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

Outcomes of different perioperative management strategies of patients on chronic anticoagulation in elective total hip and knee arthroplasty: a systematic review

INTRODUCTION

There are currently different management guidelines for patients undergoing elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) that are on long-term anticoagulation. The timing of discontinuation and restarting the anticoagulation is challenging during the postoperative care, which often involves general practitioners and physiotherapists.

METHODS

The systematic review followed the PRISMA guidelines and included 3 databases: PubMed/MEDLINE, EMBASE, and Web of Science Core Collection. It was registered in the International Prospective Register for Systematic Reviews and Meta-analysis (PROSPERO) under the registration number: CRD42023408906. The risk of bias assessment was performed using the Methodological index for non-randomized studies (MINORS) criteria.

RESULTS

Six retrospective studies involving 727 patients with therapeutic anticoagulation (1,540 controls) for elective THA, TKA and revision arthroplasty have been included. The follow-up ranged from 30 days to 1 year postoperatively. All studies evaluated outcomes of warfarin therapeutic anticoagulation versus prophylactic dosages of one or more of the following: warfarin, aspirin, low-molecular-weight heparin (LMWH) and unfractionated low-dose heparin (UFH). One study did not discontinue therapeutic anticoagulation. Two studies reported no significant differences in complications between groups, whilst 3 studies had significantly higher rates of superficial wound infections, revision surgeries, postoperative haematomas, and prosthetic joint infections (PJI).

CONCLUSION

Different anticoagulation-related perioperative management strategies achieve different outcomes following elective arthroplasty in patients with therapeutic chronic anticoagulation. There is contradictory evidence regarding the need for the discontinuation of therapeutic warfarin. Retrospective data showed that individual risk stratification with multi-modal prophylaxis resulted in minimal complications.

LEVEL OF EVIDENCE

Systematic Review of Level III studies.

Medium-term outcomes of conventional versus short uncemented femoral stems for primary total hip arthroplasty in patients younger than 55 years

BACKGROUND

Short stems are designed with a bone preservation philosophy in mind. This study aims to compare the outcomes/complications and survival of a collarless fully hydroxyapatite (HA)-coated conventional tapered stem and a HA-coated partial neck-retaining uncemented short stem in patients ⩽55 years old at medium-term follow-up.

METHODS

We retrospectively studied 247 uncemented THAs operated between 2010 and 2014, comparing 146 patients treated with the fully HA-coated collarless stem (Group A) with 101 patients treated with a partial neck preserving, HA-coated short stem (Group B). 87 and 62 males were in groups A and B, respectively (p = 0.11). The mean age of the series was 46 years (17-55) (p =0.16). The mean follow-up of groups A and B were 9.9 (7-12) years and 9.7 (7-12) years, respectively (p =0.21).

RESULTS

Mean Harris Hip Score improved from 55 to 92 in group A (p <0.001) and from 54 to 95 in group B (p <0.001), without differences between groups. Mean femoral neck length preservation in groups A and B was 13.6 (0-28) mm and 26 (11-38) mm, respectively (p =0.001). 13 (8.9%) and 1 (1%) patients in groups A and B presented postoperative complications, respectively (p =0.008). The conventional stem group had more aseptic loosening (Group A 3.4% vs. Group B 0%, p =0.06) along with more Symptomatic radiolucent lines (Group A 3.4% vs. Group B 0%, p =0.06).

CONCLUSIONS

Both conventional and short stems showed excellent implant survival rates and functional outcomes at a mean follow-up of 9.8 years. However, complications and radiolucent lines were more frequent with a collarless conventional-length stem. Bone preservation of the femoral neck and diaphysis may be preferred in active young patients.

Do nonagenarians have more complications and unplanned readmissions than octogenarians following primary THA? A retrospective cohort study

INTRODUCTION

The performance of total hip arthroplasty in elderly patients, especially nonagenarians, is challenging due to higher patient frailty and medical comorbidities. We compared 90-day postoperative complications and unplanned readmissions between nonagenarians and octogenarians undergoing elective THA.

METHODS

One hundred and eleven patients undergoing elective, unilateral THA were retrospectively analyzed. Forty-four patients were nonagenarians (Group A), and 67 patients were octogenarians (Group B). Demographic data included age, gender, body mass index (BMI), ASA score and Charlson Comorbidity Index (CCI). Frailty was defined according to the Rockwood Frailty Index. All patients underwent a thorough preoperative assessment through a specific institutional clinical pathway created for this matter. Postoperative adverse events were grouped into major or minor. A regression model was used to evaluate independent risk factors for the development of complications.

RESULTS

There were no differences in the ASA score (65.9% vs. 53.7% ASA III-IV), prevalence of frailty (1% vs. 9%) and comorbidities between both groups (p > .05). The CCI was higher in nonagenarians (p = 0.007). Nonagenarians had more in-hospital complications, although most were minor (p = 0.002), none of which resulted in mortality. Ninety-day unplanned readmissions were similar between groups, with 4 (9.1%) and 6 (9%) in groups A and B, respectively (p = 1). Although age was a factor associated with the development of postoperative complications in the univariate regression model (OR 3.81, 95% CI 1.31 to 11.11, p = 0.014), it lost significance after performing the multivariate analysis (OR 2.48, 95% CI 0.78 to 7.90, p = 0.125).

CONCLUSION

The age of 90 years old was not a barrier to perform elective THA safely. Nonagenarians had higher in-hospital minor complications when compared to the younger cohort. However, age over 90 years was not an independent risk factor for unplanned readmissions or mortality. Multimodal protocols of perioperative care are paramount for improving outcomes after THA in very old patients.

The Influence of Dorr Type and Femoral Fixation on Outcomes Following Total Hip Arthroplasty for Acute Femoral Neck Fractures: A Multicenter Study

BACKGROUND

The American Academy of Orthopaedic Surgeons guidelines report moderate evidence for cementing femoral stems for hip fractures, mainly derived from hemiarthroplasty literature. This is the first large, nonregistry study examining the influence of femoral fixation, implant type, patient characteristics, and radiographic factors on outcomes after total hip arthroplasty (THA) for acute femoral neck fractures.

