Aspirin prophylaxis and surveillance of pulmonary embolism and deep vein thrombosis in total hip arthroplasty

RANDOMIZED CLINICAL TRIAL OF ASPIRIN AS PROPHYLAXIS FOR THROMBOEMBOLISM IN HIP ARTHROPLASTY

Objective

This study aims to evaluate aspirin as a chemical prophylaxis (200 mg) in total hip arthroplasty.

Methods

the study compared two groups and used ultrasonography (USG) to screen for low-deep venous thrombosis. Group 1 received 600 mg (control), and Group 2 received 200 mg of (intervention), associated with the use of elastic compression stockings and early walking.

Results

fourteen patients were allocated to Group A (200mg), and 16 to Group B (600mg); in group A (200mg), 3 cases with thrombus below the popliteal vein were detected at the first USG examination. All of them are in the left lower limb (21.4%). In group B (600 mg), 5 cases were identified after the first exam (31.2%). All cases were asymptomatic and followed the protocol with prophylaxis only with Aspirin.

Conclusion

In the statistical data, there were no differences in the presence of thrombus between the 200- and 600 mg groups, which is credited to using low-dose aspirin in low doses (200mg). Hematimetric levels returned to baseline levels and suggested there was no chronic or acute bleeding related to the use of aspirin. The manuscript was prepared according to the CONSORT guideline 2010. Level of Evidence I; Longitudinal Randomized Comparative Clinical Study.

Low-Dose Aspirin Is Adequate for Venous Thromboembolism Prevention Following Total Joint Arthroplasty: A Systematic Review

BACKGROUND

Patients undergoing total joint arthroplasty (TJA) are at risk of developing venous thromboembolism (VTE) without adequate prophylaxis. Since the American Academy of Orthopedic Surgeons issued guidelines in 2007 recommending aspirin 325 mg bis in die for 6 weeks, aspirin has been favored as the main VTE prophylaxis. However, the appropriate dose and duration of aspirin are not well-studied. This systematic review aims to identify any differences between high and low dose as well as duration for aspirin thromboprophylaxis after TJA as outlined by previous studies.

METHODS

A search was performed using Ovid MEDLINE, EMBASE, and PubMed, including articles up to July 2016. Studies were included if they contained at least 1 cohort that underwent TJA with aspirin as the sole chemoprophylaxis and reported either (1) symptomatic VTE or (2) secondary outcomes such as major bleeding or 90-day mortality.

RESULTS

Forty-five papers were included. There were no significant differences in symptomatic pulmonary embolism, symptomatic deep vein thrombosis, 90-day mortality, or major bleeding between patients receiving low-dose or high-dose aspirin. Patients treated with aspirin for <4 weeks had a higher risk of major bleeding (1.59%) vs patients treated for 4 weeks (0.15%), which may be attributed to premature cessation or differential reporting. Patients treated with aspirin for <4 weeks had a statistically higher 90-day mortality (1.95%) vs patients treated for 4 weeks (0.07%). There was no significant difference between incidence of pulmonary embolism or deep vein thrombosis and the durations of aspirin treatment.

CONCLUSION

This review suggests that low-dose aspirin is not inferior to high-dose aspirin for VTE thromboprophylaxis in TJA patients. Additionally, patients treated with aspirin for less than 4 weeks may have a higher risk of major bleeding and 90-day mortality compared to patients treated for a longer duration.

No Difference Between Low- and Regular-dose Aspirin for Venous Thromboembolism Prophylaxis After THA

BACKGROUND

Aspirin is established as an effective prophylaxis for venous thromboembolism (VTE) after THA; however, there is no consensus as to whether low- or regular-dose aspirin is more effective at preventing VTE.

QUESTIONS/PURPOSES

(1) Is there a difference in the incidence of symptomatic VTE within 90 days of elective THA using low-dose aspirin compared with regular-dose aspirin? (2) Is there a difference in the risk of significant bleeding (gastrointestinal and wound bleeding) and mortality between low- and standard-dose aspirin within 90 days after surgery?

METHODS

We retrospectively evaluated 7488 patients in our database who underwent THA between September 2012 and December 2016. A total of 3936 (53%) patients received aspirin alone for VTE prophylaxis after THA. During the study period, aspirin was prescribed as a monotherapy for VTE prophylaxis after surgery in low-risk patients (no history of VTE, recent orthopaedic surgery, hypercoagulable state, history of cardiac arrhythmia requiring anticoagulation, or receiving anticoagulation for any other medical conditions before surgery). Patients were excluded if aspirin use was contraindicated because of peptic ulcer disease, intolerance, or other reasons. Patients received aspirin twice daily (BID) for 4 to 6 weeks after surgery and were grouped into two cohorts: a low-dose (81 mg BID) aspirin group (n = 1033) and a standard-dose (325 mg BID) aspirin group (n = 2903). The primary endpoint was symptomatic VTE (deep vein thrombosis [DVT] and pulmonary embolism [PE]). Secondary endpoints included significant bleeding (gastrointestinal [GI] and wound) and mortality. Exploratory univariate analyses were used to compare confounders between the study groups. Multivariate regression was used to control for confounding variables (including age, sex, body mass index, comorbidities, and surgeon) as we compared the study groups with respect to the proportion of patients who developed symptomatic VTE, bleeding (GI or wound), and mortality within 90 days of surgery.

