Thromboembolic disease after total hip arthroplasty: who is at risk?

Non-metastatic hip fractures surgery in patients with active cancer: benefit and risk

PURPOSE

Although rare, non-metastatic proximal femoral fracture (PFF) can develop in patients with active cancer. However, little data are available regarding the risks and benefits of surgical treatment in such patients. The purpose of his study was to investigate the risks and benefits of surgical treatment of PFF in patients with and without cancer.

METHODS

We retrospectively examined the medical records of all patients treated for PFF, excluding those with pathological fracture, at our hospital from July 2013 to December 2020. The patients were divided into two groups; The active cancer group and the standard group. We investigated in both groups about surgical and medical complications during the perioperative period, walking ability two weeks postoperatively, and one-year postoperative mortality rate.

RESULT

After the inclusion and exclusion criteria, 39 patients in the active cancer group and 331 patients in the standard group were finally investigated. There were no statistically significant differences between the two groups. The complication rate did not appear statistical significance between two groups (16.7% in active cancer group vs 10.7% in standard group: p = 0.272). Walking ability was also similar in two groups. Mortality rate at one year was significantly higher in the active cancer group. (41.2% in active cancer group vs 6.0% in standard group: p < 0.05).

CONCLUSION

Although the active cancer group had a higher mortality rate at one year, which was influenced by the prognosis of the cancer, the benefits of surgical intervention, such as regaining walking ability, were the same in patients with and without active cancer.

Do breast cancer patients have increased risk of complications after primary total hip and total knee arthroplasty?

Aims

Breast cancer survivors have known risk factors that might influence the results of total hip arthroplasty (THA) or total knee arthroplasty (TKA). This study evaluated clinical outcomes of patients with breast cancer history after primary THA and TKA.

Methods

Our total joint registry identified patients with breast cancer history undergoing primary THA (n = 423) and TKA (n = 540). Patients were matched 1:1 based upon age, sex, BMI, procedure (hip or knee), and surgical year to non-breast cancer controls. Mortality, implant survival, and complications were assessed via Kaplan-Meier methods. Clinical outcomes were evaluated via Harris Hip Scores (HHSs) or Knee Society Scores (KSSs). Mean follow-up was six years (2 to 15).

Results

Breast cancer patient survival at five years was 92% (95% confidence interval (CI) 89% to 95%) after THA and 94% (95% CI 92% to 97%) after TKA. Breast and non-breast cancer patients had similar five-year implant survival free of any reoperation or revision after THA (p ≥ 0.412) and TKA (p ≥ 0.271). Breast cancer patients demonstrated significantly lower survival free of any complications after THA (91% vs 96%, respectively; hazard ratio = 2 (95% CI 1.1 to 3.4); p = 0.017). Specifically, the rate of intraoperative fracture was 2.4% vs 1.4%, and venous thromboembolism (VTE) was 1.4% and 0.5% for breast cancer and controls, respectively, after THA. No significant difference was noted in any complications after TKA (p ≥ 0.323). Both breast and non-breast cancer patients experienced similar improvements in HHSs (p = 0.514) and KSSs (p = 0.132).

Conclusion

Breast cancer survivors did not have a significantly increased risk of mortality or reoperation after primary THA and TKA. However, there was a two-fold increased risk of complications after THA, including intraoperative fracture and VTE.

An analysis of risk factors for venous thromboembolism in primary versus revision total joint arthroplasty

Background

One of the most serious complications after primary or revision lower extremity total joint arthroplasty (TJA) is venous thromboembolism disease (VTE). Identifying patients at high risk for VTE allows tailoring of prophylactic anticoagulation regimens to those most vulnerable. This study aimed to identify risk factors for VTE in primary and revision lower extremity TJA.

Methods

The Electronic Medical Record was queried from a single academic institution for all patients who underwent a lower extremity TJA between 2007 and 2020. Demographics, comorbid conditions, perioperative characteristics, and postoperative complications were identified. An Elastic Net Multiple Logistic Regression Model was used to assess 49 covariates and predict those associated with a significant risk of VTE.

Results

We identified 4900 primary and revision total knee arthroplasty (TKA) and total hip arthroplasty (THA) patients. There was no significant difference between primary and revision THA. Primary TKA had a higher rate of VTE than revision TKA. Significant risk factors identified for VTE in THA patients include histories of deep vein thrombosis (DVT), pulmonary embolism (PE), metastatic tumors, hemiplegia, and Hispanic ethnicity. Risk factors for VTE in TKA patients include histories of DVT, PE, metastatic tumors, and postoperative warfarin and heparin use. In all patients, age was a significant predictor of VTE risk.

Conclusion

Our work identifies many risk factors for VTE following TJA. While the increased rate of VTE in some populations may represent selection bias, it also highlights the incomplete understanding of the etiology and prevention of this complication in the joint arthroplasty population and requires further study.

Varicose veins as a risk factor for venous thromboembolism in arthroplasty patients: Meta-analysis

OBJECTIVE

A meta-analysis to determine if patients with varicose veins are at an increased risk of venous thromboembolism (VTE) when undergoing major lower limb arthroplasty.

METHODS

Medline, Embase, and Cochrane Library databases were searched using appropriate terms for studies that reported post-operative VTE in patients who had lower limb arthroplasty with any history of varicose veins. Methodological quality of included studies was quantified using the Risk of Bias (ROB) assessment tools. Findings were reported using the meta-analysis of observational studies in epidemiology (MOOSE) checklist.

RESULTS

A total of 129 studies were identified with 11 observational studies being eligible for inclusion. This consisted of 265,194 patients who underwent lower limb arthroplasty, 2188 of which had pre-existing varicose veins. Overall, VTE occurred in 1845 patients, and 122 cases had varicose veins present at time of arthroplasty. Meta-analysis indicates that patients undergoing lower limb arthroplasty with varicose veins are at increased risk of having a VTE, OR 2.37, 95% CI 1.54-3.63, (p < 0.001). One study evaluated if previous varicose veins surgery influenced the risk of VTE in arthroplasty patients, OR 0.96 (95% CI 0.7-1.28), p = 0.429.

CONCLUSIONS

Varicose veins and lower limb arthroplasty are known independent risk factors for VTE. There is a paucity of data regarding the risk of VTE in patients undergoing lower limb arthroplasty who have co-existing varicose veins. This meta-analysis shows that patients with varicose veins are at an increased risk of VTE when undergoing major lower limb arthroplasty. Further studies are required in order to determine if such patients should undergo varicose vein surgery before undertaking major lower limb joint replacement.

Total Joint Arthroplasty in Patients With Atrial Septal Defects: What Are the 90-Day Complications?