METHODS

A multicenter retrospective study was performed of 709 THA cases (199 cemented, 510 cementless) for femoral neck fractures from 2006 to 2020 at three large academic institutions. Demographics, perioperative characteristics, and radiographs were reviewed. Kaplan-Meier survivorship curves were generated for multiple outcomes. Univariate and multivariate analyses were performed with P ≤ .05 denoting significance.

RESULTS

Cementless stems had a higher all-cause aseptic femoral revision rate (5.1 versus 0.5%, P = .002) and periprosthetic femoral fracture rate (4.3 versus 0%, P = .001). Each successive Dorr type had a higher fracture rate with cementless implants: 2.3%, 3.7%, and 15.9% in Dorr A, B, and C, respectively (P < .001). Logistic regression analyses confirmed that cementless stems (P = .02) and Dorr C bone (P = .001) are associated with periprosthetic fractures; collared implants and prophylactic cables did not protect against fractures. There was no difference in rates of dislocation, septic revision, or mortality between groups.

CONCLUSION

Cementless stems during THA for femoral neck fractures have a higher aseptic femoral revision rate, specifically for periprosthetic fractures. Dorr C bone was particularly prone with an alarmingly high fracture rate. All fractures occurred in cementless cases, suggesting that cemented stems may minimize this complication.

LEVEL OF EVIDENCE

III.

Intraoperative unfractionated heparin before femoral component cementation should be avoided in femoral neck fracture treated with hybrid total hip arthroplasty

PURPOSE

To compare the incidence of perioperative thromboembolic events in femoral neck fracture (FNF) patients treated with hybrid total hip arthroplasty (THA) with intraoperative unfractionated heparin (UFH) versus a control group without intraoperative UFH before femoral component cementation.

METHODS

We compared 139 cases without UFH (group A) versus 134 who received 10 UI/kg UFH (group B). Indication of UFH before cementation depended on the preferences of the anaesthesiologists in each case. We assessed intraoperative bone cement implantation syndrome (BCIS) and 30-day thromboembolic events, and 90-day and 1-year mortality. BCIS was classified as per Donaldson et al.'s classification according to the degree of hypotension, arterial desaturation or loss of consciousness.

RESULTS

BCIS was observed in 51 (18%) cases, including 37 (13%) grade 1 and 14 (5%) grade 2. Forty-seven BCISs (35%) were observed in group B and 4 (3%) in group A (p < 0.001). Multivariate regression showed that intraoperative UFH (OR = 18, CI 95% 6-52) and consumption of oral anticoagulants (OR = 3.3, CI 95% 1-10) increased the risk of BCIS. Five patients further developed a 30-day pulmonary embolism in group B, while 2 presented this complication in group A (p = 0.231). No association between BCIS and 30-day thromboembolic events was found (p = 0.62). 90-day (1% each, p = 0.98) and 1-year (2% vs. 3%, p = 0.38) mortality were similar.

CONCLUSIONS

BCIS was a frequent finding in FNF patients treated with hybrid THA. We found a paradoxically significant increase in BCIS with the use of UFH. Heparin did not seem to prevent BCIS, other thromboembolic events and mortality in this group of patients.

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

Background

Methods

Results

Conclusions

Level of evidence

The Effect of Femoral Fixation on Revision and Mortality Following Elective Total Hip Arthroplasty in Patients Over the Age of 65 years. An Analysis of the American Joint Replacement Registry

BACKGROUND

With the overwhelming use of cementless femoral fixation for primary total hip arthroplasty in the United States, the associations of stem fixation on the risk of revision and mortality are poorly understood. We evaluated the relationship between femoral fixation and risk of revision and mortality in patients included in the American Joint Replacement Registry.

METHODS

Elective, primary, unilateral total hip arthroplasties in the American Joint Replacement Registry, in patients over the age of 65 years were considered. In total, 9,612 patients with a cemented stem were exact matched 1:1 with patients who received a cementless stem based on age, gender, and the Charlson Comorbidity Index. Outcomes compared between the groups included need and reason for revision at 90 days and 1 year; in-hospital, 90-day, and 1-year mortality; and mortality after early revision. Covariates were used in linear regression analyses.

RESULTS

Cemented fixation was associated with a 37% reduction in the risk of 90-day revision, and a reduction in the risk of revision for periprosthetic fracture of 87% at 90 days and 81% at 1 year. Cemented fixation was associated with increased 90-day and 1-year mortality (odds ratio [OR] 3.15, confidence interval [CI] 2.24-4.43 and OR 2.36, CI 1.86-3.01, respectively). Patients who underwent subsequent revision surgery within the first year exhibited the highest mortality risk (OR 3.23, CI 1.05-9.97).

CONCLUSION

In this representative sample of the United States, 90-day revision for any reason and for periprosthetic fracture was significantly reduced in patients with a cemented stem. This benefit must be weighed against the association with increased mortality and with the high risk of mortality associated with early revision, which was more prevalent with cementless fixation.