RESULTS

The 90-day incidence of symptomatic VTE was 1.0% in the 325-mg group and 0.6% in the 81-mg group (p = 0.35). Symptomatic DVT incidence was 0.8% in the 325-mg group and 0.5% in the 81-mg group (p = 0.49), and the incidence of symptomatic PE was 0.3% in the 325-mg group and 0.2% in the 81-mg group (p = 0.45). Furthermore, bleeding was observed in 0.8% of the 325-mg group and 0.5% of the 81-mg group (p = 0.75), and 90-day mortality was not different (0.1%) between the groups (p = 0.75). After accounting for confounders, regression analyses showed no difference between aspirin doses and the 90-day incidence of symptomatic VTE (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.29-2.85; p = 0.85) or symptomatic DVT (OR, 0.96; 95% CI, 0.26-3.59; p = 0.95).

CONCLUSIONS

We found no difference in the incidence of symptomatic VTE after THA with low-dose compared with standard-dose aspirin. In the absence of compelling evidence to the contrary, low-dose aspirin appears to be a reasonable option for VTE prophylaxis in otherwise healthy patients undergoing elective THA.

LEVEL OF EVIDENCE

Level III, therapeutic study.

PROSPECTIVE STUDY OF ASPIRIN FOR THROMBOEMBOLISM PROPHYLAXIS IN TOTAL HIP ARTHROPLASTY

Objectives:

To evaluate the effectiveness of aspirin as prophylaxis for deep venous thrombosis (DVT) in patients undergoing total hip arthroplasty (THA), and to analyze the incidence of bleeding during the post-operative period.

Methods:

This prospective study carried out in 2017 consisted of 37 patients indicated for THA with high risk for DVT. Immediately after the procedure, aspirin, elastic compression socks and early deambulation were initiated. Doppler ultrasound was performed in the legs 6 days and 6 weeks post-procedure to rule out venous thromboembolism. Hematometric variables and clinical criteria were used to detect bleeding.

Results:

The incidence of VTE (venous thromboembolism) 6 days post-procedure was 21.6%. By 6 weeks post-procedure, it dropped to 8.1%, (p = 0.102). Only 2.7% were diagnosed with VTE, 6 days and also 6 weeks post-procedure. Within the immediate postoperative period, hemoglobin was lower (p < 0.001), in contrast to 6 weeks after surgery, when it returned to baseline levels.

Conclusion:

Aspirin was an effective chemical prophylaxis for venous thromboembolism in high-risk patients who underwent THA. There was no clinical record of postoperative bleeding and hematometric levels suggested that there was no chronic bleeding. Level of Evidence II; Prospective study.

Venous Thromboembolic Disease in Uncemented Total Hip Replacement Surgery–a One-Year Follow-up of 490 Patients

A retrospective study of the morbidity and mortality from deep vein thrombosis (DVT) and pulmonary embolus (PE) in 490 consecutive patients undergoing uncemented total hip replacement was carried out in a district general hospital. Special diagnostic tests for DVT and PE were not available. Patients were followed up for one year. There were three deaths in hospital and eight further deaths during the first year, all unrelated to DVT and PE. The clinical incidence of venous thromboembolism was 2.04%. While clinical diagnosis of venous thromboembolic disease probably underestimates its incidence, the figures for mortality are accurate. With every patient accounted for one year after operation, there were no deaths attributable to PE in this series.

Aspirin and the prevention of venous thromboembolism following total joint arthroplasty: commonly asked questions

The number of arthroplasties being performed increases each year. Patients undergoing an arthroplasty are at risk of venous thromboembolism (VTE) and appropriate prophylaxis has been recommended. However, the optimal protocol and the best agent to minimise VTE under these circumstances are not known. Although many agents may be used, there is a difference in their efficacy and the risk of bleeding. Thus, the selection of a particular agent relies on the balance between the desire to minimise VTE and the attempt to reduce the risk of bleeding, with its undesirable, and occasionally fatal, consequences.

Acetylsalicylic acid (aspirin) is an agent for VTE prophylaxis following arthroplasty. Many studies have shown its efficacy in minimising VTE under these circumstances. It is inexpensive and well-tolerated, and its use does not require routine blood tests. It is also a ‘milder’ agent and unlikely to result in haematoma formation, which may increase both the risk of infection and the need for further surgery. Aspirin is also unlikely to result in persistent wound drainage, which has been shown to be associated with the use of agents such as low-molecular-weight heparin (LMWH) and other more aggressive agents.

The main objective of this review was to summarise the current evidence relating to the efficacy of aspirin as a VTE prophylaxis following arthroplasty, and to address some of the common questions about its use.

There is convincing evidence that, taking all factors into account, aspirin is an effective, inexpensive, and safe form of VTE following arthroplasty in patients without a major risk factor for VTE, such as previous VTE.

