris Hip Scores were 71.8 for patients with osteonecrosis and 88.6 for osteoarthritis. Eight of 10 hips were pain-free at final follow-up. Two of the 10 primary THAs required late revision at 7 and 10 years after the index arthroplasty. One patient (2 hips and 1 knee) had chronic bilateral lower extremity pain. Total knee arthroplasty range of motion averaged from 7.5° to 118°. Average final Knee Society function score was 79, and objective score was 88. One of 4 patients with primary TKA required a manipulation under anesthesia. No reoperations were required in this group. Overall, patients with heart transplantations on immunosuppression had generally good pain relief after THA and TKA. There were no infections in this small cohort; however, there were many complications.     

关节置换术后下肢深静脉血栓形成的解剖分布

目的 探讨初次全膝关节置换术和全髋关节置换术后下肢深静脉血栓形成的解剖分布特点.方法 回顾性分析2007年6月至2012年5月接受初次全膝关节置换术或全髋关节置换术后经下肢静脉造影诊断为下肢深静脉血栓形成的272例患者的病例资料,全膝关节置换组110例,全髋关节置换组162例.观察静脉造影中两种术式术后下肢深静脉血栓形成的部位及其差异.结果 全膝关节置换组中,中心型血栓10例、周围型血栓94例、混合型血栓6例;全髋关节置换术组中,中心型血栓3例、周围型血栓140例、混合型血栓19例.两组血栓类型的差异有统计学意义(x2=9.996,P=0.007).全膝关节置换术和全髋关节置换术后血栓最易累及部位依次为肌间静脉193例(71.0％,193/272)、胫后静脉98例(36.0％,98/272)、腓静脉85例(31.3％,85/272)、胫前静脉24例(8.8％,24/272)、腘静脉24例(8.8％,24/272)、髂股静脉20例(7.4％,20/272).周围型血栓中,全膝关节置换组比全髋关节置换组更容易累及多支静脉,两组差异有统计学意义(x2=14.712,P=0.000).在孤立性血栓中,无胫前静脉血栓形成.在多支静脉血栓中,两组均以累及胫后静脉、腓静脉、肌间静脉血栓中的两支或三支常见.结论 全膝关节置换术和全髋关节置换术后下肢深静脉血栓形成的解剖分布不同.     

Rivaroxaban, an oral, direct factor Xa inhibitor: a new option for thromboprophylaxis

Patients undergoing major orthopedic surgery, including total hip arthroplasty (THA) and total knee arthroplasty (TKA), are at high risk for developing venous thromboembolism (VTE). Although largely a preventable complication, VTE develops in a significant proportion of patients, highlighting the need for improved methods of VTE prevention. Current thromboprophylactic options are limited by unpredictable pharmacokinetics and pharmacodynamics (vitamin K antagonists), parenteral/subcutaneous administration (heparin and low-molecular-weight heparins), complicated dosing, and increased risk of bleeding.Rivaroxaban is an oral, direct Factor Xa inhibitor that has recently received marketing authorization in the United States for prophylaxis of deep vein thrombosis in patients undergoing hip or knee replacement surgery. The clinical pharmacology of rivaroxaban supports a convenient, oral, once-daily dosing regimen without the need for routine coagulation monitoring after THA or TKA. A comprehensive phase II and III study program supports its safety and efficacy for VTE prevention after THA or TKA. Phase III results have demonstrated the superior efficacy of rivaroxaban regimens compared with enoxaparin regimens, with similar rates of major bleeding. This article provides an overview of the phase II and III results that support the use of this agent for the prevention of VTE after elective total hip or knee replacement.     

The Application of Thromboelastography in Understanding and Management of Ecchymosis After Total Knee Arthroplasty

Background

Ecchymosis is a common complication after total knee arthroplasty (TKA). However, only a few studies have been conducted to determine the coagulation status of these patients. Using thromboelastography (TEG), a new technique recording the viscoelastic changes of a whole-blood sample, this study was performed to understand the ecchymosis-related coagulation status and its risk factors.