Background

Methods

Results

Conclusions

Level of evidence

Factors associated with 90-day acute ischemic stroke in patients ≥70 years old with total hip arthroplasty for hip fracture

Background

Postoperative ischemic stroke is a devastating complication following total hip arthroplasty (THA). The purpose of the current study was to investigate the incidence of postoperative acute ischemic stroke (AIS) in patients ≥70 years old with THA for hip fracture after 90 days and independent risk factors associated with 90-day AIS.

Methods

A multicenter retrospective study was conducted, patients ≥70 years old with THA for hip fracture under general anesthesia were included from February 2017 to March 2020. Patients with AIS within 90 days after THA were identified as AIS group; patients with no AIS were identified as no AIS group. The baseline characteristics and risk factors were collected, multivariable logistic regression was used to identify independent risk factors of 90-dayAIS.

Results: 2517 patients (mean age 76.18 ± 6.01) were eligible for inclusion in the study. 2.50% (63/2517) of patients had 90-day AIS. Compared with no AIS, older age, diabetes, hyperlipidemia, atrial fibrillation (AF) and higher D-dimer value were more likely in patients with AIS (P < 0.05), and anticoagulant use was fewer in patients with AIS. ROC curve analysis showed that the optimal cut point of D-dimer for AIS was D-dimer≥4.12 μg/ml. Multivariate logistic regression analysis showed that D-dimer≥4.12 μg/ml [adjusted odds ratio (aOR), 4.44; confidence interval (CI), 2.50–7.72; P < 0.001], older age (aOR, 1.08; 95%CI, 1.03–1.12; P < 0.001), hyperlipidemia (aOR, 2.28; 95%CI, 1.25–4.16; P = 0.007), atrial fibrillation (aOR, 5.84; 95% CI, 1.08–15.68; P = 0.001), and diabetes (aOR, 2.60; 95% CI, 1.56–4.39; P < 0.001) were associated with increased risk of 90-day AIS after THA.

Conclusions

In conclusion, we found that the incidence of 90-day AIS in patients≥70 years old with THA for hip fracture was 2.5%. Older age, diabetes, hyperlipidemia, AF and higher D-dimer value were independent risk factors for 90-day AIS in patients≥70 years old with THA for hip fracture.

Multimodal prophylaxis in patients with a history of venous thromboembolism undergoing primary elective hip arthroplasty

Aims

We studied the safety and efficacy of multimodal thromboprophylaxis in patients with a history of venous thromboembolism (VTE) who undergo total hip arthroplasty (THA) within the first 120 postoperative days, and the mortality during the first year. Multimodal prophylaxis includes discontinuation of procoagulant medications, VTE risk stratification, regional anaesthesia, an intravenous bolus of unfractionated heparin prior to femoral preparation, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient’s risk of VTE.

Methods

Between 2004 to 2018, 257 patients with a proven history of VTE underwent 277 primary elective THA procedures by two surgeons at a single institution. The patients had a history of deep vein thrombosis (DVT) (186, 67%), pulmonary embolism (PE) (43, 15.5%), or both (48, 17.5%). Chemoprophylaxis included aspirin (38 patients), anticoagulation (215 patients), or a combination of aspirin and anticoagulation (24 patients). A total of 50 patients (18%) had a vena cava filter in situ at the time of surgery. Patients were followed for 120 days to record complications, and for one year to record mortality.

Results

Postoperative VTE was diagnosed in seven patients (2.5%): DVT in five, and PE with and without DVT in one patient each. After hospitalization, three patients required readmiss-ion for evacuation of a haematoma, one for wound drainage, and one for monitoring of an elevated international normalized ratio (INR). Seven patients died (2.5%). One patient died five months postoperatively of a PE during open thrombectomy. She had discontinued anticoagulation. One patient died of a haemorrhagic stroke while receiving Coumadin. PE or bleeding was not suspected in the remaining five fatalities.

Conclusion

Multimodal prophylaxis is safe and effective in patients with a history of VTE. Postoperative anticoagulation should be prudent as very few patients developed VTE (2.5%) or died of suspected or confirmed PE. Mortality during the first year was mostly unrelated to either VTE or bleeding. Cite this article: Bone Joint J 2020;102-B(7 Supple B):71–77.

Prevention of Pulmonary and Venous Thromboembolism Post Coronary Artery Bypass Graft Surgery - Literature Review

Objective

The current review evaluates recent literature on the different aspects of prophylaxis in postoperative pulmonary and venous thromboembolism and their main risk factors.

Methods

The literature survey was carried out based on the PubMed data using the keywords “coronary artery bypass graft” and “venous thromboembolism” as components of the search field title.

Results

Studies reported several risk factors for postoperative thromboembolism including advanced age, postoperative immobilization, type of thromboprophylaxis, obesity, and location of the surgery.

Conclusion

According to the studies, tailored prophylaxis could be easily adapted to decrease the intensity and duration of postoperative thromboembolism in a patient with several disorders and comorbidities, especially in cardiovascular disease.

Lower Activity and Function Scores Are Associated with a Higher Risk of Preoperative Deep Venous Thrombosis in Patients Undergoing Total Hip Arthroplasty

This study was performed to investigate the relationship between patients’ activity and function levels and the incidence of preoperative deep venous thrombosis (DVT) prior to total hip arthroplasty (THA). We retrospectively reviewed 500 patients admitted for primary or revision THA from July 2014 to October 2018. The diagnosis of DVT was confirmed using Doppler ultrasonography 1 month before THA. The patients’ activity and hip function were evaluated using several clinical scores: the Harris Hip Score (HHS), Oxford Hip Score (OHS), University of California Los Angeles (UCLA) activity score, and visual analog scale (VAS) score. Those scores and the medical history were examined for correlations with preoperative DVT using univariate and multivariate models. Univariate regression analysis showed that older age, current steroid use, anticoagulant use, a history of DVT, collagen disease, a lower UCLA activity score, and a lower OHS were associated with an elevated risk of preoperative DVT. The multivariate analyses showed that a higher UCLA activity score (odds ratio (OR): 0.0049–0.012) and higher OHS (OR: 0.0012–0.0088) were associated with a lower risk of preoperative DVT in each model. Age (OR: 1.07 in both models), current steroid use (OR: 9.32–10.45), and a history of DVT (OR: 27.15–74.98) were associated with a higher risk of preoperative DVT in both models. Older age, current steroid use, a history of DVT, a lower UCLA activity score, and a lower OHS were risk factors for preoperative DVT before THA, even when controlling for potential confounders. Patients exhibiting low activity and low function levels were more likely to have DVT, even before surgery.