Cite this article: Bone Joint J 2017;99-B:1420–30.

Low-Dose Aspirin Is Effective Chemoprophylaxis Against Clinically Important Venous Thromboembolism Following Total Joint Arthroplasty: A Preliminary Analysis

BACKGROUND

Aspirin is a safe and effective prophylaxis for the prevention of venous thromboembolism following total joint arthroplasty. The optimal dose of aspirin prophylaxis is unknown. Our hypothesis was that lower-dose aspirin is as effective as higher-dose aspirin for the prevention of venous thromboembolism and is associated with fewer gastrointestinal side effects.

METHODS

In a prospective, crossover study, we analyzed 4,651 primary total joint arthroplasty cases performed from July 2013 to June 2015. For 4 weeks, 3,192 patients received enteric-coated 325-mg aspirin twice daily (the 325-mg aspirin group) and 1,459 patients received 81-mg aspirin twice daily (the 81-mg aspirin group). There were no significant differences (p > 0.05) in sex, body mass index, or Charlson Comorbidity Index between the two patient populations. Recorded complications occurring within 90 days postoperatively included symptomatic venous thromboembolism (deep venous thrombosis and pulmonary embolism), gastrointestinal complications, acute periprosthetic joint infection, and death.

RESULTS

The incidence of venous thromboembolism of 0.1% (95% confidence interval [CI], 0% to 0.3%) in the 81-mg aspirin group (1 with deep venous thrombosis and 1 with pulmonary embolism) was not significantly different (p = 0.345) from 0.3% (95% CI, 0.1% to 0.6%) in the 325-mg aspirin group (7 with deep venous thrombosis and 5 with pulmonary embolism). The incidence of gastrointestinal bleeding or ulceration of 0.3% (95% CI, 0% to 0.5%) in the 81-mg aspirin group was slightly, but not significantly (p = 0.66), lower than the 0.4% (95% CI, 0.2% to 0.6%) in the 325-mg aspirin group. The incidence of acute periprosthetic joint infection was 0.2% (95% CI, 0% to 0.4%) in the 81-mg aspirin group compared with 0.5% (95% CI, 0.2% to 0.7%) in the 325-mg aspirin group (p = 0.28). The 90-day mortality rate was similar in both groups at 0.1% (95% CI, 0% to 0.2%) in the 81-mg aspirin group and 0.1% (95% CI, 0% to 0.2%) in the 325-mg aspirin group (p = 0.78).

CONCLUSIONS

Our study demonstrates that low-dose aspirin is not inferior to high-dose aspirin for venous thromboembolism prophylaxis following total joint arthroplasty. This is not unexpected, as the available literature demonstrates that low-dose aspirin is as effective as higher-dose aspirin in the prevention of acute coronary syndrome and cerebrovascular events.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Aspirin as Thromboprophylaxis in Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Venous thromboembolism (VTE) comprises pulmonary embolism and deep vein thrombosis and is a complication of particular concern in lower limb arthroplasty. In recent years, aspirin has emerged as a potential alternative thromboprophylactic agent, particularly after its acceptance as a recommended agent by the American College of Chest Physicians. Aspirin is favorable due to its relative cost-effectiveness and convenience compared to novel oral anticoagulants and warfarin. However, its efficacy since its inclusion in the American College of Chest Physicians guidelines remains unclear. The present systematic review aimed to establish the efficacy of aspirin in preventing VTE in total hip and knee arthroplasty.

METHODS

Electronic searches were performed using 6 databases from up to June 2015, identifying all relevant studies. Data were extracted and meta-analyzed.

RESULTS

Eleven relevant studies were identified for inclusion in the present meta-analysis. The overall rate of deep vein thrombosis and pulmonary embolism in both hip and knee arthroplasty was 1.2% and 0.6%, respectively. The rate of major bleeding was 0.3%. Pooled mortality rate was 0.2%. All findings demonstrated a high and significant degree of heterogeneity.

CONCLUSION

Aspirin, both alone and in multimodal approaches to thromboprophylaxis, confers a low rate of VTE, with a low risk of major bleeding complications. However, the evidence for its use is limited by the low quality of studies and variation in dose in dosing regimes. Future randomized controlled trials should investigate the efficacy of aspirin, as well as the ideal dosing protocol for its use in thromboprophylaxis in arthroplasty.

Patient-reported compliance with thromboprophylaxis using an oral factor Xa inhibitor (rivaroxaban) following total hip and total knee arthroplasty

This prospective study examines patient non-compliance (NC) for an oral factor Xa inhibitor (Rivaroxaban) when used as venous thromboembolic (VTE) prophylaxis following lower limb arthroplasty. A total of 3145 patients underwent surgery from May 2010 to December 2011. At 6 weeks patients completed an anonymous self-administered questionnaire. Postoperatively 2947 (94%, 2947/3145) received Rivaroxaban. 2824 (96%, 2824/2947) completed all in-hospital doses. Seven percent (203/2824) of patients did not attend the 6-week follow-up. Two thousand one hundred sixty-three (83%, 2163/2621) completed all prescribed doses, 98 (4%, 98/2621) were NC and 360 (14%, 360/2621) had incomplete data. Gender, age, body mass index and preoperative hemoglobin all correlated with NC (p < 0.05). Type and side of surgery did not correlate with compliance (p > 0.05). Patient-reported NC for Rivaroxaban is 4% which compares favorably to other VTE prophylaxis modalities.

