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Comparison of a low molecular weight heparin and warfarin in prevention of deep vein thrombosis after total hip arthroplasty
Abstracts From the AAHKS Sixth Annual Meeting 229 Method: All patients undergoing isolated patellar revision for a failed metal backed patella (MBP) by the two senior authors with a minimum 2-year follow-up were retrospective reviewed. Radiographs were reviewed and clinical outcome was assessed using the Knee Society Clinical Rating System (KSCRS). Results: Forty-one patienta with 42 knees were identified. Follow-up averaged 46 months (range 24-96 months). Average time from index to revision surgery was 52 months (range 9-84 months). KSCRS averaged 106 preoperatively and 167 at last follow-up. All revision operations involved removal of the failed MBP and insertion of a new cemented all polyethylene patelLa in addition to synovectomy for metallosis. The overall complication rate was 19%. These consisted of 5 patients with septic knees, 2 with recurrent patdlar subluxation and 1 with recurrent knee instability and pain. Discussion and Conclusion: Failure of the polyethylene component of metal backed patellae is a common indication for revision knee ar~hroplasty. Isolated revision of failed MBP with synovectomy is associated with a high complication rate. The effectiveness of isolated patellar revision is questioned due to its high complication rate.
to 12%; low dose warfarin prophylaxis has an associated prevalence of bleeding problems in 1 m 4% of patients but no significant difference had been demonstrated compared with LMWH. In this study, a statistically greater frequency of bleeding complications rdated to the wound was associated with use of LMWH resulting in one reoperation. Conclusion: It remains to be determined whether LMWH preparations can effectively reduce the prevalence of DVT without incurring an unacceptable increase in bleeding events. It may be premature to abandon the use of warfarin in favor of LMWt-I until a favorable risk-benefit profile of these agents can be demonstrated.
PAPER#42 *ENOXAPARIN VS. WARFARIN: HOSPITAL MANAGEMENT FOR DVT
PREVENTION clifford W. Colwen, Jr., MD, LaJolla, CA, J. Hinson, MD, J. McCutchen, MD, R. Paulson, MD, D. Collis, MD
PAPER#41 *COMPARISON OF A L O W MOLECULAR W E I G H T HEPARIN AND WARFARIN IN PREVENTION OF DEEP VEIN THROMBOSIS AFTER TOTAL HIP ARTHROPLASTY
Vincent D. Pellegrini, Jr,, MD, Hershey, PA, Saara Totterman, MD, David C. Ayers, MD, Norman Johanson, MD, Bernard N. StuIberg, MD, Aaron Rosenberg, MD, Craig Kessler, MD, Charles Francis, MD The use of iow molecular weight heparins (LMWH) for thromboprophylaxis following total joint arthroplasty has gained popularity. While a greater efficacy in preventing thromboembolism has been demonstrated, there is suggestion that their use is accompanied by an increase in bleeding complications. Purpose: This study" was designed to analyze both efficacy and complications associated with dakepatin sodium (Fragmin®), a low molecular weight heparin, compared with warfarin as thromboprophylaxis agents following total hip replacement (THA). Methods: Consecutive patients undergoing unilateral, primary or revision, total hip arthroplasty at seven teaching hospitals were prospectively considered for entry into the study. Those randomized to Fragmin® received 2500 IU preoperatively, 2500 IU on the postoperative evening, and 5000 IU daily thereafter; in the warfarin group, daily doses were adjusted to maintain the 1NR between 2 and 2.5. Between May 1992 and March 1995, a total of 580 patients were enrolled, 550 were included in ir~tentinn to treat analysis, and 382 completed contrast venography as endpoint determination for deep venous thrombosis (DVT). Bilateral contrust venography was performed between postoperative days 6-10 with nonionic contrast. All studies were reviewed by a single vascular radiologist at the primary center. Results: Overall DVT prevalence was 14% in the Fragrnin® and 26% in the warfarin groups (p=0.003). Proximal DVT occurred in 4% and 8% (p=0.078) while calf DVT occurred in 11% and 23% of the Fragmin® and warfarin groups, respectively. Two patients suffered nonfatal pulmonary embolism in each group. Patients over the age of 65 were twice as likely to develop DVT as those who were younger. Blood loss was comparable between the groups, but transfusion was necessary after the operative day in 48°£ of Fragmin® and 31% of warfarin patients (p<0.00i). Bleeding complications occurred in 11% of Fragmin® and 4.3% of warfarin patients; some patients experienced more than one bleeding event. Adverse hemorrhagic events involving the wound occurred 13 times in the Fragmin® and 3 times in the warfarin group (p=O.01); one Fragmin® patient experienced transient thrombocytopenia and required reoperatton for evacuation of a draining hematoma. Discussion: The results of this study are in keeping with previous reports demonstrating superiority of LMWH preparations over warfarin in DVT prophylaxis following THA. Specifically, both proximal and calf DVT were reduced by* 50% with LMWH compared with warfarin. However, previous reports of LMWH have also noted total "major" and "minor" bleeding complications to range from 8
* D e n o t e s t h a t s o m e t h i n g of v a l u e w a s r e c e i v e d . Presenters are boldfaced.
