BACKGROUND: Enoxaparin is a low-molecular-weight heparin indicated in Europe and North America for the prevention of venous thromboembolism (VTE) in patients undergoing major orthopedic surgery. Registration trials of enoxaparin have been conducted primarily in Caucasian populations, and the efficacy and safety of enoxaparin in Japanese patients have not been demonstrated. We evaluated three dosage regimens of postoperative enoxaparin in Japanese patients undergoing elective total hip or knee arthroplasty.
METHODS: Two multicenter, randomized, double-blind studies enrolled 436 and 396 Japanese adults undergoing total hip or knee arthroplasty, respectively. The dosage regimens of enoxaparin were 20 mg once daily (qd), 40 mg qd, 20 mg twice daily (bid), or placebo for 14 consecutive days. The primary efficacy endpoint was the incidence of VTE in the modified intention-to-treat (mITT) population up to 15 days after surgery. VTE was defined as a composite of deep vein thrombosis (determined by venography) and symptomatic pulmonary embolism (confirmed by appropriate objective methods). Patients were also followed up at 90 days for VTE events. The primary safety outcome was the incidence of any bleeding during treatment and the follow-up period.
RESULTS: In the mITT populations, the incidence of VTE was 41.9% and 60.8% in the placebo groups after hip or knee arthroplasty, respectively, 25.9% and 44.9% in the enoxaparin 20 mg qd groups, 33.8% and 35.1% in the enoxaparin 40 mg qd groups, and 20.0% and 29.8% in the enoxaparin 20 mg bid groups. Only enoxaparin 20 mg bid significantly lowered the risk of VTE relative to placebo (by 52.2% and 51.0% after hip and knee arthroplasty, respectively). At the 90-day follow-up, no further cases of VTE were reported. In both the hip and knee studies, the four treatment groups did not differ significantly regarding the incidence of patients with any bleeding.
CONCLUSIONS: Our findings support the use of enoxaparin (20 mg bid daily, commencing 24-36 h postoperatively) in Japanese patients undergoing total hip or knee arthroplasty.
BACKGROUND: Venous thromboembolism (VTE) is a common and potential serious complication in lower extremity surgeries, especially in hip and knee arthroplasty. Pulmonary embolism is one of the most fatal complications. The recognition of VTE in the lower limb has been considered as an indication for anticoagulation. Many studies have shown that thrombophilia is one factor of VTE and the most common causes are protein C, protein S and antithrombin III deficiency, factor V leiden and dysfibrinogenemia. VTE is a disease of Western populations because of well documentation of incidence and many studies about thrombophilia. In Thailand, the prevalence of VTE has been unclear.
OBJECTIVE: The present prospective study evaluated the prevalence of thrombophilia and venous thromboembolism after total knee arthroplasty in patients who did not receive prophylactic treatment of VTE in Phramongkutklao Hospital.
STUDY DESIGN: Descriptive prospective consecutive case studies.
SETTING: The Department of Orthopedic Surgery, Phramongkutklao Hospital, Bangkok Thailand.
MATERIAL AND METHOD: Blood sample was examined at 2-3 weeks before TKA for measuring the level of thrombophilia. Bilateral ascending contrast venography of the lower extremities was performed routinely between 6th-10th post operative days after total knee arthroplasty.
RESULTS: The authors studied 100 patients, 94 primary TKA and 6 revisions TKA. Sixty-one (61%) were positive for deep vein thrombosis. Eleven patients with positive venograms showed bilateral DVT twelve (12%) had a proximal DVT one was protein C deficiency, nine were protein S deficiency, 18 were antithrombin III deficiency, and 36 were positive study for FDP(D-dimer), However, no one was found with factor V leiden. Odds ratio of protein S deficiency was 0.9506, Antithrombin III deficiency was 0.7376, and FDP(D-dimer) was 1.229. The protein C deficiency and factor V leiden was undetermined.
CONCLUSION: Patients who have total knee arthroplasty performed are at high risk for deep venous thrombosis. Although fetal pulmonary embolism rarely occurs in Thai populations, mechanical prevention was routinely used and prophylactic regimen should be a part of management of patients who undergo total knee arthroplasty.
BACKGROUND: The definition of gastrocneumus and soleus deep-vein thrombosis (DVT) remains controversial. The purpose of this study was to evaluate the clinical significance of muscular deep-vein thrombosis after total knee arthroplasty (TKA).
METHODS: This study consisted of 359 consecutive patients undergoing TKA evaluated for DVT by ascending venography. Venographies were performed 5 to 7 days after surgery. Those patients showing positive DVT underwent a follow-up venographic study at 3 months. The evaluation parameters included clinical symptoms, late DVT, thrombus propagation and pulmonary embolism. The data from patients with isolated muscular DVT were compared statistically with those patients with DVT of the leg veins and combined DVT.