Mechanical calf compression and aspirin prophylaxis for total knee arthroplasty

We used aspirin and mechanical calf pneumatic compression for thromboembolism prophylaxis in 856 consecutive primary and revision total knee arthroplasties. Regional anesthesia was used in 97% of the procedures. Duplex ultrasonography was performed before discharge. We advised patients with calf thrombi to continue aspirin and have repeat duplex scans in 7 to 10 days. Patients with popliteal or femoral thrombi were given low-molecular-weight heparin and warfarin for 6 weeks. Using this protocol, the 90-day mortality rate was 0.14%. There was one fatal myocardial infarction. Three patients developed symptomatic nonfatal pulmonary embolisms, two occurring early and one late. Deep vein thrombosis occurred in 56 patients (9.3%). Only nine patients (1.5%) had symptomatic thrombosis, with four ipsilateral calf and five ipsilateral proximal thrombi. The data confirm the efficacy of a multimodal protocol with calf mechanical prophylaxis for almost all patients undergoing primary or revision total knee arthroplasty.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Effect on deep venous thrombosis with flexion during total knee arthroplasty

This study investigates the relationship between intraoperative extreme flexion and tibia-femoral dislocation during total knee arthroplasty on the prevalence of postoperative deep venous thrombosis. Knees were randomized into two groups. The control group underwent the procedure according to normal protocol, which kept the knee in extreme flexion and maintained dislocation for the duration of the exposure, whereas the variable group underwent the procedure modified to minimize the total amount of time the knee was hyperflexed and dislocated. Venograms were positive in 42% (39/92) of the control knees and 38% (30/79) of the modified group (p = 0.6). Proximal deep venous thrombosis were found in 12% (11/92) of the control knees and in 16% (13/79) of the modified knees (p = 0.4). No statistical difference could be detected between the two techniques in regards to the incidence of deep venous thrombosis.

Usefulness of arterial blood gas analysis and D-dimer measurement in the assessment of pulmonary embolism after orthopedic surgery

BACKGROUND

Deep venous thrombosis (DVT) and pulmonary embolism (PE) after spinal or lower extremity surgery are well recognized as common complications. Since 1995 we have investigated the incidence of PE after orthopedic surgery using ventilation-perfusion (V/Q) lung scans, and the prevalence of PE was about 10%. With a view to detecting early-stage PE by simple examinations, we evaluated the use of both the blood gas analysis and the D-dimer measurement after spinal or lower extremity surgery.

METHODS

Altogether, 85 patients who underwent spinal or lower extremity surgery were eligible for the study. Pneumatic sequential leg compression devices (PSLCDs) were utilized continuously both intra- and postoperatively. Arterial blood gas analysis and D-dimer measurement were performed pre- and postoperatively on days 3 and 7. We set lung scan criteria as follows: postoperative decrease in Pa(O2) (deltaPa(O2) by > or = 10 torr (group G), postoperative D-dimer of > or = 1 microg/ml (group D), or both. Patients with the criteria went on to undergo lung scans, and PE was diagnosed by the existence of any mismatch between ventilation-perfusion (V/Q) lung scans.

RESULTS

A total of 44 (51.8%) patients met the lung scan criteria and underwent perfusion lung scans, 10 (11.7%) of whom were diagnosed as PE. In groups G and D, about 30% showed PE. Moreover, six (85.7%) of the seven patients with both criteria showed a significant increase (83.7%) in the prevalence of PE.

CONCLUSIONS

Patients with the above criteria showed a high prevalence of PE. Moreover, 10 (11.7%) of the 85 patients were diagnosed as having PE, which corresponded to the prevalence in our former studies where lung scans were performed in all patients. The blood gas analysis and the D-dimer measurement may be utilized as the first screening examinations.

The John Charnley Award: heritable thrombophilia and development of thromboembolic disease after total hip arthroplasty

We retrospectively assessed whether heritable thrombophilia-hypofibrinolysis was more common in patients developing venous thromboembolism after total hip replacement than among control patients who did not develop venous thromboembolism, as an approach to better identify causes of venous thromboembolism after total hip arthroplasty. Twenty patients with proximal deep venous thrombosis after THA and 23 patients with symptomatic pulmonary embolism were compared with 43 control patients who did not have postoperative venous thromboembolism. Five of 42 patients with venous thromboembolism (12%) and 0 of 43 control patients (0%) had antithrombin III deficiency (< 75%). Nine of 42 patients with venous thromboembolism (21%) and 2 of 43 control patients (4.7%) had protein C deficiency (< 70%). Ten of 43 patients with venous thromboembolism (9 heterozygous, 1 homozygous; 23%) and 1 of 43 control patients (heterozygous; 2%) had the prothrombin gene mutation. Patients who had venous thromboembolism after total hip arthroplasty were more likely than matched control patients to have heritable thrombophilia with antithrombin III or protein C deficiency, or homo-heterozygosity for the prothrombin gene mutation. Screening for these three tests of heritable thrombophilia before total hip arthroplasty should improve the identification of patients with a reduced risk of venous thromboembolism who may need only mild thromboprophylaxis, and of those patients with heritable thrombophilia in whom prophylaxis should be more aggressive.