Implementation and Validation of the 2013 Caprini Score for Risk Stratification of Arthroplasty Patients in the Prevention of Venous Thrombosis

Appropriate chemoprophylaxis choice following arthroplasty requires accurate patient risk assessment. We compared the results of our prospective department protocol to the Caprini risk assessment model (RAM) retrospectively in this study group. Our goal was to determine whether the department protocol or the Caprini score would identify venous thromboembolism (VTE) events after total joint replacement. A secondary purpose was to validate the 2013 Caprini RAM in joint arthroplasty and determine whether patients with VTE would be accurately identified using the Caprini score. A total of 1078 patients met inclusion criteria. A Caprini score of 10 or greater is considered high risk and a score of 9 or less is considered low risk. The 2013 version of the Caprini RAM retrospectively stratified 7 of the 8 VTE events correctly, while only 1 VTE was identified with the prospective department protocol. This tool provided a consistent, accurate, and efficacious method for risk stratification and selection of chemoprophylaxis.

Impact of Co-Morbidities on the Cost of Care in Primary Elective Joint Arthroplasty

BACKGROUND

The Comprehensive Care for Joint Replacement model is the newest iteration of the bundled payment methodology introduced by the Centers for Medicare and Medicaid Services. Comprehensive Care for Joint Replacement model, while incentivizing providers to deliver care at a lower cost, does not incorporate any patient-level risk stratification. Our study evaluated the impact of specific medical co-morbidities on the cost of care in total joint arthroplasty (TJA) patients.

METHODS

A retrospective study was conducted on 1258 Medicare patients who underwent primary elective TJA between January 2015 and July 2016 at a single institution. There were 488 males, 552 hips, and the mean age was 71 years. Cost data were obtained from the Centers for Medicare and Medicaid Services. Co-morbidity information was obtained from a manual review of patient records. Fourteen co-morbidities were included in our final multiple linear regression models.

RESULTS

The regression models significantly predicted cost variation (P < .001). For index hospital costs, a history of cardiac arrhythmias (P < .001), valvular heart disease (P = .014), and anemia (P = .020) significantly increased costs. For post-acute care costs, a history of neurological conditions like Parkinson's disease or seizures (P < .001), malignancy (P = .001), hypertension (P = .012), depression (P = .014), and hypothyroidism (P = .044) were associated with increases in cost. Similarly, for total episode cost, a history of neurological conditions (P < .001), hypertension (P = .012), malignancy (P = .023), and diabetes (P = .029) were predictors for increased costs.

CONCLUSION

The cost of care in primary elective TJA increases with greater patient co-morbidity. Our data provide insight into the relative impact of specific medical conditions on cost of care and may be used in risk stratification in future reimbursement methodologies.

Current risk factors for asymptomatic venous thromboembolism in patients undergoing total hip arthroplasty

Objective: A history of venous thromboembolism (VTE) is a risk factor for newly formed VTE after total hip arthroplasty (THA). However, its morbidity and association with postoperative VTE are not clear and, therefore, were investigated in this study. Methods: Four-hundred and nineteen patients scheduled for primary THA were included. We preoperatively identified any VTE factors such as obesity, age, and history of VTE by interviewing and duplex ultrasonography for all patients, and the patients were assigned into 'high-' or 'low-risk' groups, that were the indication whether chemoprophylaxis was administered after surgery. Postoperative VTE was also examined on the day 7 by enhanced computed tomography (CT) for all patients. Results: Preoperative VTE were detected in 48 patients (11.4%), and postoperative VTE were found in 44 (10.5%). Linear and multivariate logistic regression analysis revealed osteonecrosis and preoperative VTE were the independent factors associated with postoperative VTE (Odds ratio (OR) 1.0 e-7 and 5.00, respectively). In the survey of each risk group, only preoperative VTE was recognized as a risk factor for high-risk group, and longer operation time for low-risk group. Conclusion: The present study confirmed high frequency of preoperative VTE which was still the strongest risk factor for postoperative asymptomatic VTE.

Risk of Ischemic Stroke After Perioperative Atrial Fibrillation in Total Knee and Hip Arthroplasty Patients

BACKGROUND

To determine if new-onset perioperative atrial fibrillation during arthroplasty represents a benign response to intraoperative cardiac stress or is a risk factor for stroke, we evaluated the subsequent risk of ischemic stroke in patients with new-onset atrial fibrillation occurring during primary total knee arthroplasty (TKA) and total hip arthroplasty (THA).

METHODS

Discharge data of all adult patients undergoing primary TKA or THA from 1997 to 2013 were queried via the New York Statewide Planning and Research Cooperative System database to find patients with new-onset perioperative atrial fibrillation. These patients were then followed up over time to determine their risk of ischemic stroke.

RESULTS

Of the 312,636 TKA and 215,610 THA unique patient admissions, 3646 (0.7%) had a diagnosis of new-onset perioperative atrial fibrillation. The cohort of patients with this finding was 58.9% female with an average age of 73.6 years and higher prevalence of vascular risk factors. Adjusting for validated stroke risk factors, the risk of ischemic stroke within 1 year after THA or TKA in patients with new-onset atrial fibrillation was 2.7 times higher than in those without a history of atrial fibrillation (odds ratio: 2.7, 95% confidence interval: 1.5-4.8). Hospital length of stay and charges for patients with new-onset atrial fibrillation were also greater than patients with either a prior diagnosis or no diagnosis of atrial fibrillation.

CONCLUSION

New-onset atrial fibrillation during TKA and THA may indicate risk of ischemic stroke following surgery that should warrant medical follow-up and may increase hospital length of stay and charges.

History of Breast Cancer Increases 90-Day Pulmonary Embolism Rates and Reimbursements After Total Hip Arthroplasty: A National Matched-Pair Analysis

BACKGROUND

Rates of total hip arthroplasty (THA) are projected to increase in the coming decades. Multiple studies have focused on identifying risk factors for adverse events after joint arthroplasty, and recent attention has been directed toward cancer. Very limited data have been published examining the effects of history of malignancy on outcomes after THA. With a concomitant increase in breast cancer diagnosis and treatments in recent years, it is expected that orthopedic surgeons will likely see more breast cancer survivors in clinic. The purpose of this study is to examine the effects of a personal history of breast cancer on 90-day outcomes after THA.

METHODS

We conducted a retrospective case-control study of the entire Medicare records. The endpoints of this study included length of stay, medical complications, surgical complications, and costs (examined here as reimbursements). Patients were matched by age and gender in order to decrease confounding. A 1:1 matching was performed.