Multimodal Thromboprophylaxis in Patients With a History of Venous Thromboembolism Undergoing Primary and Revision Knee Arthroplasty

Background: Patients with a history of venous thromboembolism (VTE) undergoing total knee arthroplasty (TKA) are at a high risk of postoperative VTE. Purpose: In this high-risk population, we sought to evaluate the safety and efficacy of multimodal thromboprophylaxis. The regimen consisted of discontinuation of procoagulant medications, VTE risk stratification, regional anesthesia, rapid mobilization, perioperative use of pneumatic compression devices, vigorous ankle dorsiflexion during the recovery period, and chemoprophylaxis tailored to the patient's risk of VTE. Methods: We conducted a retrospective chart review of 141 consecutive patients with a history of VTE who underwent 177 elective TKA procedures between 2005 and 2019 by 2 arthroplasty surgeons at a single institution. The patients had a history of deep venous thrombosis (DVT) (n = 127; 72%), pulmonary embolism (PE) (n = 20; 11%), or both (n = 30; 17%). Postoperative chemoprophylaxis included aspirin (n = 20; 11%), anticoagulation (n = 135; 77%), or a combination of aspirin and anticoagulation (n = 21; 12%). Complications within 120 days, including VTE events, wound complications, bleeding, and unplanned readmissions, were recorded, as was 1-year mortality. Results: Five patients (2.8%) developed symptomatic DVT (3 distal, 2 proximal), and 4 patients (2.3%) developed symptomatic PE. The most common postdischarge complications were wound infection (n = 6; 3.4%) and stiffness requiring manipulation under anesthesia (n = 5; 2.8%). There was 1 emergency room visit and 13 unplanned readmissions; 3 patients developed intra-articular hematomas or prolonged wound drainage and recovered uneventfully. All patients were alive 1 year after surgery. Conclusion: The findings of this retrospective study suggest that multimodal prophylaxis may be safe and effective in patients with a history of VTE undergoing primary and revision TKA. More rigorous study is warranted.

Preliminary outcomes of the cementless UNITED hip system for primary total hip arthroplasty at a minimum 2-year follow-up

INTRODUCTION

This study aimed to report the initial results of the cementless UNITED hip system in primary total hip arthroplasty (THA) with a minimum follow-up of 2 years.

METHODS

We retrospectively studied a consecutive series of 203 cementless THAs in 180 patients operated between 2015-2017. We included 89 female and 91 male patients with a mean age of 67 (28 to 89) years. The mean follow-up was 40 (29 to 62) months. Clinical outcome scores and radiographs were measured. Survival was calculated defining failure as the need for any further femoral or acetabular revision, irrespective of the reason.

RESULTS

No femoral component loosening was detected. One patient had a Vancouver-B1 intraoperative periprosthetic femoral fracture treated with implant retention and cerclage wires. Two acetabular components were revised for aseptic loosening. Three patients suffered an acute infection treated with debridement, antibiotics, and implant retention. The mean Merle d'Aubigné et Postel scores improved from 13 (4 to 16) points preoperatively to 17 (12 to 18) points at the latest follow-up (p < 0.001). At a mean time of 40 months of follow-up, the survival was 99% and 100% for the acetabular and the femoral components, respectively.

CONCLUSION

This cementless design showed excellent preliminary outcomes in terms of fixation and patient satisfaction, comparable to that of other well-known similar systems.

Non-Inferiority of Aspirin for Venous Thromboembolism Prophylaxis After Hip Arthroplasty in a Statewide Registry

BACKGROUND

Uncertainty remains surrounding the use of aspirin as a sole chemoprophylactic agent to reduce the risk of venous thromboembolism (deep vein thrombosis or pulmonary embolism) and bleeding after primary total hip arthroplasty.

METHODS

We performed a non-inferiority analysis of a retrospective cohort of patients undergoing total hip arthroplasty from April 1, 2013 to December 31, 2018. Cases were retrieved from the Michigan Arthroplasty Registry Collaborative Quality Initiative database and performed by 355 surgeons at 61 hospitals throughout Michigan. Surgical setting ranged from small community hospitals to large academic and non-academic centers. The primary outcomes were post-operative venous thromboembolism event or death and bleeding event.

RESULTS

Of the 59,747 patients included, 32,878 (55.03%) were female, and the mean age was 64.5. A total of 462 (0.77%) composite venous thromboembolism events occurred. There were 221 (0.71%) and 129 (0.80%) venous thromboembolism events in patients receiving aspirin only and anticoagulants only, respectively. Aspirin was non-inferior to anticoagulants for composite venous thromboembolism events (odds ratio 0.99, 95% confidence interval 0.79-1.26, P < .001). Bleeding events occurred in 767 (1.28%) patients, with 304 (0.97%) and 281 (1.74%) bleeding events in patients receiving aspirin only and anticoagulants only, respectively. Aspirin was non-inferior to anticoagulants for bleeding events (odds ratio 0.62, 95% confidence interval 0.52-0.74, P < .001).

CONCLUSION

Aspirin is not inferior to other anticoagulants as pharmacologic venous thromboembolism prophylaxis with regards to post-operative risk of venous thromboembolism or bleeding. Sole use of aspirin for venous thromboembolism prophylaxis after total hip arthroplasty should be considered in the appropriate patient.

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.

Clinical efficacy of risk-stratified prophylaxis with low-dose aspirin for the management of symptomatic venous thromboembolism after total hip arthroplasty

BACKGROUND

Pulmonary thromboembolism (PTE) and deep vein thrombosis (DVT) are serious complications after total hip arthroplasty (THA). Aspirin has been considered a safe and cost-effective prophylaxis for venous thromboembolism (VTE), and there have been some reports about the incidence of PTE (0%-0.57%) and DVT (0.1%-0.35%) with low-dose aspirin for prophylaxis after THA. The aim of this study was to investigate the incidence of postoperative symptomatic VTE in our hospital and to evaluate the clinical efficacy of our prophylactic regimen.

PATIENT AND METHODS

We retrospectively reviewed the medical records of consecutive patients who underwent THA in our hospital between 2011 and 2016. A total of 3295 hips (male: 337 patients, 365 hips; female: 2527 patients, 2930 hips) were enrolled in this study. Patients were divided into low-risk and high-risk groups. Low-risk patients were administered aspirin (100 mg/day) for 28 days postoperatively. High-risk patients, such as those diagnosed with obesity and/or with a history of VTE, received anticoagulants (enoxaparin or edoxaban) for 5 days postoperatively, followed by a dose of aspirin for 28 days. Based on our criteria, 218 of 3295 hips were considered high risk.