LEVEL OF EVIDENCE

Prognostic study, Level II-1 (lesser-quality RCT). See the Guidelines for Authors for a complete description of levels of evidence.

Thromboembolic disease prophylaxis in patients with hip fracture: a multimodal approach

OBJECTIVES

To assess if pneumatic compression in conjunction with chemoprophylaxis is an effective way to reduce the incidence of deep vein thrombosis in orthopedic trauma patients sustaining fragility hip fractures.

DESIGN

Two hundred patients admitted to the authors' institution between May 1998 and June 2002 for fractures of the hip were prospectively studied. All patients were treated operatively and received the VenaFlow calf compression device on both lower extremities immediately following surgery. Chemical prophylaxis of either aspirin (n = 67) or warfarin (n = 133) was administered in addition to mechanical compression. A noninvasive serial color flow duplex scan was performed 1 to 11 days postoperatively (mean 4.5 days) to determine the presence or absence of deep vein thrombosis. All patients were followed clinically 3 months postoperatively for a clinical evaluation of symptomatic deep vein thrombosis or pulmonary embolism.

RESULTS

Overall, the incidence of deep vein thrombosis was 3.5% (7 of 200) and included only 1 proximal thrombosis (1 out of 200, or 0.5%) and no pulmonary embolism. Five of the 7 patients positive for deep vein thrombosis were in the mechanical compression and warfarin prophylaxis group and 2 were in the aspirin arm of the study. For patients with deep vein thrombosis, the average number of risk factors was 3.71, whereas patients without clots averaged 1.75 clinical risk factors (P < or = 0.05). Three patients in the warfarin group developed bleeding complications (1 with a gastrointestinal bleed and 2 with minor bleeding not at the operative site). No evidence of a symptomatic deep vein thrombosis or pulmonary embolism was reported within a 3-month period following hospitalization.

CONCLUSIONS

Our findings suggest mechanical compression with the VenaFlow calf compression device in conjunction with chemoprophylaxis is an effective means of reducing thromboembolic disease in this high-risk population.

Deep venous thrombosis risk assessment, incidence, and prophylaxis in foot and ankle surgery

As discussed in this review, DVT and PE are dangerous clinical diagnoses that can occur following foot and ankle surgery. The authors have provided a clinical protocol, a risk assessment tool, and treatment guidelines for this condition that can be applied to the everyday practice of foot and ankle surgeons. Unlike recommendations in previous studies, the authors believe that podiatric and orthopedic surgeons operating on the foot and ankle should evaluate each patient carefully and consider pharmacologic prophylaxis against DVT formation when significant risk factors are present.

Pneumatic compression hemodynamics in total hip arthroplasty

A crossover study was performed to evaluate the effect of several pneumatic compression devices and active dorsoplantar flexion in 10 patients who underwent total hip arthroplasty. Using the Acuson 128XP/10 duplex ultrasound unit with a 5-MHz linear array probe, peak venous velocity and venous volume were assessed above and below the greater saphenous vein and common femoral vein junction. A computer generated randomization table was used to determine the order of the test conditions. The pneumatic compression devices evaluated included two foot pumps, one foot and calf pump, one calf pump, and three calf and thigh pumps. Statistical analyses included analysis of variance and analysis of variance with covariance between devices and patients. The covariates tested were the baseline measurements and the order in which the devices were tested. Differences between devices relate in part to the frequency and rate of inflation and the location and type of compression. Pulsatile calf and foot and calf pneumatic compression with a rapid inflation time produced the greatest increase in peak venous velocity, whereas compression of the calf and thigh showed the greatest increase in venous volume. Because patient and nursing compliance is essential to the success of mechanical prophylaxis for thromboembolic disease, the more simple, yet efficacious, devices that are easier to apply and less cumbersome appear to have a greater likelihood of success. In the active and alert patient, active dorsoplantar flexion should be encouraged.