RESULTS

After age and demographics matching, our findings demonstrated that patients with a history of breast cancer have increased rates of pulmonary embolism (0.59% vs 0.45%, P = .003), increased use of chest computed tomography (1.72% vs 1.18%, P < .001), and higher mean 90-day reimbursements (mean $15,432 vs mean $14,701, P = .011) in the 90 days following surgery. Other medical and surgical complications were equally distributed in both cohorts.

CONCLUSION

Surgeons should be aware of the increased rate of pulmonary embolism and have a more aggressive thromboprophylaxis protocol in these patients.

ABO Blood Group Is a Predictor for the Development of Venous Thromboembolism After Total Joint Arthroplasty

BACKGROUND

The study's purpose was to determine if there is an association between ABO blood group and the development of symptomatic venous thromboembolism (VTE) after total joint arthroplasty (TJA).

METHODS

A total of 28,025 patients who underwent primary TJA at a single health care system from 2000 to 2014 were retrospectively reviewed from electronic records. Patients who experienced a symptomatic VTE were identified. A multivariate regression model adjusted for known potential risk factors, including age, gender, body mass index, surgery type, previous VTE, smokers, rheumatologic diseases, malignancy, hypercoagulable state, and VTE prophylaxis, was developed to test the association of ABO blood group and postoperative VTE. Separate multivariate regressions were performed for total knee arthroplasty and total hip arthroplasty, specifically looking at pulmonary embolism.

RESULTS

The risk of symptomatic VTE after TJA was increased in AB blood group patients (odds ratio = 1.4; P = .03). Furthermore, the risk of pulmonary embolism was increased after total knee arthroplasty in AB blood group patients (odds ratio = 2.24; P = .001) but not after total hip arthroplasty (P = .742).

CONCLUSION

AB blood group increased the risk of VTE after TJA. Patient's ABO blood group should be considered in terms of risk stratification and selection of appropriate postoperative VTE prophylaxis.

The Clinical Severity of Patients Diagnosed With an In-Hospital Pulmonary Embolism Following Modern, Elective Joint Arthroplasty Is Unrelated to the Location of Emboli in the Pulmonary Vasculature

BACKGROUND

In the event of a postoperative pulmonary embolism (PE), it is generally believed that patients with centrally located emboli will have worse clinical symptoms than those with segmental or subsegmental ones. We studied if a relationship exists between the clinical severity at the time of PE diagnosis and the location of the emboli within the pulmonary vasculature.

METHODS

All 269 patients who developed an in-hospital, computed tomography pulmonary angiography-proved, PE following elective total hip arthroplasty or total knee arthroplasty in our institution were studied. The clinical severity of the PE was calculated using the Pulmonary Embolism Severity Index (PESI) that classifies patients in 5 classes (class 5: most severe). All computed tomography pulmonary angiographies were re-reviewed to determine the location of the emboli within the pulmonary vasculature (central, segmental, or subsegmental-unilateral or bilateral). The association between PESI and the PE location was examined.

RESULTS

The most proximal location of the emboli was central in 62, segmental in 139, and subsegmental in 68. There were 180 unilateral and 89 bilateral PE patients. There was no association between the PESI and the location of the emboli within the pulmonary vasculature (P = .32). Patients with bilateral or unilateral lung involvement had similar PESI (P = .78).

CONCLUSION

The PESI, a recognized, validated predictor of mortality after PE was similar in patients with central, segmental, or subsegmental PE; and in patients with unilateral or bilateral lung involvement. The present study may aid clinicians while assessing and discussing the severity of PE symptoms with patients at the time of diagnosis.

One-Year All-Cause Mortality of Patients Diagnosed as Having In-Hospital Pulmonary Embolism After Modern Elective Joint Arthroplasty Is Low And Unaffected By Radiologic Severity

BACKGROUND

We studied the 1-year complication rate of patients diagnosed as having a pulmonary embolism (PE) after elective total hip arthroplasty (THA) and total knee arthroplasty (TKA) surgery and the distribution of emboli in the pulmonary circulation, and determined if a relationship exists between the location of the PE and age, gender, body mass index, preoperative predisposing factors, American Society of Anesthesiology classification, type of surgery, prophylaxis, hospital stay, transfer to a higher level of care, and mortality.

METHODS

Two hundred sixty-nine patients who developed an in-hospital PE proved by computed tomography pulmonary angiography after elective THA or TKA between 2005 and 2012 were studied.

RESULTS

The most proximal location of the emboli was central in 62, segmental in 139, and subsegmental in 68. Nineteen patients (7%) developed a bleeding complication during PE treatment. Twenty-nine patients (11%) were readmitted during the first year. Two patients (0.74%) died: one had a segmental PE after TKA. He died 11 months after surgery due to an autopsy-proven sepsis. The second patient developed a segmental PE after THA. She was anticoagulated, developed an intracranial bleed, and died 8 months after surgery. Multivariate analysis showed that demographic variables, American Society of Anesthesiology class, preoperative comorbidities (with the exception of arrhythmia), and the presence of preoperative predisposing factors had no effect in the location of the PE.

CONCLUSION

The 1-year mortality rate of these patients is low. Death can be caused by bleeding complications secondary to anticoagulation or by unrelated conditions. This information may aid clinicians while counseling patients who developed a PE after surgery, particularly those with small subsegmental emboli.

Risk factors for venous thromboembolism after total hip and total knee arthroplasty: a meta-analysis

INTRODUCTION

Venous thromboembolism (VTE) is a common complication after total hip arthroplasty (THA) or total knee arthroplasty (TKA) and may be the cause for a secondary PE and associated morbidity/mortality. We performed a systematic literature review of risk factors and risk reduction of VTE after THA or TKA.

MATERIALS AND METHODS

A systematic search of PubMed database, the Cochrane Library, OVID MEDLINE and American Academy of Orthopaedic Surgeons (AAOS), without restriction of publication data and language, was conducted. We performed a meta-analysis of ten factors for VTE after THA or TKA. Four authors independently assessed data extraction and quality of the studies using the Newcastle-Ottawa Scale (NOS) as quality assessment tool. Assessment of heterogeneity and analysis of data were operated by Review Manager 5.2.9.

RESULTS

Fourteen retrospective case-control or prospective cohort studies, which included 18,075 patients who developed VTE after THA or TKA of a total of 1,723,350 cases, were selected. Our results demonstrated that, among all ten factors investigated, 3 main risk factors were significantly associated with VTE after THA or TKA: history of VTE (RR > 10.6), varicose vein (RR > 2.7) and congestive cardiac failure (RR 2). There was also an increase of VTE risk ranging from 8 to 30 % for female gender < age (≥80) < hypertension < (active) cancer < obesity (BMI ≥ 30) < (black) race. Data analysis revealed that diabetes mellitus had no significant relationship with VTE after THA or TKA.