Methods: Safety and efficacy study comparing enoxaparin sodium (E) and warfarin (W) was performed in 2,155 patients undergoing Total Hip Arthroplasty at 156 U.S. sites. Patients were randomized to E (n=i,082) 30rag q12h, or W (n=1,073) INR adjusted. Clinical evaluation for venous thromboembotic disease (V-fED) was performed daily during hospitalization, at 6 and 12 weeks postoperatively. VTED was confirmed by venography, duplex ultrasound, lung scan or angiography. Major and minor bleeding, and associated adverse events were compiled. Results: Length of administration of E was 6.97 days and W was 6.33 days. Clinically suspected VTED was confirmed in 25 E (2.31%) and 22 W (2.05%) patients. One-halfVTED in the E group occurred between day 14 and 56. Onethird VTED in the W group occurred during the first 7 days. Clinically significant bleeding were 13 E and 6 W. Total Bleeding rates were 1.2% E and 0.56% W. NSAIDS were present in four E bleeds and two W bleeds. There were 5 (0.48%) deaths in E patients and 11 (1.02%) W patients. Three E (0.27%) and seven W (0.65%) deaths were due to unexplained cardiac arrest or suspected PE, one proven VTED death in each group. None were rdated to bleeding or drug. Conclusion: Use of E or W six to seven postoperative days produced low rates of dinically apparent VIED (<2.5%) and low postoperative VTED deaths (<0.5%) over 12 weeks. E produced more operative site bleeding than W; NSAIDS may be associated with bleeding. The 12 week all-cause mortality was 0.74%.
PAPER#43 THE INCIDENCE OF THROMBOEMBOL1SM FOLLOWING TOTAL HIP ARTHROPLASTY UNDER HYPOTENSIVE EPIDURAL ANESTHESIA
Geoffrey H. Westrich, MD, New York, NY, Eduardo A. Salvati, MD, Thomas P. Sculco, MD, Chitranjan S. Ranawat, MD James V. Bono, MD Purpose: The purpose of the study was to determine the incidence of thromboembolism in a large cohort of primary total hip arthropLasty patients treated with hypotensive epidural anesthesia and aspirin. Methods: The incidence of thromboembolism during hospitalization and after discharge was studied following 2,592 unilateral, primary total hip arthroplasty (THA) procedures performed under hypotensive epidural anesthesia by three experienced senior surgeons during a three year period from January 1, 1990 to December 31, 1993. The surgery was performed expediently, through a posterolateral approach, trying to minimize femoral vein obstruction. Postoperatively, patients used elastic stockings, ambulated early, and received aspirin 325mg twice a day for one month to reduce the risk of thromboembolism and heterotopic ossification. Results: Overall, 2,592 unilateral, primary THA were performed. Venograms were performed in 78.6% (2,037/2,592) of the patients, venous Doppler uhrasound in I0.3% (266/2,592) of the patients. Thus, only 14.2% (369/2,592) of the patients did not have a screening test for thromboembobsm. Overall, deep venous thrombosis (DVT) was diagnosed in 8.7% (226/2,592) of the patients, and in 10.4% (211/2,037) of the patients who had venograma. In-hospital proximal dots were present in 2.3% (47/2,037) and distal in 6.1% (124/2,037) and both proximal and distal clots in 2.0% (40/2,037) of the patients. Overall, m-hospital and out-of-hospital pulmonary embolus 0?E) was diagnosed by ventflation-perfnsion
to 12%; low dose warfarin prophylaxis has an associated prevalence of bleeding problems in 1 m 4% of patients but no significant difference had been demonstrated compared with LMWH. In this study, a statistically greater frequency of bleeding complications rdated to the wound was associated with use of LMWH resulting in one reoperation. Conclusion: It remains to be determined whether LMWH preparations can effectively reduce the prevalence of DVT without incurring an unacceptable increase in bleeding events. It may be premature to abandon the use of warfarin in favor of LMWt-I until a favorable risk-benefit profile of these agents can be demonstrated.