Thromboembolic disease prophylaxis in total knee arthroplasty using intraoperative heparin and postoperative pneumatic foot compression

A prospective study was performed to assess the clinical efficacy of intraoperative heparin combined with postoperative pneumatic foot compression and aspirin for thromboembolic disease prophylaxis after primary total knee arthroplasty (TKA). This group of 48 patients all had a primary TKA performed under epidural anesthesia. The cohort of patients was compared with a similar cohort of patients matched for age and comorbidity. The control group consisted of 61 patients (41 unilateral patients, 20 bilateral patients) with 81 TKAs who received epidural anesthesia and postoperative pneumatic foot compression and aspirin. The same surgeon and anesthesiologist performed all cases. All patients had the pneumatic foot compression device applied in the recovery room and received 325 mg of enteric-coated aspirin twice a day beginning the night of surgery. Venography was performed on the fifth postoperative day for both groups to determine the incidence of deep vein thrombosis (DVT). In the control group with postoperative pneumatic foot compression (group 1), the overall incidence of DVT was 27% (22 of 81), with 10% (8 of 81) major calf DVT and no proximal (popliteal or femoral) DVT. In the study group with intraoperative heparin and postoperative pneumatic foot compression (group 2), the overall incidence of DVT was 25% (12 of 48), with 8% (4 of 48) major calf DVT and no proximal DVT. There was no statistically significant difference between groups 1 and 2 for the incidence of overall DVT (P > .05) or major calf DVT (P > .05). No complications were associated with the use of intraoperative heparin or the pneumatic compression device, and no patient developed a symptomatic pulmonary embolism up to 3 months postoperatively. Although this study confirms that pneumatic foot compression combined with aspirin is an effective form of DVT prophylaxis after TKA, the added benefit of intraoperative heparin was not statistically proven. Although greater statistical power is needed to determine whether intraoperative heparin provides an added benefit, this study reveals a low incidence of DVT in TKA with this protocol.

Efficacy of prophylaxis against thromboembolism with intermittent pneumatic compression after primary and revision total hip arthroplasty

BACKGROUND

Thromboembolism is a common and important complication after total hip arthroplasty. A variety of pharmacological and mechanical measures have been proposed for prophylaxis. The purpose of the present study was to evaluate the efficacy of intermittent pneumatic compression as prophylaxis against thromboembolism following total hip arthroplasty.

METHODS

The prospective study involved a consecutive series of 425 patients in whom a total of 502 (324 primary and 178 revision) total hip arthroplasties had been performed by two surgeons. The patients were managed intraoperatively and postoperatively with use of thigh-high elastic compression stockings and thigh-high intermittent pneumatic compression sleeves. Experienced vascular technologists performed venous duplex ultrasonography on both lower extremities of all patients at a mean of six days (range, two to fifteen days) postoperatively. All patients were followed for at least one year in order to detect late thromboembolism.

RESULTS

An asymptomatic deep-vein thrombosis was noted on the scans made after twenty-three (4.6 percent) of the 502 procedures. Nineteen (3.8 percent) of the arthroplasties were followed by the development of a proximal thrombosis and four (0.8 percent), a distal thrombosis. Nineteen of the thromboses were ipsilateral (eighteen were proximal and one, distal), and four were contralateral (one was proximal and three, distal). No symptomatic deep-vein thrombosis developed in the hospital. In addition, three (two proximal and one distal) symptomatic ipsilateral deep-vein thromboses (a prevalence of 0.6 percent) developed three to twenty-three weeks after postoperative scans revealed negative findings and the patients were discharged from the hospital. Three symptomatic pulmonary embolisms (a prevalence of 0.6 percent) were confirmed by ventilation-perfusion scanning while the patients were in the hospital. There were no symptomatic pulmonary embolisms after discharge, and there were no fatal pulmonary embolisms. With the numbers available, we were unable to detect an association between deep-vein thrombosis and age (p = 0.76), gender (p = 0.13), body-mass index (p = 0.12), type of arthroplasty (primary or revision) (p = 0.12), operative approach (p = 0.37), duration of the operation (p = 0.21), type of anesthesia (general or regional) (p = 0.51), units of blood transfused (autologous, p = 0.79; homologous, p = 0.57), blood type (p = 0.18), or the presence of a so-called classic risk factor for the development of thrombosis (p = 0.22). Five arthroplasties (1.0 percent) were followed by the development of a wound hematoma, but only one hematoma necessitated operative drainage.

CONCLUSIONS

The use of intraoperative and postoperative thigh-high intermittent pneumatic compression, combined with duplex ultrasonography performed by experienced vascular technologists, is effective for prophylaxis against thromboembolism after both primary and revision total hip arthroplasties. The low prevalence of deep-vein thrombosis (4.6 percent) and symptomatic pulmonary embolism (0.6 percent) is comparable with that associated with pharmacological prophylaxis.

Prophylaxis against deep venous thrombosis after total knee arthroplasty. Pneumatic plantar compression and aspirin compared with aspirin alone