RESULTS

No VTE-related mortality was observed. One patient developed symptomatic PTE, and one patient developed symptomatic DVT. Both were successfully treated. Postoperative fatal bleeding or bleeding from any organ such as gastrointestinal and cerebral hemorrhage were not observed. A low incidence (0.03%) was observed for symptomatic DVT and PTE.

CONCLUSIONS

This study demonstrated that the hospital's risk-stratified protocol using low-dose aspirin or anticoagulants was clinically effective in preventing symptomatic VTE. These results were considerably better than those reported from Western countries. However, all patients in this study were the Japanese. It was unclear whether similar results were given to non-Japanese patients. Therefore, this protocol needs severe carefulness to be applied to non-Japanese populations.

Risk factors for venous thromboembolism in total shoulder arthroplasty

Background

Although venous thromboembolism (VTE) has been studied in lower-extremity arthroplasty, there are few guidelines regarding established risk factors for VTE in total shoulder arthroplasty (TSA). With literature suggesting the VTE rate may be as high as 13%, VTE prevention and risk factors should be considered in preoperative planning.

Methods

All TSAs from 2011 through 2016 were queried from the National Surgical Quality Improvement Program database. Age, sex, body mass index, American Society of Anesthesiologists class, ethnicity, functional status, comorbidities, discharge destination, surgical indication, length of stay, and operative time were compared between patients with and without 30-day postoperative VTE. Pearson χ² and t tests were used to assess baseline categorical and continuous variables, respectively. Multivariate logistic regression analysis was conducted to determine associated independent risk factors for VTE.

Results

The analysis included 13,299 patients; VTE developed in 83 patients (0.62%). Patients with VTE were older (72 years vs. 69 years) and had a longer hospital stay (3.5 days vs. 1.9 days). Compared with patients with no VTE, patients with VTE were more likely to undergo TSA for proximal humeral fractures, to be discharged to a rehabilitative center, to have a preoperative albumin level lower than 3.5 g/dL, to undergo non-elective surgery, to have an American Society of Anesthesiologists class of 3 or greater, to have a surgical-site infection develop, and ultimately to need a shoulder reoperation (all P < .05). Multivariate logistic regression analysis revealed that hypoalbuminemia (albumin level < 3.5 g/dL), an increased length of stay, and African American ethnicity were independent risk factors for VTE development.

Conclusion

Patients with hypoalbuminemia, an increased length of stay, and African American ethnicity are at an increased risk of VTE after shoulder arthroplasty. A high index of suspicion is warranted for elderly patients with fractures who may need preoperative medical optimization.

Impaction Bone Grafting or Uncemented Modular Stems for the Treatment of Type B3 Periprosthetic Femoral Fractures? A Complication Rate Analysis

BACKGROUND

Because the gold standard for the treatment of Vancouver type-B3 periprosthetic femoral fractures (PFFs) is yet to be defined, we sought to analyze the complication rate between the impaction bone grafting (IBG) technique with a cemented stem and reconstruction with an uncemented distally-fixed modular stem (DFMS).

METHODS

We retrospectively studied 54 B3 PFFs operated between 2000 and 2016, comparing the complication rate of 33 patients treated with the IBG technique (group A) with 21 patients treated with a DFMS (group B). Median follow-up of groups A and B were 75 months (interquartile range [IQR], 36-111 months) and 55 months (IQR, 32-73 months), respectively (P = .008). Median age of groups A and B were 78 years (IQR, 74-83 years) and 81 years (IQR, 74-86 years), respectively (P = .30). Median grade of Endo-Klink femoral bone defect was 3 (IQR, 3-3) for both groups (P = .11). We performed a multiple regression analysis to determine risk factors for complications including the following variables: age, initial diagnosis, and surgical technique.

RESULTS

As for infection outcomes, 2-stage revision surgery was more frequent in group A than in group B (4 vs 0, P = .003). Group A presented more implant failures than group B (5 vs 1, P = .195). We found 4 dislocations in group B and 2 in group A (P = .192). Multiple regression analysis showed a significant association between surgical technique and complication rate (P = .01). The IBG technique presented an odds risk for complications of 4.77 (P = .016; IQR, 1.33-17.21).

CONCLUSION

Femoral reconstruction with the IBG technique evidenced an ostensibly higher complication rate than that of DFMS for the treatment of B3 PFF.

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.

Similar Clinical Outcomes with Preoperative and Postoperative Start of Thromboprophylaxis in THA: A Register-based Study

BACKGROUND

Elective THA is associated with a high risk of thromboembolic events. Although these events may be less common now than they were in the past, they can be serious, and most patients undergoing the procedure therefore still receive thromboprophylaxis. However, controversy remains regarding whether to begin thromboprophylaxis before THA or after to best balance the risks of clotting and bleeding.

QUESTIONS/PURPOSES

We asked the following questions: (1) Is there a difference in bleeding events with pre- versus postoperative thromboprophylaxis? (2) Is there a difference in thromboembolic episodes after THA between the two regimens? (3) How do the two approaches of thromboprophylaxis influence mortality, readmissions, and other complications?

METHODS

We used a population-based followup design with predefined data based on international health codification to assess clinical effects of LMWH prophylaxis initiated before or after THA. We took data limited to primary THAs done in Norway between January 1, 2008, and December 31, 2011, from the Norwegian Arthroplasty Register and the National Patient Register to have necessary data elements to complete the study. The two registers were merged after identifying patients with their 11-digit personal identification number (Social Security number). We obtained data regarding demographics, administrative and surgical details, and episode histories for prophylaxis-related events within 180 days of surgery. A total of 25,163 patients undergoing THA were included for analysis, and 9977(40%) versus 15,186 (60%) patients received pre- and postoperative LMWH, respectively. We performed statistical adjustment for differences in baseline characteristics using multivariate logistic regression.

