Replacement Arthroplasty: Hirsh J

Eikelboom JW, Karthikeyan G, Fagel N, Hirsh J. · Department of Medicine, McMaster University, Hamilton, ON, Canada. · Chest. · Pubmed #19201714 No free full text.

Abstract: The recently published American Association of Orthopedic Surgeons (AAOS) guidelines for the prevention of venous thromboembolism (VTE) in patients undergoing hip or knee surgery conflict with long-established and widely used American College of Chest Physicians (ACCP) guidelines. Both guidelines accepted that the most important goal of thromboprophylaxis in patients undergoing hip or knee replacement is to prevent pulmonary embolism (PE). The ACCP guidelines included asymptomatic (and symptomatic) deep vein thrombosis (DVT) detected by venography as a measure of the efficacy of thromboprophylaxis, whereas the AAOS rejected DVT as a valid outcome because the panelists considered the link between DVT and PE to be unproven. The AAOS position is inconsistent with evidence from imaging studies linking DVT with PE and from clinical studies demonstrating a parallel reduction of DVT and PE when antithrombotic agents are compared with placebo or untreated controls. The AAOS panel ignored the randomized data demonstrating that thromboprophylaxis reduces both DVT and PE, and many of their recommendations are based on expert opinion and lack a scientific basis. We recommend the ACCP guidelines because the methodology is explicit and rigorous and the treatment recommendations reflect all of the evidence from the randomized trials. Adoption of the ACCP guideline will ensure that patients undergoing hip and knee arthroplasty receive the best available therapies for prevention of VTE and reduce disability and death due to this common and potentially preventable condition.

Heit JA, Elliott CG, Trowbridge AA, Morrey BF, Gent M, Hirsh J. · Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA. · Ann Intern Med. · Pubmed #10836911 links to  free full text

Abstract: BACKGROUND: The optimal duration of prophylaxis against venous thromboembolism after total hip or knee replacement is uncertain. OBJECTIVE: To determine the efficacy and safety of extended out-of-hospital prophylaxis with low-molecular-weight heparin (ardeparin sodium). DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: 33 community, university, or university-affiliated hospitals. PATIENTS: 1195 adults who had elective total hip or knee replacement and completed 4 to 10 days of postoperative ardeparin prophylaxis. INTERVENTION: Daily subcutaneous ardeparin (100 anti-Xa IU/kg of body weight) or placebo from time of hospital discharge to 6 weeks after surgery. MEASUREMENTS: Symptomatic, objectively documented venous thromboembolism or death, along with major bleeding, from time of hospital discharge to 12 weeks after surgery. RESULTS: Patients who received ardeparin (n = 607) and those who received placebo (n = 588) did not differ significantly in the cumulative incidence of venous thromboembolism or death (9 cases [1.5%] compared with 12 cases [2.0%]; odds ratio, 0.7 [95% CI, 0.3 to 1.7]; P > 0.2; absolute difference, -0.56 percentage points [CI, -2.2 to 1.1 percentage points]) or major bleeding (2 cases [0.3%] compared with 3 cases [0.5%]). CONCLUSIONS: Among patients who had total knee or total hip replacement and received 4 to 10 days of postoperative ardeparin prophylaxis, the cumulative incidence of symptomatic venous thromboembolism or death after hospital discharge was not significantly reduced by extended out-of-hospital ardeparin prophylaxis. Extended ardeparin use could provide a maximum 2.2-percentage point true reduction in such events. The benefit of extended ardeparin use is not clinically important for most patients. Future research should identify high-risk patients who would benefit most from extended prophylaxis.

Anderson FA, Hirsh J, White K, Fitzgerald RH, Anonymous00010. · Center for Outcomes Research, Department of Surgery, University of Massachusetts Medical School, 365 Plantation Street, Suite 185, Worcester, MA, USA. · Chest. · Pubmed #14668417 links to  free full text

Abstract: BACKGROUND: The Hip and Knee Registry is an observational database comprising data on practices of US orthopedic surgeons during 1996 to 2001. We examined trends in the use of prophylaxis for venous thromboembolism (VTE) among patients who underwent primary total hip arthroplasty (THA) or total knee arthroplasty (TKA). METHODS: Data on 9,327 THA and 13,846 TKA patients were submitted between 1996 and 2001 by 464 orthopedic surgeons from 319 hospitals in 42 of the United States. RESULTS: During 1996 to 2001, 44% of THA patients and 38% of TKA patients were male, and 93% and 92% were white, respectively. The median age of THA and TKA patients increased from 66 to 68 years and 68 to 69 years, respectively, between 1996 and 2001 (p < 0.001), while the mean length of hospital stay decreased from 4.7 to 3.7 days and 4.5 to 3.7 days, respectively (p < 0.001). Use of spinal or epidural anesthesia increased from 34 to 46% for THA and 43 to 54% for TKA patients (p < 0.001). One or more types of thromboprophylaxis were administered to 99% of patients. The following were the most common types of thromboprophylaxis: elastic stockings (61% and 58%), warfarin (56% and 53%), low-molecular-weight heparin (38% and 40%), and intermittent pneumatic compression (35% and 32%) in THA and TKA patients, respectively. Aspirin was used for thromboprophylaxis in 4% of THA and 7% of TKA patients. One or more type of in-hospital prophylaxis matching the 2001 American College of Chest Physicians (ACCP) recommendations were administered to 89% of THA and 91% of TKA patients between 1996 and 2001. During this period, in-hospital use of ACCP prophylaxis recommendations increased from 88 to 94% following THA (p < 0.001). This increase was also observed for prophylaxis administered to TKA patients, although this did not reach statistical significance. CONCLUSIONS: Recent trends in the management of patients undergoing THA and TKA in the United States, including shorter lengths of hospital stay and increased use of spinal/epidural anesthesia, present a challenge to orthopedic surgeons who wish to provide their patients with effective prophylaxis for VTE. Despite these challenges, nearly all surgeons participating in the Hip and Knee Registry are providing types of prophylaxis consistent with evidence-based consensus recommendations. Although there are concerns regarding increased bleeding risk due to the use of anticoagulants in patients receiving spinal/epidural anesthesia, there was a significant increase in the use of spinal/epidural anesthesia between 1996 and 2001. During this same period, the proportion of patients receiving spinal/epidural anesthesia who were also administered anticoagulants as prophylaxis increased significantly.