A prospective, randomized study was conducted to assess the efficacy of pulsatile pneumatic plantar compression for prophylaxis against deep venous thrombosis after total knee arthroplasty performed with use of regional anesthesia. One hundred and twenty-two patients (164 knees) who were scheduled to have a unilateral or a one-stage bilateral total knee arthroplasty were separately randomized to be managed with either aspirin alone or the pulsatile pneumatic plantar-compression device and aspirin. The prevalence of deep venous thrombosis was 27 per cent (twenty-two of eighty-one knees) in the group treated with pneumatic plantar compression compared with 59 per cent (forty-nine of eighty-three knees) in the patients managed with aspirin alone (the control group) (p < 0.001). A significant difference was also noted in the group that had had a unilateral arthroplasty (a prevalence of 27 per cent [eleven of forty-one knees] in the group treated with pneumatic plantar compression, compared with 67 per cent [twenty-six of thirty-nine knees] in that treated with aspirin alone; p < 0.006) and in the group that had had a one-stage bilateral procedure (a prevalence of 28 per cent [eleven of forty knees] in the group treated with pneumatic plantar compression, compared with 52 per cent [twenty-three of forty-four knees] in that treated with aspirin alone; p < 0.03). No proximal thrombi were noted in any patient who used the pulsatile pneumatic plantar-compression device, while the prevalence of proximal thrombosis in the popliteal or femoral veins was 14 per cent (twelve of eighty-three knees) in the group treated with aspirin alone (p < 0.0003). In the group treated with a unilateral procedure and aspirin alone the prevalence of proximal thrombosis was 13 per cent (five of thirty-nine knees; p < 0.02), while in the group treated with a bilateral procedure and aspirin alone it was 16 per cent (seven of forty-four knees; p < 0.01). Only in the patients who had had a unilateral procedure was use of the compression device associated with significantly less edema postoperatively than was use of aspirin alone. The change between the preoperative and postoperative circumferences of the thigh and leg was significantly less (9 +/- 4.1 millimeters [mean and standard deviation] less for the thigh [p < 0.01] and 6 +/- 3.9 millimeters less for the leg [p < 0.049]) with the compression device than with aspirin alone. In addition, there was significantly less mean drainage (98 +/- 61.1 milliliters) in the group treated with a unilateral procedure and pneumatic compression, compared with that treated with a unilateral procedure and aspirin alone (p < 0.041). An internal timer of the compression device was used to assess the compliance of the patient with use of the device, and a relationship between deep venous thrombosis and the total duration of treatment with the device was found. The patients in whom deep venous thrombosis did not develop used the device for a mean of 96 +/- 23.4 hours (range, sixty to 164 hours) postoperatively, or 19.2 +/- 5.1 hours a day, while those in whom thrombosis developed used it for a mean of 67 +/- 21.1 hours (range, twenty-six to 101 hours), or 13.4 +/- 4.3 hours a day (p < 0.001). No untoward effects were noted in any patient who used the device. This study confirms the safety and efficacy of pulsatile pneumatic plantar compression and aspirin compared with aspirin alone and supports the use of mechanical compression for prophylaxis against deep venous thrombosis and for reduction of edema in patients who have had a total knee arthroplasty. In addition, we found a direct relationship between compliance with the use of this device and its efficacy in reducing deep venous thrombosis.

Current Status of Anticoagulation Therapy After Total Hip and Total Knee Arthroplasty

Postoperative venous thromboembolism in the pelvis and lower extremities is a potentially life-threatening complication in patients undergoing elective total hip and total knee arthroplasty. Numerous pharmacologic methods of prophylaxis have been used in the past with varying degrees of success. Warfarin has been proved effective as a prophylactic agent after total hip arthroplasty but has been less efficacious after total knee arthroplasty. The low-molecular-weight heparins have recently been approved for prophylaxis after total hip and total knee arthro-plasty and are an acceptable alternative to warfarin. This new class of drugs appears to have the advantage of predictable subcutaneous bioavailability, which allows less frequent administration and laboratory monitoring and offers a decrease in the occurrence of side effects.

Hypotensive epidural anesthesia for total hip arthroplasty: a review

Hypotensive epidural anesthesia provides arterial hypotension to maintain a mean arterial pressure of 50 mmHg and it can be used to reduce blood loss during total hip replacement. The technique combines an extensive epidural blockade with an intravenous infusion of low-dose epinephrine. This results in arterial hypotension, but with preservation of central venous pressure, heart rate, stroke volume, cardiac output, and an augmentation of blood flow to the lower extremity. The technique does not appear to adversely affect cardiac, renal, or cerebral function and is used safely in patients with hypertension, ischemic heart disease, and in the elderly. Intraoperative blood losses during primary total hip replacement are between 100 and 300 mL. Perioperative transfusions have declined with the introduction of the technique. Radiological evidence of improved fixation of cemented acetabular components has been observed. Rates of deep-vein thrombosis are low: 2-3% proximal deep-vein thrombosis with an overall rate of 10%. In-hospital mortality is 0.1%; lower than previously published rates. In conclusion, hypotensive epidural anesthesia is safe and provides a number of advantages over conventional anesthetic techniques for total hip replacement.