RESULTS

After adjustment for age, sex, operation time, year of surgery, and American Society of Anesthesiologists class, we could not show major differences in bleeding events; (odds ratio [OR], 1.04; 95% CI, 0.88-1.22; p = 0.660), thromboembolic episodes; (OR, 1.03; 95% CI, 0.84-1.27; p = 0.786), or other postoperative clinical complications; (OR, 0.86; 95% CI, 0.76-0.99; p = 0.034), with the two regimens. Six-month mortality was similar, (OR, 0.76; 95% CI, 0.56-1.05; p = 0.093), and the readmission rate was higher in the preoperative group; (OR, 0.92; 95% CI, 0.85-0.97; p = 0.016).

CONCLUSIONS

The risk for postoperative complications seems to be comparable whether LMWH prophylaxis is initiated before or after THA. The postoperative approach reduces costs, decreases risks related to neuraxial anesthesia, and facilitates same-day admissions. Methods for individual risk assessment including laboratory tests would be feasible.

LEVEL OF EVIDENCE

Level III, therapeutic study.

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.

Skin staples versus intradermal wound closure following primary hip arthroplasty: a prospective, randomised trial including 231 cases

Intradermal wound closure is controversial in primary total hip arthroplasty. Randomised, controlled trials in wound closure following a total hip arthroplasty (THA) are scarce. Our hypothesis was that skin staples closure would be related to a similar complication rate and operative time as intradermal closure with polypropylene. From September 2011 to May 2012, 231 THAs in 219 patients with an average age of 62 years old (range: 21-91) were performed. No differences were observed in both groups according to sex, age, BMI and comorbidities (p = 0,82). Cases were divided into 3 groups according to medical factors that influence wound healing: group 1 (no medical history, 70.5%), group 2 (diabetes, tobacco smokers, obesity, corticosteroids, rheumatoid disease, 25%) and group 3 (organ transplantation, neoplastic patients or 2 or factors of group 2, 4.5%). Once randomised using a computer-generated method, all patients remained within the group to which they were allocated to wound closure with skin staples (Leukosan® SkinStapler PTW-35, BSN, Germany) that were used in 112 THAs in 105 patients (48%), or continuous 3.0 intradermal non-absorbable polypropylene suture (Prolene™ 0, Ethicon Inc. Somerville, New Jersey, USA) in 119 THA´s in 115 patients (52%). A 3.8% wound complication rate was observed in this series, with a 2.1% complication rate for the group that was closed with skin staples and a 1.7% rate for the group with intradermal suture (p = 0.7). All the complications were treated conservatively except for one acute deep infection (0.4%) that was successfully treated with debridement, component retention and intravenous antibiotics. There were no differences in both groups related to operative time or wound length.In these series of primary elective THAs, skin staples were associated with a similar complication rate to an intradermal closure technique.

The modern, hybrid total hip arthroplasty for primary osteoarthritis at the Hospital for Special Surgery

We describe our technique and rationale using hybrid fixation for primary total hip arthroplasty (THA) at the Hospital for Special Surgery. Modern uncemented acetabular components have few screw holes, or no holes, polished inner surfaces, improved locking mechanisms, and maximised thickness and shell-liner conformity. Uncemented sockets can be combined with highly cross-linked polyethylene liners, which have demonstrated very low wear and osteolysis rates after ten to 15 years of implantation. The results of cement fixation with a smooth or polished surface finished stem have been excellent, virtually eliminating complications seen with cementless fixation like peri-operative femoral fractures and thigh pain. Although mid-term results of modern cementless stems are encouraging, the long-term data do not show reduced revision rates for cementless stems compared with cemented smooth stems. In this paper we review the conduct of a hybrid THA, with emphasis on pre-operative planning, surgical technique, hypotensive epidural anaesthesia, and intra-operative physiology.

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.

Preliminary analysis on the MD-4® plasma-sprayed titanium acetabular component

Objectives

To evaluate the short-term performance of a type of implant manufactured in Brazil.

Methods

This study analyzed a cohort of 60 patients who underwent implantation of MD-4^® acetabular components during primary hip arthroplasty procedures performed between January 1, 2010, and August 1, 2012. The patients were studied retrospectively with regard to clinical behavior, stability and radiological osseointegration. The patients were followed up for a minimum of 12 months and a maximum of 42 months (mean: 27) and were evaluated by means of the Harris Hip Score, SF-36 questionnaire and serial conventional radiographs.

Results

All the components were radiologically stable, without evidence of migration or progressive radiolucency lines. On average, the Harris Hip Score evolved from 36.1 to 92.1 (p < 0.001) and the SF-36 showed significant increases in all its domains (p < 0.001). No differences were observed among patients with osteoarthrosis, osteonecrosis, hip dysplasia or other conditions.

Conclusions

The short-term results showed clinical and radiological signs of stability and osseointegration of the implants, which may represent a predictive factor regarding medium-term survival of this acetabular component.

Thromboprophylaxis with dabigatran leads to an increased incidence of wound leakage and an increased length of stay after total joint replacement

Since the introduction of the National Institute for Health and Care Excellence (NICE) guidelines on thromboprophylaxis and the use of extended thromboprophylaxis with new oral agents, there have been reports of complications arising as a result of their use. We have looked at the incidence of wound complications after the introduction of dabigatran for thromboprophylaxis in our unit.

We investigated the rate of venous thromboembolism and wound leakage in 1728 patients undergoing primary joint replacement, both before and after the introduction of dabigatran, and following its subsequent withdrawal from our unit.

We found that the use of dabigatran led to a significant increase in post-operative wound leakage (20% with dabigatran, 5% with a multimodal regimen; p < 0.001), which also resulted in an increased duration of hospital stay. The rate of thromboembolism in patients receiving dabigatran was higher (1.3%) than in those receiving the multimodal thromboprophylaxis regimen, including low molecular weight heparin as an inpatient and the extended use of aspirin (0.3%, p = 0.047). We have ceased the use of dabigatran for thromboprophylaxis in these patients.

Cite this article: Bone Joint J 2014;96-B:122–6.