RESULTS: Of 359 patients, 175 (49%) developed venographic DVT including 160 with distal and 15 with proximal DVT. Of the 160 cases with distal DVT, 83 (52%) involved the gastroneumus and soleus muscular veins. Of these 83 cases, 38 (46%) were isolated muscular DVT and 45 (54%) involved muscular branches and major leg veins including the anterior and posterior tibial and peroneal veins. Patients with isolated muscular DVT showed comparable rates of clinical symptoms, late DVT, thrombus propagation and no pulmonary embolism compared with patients with DVT in the major leg veins (p = 0.874, 0.398 and 1.000) and patients with combined DVT (p = 0.155, 0.592 and 1.000).
CONCLUSION: The clinical significance of isolated muscular DVT is comparable to that of the major leg veins and combined DVT. Muscular DVT in the calf is considered a significant clinical entity and should be treated accordingly.
We evaluated a total of 473 knees (264 patients) to determine the prevalence of deep vein thrombosis and pulmonary embolism (PE) in those who were not given thromboprophylaxis after total knee arthroplasty (TKA). Deep vein thrombosis was diagnosed by roentgenographic venography, and PE was diagnosed by perfusion lung scanning. In patients with bilateral TKA, 47 (11%) of 418 venograms showed positive findings for thrombi, whereas in patients with unilateral TKA, 11 (20%) of 55 venograms showed positive findings for thrombi (P = .758). No patient had symptoms of PE, and findings for the perfusion lung scans were negative in all patients. We neither treat our patients for deep vein thrombosis and PE prophylactically nor therapeutically unless patient has a symptomatic PE.
BACKGROUND: There are many reports about deep vein thrombosis from Western regions but few reports are from Asian countries especially Thailand.
OBJECTIVES: The purpose of the present study was to reveal the incidence of deep vein thrombosis in postoperative hip fracture patients.
MATERIAL AND METHOD: Ninety six patients who had intertrochanteric fracture or femoral neck fracture were included. They had fixation or hemiarthroplasty performed according to their indications. Bilateral Venography was performed on the sixth to tenth day after surgery.
RESULTS: The positive venography result was 47.9%. Only nine patients with positive results had signs and symptoms of deep veins thrombosis. Distal DVT was found in 43.5% of the positive group. Proximal DVT was 56.5%. No patients had symptoms of pulmonary embolism.
CONCLUSION: The incidence of deep vein thrombosis in Thailand is the same as in Western countries. The prophylaxis regimen may become a part of the line of management in elderly patients with hip fracture. Further studies about the natural history or complications of deep vein thrombosis should be of concern.
PURPOSE: To study the incidence of deep vein thrombosis in Indian patients undergoing total hip arthroplasty with or without prophylaxis, and the effect of enoxaparin on deep vein thrombosis.
METHODS: The study covered a total of 50 hips in 40 patients who underwent total hip arthroplasty. Patients were assessed for deep vein thrombosis using Doppler ultrasonography. The hips were numbered and divided into 2 groups: the odd-numbered hips did not receive any thrombo-prophylaxis, whereas the even-numbered hips received 40 mg of enoxaparin subcutaneously, once a day for 2 weeks, until the time of discharge.
RESULTS: Deep vein thrombosis was not found in both groups. We found wound haematomas in 9 patients (all of whom were on enoxaparin) (p<0.05), superficial infection in 2 patients (one on enoxaparin, one not), and local bruising in 4 patients (all of whom were on enoxaparin). Major haemorrhage did not occur in any of the cases.
CONCLUSION: The incidence of deep vein thrombosis in Indian patients is very low compared to that in European and American patients. Enoxaparin failed to provide any advantage to the patients. It is therefore not advisable to give prophylaxis/low-molecular-weight heparin for deep vein thrombosis to patients undergoing total hip arthroplasty without any risk factors.
PURPOSE: To investigate the incidence of deep vein thrombosis (DVT) among elderly Hong Kong Chinese patients suffering from acute hip fracture and to analyse the risk factors associated with DVT.
METHODS: A total of 100 consecutive Chinese hip fracture patients with a mean age of 80 years were investigated serially using duplex ultrasound scans preoperatively and at 1 week, 3 to 6 weeks, and 3 months postoperatively. No chemoprophylaxis or prophylaxis against DVT was given.
RESULTS: 95 patients completed 3 duplex scans during hospitalisation; 5 (5.3%) of them were found to have developed DVT over the ilio-femoral venous segment. Of the 90 patients who had no DVT, 73 were reassessed 3 months after operation; one of them was found to have developed calf DVT. Older patients, chairbound or dependent patients, and patients living in institutions carried a higher risk of developing DVT.
CONCLUSION: This prospective study shows that the incidence of DVT developing after acute hip fracture in Chinese geriatric patients was low. We therefore do not recommend routine chemoprophylaxis for elderly patients with hip fracture.
INTRODUCTION: The prevalence of deep vein thrombosis (DVT) in the West is reported to be as high as 50% after hip surgery. A study performed 14 years ago showed the incidence in Singapore to be <10%. Lately, some case-control and cross-sectional studies have suggested hyperhomocysteinaemia as an independent risk factor for DVT. This study investigates the local incidence of DVT and plasma hyperhomocysteinaemia in elderly patients presenting with proximal hip fracture.