CONCLUSIONS

This study highlighted the role of nine significant risk factors in the development of VTE after THA or TKA. Among all risk factors, history of VTE seems the one main indication for more potent anticoagulation. All other risk factors need to be considered and discussed with patients individually and balanced against the risk of bleeding and infection. Individual patient risk assessment, rather than a "blanket policy", is considered the best management strategy before deciding on the type of chemical prophylaxis.

Total joint arthroplasty in cancer patients

Increasing numbers of total joint arthroplasty (TJA) patients have a history, or an active diagnosis, of cancer. We aimed to evaluate the risk of early postoperative complications in these patients. In our series, a history of malignancy was associated with an elevated risk of ischemic cardiac events and postoperative deep vein thrombosis (DVT), while active malignancy was associated with increased respiratory and renal complications, hematoma/seroma formation and early postoperative mortality. Both groups presented increased rates of overall in-hospital complications. Patients with bone metastasis to the hip demonstrated increased DVT and 90-day mortality rates. Cancer patients have increased morbidity and mortality after TJA and should undergo comprehensive medical optimization and adapted thromboprophylaxis.

Risk of venous thromboembolism after shoulder arthroplasty in the Medicare population

BACKGROUND

Chemoprophylaxis for venous thromboembolism (VTE) is considered standard of care after lower but not after upper extremity arthroplasty. Medicare claims data were analyzed to determine the national incidence of symptomatic VTE after shoulder arthroplasty during the index surgical admission and after discharge.

METHODS

Incidence of VTE was compared between shoulder arthroplasty and lower extremity arthroplasty, and patient-specific risk factors for pulmonary embolism were determined for shoulder arthroplasty. Finally, the incidence of surgical site bleeding was determined for each type of procedure.

RESULTS

VTE complications occurred in 1.2% of lower extremity and 0.53% of shoulder arthroplasties. Patient factors that were associated with an increased risk of VTE included a principal diagnosis of fracture, history of VTE, cardiac arrhythmia, presence of a metastatic tumor, coagulopathy, congestive heart failure, alcohol abuse, and obesity. Adjusted rates of VTE were generally higher for lower extremity compared with shoulder arthroplasties. Prevalence of readmission for VTE was higher for shoulder hemiarthroplasty than for total shoulder arthroplasty. Wound hematoma rates were similar between shoulder and lower extremity procedures.

CONCLUSIONS

VTE rates after shoulder arthroplasty were generally lower than those after lower extremity arthroplasty. We believe that the risk of bleeding combined with the lower rates of VTE with existing lower rates of chemoprophylaxis does not warrant the routine use of anticoagulation. Use of mechanical prophylaxis combined with aspirin may be sufficient for shoulder arthroplasty patients who are not at increased risk of VTE. Chemoprophylaxis with agents other than aspirin may be warranted in patients with a demonstrated risk of VTE.

Modifier 22 for acetabular fractures in morbidly obese patients: does it affect reimbursement?

BACKGROUND

Modifier 22 in the American Medical Association's Current Procedural Terminology (CPT®) book is a billing code for professional fees used to reflect an increased amount of skill, time, and work required to complete a procedure. There is little disagreement that using this code in the setting of surgery for acetabulum fractures in the obese patient is appropriate; however, to our knowledge, the degree to which payers value this additional level of complexity has not been determined.

QUESTIONS/PURPOSES

We asked whether (1) the use of Modifier 22 increased reimbursements in morbidly obese patients and (2) there was any difference between private insurance and governmental payer sources in treatment of Modifier 22.

METHODS

Over a 4-year period, we requested immediate adjudication with payers when using Modifier 22 for morbidly obese patients with acetabular fractures. We provided payers with evidence of the increased time and effort required in treating this population. Reimbursements were calculated for morbidly obese and nonmorbidly obese patients. Of the 346 patients we reviewed, 57 had additional CPT® codes or modifiers appended to their charges and were excluded, leaving 289 patients. Thirty (10%) were morbidly obese and were billed with Modifier 22. Fifty-three (18%) were insured by our largest private insurer and 69 (24%) by governmental programs (Medicare/Medicaid). Eight privately insured patients (15%) and seven governmentally insured patients (10%) were morbidly obese and were billed with Modifier 22. For our primary question, we compared reimbursement rates between patients with and without Modifier 22 for obesity within the 289 patients. We then performed the same comparison for the 53 privately insured patients and the 69 governmentally insured patients.

RESULTS

Overall, there was no change in mean reimbursement when using Modifier 22 in morbidly obese patients, compared to nonmorbidly obese patients (USD 2126 versus USD 2149, p < 0.94). There was also no difference in mean reimbursements with Modifier 22 in either the privately insured patients (USD 3445 versus USD 2929, p = 0.16) or the governmentally insured patients (USD 1367 versus USD 1224, p=0.83).

CONCLUSIONS

Despite educating payers on the increased complexity and time needed to deal with morbidly obese patients with acetabular fractures, we have not seen an increased reimbursement in this challenging patient population. This could be a disincentive for many centers to treat these challenging injuries. Further efforts are needed to convince government payer sources to increase compensation in these situations.

LEVEL OF EVIDENCE

Level IV, economic and decision analyses. See Instructions for Authors for a complete description of levels of evidence.

Safety and efficacy of multimodal thromboprophylaxis following total knee arthroplasty: a comparative study of preferential aspirin vs. routine coumadin chemoprophylaxis

Multimodal thromboprophylaxis encompasses preoperative VTE risk stratification, regional anesthesia, mechanical prophylaxis, and early mobilization. We determined if aspirin can be safely used for adjuvant chemoprophylaxis in patients who have a low thromboembolic risk. 1016 consecutive patients undergoing TKA received multimodal thromboprophylaxis. Aspirin was used in 67% of patients and Coumadin 33% (high risk patients, or who were on Coumadin before surgery). This study group was compared to 1001 consecutive patients who received multimodal thromboprophylaxis and routine Coumadin chemoprophylaxis. There was no significant difference in rates of VTE, PE, bleeding, complications, readmission and 90-day mortality between the two groups. There was a significantly higher rate of wound related complications in the control group (p=0.03). Multimodal thromboprophylaxis with aspirin given to the majority of patients at a low VTE risk is safe and effective in patients undergoing primary TKA.