O'Donnell M, Linkins LA, Kearon C, Julian J, Hirsh J. · Henderson Research Centre, Hamilton, Ontario, Canada. · Arch Intern Med. · Pubmed #12796074 links to  free full text

Abstract: BACKGROUND: Numerous trials and meta-analyses have shown that extended out-of-hospital prophylaxis with low-molecular-weight heparin reduces asymptomatic and symptomatic venous thromboembolism after total hip arthroplasty. We hypothesized that knowledge of the results of screening tests may have resulted in overdiagnosis of symptomatic venous thromboembolism in many of these studies. The purpose of this analysis was to obtain an accurate estimate of the absolute risk reduction (ARR) of symptomatic venous thromboembolism after discharge from hospital in controlled studies that avoided this potential bias for overdiagnosis. METHODS: Articles were identified using MEDLINE, EMBASE, and the Cochrane Library databases (January 1980-April 2002). Studies were eligible if the assessment of symptomatic venous thromboembolism was standardized and performed independently of mandatory objective testing. RESULTS: Two studies (907 patients) were eligible for assessment of symptomatic venous thromboembolism, 5 studies (1917 patients) for symptomatic pulmonary embolism, and 7 studies (2425 patients) for fatal pulmonary embolism. In controls vs extended treatment groups, after hospital discharge, the frequency of symptomatic venous thromboembolism was 2.7% vs 1.1% (ARR, 1.56%; 95% confidence interval [CI], -0.21% to 3.3%; number needed to treat, 64); symptomatic pulmonary embolism was 0.36% vs 0% (ARR, 0.36%; 95% CI, -0.3% to 1.36%; number needed to treat, 278); and fatal pulmonary embolism was 0.09% vs 0% (ARR, 0.09%; 95% CI, -0.08% to 0.27%; number needed to treat, 1093). CONCLUSIONS: The absolute reduction in symptomatic venous thromboembolism attributed to extended prophylaxis in some studies and meta-analyses seems to have been overestimated.

Ginsberg JS, Turkstra F, Buller HR, MacKinnon B, Magier D, Hirsh J. · Hamilton Civic Hospitals Research Centre, McMaster University, Ontario, Canada. · Arch Intern Med. · Pubmed #10724052 links to  free full text

Abstract: BACKGROUND: Although the incidence of the postthrombotic syndrome (PTS) has been addressed in patients with symptomatic deep vein thrombosis (DVT), less information is available on the incidence in patients who develop asymptomatic DVT after major hip or knee arthroplasty. OBJECTIVES: To determine whether symptomatic PTS occurs more frequently in patients who develop DVT after hip or knee arthroplasty than those who are free of DVT and to provide an estimate of the incidence of PTS in patients who had undergone major hip or knee arthroplasty and had proximal DVT, distal (calf) DVT, or no DVT. DESIGN AND SETTING: A cross-sectional study conducted at the Hamilton Health Sciences Corporation, Hamilton, Ontario, and the Academic Medical Centre, Amsterdam, the Netherlands. SUBJECTS AND METHODS: Two hundred fifty-five subjects who had undergone major hip or knee arthroplasty 2 to 7 years previously and had routine predischarge venography showing proximal DVT (n = 25), distal DVT (n = 66), or no DVT (n = 164) were enrolled from March 1993 through December 1998. The presence of symptomatic PTS confirmed by the presence of objectively confirmed venous valvular incompetence was ascertained. RESULTS: The rates of PTS were low and not significantly different among the 3 subgroups: 1 (4.0%, 95% confidence interval [CI] = 0.1%-20.4%) of 25 patients with proximal DVT, 4 (6.1%, 95% CI = 1.7%-14.8%) of 66 patients with distal DVT, and 7 (4.3%, 95% CI = 1.7%-8.6%) of 164 patients with no DVT. CONCLUSIONS: Symptomatic PTS is an uncommon complaint after major hip or knee arthroplasty. Patients who develop postoperative proximal or distal DVT and who receive 6 to 12 weeks of anticoagulant therapy are not predisposed to PTS.