PAPER#42 *ENOXAPARIN VS. WARFARIN: HOSPITAL MANAGEMENT FOR DVT
PREVENTION clifford W. Colwen, Jr., MD, LaJolla, CA, J. Hinson, MD, J. McCutchen, MD, R. Paulson, MD, D. Collis, MD
PAPER#41 *COMPARISON OF A L O W MOLECULAR W E I G H T HEPARIN AND WARFARIN IN PREVENTION OF DEEP VEIN THROMBOSIS AFTER TOTAL HIP ARTHROPLASTY
Vincent D. Pellegrini, Jr,, MD, Hershey, PA, Saara Totterman, MD, David C. Ayers, MD, Norman Johanson, MD, Bernard N. StuIberg, MD, Aaron Rosenberg, MD, Craig Kessler, MD, Charles Francis, MD The use of iow molecular weight heparins (LMWH) for thromboprophylaxis following total joint arthroplasty has gained popularity. While a greater efficacy in preventing thromboembolism has been demonstrated, there is suggestion that their use is accompanied by an increase in bleeding complications. Purpose: This study" was designed to analyze both efficacy and complications associated with dakepatin sodium (Fragmin®), a low molecular weight heparin, compared with warfarin as thromboprophylaxis agents following total hip replacement (THA). Methods: Consecutive patients undergoing unilateral, primary or revision, total hip arthroplasty at seven teaching hospitals were prospectively considered for entry into the study. Those randomized to Fragmin® received 2500 IU preoperatively, 2500 IU on the postoperative evening, and 5000 IU daily thereafter; in the warfarin group, daily doses were adjusted to maintain the 1NR between 2 and 2.5. Between May 1992 and March 1995, a total of 580 patients were enrolled, 550 were included in ir~tentinn to treat analysis, and 382 completed contrast venography as endpoint determination for deep venous thrombosis (DVT). Bilateral contrust venography was performed between postoperative days 6-10 with nonionic contrast. All studies were reviewed by a single vascular radiologist at the primary center. Results: Overall DVT prevalence was 14% in the Fragrnin® and 26% in the warfarin groups (p=0.003). Proximal DVT occurred in 4% and 8% (p=0.078) while calf DVT occurred in 11% and 23% of the Fragmin® and warfarin groups, respectively. Two patients suffered nonfatal pulmonary embolism in each group. Patients over the age of 65 were twice as likely to develop DVT as those who were younger. Blood loss was comparable between the groups, but transfusion was necessary after the operative day in 48°£ of Fragmin® and 31% of warfarin patients (p<0.00i). Bleeding complications occurred in 11% of Fragmin® and 4.3% of warfarin patients; some patients experienced more than one bleeding event. Adverse hemorrhagic events involving the wound occurred 13 times in the Fragmin® and 3 times in the warfarin group (p=O.01); one Fragmin® patient experienced transient thrombocytopenia and required reoperatton for evacuation of a draining hematoma. Discussion: The results of this study are in keeping with previous reports demonstrating superiority of LMWH preparations over warfarin in DVT prophylaxis following THA. Specifically, both proximal and calf DVT were reduced by* 50% with LMWH compared with warfarin. However, previous reports of LMWH have also noted total "major" and "minor" bleeding complications to range from 8
* D e n o t e s t h a t s o m e t h i n g of v a l u e w a s r e c e i v e d . Presenters are boldfaced.