II Italian intersociety consensus statement on antithrombotic prophylaxis in orthopaedics and traumatology: arthroscopy, traumatology, leg immobilization, minor orthopaedic procedures and spine surgery

Pharmacological prophylaxis for preventing venous thromboembolism (VTE) is a worldwide established procedure in hip and knee replacement surgery, as well as in the treatment of femoral neck fractures, but few data exist in other fields of orthopaedics and traumatology. Thus, no guidelines or recommendations are available in the literature except for a limited number of weak statements about knee arthroscopy and lower limb fractures. In any case, none of them are a multidisciplinary effort as the one here presented. The Italian Society for Studies on Haemostasis and Thrombosis (SISET), the Italian Society of Orthopaedics and Traumatology (SIOT), the Association of Orthopaedic Traumatology of Italian Hospitals (OTODI), together with the Italian Society of Anesthesia, Analgesia, Resuscitation and Intensive Care (SIAARTI) and the Italian Society of General Medicine (SIMG) have set down easy and quick suggestions for VTE prophylaxis in a number of surgical conditions for which only scarce evidence is available. This inter-society consensus statement aims at simplifying the approach to VTE prophylaxis in the single patient with the goal to improve its clinical application.

Aspirin for elective hip and knee arthroplasty: a multimodal thromboprophylaxis protocol

PURPOSE

Multimodal thromboprophylaxis includes preoperative thromboembolic risk stratification and autologous blood donation, surgery performed under regional anaesthesia, postoperative rapid mobilisation, use of pneumatic compression devices and chemoprophylaxis tailored to the patient's individual risk. We determined the 90-day rate of venous thromboembolism (VTE), other complications and mortality in patients who underwent primary elective hip and knee replacement surgery with multimodal thromboprophylaxis.

METHODS

A total of 1,568 consecutive patients undergoing hip and knee replacement surgery received multimodal thromboprophylaxis: 1,115 received aspirin, 426 received warfarin and 27 patients received low molecular weight heparin and warfarin with or without a vena cava filter.

RESULTS

The rate of VTE, pulmonary embolism, proximal deep vein thrombosis (DVT) and distal DVT was 1.2, 0.36, 0.45 and 0.36 %, respectively, in patients who received aspirin. The rates in those who received warfarin were 1.4, 0.9, 0.47 and 0.47 %, respectively. The overall 90-day mortality rate was 0.2 %.

CONCLUSIONS

Multimodal thromboprophylaxis in which aspirin is administered to low-risk patients is safe and effective following primary total joint replacement.

Perioperative implications of surgery in elderly patients with hip fractures: an evidence-based review

Hip fracture is a major cause of morbidity, mortality and loss of independence for the elderly. Surgical fixation of the fractured hip remains the standard of care to allow for early mobilisation and a return to independence. Operative management in this population carries its own set of problems. The altered physiological state of the older person, often coupled with significant comorbidity, can present challenges for the anaesthetist, the surgeon and the rest of the perioperative team. This article provides an evidence-based review of the important perioperative factors associated with hip fractures in the older person and their management.

Smoking and outcomes after knee and hip arthroplasty: a systematic review

OBJECTIVE

Studies have suggested higher rates of perioperative and postoperative complications in smokers compared to nonsmokers. The objective of this systematic review was to assess the association of smoking and postoperative outcomes following total hip arthroplasty (THA) or total knee arthroplasty (TKA).

METHODS

A search of 6 databases (The Cochrane Library, Scopus, Proquest Dissertation abstracts, CINAHL, Ovid Medline, and Embase) was performed by a Cochrane librarian. All titles and abstracts were screened by 2 independent reviewers with expertise in performing systematic reviews. Studies were included if they were fully published reports that included smoking and any perioperative or postoperative clinical outcome in patients with TKA or THA.

RESULTS

A total of 21 studies were included for the review, of which 6 provided multivariable-adjusted analyses, 14 univariate analyses, and one statistical modeling. For most outcomes, results from 1-2 studies could be pooled. Current smokers were significantly more likely to have any postoperative complication (risk ratio 1.24, 95% CI 1.01 to 1.54) and death (risk ratio 1.63, 95% CI 1.06 to 2.51) compared to nonsmokers. Former smokers were significantly more likely to have any post-operative complication (risk ratio 1.32, 95% CI 1.05 to 1.66) and death (risk ratio 1.69, 95% CI 1.08 to 2.64) compared to nonsmokers.

CONCLUSION

This systematic review found that smoking is associated with significantly higher risk of postoperative complication and mortality following TKA or THA. Studies examining longterm consequences of smoking on implant survival and complications are needed. Smoking cessation may improve outcomes after THA or TKA.

Incidence of symptomatic venous thromboembolism in oncologic patients undergoing lower-extremity endoprosthetic arthroplasty

BACKGROUND

As both cancer and major orthopaedic surgery are risk factors for venous thromboembolism, patients undergoing lower-extremity oncologic endoprosthetic arthroplasty for neoplastic processes are at substantial risk of the development of symptomatic venous thromboembolism. Therefore, the primary purpose of this study was to determine the incidence of symptomatic venous thromboembolism in patients undergoing lower-extremity oncologic endoprosthetic arthroplasty. Secondary purposes were to assess whether chemoprophylaxis influenced the incidence of venous thromboembolism, surgical complications, or the incidence of local sarcoma recurrence. We also sought to determine whether any known risk factors for venous thromboembolism could be identified in this patient population.

METHODS

We performed a retrospective comparative review of 423 patients who had undergone mega-endoprosthetic reconstruction following cancer resection. Univariate analysis was used to assess the association between chemoprophylaxis and the incidence of venous thromboembolism, to postulate the surgical complications associated with chemoprophylaxis, and to assess the rate of recurrence of local sarcoma as well the association between risk factors and venous thromboembolism.

RESULTS

Seventeen patients (4.0%) (95% confidence interval: 2.5% to 6.3%) had a venous thromboembolic event, ten with deep venous thrombosis and seven with nonfatal pulmonary embolism. Risk factors and chemoprophylactic regimens were not statistically associated with the occurrence of venous thromboembolism.

CONCLUSIONS

The incidence of symptomatic venous thromboembolism in our group of cancer patients who underwent lower-extremity endoprosthetic arthroplasty was lower than anticipated. A significant difference was not identified between the use of any or no chemoprophylactic agent and the incidence of venous thromboembolism or complication rates. No risk factors were associated with the incidence of symptomatic venous thromboembolism.

Hematologic genetic testing in high-risk patients before knee arthroplasty: a pilot study

BACKGROUND

Patients with a personal or familial history of thromboembolism are considered at higher risk for thromboembolic disease after knee arthroplasty. While it remains unclear why some patients develop deep vein thrombosis (DVT) or pulmonary embolism (PE) despite similar operative procedures and the same prophylactic regimen, we presume one explanation would be genetic predisposition.