MATERIALS AND METHODS: We recruited 104 consecutive patients from April 2001 to November 2001 who satisfy certain criteria. Firstly, patients of both genders who were >55 years old with radiological diagnosis of neck of femur fracture, intertrochanteric or subtrochanteric fracture. Secondly, these patients must not have any haemorrhagic or thrombogenic disease. Thirdly, patients were not given folate and B complex pre- or postoperation. Duplex ultrasound was then done for these patients on the 5th to 7th postoperative day.
RESULTS: The incidence of DVT above the trifurcation was 7.7%, no incidence of pulmonary embolism (PE) was detected. The incidence of hyperhomocysteinaemia was 52.3%.
CONCLUSIONS: The incidence of DVT in the local population after proximal hip fracture is much lower than in the West. The use of DVT prophylaxis in Asians should be selective to avoid incurring extra cost and its associated morbidity. Case-control studies and cross-sectional studies clearly indicate that hyperhomocysteinaemia is an independent risk factor for venous thrombosis. Given the high incidence of hyperhomocysteinaemia in our elderly with hip fracture, the prophylactic correction of hyperhomocysteinaemia with folate and vitamin B supplements is justified.
UNLABELLED: Deep vein thrombosis (DVT) and pulmonary embolism (PE) are considered uncommon in Asian populations and thrombo-prophylaxis is rarely indicated. The objective of this study was to investigate the incidence of DVT and PE after total knee replacement in an Asian population.
MATERIAL AND METHOD: There were 100 patients who underwent total knee replacement enrolled in this study. No thrombo-prophylaxis was given to these patients. The possible risk factors such as age, sex, body mass index (BMI), operative time and the post-operative blood loss were recorded.
RESULTS: The duplex ultrasonography (controlled) showed no evidence of DVT in all cases. There were 67 patients who completed radionuclide venography in this study. The incidence of DVT from positive radionuclide venography was 24% (16/67 patients) and PE was 12% (8/67 patients). All patients with positive imaging studies were asymptomatic. The risk factors were similar in both groups.
CONCLUSION: The incidence of DVT and PE in post-operative total knee replacement surgery, although lower than the incidence in Western populations, is higher than previously assumed. The radionuclide venography is less invasive and a useful diagnostic method for both DVT and PE. Because all patients with DVT and PE are asymptomatic, the use of thrombo-prophylaxis should be considered for risk and benefit.
PURPOSE: To investigate the incidence of deep vein thrombosis (DVT) following total knee arthroplasty in an Asian population.
METHODS: A prospective study of 149 consecutive cases of total knee arthroplasty done for osteoarthritis was conducted over a 5-year period. All patients underwent duplex ultrasonographic assessment of the lower limbs within the first postoperative week.
RESULTS: The incidence of proximal DVT was found to be 4.38% in this study. Symptomology was statistically significant in predicting the presence of proximal DVT in all cases. General anaesthesia was associated with a statistically significant-higher incidence of DVT as compared with regional anaesthesia. There was a significant association between a sedentary lifestyle and the development of DVT.
CONCLUSION: The incidence of proximal DVT in Asian patients after total knee arthroplasty is higher than that previously reported for this demographic group.
Enoxaparin is a low-molecular-weight heparin indicated in Europe and North America for the prevention of venous thromboembolism (VTE) in patients undergoing major orthopedic surgery. Registration trials of enoxaparin have been conducted primarily in Caucasian populations, and the efficacy and safety of enoxaparin in Japanese patients have not been demonstrated. We evaluated three dosage regimens of postoperative enoxaparin in Japanese patients undergoing elective total hip or knee arthroplasty.
METHODS:
Two multicenter, randomized, double-blind studies enrolled 436 and 396 Japanese adults undergoing total hip or knee arthroplasty, respectively. The dosage regimens of enoxaparin were 20 mg once daily (qd), 40 mg qd, 20 mg twice daily (bid), or placebo for 14 consecutive days. The primary efficacy endpoint was the incidence of VTE in the modified intention-to-treat (mITT) population up to 15 days after surgery. VTE was defined as a composite of deep vein thrombosis (determined by venography) and symptomatic pulmonary embolism (confirmed by appropriate objective methods). Patients were also followed up at 90 days for VTE events. The primary safety outcome was the incidence of any bleeding during treatment and the follow-up period.
RESULTS:
In the mITT populations, the incidence of VTE was 41.9% and 60.8% in the placebo groups after hip or knee arthroplasty, respectively, 25.9% and 44.9% in the enoxaparin 20 mg qd groups, 33.8% and 35.1% in the enoxaparin 40 mg qd groups, and 20.0% and 29.8% in the enoxaparin 20 mg bid groups. Only enoxaparin 20 mg bid significantly lowered the risk of VTE relative to placebo (by 52.2% and 51.0% after hip and knee arthroplasty, respectively). At the 90-day follow-up, no further cases of VTE were reported. In both the hip and knee studies, the four treatment groups did not differ significantly regarding the incidence of patients with any bleeding.
CONCLUSIONS:
Our findings support the use of enoxaparin (20 mg bid daily, commencing 24-36 h postoperatively) in Japanese patients undergoing total hip or knee arthroplasty.