Economic Impact of Venous Thromboembolism Following Major Orthopaedic Surgery in Japan

OBJECTIVES

Venous thromboembolism (VTE) is the most frequent complication following major orthopaedic surgery (MOS). Although studies in Western populations have demonstrated significantly higher costs for patients with VTE versus those without VTE after MOS, there is a paucity of such data in Japan. This study was conducted to understand the costs and VTE rates in Japanese patients.

METHODS

Data were extracted from a hospital claims database. MOS was defined as total hip replacement, total knee replacement, or hip fracture repair. Subjects who underwent more than one MOS during the same admission were excluded. Identified VTE cases were matched on a 1:2 matching scheme on the basis of surgery type, hospital, and date of surgery (±6 months). The primary outcome was the difference in 90-day costs. Secondary outcomes included differences in total 6-month costs postsurgery and average length and cost of initial hospital stay.

RESULTS

The 90-day cumulative VTE incidence was 0.774%, with 94% of the cases occurring within 30 days postsurgery. Total 90-day costs were significantly higher in patients with VTE (difference of 864,153 Japanese yen [US $10,538]). Average length of stay was longer for patients with VTE (66 days vs. 42 days). Costs incurred by patients with VTE were on average much higher than those incurred by patients without VTE throughout 5 months postsurgery.

CONCLUSIONS

The development of a VTE in patients undergoing MOS results in a 1.5-fold increase in the length of stay and a 1.7-fold increase in 90-day costs. Findings indicate that the avoidance of VTEs through more effective prophylaxis will help to reduce the economic burden associated with MOS.

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.

The venous thromboembolic complications of shoulder and elbow surgery

We investigated the incidence of and risk factors for venous thromboembolism (VTE) following surgery of the shoulder and elbow and assessed the role of thromboprophylaxis in upper limb surgery. All papers describing VTE after shoulder and elbow surgery published in the English language literature before 31 March 2012 were reviewed. A total of 14 papers were available for analysis, most of which were retrospective studies and case series. The incidence of VTE was 0.038% from 92 440 shoulder arthroscopic procedures, 0.52% from 42 261 shoulder replacements, and 0.64% from 4833 procedures for fractures of the proximal humerus (open reduction and internal fixation or hemiarthroplasty). The incidence following replacement of the elbow was 0.26% from 2701 procedures. Diabetes mellitus, rheumatoid arthritis and ischaemic heart disease were identified as the major risk factors.

The evidence that exists on thromboprophylaxis is based on level III and IV studies, and we therefore cannot make any recommendations on prophylaxis based on the current evidence. It seems reasonable to adopt a multimodal approach that involves all patients receiving mechanical prophylaxis, with chemical prophylaxis reserved for those who are at high risk for VTE.

Cite this article: Bone Joint J 2013;95-B:70–4.

High failure rate with the GAP II ring and impacted allograft bone in severe acetabular defects

BACKGROUND

Reconstruction rings and bone allografts have been proposed to manage severe acetabular bone loss. However, a high early failure rate of the Graft Augmentation Prosthesis (GAP) II reinforcement ring (Stryker Orthopaedics, Mahwah, NJ, USA) has been reported in one small series.

QUESTIONS/PURPOSES

We therefore determined (1) the survival of this device in combination with impacted morselized allograft bone in patients with severe defects and (2) the complication rate.

METHODS

We retrospectively reviewed 24 patients (21 aseptic and three septic) with severe acetabular bone loss (10 hips with Type III defects and 14 with Type IV defects according to the American Academy of Orthopaedic Surgeons classification). We determined function and numbers of failures. The minimum followup was 24 months (mean, 34 months; range, 24-72 months).

RESULTS

At latest followup, the reconstruction had failed in nine of the 24 patients: six with aseptic loosening, three with infection. The average postoperative Merle d'Aubigné-Postel score of the patients whose reconstructions had not failed was 16.6 points; at latest followup, these patients had radiographic evidence of incorporation and consolidation of bone allografts. Seven of the nine patients whose reconstructions had failed underwent reoperation. Fatigue fracture of the ring at the plate-cup union occurred in five patients at an average of 45 months postoperatively. All patients with failed reconstructions who underwent reoperation were treated with Trabecular Metal(™) (Zimmer Inc, Warsaw, IN, USA) cups and were functioning well at latest followup.

CONCLUSIONS

We observed a high rate (37%) of early catastrophic failures of the GAP II reconstruction ring, particularly in patients with Type IV defects. Due to this high failure rate, we have abandoned its use.

LEVEL OF EVIDENCE

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

Chinese orthopedic surgeons' practice regarding postoperative thromboembolic prophylaxis after major orthopedic surgery

OBJECTIVE

To assess Chinese surgeon practice of thromboprophylaxis following major orthopedic surgery.

METHODS

A questionnaire survey was conducted amongst Chinese orthopedic surgeons. A total of 293 surgeons were surveyed concerning five key aspects of thromboembolic prophylaxis after major orthopedic surgery at the proseminar of Chinese guidelines for prevention of venous thromboembolism (VTE) after major orthopedic surgery in January of 2009.

RESULTS

Totally, 208 surgeons (71.0%) responded, successfully completing the questionnaire. Of them, 57.6% respondents selected combined basic, mechanical, and pharmacologic methods for thromboprophylaxis; 51.0% respondents prefer starting prophylaxis 12-24 hours after surgery; 60.3% surgeons would use chemoprophylaxis for 7-10 days; 47.6% respondents prefer VTE prevention based on patients' special conditions and needs upon discharge."Safety" was the most repeated and emphasized factor during VTE prophylaxis.

CONCLUSIONS

Multimodal thromboprophylaxis is frequently used after major orthopedic surgery. Half surgeons prefer to start chemoprophylaxis 12-24 hours after surgery. Thromboprophylaxis regimen varies for discharged patients.