QUESTIONS/PURPOSES

We determined the frequency of 12 factors including antithrombin III activity, prothrombin gene mutations, and the presence of phospholipid antibodies in a high-risk patient cohort and compared those findings with the known prevalence in the population at large.

PATIENTS AND METHODS

Patients identified preoperatively as having a personal or familial history of DVT and/or PE were referred for hemostatic serum and genetic tests, including % antithrombin III activity (ATIII), protein C and protein S activities, APC resistance, Factor V gene (Leiden) mutations, prothrombin gene mutations, lupus anticoagulant antibody presence, cardiolipin antibody presence, phosphatidyl antibody presence, β2-glycoprotein antibody presence, and serum homocysteine and lipoprotein(a) levels The frequencies of varying abnormalities were identified and compared to the prevalence reported in the literature.

RESULTS

Forty-three of 1944 patients undergoing knee arthroplasty had a history of DVT or PE. Sixteen of 43 (37%) patients had an abnormality and eight of these (19%) had two or more abnormalities. The frequency of nine of the 12 tests appeared to be greater in this cohort than in the population at large.

CONCLUSIONS

Patients with a personal or familial history of DVT or PE appear to have a high frequency of hereditary prothrombotic abnormalities. Preoperative evaluation by a hematologist may be warranted in patients with a personal or familial history of DVT or PE as the postoperative anticoagulation protocols may be altered and identification of these abnormalities may affect a patient's risk for other disease states.

LEVEL OF EVIDENCE

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

Mechanical thromboprophylaxis for patients undergoing hip fracture surgery

PURPOSE

To evaluate the rates of deep vein thrombosis (DVT) and pulmonary embolism (PE) in hip fracture patients receiving mechanical thromboprophylaxis.

METHODS

123 men and 311 women (mean age, 76 years) admitted to our institution with hip fractures were included. 95% of patient received mechanical prophylaxis using pneumatic calf pumps intermittently for 20 hours or less per day before and after surgery. At the surgeon's discretion, 161 (37%) of them received concomitant chemical prophylaxis in the form of subcutaneous low-molecular-weight heparin (enoxaparin). Signs and symptoms of DVT and PE were monitored daily, as were calf and thigh circumference. Diagnoses were confirmed by duplex ultrasonography of the lower limbs and/or spiral computed tomography scan of the thorax.

RESULTS

13 patients developed symptomatic venous thromboembolism (VTE); 11 were DVT and 2 were PE. Among DVT patients, 2 had proximal and 9 had distal DVT. All these patients underwent anticoagulation and were discharged without any complications. No patients developed complications from pneumatic calf pumps (foot drop, skin abrasions or stasis). Eight patients developed bleeding tendencies during hospitalisation. No patient developed surgical wound infections. 12 patients died during hospitalisation; 8 of them from acute myocardial infarction or pneumonia, and none from PE. The median length of hospital stay was significantly longer in patients with VTE.

CONCLUSION

Routine use of mechanical thromboprophylaxis is recommended in patients undergoing hip fracture surgery.

Risk factors for pulmonary embolism after hip and knee arthroplasty: a population-based study

Pulmonary embolism (PE) is a cause of death after total hip and knee arthroplasty (THA, TKA). We characterised the patient population suffering from in-hospital PE and identified perioperative risk factors associated with PE using nationally representative data. Data from the National Hospital Discharge Survey between 1990 and 2004 on patients who underwent primary or revision THA/TKA in the United States were analysed. Multivariate regression analysis was performed to determine if perioperative factors were associated with increased risk of in-hospital PE. An estimated 6,901,324 procedures were identified. The incidence of in-hospital PE was 0.36%. Factors associated with an increased risk for the diagnosis of PE included: revision THA, female gender, dementia, obesity, renal and cerebrovascular disease. An increased association with PE was found among patients with diagnosis of Adult Respiratory Distress Syndrome (ARDS), psychosis (confusion), and peripheral thrombotic events. Our findings may be useful in stratifying the individual patient's risk of PE after surgery.

Assessment of thrombotic risk factors predisposing to thromboembolic complications in prosthetic orthopedic surgery

BACKGROUND

Congenital thrombophilia is responsible for thromboembolic complications despite prolonged low-molecular-weight heparin (LMWH) prophylaxis following hip and knee endoprosthesis surgery.

METHODS

A series of 86 patients with hip or knee endoprosthesis surgery were assessed 1 year after operation. Antithrombin III, protein C, and protein S were determined, and the activated protein C sensitivity ratio was measured. We screened for the presence of lupus anticoagulant, factor V Leiden mutation, and polymorphism of prothrombin G20210A. The lower limb venous circulation was monitored by color Doppler ultrasonography. Pulmonary embolism (PE) was diagnosed using ventilation and perfusion scintigraphy.

RESULTS

In all, 33 patients had thromboembolic complications, 18 with thrombophilia (7 with combined form). Of the 53 patients without complications 12 had thrombophilia (2 with combined form). The differences were statistically significant. The risk score, the prevalence of FV Leiden and prothrombin G20210A mutations, and lupus anticoagulant were also significantly higher in the symptomatic group. Deep vein thrombosis (DVT) developed preoperatively in 15 patients; DVT and PE in 4 patients; thrombophilia was diagnosed in 53% and 75% of these cases. In all, 17 patients had postoperative thromboembolic complications: DVT developed in nine and PE in one patient (all with thrombophilia); DVT + PE developed in seven patients (all but one had thrombophilia).

CONCLUSIONS

Significant differences were found in the incidence (P < or = 0.01) of thrombophilia and the risk score (P < or = 0.02) between symptomatic and asymptomatic patients. We recommend preoperative thrombophilia screening for patients with a history or familial prevalence of thromboembolism and/or with a high risk score (> or =15). In cases of thrombophilia, the form and duration of anticoagulant treatment must be decided individually.