Revision total hip arthroplasty with the BIAS (Biologic Ingrowth Anatomic System) femoral component. Three to six-year results

The BIAS femoral component was used for most of the revision total hip arthroplasties performed during a four-year period by one surgeon. Forty-one BIAS femoral components were implanted in thirty-nine patients and were followed prospectively for a mean of five years (range, three to six years). The mean age of the patients was fifty-seven years. Twenty-eight (68 percent) of the femora were classified preoperatively as having severe loss of bone distal to the intertrochanteric line. Cancellous autogenous graft from the iliac crest or fresh-frozen cancellous allograft was used in all hips to fill the proximal defects. Weight-bearing was delayed for three months after the operation. Clinical and radiographic evaluation was performed with the use of accepted criteria. The mean preoperative Harris hip score was 36 points (range, 0 to 71 points) and improved postoperatively to 85 points (range, 53 to 100 points). Thirty-two (78 percent) of the hips had a good or excellent result at the most recent follow-up examination. Thirty-six patients (thirty-eight hips [93 percent]) had no or slight pain, and twenty-nine patients (thirty hips [73 percent]) walked with a slight or no limp. There was an association between one or more previous revisions of the femoral component and an increased prevalence of pain in the thigh or hip (p < 0.009). Radiographic analysis showed that thirteen components (32 percent) subsided, but eleven of them stabilized and subsidence was not associated with less satisfactory clinical results. The hip scores were not notably lower in this group. No component was revised, and no patient had clinical symptoms for which revision was indicated at the most recent examination. Revision total hip arthroplasty with use of this implant, which has a partial proximal porous coating and which is inserted without cement, provided similar clinical results but inferior fixation, as seen on radiographs, compared with reported revisions in which components were implanted with modern cementing techniques. However, the apparent reconstitution of femoral bone structure in areas of previous osteolysis or cortical thinning is encouraging. The senior one of us no longer routinely uses this specific implant for revision arthroplasty done without cement, but does use a similar, revised version of the prosthesis.

The prevalence of deep venous thrombosis after total hip arthroplasty with hypotensive epidural anesthesia

A prospective, randomized trial was done to evaluate the prevalence of deep venous thrombosis following primary unilateral or bilateral total hip arthroplasty with use of hypotensive epidural anesthesia, external pneumatic-compression boots, and aspirin (Group I) and with use of hypotensive epidural anesthesia and aspirin (Group II). All operations were performed by two of us (E. A. S. and T. P. S.) through a posterolateral approach. Two hundred and thirty-one patients who were more than thirty-nine years old and who had a total of 250 primary total hip arthroplasties were included in the study. There were 113 patients (124 hips) in Group I and 118 patients (126 hips) in Group II. All patients had venography on the sixth, seventh, or eighth postoperative day. Group I had no proximal thrombi, seven distal thrombi (6 per cent), and one late pulmonary embolus (1 per cent). Group II had one proximal thrombus (popliteal) (1 per cent), eight distal thrombi (6 per cent), and one late pulmonary embolus (1 per cent). The difference was not significant (p = 0.65). However, a significant difference may have been noted if the study population had been larger. The combination of hypotensive epidural anesthesia and aspirin is effective prophylaxis against deep venous thrombosis in patients who have a primary total hip arthroplasty. The extremely low rate of deep venous thrombosis in the present study may be attributed to the use of hypotensive epidural anesthesia and the associated decrease in blood loss and transfusion requirements.(ABSTRACT TRUNCATED AT 250 WORDS)

Porous-coated total hip arthroplasty in rheumatoid arthritis

Thirty-five porous-coated total hip arthroplasties were implanted in 25 patients with juvenile-onset or adult-onset rheumatoid arthritis and prospectively followed for a mean of 4.5 years (range, 3-6.5 years). Using the Harris hip rating, the mean hip score at the final follow-up evaluation was 91, and 86% of the hips had a good or excellent result. Thirty-one hips had no hip or thigh pain, while four had occasional slight pain. After surgery, 10 patients were employed and the remainder were ambulatory. There were no early or late deep infections. There was one reoperation for recurrent dislocation of the hip, but the components were not removed. Radiographic evaluation of the acetabular component showed that only one component had a complete radiolucent line in all three zones. Three femoral components had nonprogressive subsidence. At this intermediate-term follow-up period, porous-coated total hip arthroplasty is a promising technique that is likely to be successful in young patients with rheumatoid arthritis.

A prospective study of 100 consecutive Harris-Galante porous total hip arthroplasties. 2-5-year results

This is a prospective study of the authors' first 100 Harris-Galante porous total hip arthroplasties (THA) that were followed for 2-5 years. The mean age of the 83 patients was 43 years. Using the Harris hip rating system, 80% of the hips were rated as excellent, 13% as good, 5% as fair, and 2% as poor at final evaluation. Eighty percent of the hips had no pain, 11% had slight or occasional pain, 8% had activity-related pain, and 1% had moderate pain. Eighty-seven percent of the hips had no limp, 8% had a slight limp, and 5% had a moderate limp. One femoral component, placed as a conversion of a loose bipolar hemiarthroplasty, has been removed for loosening. Two other hips have been reoperated, one for lengthening the femoral neck and one for changing the acetabular liner. There were no problems with acetabular screw fixation and no component migrated. Only two hips had 1 mm nonprogressive radiolucent lines in all three zones. Femoral component subsidence of 3 or more mm was measured in 16 hips, but was progressive in only 1. Radiolucent and radiodense lines were frequently seen in the nonporous coated regions of the femoral stem. Loss of proximal medial femoral bone density was seen in 59% of hips, and calcar resorption was seen in 16% of hips. Although the clinical results of this uncemented implant system were good or excellent in 93% of hips, the high incidence of femoral component subsidence is worrisome.