Risk Factor Analysis for 30-Day Mortality After Primary THA in a Single Institution

The purpose of this study was to determine the prevalence of, and associated risk factors for, 30-day perioperative death following primary total hip arthroplasty (THA). Data of all the patients were compiled from the computerized total joint registry at a single institution. Between May 1993 and May 2006, 3,232 consecutive primary THA (2,453 elective and 779 nonelective) were performed. Eleven deaths occurred during the first month after surgery (0.34 %). Thirty-day mortality rate after elective THA was 0.08 % (two of 2,453 IC 95 %(0-0.4)). The 30-day mortality rate after nonelective THA was 1.15 % (nine of 779 IC 95 %(0.7-2.4). To analyze the factors that could have contributed with death, we conducted a 4-to-1 nested case-control study. Control cases were strictly matched by sex, age, surgeon, prosthesis fixation mode, and date of surgery. Conditional logistic regression was used to evaluate the association of risk factors with mortality. Elective surgery was associated with a lower risk of mortality with an odds ratio (OR) of 0.07 (95 % CI 0.008-0.6);p = 0.015. American Society of Anesthesiologists (ASA) score III-IV increased the mortality risk 13 times (OR 13.7; 95 % CI 1.6-114.8). Cardiovascular disease increased the risk for mortality eight times (OR 8.83 (95 % CI 1.78-43.6). Time delay before surgery showed a trend towards significance (p = 0.06). Aggressive vs. nonaggressive thromboembolism prophylaxis and the amount of blood transfusions required were not associated with a higher risk of death. Patients undergoing a THA due to fractures, patients with high ASA score, and those with cardiovascular disease were the highest risk factors for 30-day mortality after primary THA.

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.

Meta-analysis of cause of death following total joint replacement using different thromboprophylaxis regimens

We performed a meta-analysis of modern total joint replacement (TJR) to determine the post-operative mortality and the cause of death using different thromboprophylactic regimens as follows: 1) no routine chemothromboprophylaxis (NRC); 2) Potent anticoagulation (PA) (unfractionated or low-molecular-weight heparin, ximelagatran, fondaparinux or rivaroxaban); 3) Potent anticoagulation combined (PAC) with regional anaesthesia and/or pneumatic compression devices (PCDs); 4) Warfarin (W); 5) Warfarin combined (WAC) with regional anaesthesia and/or PCD; and 6) Multimodal (MM) prophylaxis, including regional anaesthesia, PCDs and aspirin in low-risk patients. Cause of death was classified as autopsy proven, clinically certain or unknown. Deaths were grouped into cardiopulmonary excluding pulmonary embolism (PE), PE, bleeding-related, gastrointestinal, central nervous system, and others (miscellaneous). Meta-analysis based on fixed effects or random effects models was used for pooling incidence data. In all, 70 studies were included (99 441 patients; 373 deaths). The mortality was lowest in the MM (0.2%) and WC (0.2%) groups. The most frequent cause of death was cardiopulmonary (47.9%), followed by PE (25.4%) and bleeding (8.9%). The proportion of deaths due to PE was not significantly affected by the thromboprophylaxis regimen (PA, 35.5%; PAC, 28%; MM, 23.2%; and NRC, 16.3%). Fatal bleeding was higher in groups relying on the use of anticoagulation (W, 33.8%; PA, 9.4%; PAC, 10.8%) but the differences were not statistically significant. Our study demonstrated that the routine use of PA does not reduce the overall mortality or the proportion of deaths due to PE.

The use of femoral struts and impacted cancellous bone allograft in patients with severe femoral bone loss who undergo revision total hip replacement

We determined the midterm survival, incidence of peri-prosthetic fracture and the enhancement of the width of the femur when combining struts and impacted bone allografts in 24 patients (25 hips) with severe femoral bone loss who underwent revision hip surgery. The pre-operative diagnosis was aseptic loosening in 16 hips, second-stage reconstruction in seven, peri-prosthetic fracture in one and stem fracture in one hip. A total of 14 hips presented with an Endoklinik grade 4 defect and 11 hips a grade 3 defect. The mean pre-operative Merle D’Aubigné and Postel score was 5.5 points (1 to 8).

The survivorship was 96% (95% confidence interval 72 to 98) at a mean of 54.5 months (36 to 109). The mean functional score was 17.3 points (16 to 18). One patient in which the strut did not completely bypass the femoral defect was further revised using a long cemented stem due to peri-prosthetic fracture at six months post-operatively. The mean subsidence of the stem was 1.6 mm (1 to 3). There was no evidence of osteolysis, resorption or radiolucencies during follow-up in any hip. Femoral width was enhanced by a mean of 41% (19% to 82%). A total of 24 hips had partial or complete bridging of the strut allografts.

This combined biological method was associated with a favourable survivorship, a low incidence of peri-prosthetic fracture and enhancement of the width of the femur in revision total hip replacement in patients with severe proximal femoral bone loss.

Natural course of asymptomatic deep venous thrombosis in hip surgery without pharmacologic thromboprophylaxis in an Asian population

BACKGROUND

The clinical importance of asymptomatic deep venous thrombosis in elective hip surgery is not clearly known.

QUESTIONS/PURPOSES

We determined the preoperative and postoperative incidences of asymptomatic deep venous thrombosis, identified preoperative factors associated with postoperative deep venous thrombosis or pulmonary embolism, and established its natural course in patients who underwent elective hip surgery without receiving pharmacologic thromboprophylaxis.

PATIENTS AND METHODS

We reviewed 184 patients who underwent consecutive elective hip surgeries with a mechanical thromboprophylaxis regimen including combined general and epidural anesthesia, intraoperative calf bandaging, early mobilization, and postoperative intermittent pneumatic compression with additional use of elastic stockings. Duplex ultrasonography was performed routinely to diagnose deep venous thrombosis in all patients before surgery and on Postoperative Days 3 and 21. All patients with postoperative deep venous thrombosis underwent additional ultrasonography at 3-month intervals, and all patients were followed postoperatively for 6 months or more.