VKORC1 variant genotypes influence warfarin response in patients undergoing total joint arthroplasty: a pilot study

Warfarin dosing algorithms do not account for genetic mutations that can affect anticoagulation response. We retrospectively assessed to what extent the VKORC1 variant genotype would alter the likelihood of being a hyperresponder or hyporesponder to warfarin in patients undergoing total joint arthroplasty. We used the international normalized ratio (INR) on the third postoperative day of 3.0 or greater to define warfarin hyperresponders and 1.07 or less to define hyporesponders. A control group of normal responders was identified. From a cohort of 1125 patients receiving warfarin thromboprophylaxis, we identified 30 free of predisposing factors that could affect warfarin response: 10 hyperresponders, eight hyporesponders, and 12 normal responders. Homozygous carriers of the VKORC1 mutant AA genotype were more likely (compared with carriers of GA or GG genotypes) to be hyperresponders (odds ratio, 7.5; 95% confidence interval, 1.04-54.1). Homozygous carriers of the GG (normal) genotype were more likely (compared with carriers of AA or GA genotypes) to be hyporesponders (odds ratio, 9; 95% confidence interval, 1.14-71). Preoperative screening for the VKORC-1 genotype could identify patients with a greater potential for being a hyperresponder or hyporesponder to warfarin. This may allow an adjusted pharmacogenetic-based warfarin dose to optimize anticoagulation, reducing postoperative risks of bleeding and thrombosis or embolism.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Genetic polymorphisms in venous thrombosis and pulmonary embolism after total hip arthroplasty: a pilot study

Deep venous thrombosis (DVT) after major orthopaedic surgery is a substantial concern. We asked whether the single or combined presence of thrombophilic genetic polymorphisms might further increase the already high risk for venous thrombosis and pulmonary embolism (PE) after THA. We therefore compared the prevalence of factor V Leiden, prothrombin G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, and plasminogen activator inhibitor 4G/5G polymorphisms between 50 patients with symptomatic DVT within 3 weeks after elective THA and an asymptomatic control group of 85 patients. We found no major difference for the presence of a single mutation between the groups. Factor V Leiden and homozygous MTHFR C667T mutations were of borderline significance with odds ratios (95% confidence intervals) of 3.73 (0.89-15.63) and 2.93 (0.92-9.29), respectively. Patients with homozygous or combined heterozygous status of MTHFR C677T and A1298C mutation had a higher frequency of DVT after elective THA (odds ratio, 2.86; 95% confidence interval, 1.32-6.35) than those with wild-type. The presence of a single mutation may not further increase the already high risk for symptomatic DVT after THA, whereas combinations of mutations of distinct polymorphisms might be important. However, prospective studies with a larger number of patients are needed before we would recommend preoperative screening.

LEVEL OF EVIDENCE

Level III, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Aspirin decreases the prevalence and severity of heterotopic ossification after 1-stage bilateral total hip arthroplasty for osteoarthrosis

Heterotopic ossification (HO) is a frequent complication after total hip arthroplasty (THA). We retrospectively evaluated the prevalence and severity of HO in patients with osteoarthrosis who underwent 1-stage bilateral THA (OSBTHA) and compared those who received aspirin with those who received Coumadin for postoperative chemothromboprophylaxis. The aspirin group consisted of 66 patients (132 hips), with a mean age of 64 years (SD, 8.5). The Coumadin group consisted of 67 patients (134 hips), with a mean age of 60 years (SD, 10.2). Overall, HO was detected in 124 hips (46.6%). There were 43 hips (32.5%) with HO in the aspirin group and 81 (60.4%) in the Coumadin group (P < .00005). Aspirin significantly decreases the prevalence and severity of HO in comparison to Coumadin after OSBTHA.

Mandated venous thromboembolism prophylaxis: possible adverse outcomes

The purpose of this study was to assess the prevalence and seriousness of adverse outcomes owing to mandatory venous thromboembolism (VTE) prophylaxis. A retrospective study of administrative claims data was conducted to look at the rate of VTEs and other complications in patients undergoing hip and knee arthroplasty. Additional analysis was done to determine whether patient characteristics could explain findings. Although rates of VTE remain unchanged from 2003 to 2007, the rate of immediate postprocedure hematoma, seroma, and hemorrhage went from 1.4% in 2003 to 9.6% in 2006. Return to a more conservative prophylaxis approach resulted in a marked decrease in rates of significant bleeding events. Although preventing VTEs is an important quality concern, mandating prophylaxis for all patients could have unintended adverse outcomes. These guidelines might need to be reevaluated for hip and knee arthroplasty patients.

Thromboembolic risk assessment and the efficacy of enoxaparin prophylaxis in excisional body contouring surgery

BACKGROUND

There is a paucity of evidence within the plastic surgery literature concerning risk stratification and management of patients with respect to thromboembolic disease. A retrospective chart review was conducted to examine whether the Davison-Caprini risk-assessment model could stratify patients undergoing excisional body contouring surgery, allowing prophylaxis to be managed in an evidence-based manner.

METHODS

Three hundred sixty excisional body contouring patients at the University of Texas Southwestern Medical Center in Dallas, Texas, under the senior authors' (J.M.K. and R.J.R.) care were reviewed. Patients were stratified into groups according to the risk-assessment model and into groups based on procedure. Patient characteristics were investigated for their effects on thromboembolic risk. Complications of enoxaparin administration were analyzed. The data were analyzed using appropriate statistical procedures.

RESULTS

The highest risk patients had a significantly increased rate of venous thromboembolism when compared with lower risk patients. Body mass index greater than 30 and hormone therapy use were associated with a significantly increased venous thromboembolism rate. Enoxaparin administration was associated with a statistically significant decrease in deep venous thrombosis in circumferential abdominoplasty patients. Enoxaparin administration was associated with higher bleeding rates.

CONCLUSIONS

Low-molecular-weight heparin may affect the incidence of postoperative thrombotic complications in some surgical populations. In this study, patients who scored greater than four risk factors were at significant risk for venous thromboembolism. Enoxaparin significantly decreased deep venous thrombosis risk in patients undergoing circumferential abdominoplasty. This demonstrates the need for a multicenter, prospective, randomized study to examine various thromboembolic therapies and associated possible complications in these patients.

The 2007 ABJS Nicolas Andry Award: three decades of clinical, basic, and applied research on thromboembolic disease after THA: rationale and clinical results of a multimodal prophylaxis protocol

Total hip arthroplasty is an operation with a high risk for venous thromboembolism. Three decades of research conducted at the Hospital for Special Surgery identified the exact timing of the thrombogenic stimulus during surgery, defined the role of magnetic resonance venography, and established the role of certain genetic and acquired predispositions. Based on these studies, we implemented a multimodal prophylaxis consisting of a series of safe preventive measures applied before, during, and immediately after surgery to reduce the risk of venous thromboembolism. If these safe preventive measures are strictly observed, postoperative pharmacologic prophylaxis does not need to be aggressive in the patient without predisposing factors who mobilizes promptly, thus diminishing the risk of bleeding associated with the use of anticoagulants and the overall cost of care. Our clinical experience with more than 5000 total hip arthroplasties performed during the last decade and closely followed prospectively for a minimum of 3 months clearly shows this multimodal prophylaxis is safe and effective resulting in a very low prevalence of thromboembolism.