Methods: Safety and efficacy study comparing enoxaparin sodium (E) and warfarin (W) was performed in 2,155 patients undergoing Total Hip Arthroplasty at 156 U.S. sites. Patients were randomized to E (n=i,082) 30rag q12h, or W (n=1,073) INR adjusted. Clinical evaluation for venous thromboembotic disease (V-fED) was performed daily during hospitalization, at 6 and 12 weeks postoperatively. VTED was confirmed by venography, duplex ultrasound, lung scan or angiography. Major and minor bleeding, and associated adverse events were compiled. Results: Length of administration of E was 6.97 days and W was 6.33 days. Clinically suspected VTED was confirmed in 25 E (2.31%) and 22 W (2.05%) patients. One-halfVTED in the E group occurred between day 14 and 56. Onethird VTED in the W group occurred during the first 7 days. Clinically significant bleeding were 13 E and 6 W. Total Bleeding rates were 1.2% E and 0.56% W. NSAIDS were present in four E bleeds and two W bleeds. There were 5 (0.48%) deaths in E patients and 11 (1.02%) W patients. Three E (0.27%) and seven W (0.65%) deaths were due to unexplained cardiac arrest or suspected PE, one proven VTED death in each group. None were rdated to bleeding or drug. Conclusion: Use of E or W six to seven postoperative days produced low rates of dinically apparent VIED (<2.5%) and low postoperative VTED deaths (<0.5%) over 12 weeks. E produced more operative site bleeding than W; NSAIDS may be associated with bleeding. The 12 week all-cause mortality was 0.74%.
PAPER#43 THE INCIDENCE OF THROMBOEMBOL1SM FOLLOWING TOTAL HIP ARTHROPLASTY UNDER HYPOTENSIVE EPIDURAL ANESTHESIA
Geoffrey H. Westrich, MD, New York, NY, Eduardo A. Salvati, MD, Thomas P. Sculco, MD, Chitranjan S. Ranawat, MD James V. Bono, MD Purpose: The purpose of the study was to determine the incidence of thromboembolism in a large cohort of primary total hip arthropLasty patients treated with hypotensive epidural anesthesia and aspirin. Methods: The incidence of thromboembolism during hospitalization and after discharge was studied following 2,592 unilateral, primary total hip arthroplasty (THA) procedures performed under hypotensive epidural anesthesia by three experienced senior surgeons during a three year period from January 1, 1990 to December 31, 1993. The surgery was performed expediently, through a posterolateral approach, trying to minimize femoral vein obstruction. Postoperatively, patients used elastic stockings, ambulated early, and received aspirin 325mg twice a day for one month to reduce the risk of thromboembolism and heterotopic ossification. Results: Overall, 2,592 unilateral, primary THA were performed. Venograms were performed in 78.6% (2,037/2,592) of the patients, venous Doppler uhrasound in I0.3% (266/2,592) of the patients. Thus, only 14.2% (369/2,592) of the patients did not have a screening test for thromboembobsm. Overall, deep venous thrombosis (DVT) was diagnosed in 8.7% (226/2,592) of the patients, and in 10.4% (211/2,037) of the patients who had venograma. In-hospital proximal dots were present in 2.3% (47/2,037) and distal in 6.1% (124/2,037) and both proximal and distal clots in 2.0% (40/2,037) of the patients. Overall, m-hospital and out-of-hospital pulmonary embolus 0?E) was diagnosed by ventflation-perfnsion