RESULTS

Preoperatively, we found asymptomatic deep venous thrombosis in two patients (1%); both thromboses had completely and spontaneously resolved by Postoperative Day 21. Postoperatively, no patients had a fatal or symptomatic pulmonary embolism or proximal deep venous thrombosis, but nine patients (5%) had asymptomatic distal deep venous thrombosis develop, with no preoperative associated factors. These nine patients were followed closely without anticoagulant drugs, and all thromboses had disappeared without pulmonary embolism or thrombophlebitis by 6 months.

CONCLUSIONS

The incidence of preoperative and postoperative deep venous thrombosis was low in an Asian population having elective hip surgery and a nonpharmacologic thromboprophylaxis regimen. There were no preoperative factors associated with postoperative deep venous thrombosis, and all asymptomatic deep venous thromboses resolved spontaneously without associated pulmonary embolism or thrombophlebitis.

LEVEL OF EVIDENCE

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

Risk factors for perioperative mortality after lower extremity arthroplasty: a population-based study of 6,901,324 patient discharges

The goal of this study was to provide nationally representative data on characteristics of patients who died after hip and knee arthroplasty and to determine risk factors for such outcome. Using national in-patient data collected between 1990 and 2004, we identified a cumulative in-hospital mortality rate of 0.35% among an estimated 6,901,324 procedures. The strongest independent risk factors for in-hospital mortality were pulmonary embolism and cerebrovascular complications, which increased the odds for a fatal outcome by approximately 40-fold. Preoperative risk factors for in-hospital mortality were revision total hip arthroplasty, advanced age, and the presence of a number of comorbid diseases, predominantly dementia, renal, and cerebrovascular disease. Our results can be used to identify patients at risk for fatal outcome and implement interventions to reduce such risk.

High incidence of complications from enoxaparin treatment after arthroplasty

Pulmonary embolism (PE) complicates 1% to 10% of total joint arthroplasties and generally requires immediate anticoagulation. Low-molecular-weight heparins have supplanted unfractionated heparin as the treatment of choice for PE and hold a 1A recommendation from the American College of Chest Physicians for this indication. However, the complications of enoxaparin treatment begun in close proximity to arthroplasty surgery are not well described. We examined the records of 135 patients who underwent total joint arthroplasty, experienced an in-hospital PE, and received treatment with enoxaparin at therapeutic doses (1 mg/kg body weight). The type and frequency of complications were determined and classified as major or minor. Twenty-seven percent of patients experienced minor complications and 10% experienced major complications. The incidence of major bleeding was substantially higher than rates reported for nonsurgical patients. The overall complication rate of enoxaparin treatment is similar to the rate of complications reported for unfractionated heparin treatment in this setting, but the complications are less severe.

LEVEL OF EVIDENCE

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

Clinical efficacy of mechanical thromboprophylaxis without anticoagulant drugs for elective hip surgery in an Asian population

To evaluate the clinical efficacy of mechanical thromboprophylaxis after elective hip surgery, we reviewed 3016 patients who underwent hip surgery at 5 centers. Primary total hip arthroplasty (THA), revision THA, and pelvic or femoral osteotomies were performed in 2648, 298, and 70 patients, respectively. Epidural anesthesia, intraoperative calf bandage, early mobilization, and intermittent pneumatic compression postoperatively with additional use of elastic stockings were the basic regimen for thromboprophylaxis. Postoperatively, no cases of fatal pulmonary embolism (PE) were encountered. One symptomatic PE and 4 symptomatic deep vein thrombosis cases were identified, all of which were successfully treated using heparin and warfarin. By 6 months, no deaths had occurred. We conclude that mechanical thromboprophylaxis without anticoagulant drugs is safe and effective for elective hip surgeries in our patient population.

Proximal femoral reconstructions with bone impaction grafting and metal mesh

Extensive circumferential proximal cortical bone loss is considered by some a contraindication for impaction bone grafting in the femur. We asked whether reconstruction with a circumferential metal mesh, impacted bone allografts, and a cemented stem would lead to acceptable survival in these patients. We retrospectively reviewed 14 patients (15 hips) with severe proximal femoral bone defects (average, 12 cm long; 14 type IV and one type IIIB using the classification of Della Valle and Paprosky) reconstructed with this method. The minimum followup was 20 months (average, 43.2 months; range, 20-72 months). Preoperative Merle D'Aubigné and Postel score averaged 4.8 points. With revision of the stem as the end point, the survivorship of the implant was 100% at one year and 86.6% at 72 months. The mean functional score at last followup was 14.4 points. We observed two fractures of the metal mesh at 31 and 48 months in cases reconstructed with a stem that did not bypass the mesh. Dislocation (3 cases) and acute deep infection (3 cases) were the most frequent complications. Patients with complete absence of the proximal femur may be candidates for biological proximal femoral reconstructions using this salvage procedure. Bone impaction grafting must be a routine technique if this method is selected.

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.

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.

Potent anticoagulants are associated with a higher all-cause mortality rate after hip and knee arthroplasty

Anticoagulation for thromboprophylaxis after THA and TKA has not been confirmed to diminish all-cause mortality. We determined whether the incidence of all-cause mortality and pulmonary embolism in patients undergoing total joint arthroplasty differs with currently used thromboprophylaxis protocols. We reviewed articles published from 1998 to 2007 that included 6-week or 3-month incidence of all-cause mortality and symptomatic, nonfatal pulmonary embolism. Twenty studies included reported 15,839 patients receiving low-molecular-weight heparin, ximelagatran, fondaparinux, or rivaroxaban (Group A); 7193 receiving regional anesthesia, pneumatic compression, and aspirin (Group B); and 5006 receiving warfarin (Group C). All-cause mortality was higher in Group A than in Group B (0.41% versus 0.19%) and the incidence of clinical nonfatal pulmonary embolus was higher in Group A than in Group B (0.60% versus 0.35%). The incidences of all-cause mortality and nonfatal pulmonary embolism in Group C were similar to those in Group A (0.4 and 0.52, respectively). Clinical pulmonary embolus occurs despite the use of anticoagulants. Group A anticoagulants were associated with the highest all-cause mortality of the three modalities studied.