Persistent Wound Drainage among Total Joint Arthroplasty Patients Receiving Aspirin vs Coumadin

The Effect of Chronic Anticoagulation on Early Postoperative Outcomes Following Total Knee Arthroplasty: A TriNetX Database Study

Background

Medications used for pharmacologic venous thromboembolism prophylaxis are associated with postoperative complications including bleeding, wound complications, and infection. These same medications are used for chronic anticoagulation, and little research has been done on total knee arthroplasty (TKA) complications associated with these medications, particularly manipulation under anesthesia (MUA) and revision TKA. The purpose of this study is to evaluate the rate of MUA and other early postoperative complications in patients undergoing TKA with a preoperative history of chronic anticoagulation.

Methods

The TriNetX database was retrospectively queried for all patients undergoing TKA with perioperative tranexamic acid. Patients were divided into cohorts by whether or not they had a history of chronic anticoagulant use and had an anticoagulant medication prescribed within 6 months of surgery. The cohorts were propensity score matched on demographic and comorbidity data; 7367 patients remained in each cohort after matching.

Results

Patients with chronic anticoagulant use were 1.72 times more likely to undergo an MUA (odds ratio [OR]: 1.718, 95% confidence intervals [CI]: 1.403-2.104; P < .001), 1.32 times more likely to have a revision TKA (OR: 1.324, 95% CI: 1.006-1.742; P = .044), and were 1.53 times more likely to have wound disruption (OR: 1.530, 95% CI: 1.214-1.927; P < .001) within the 1-year postoperative period.

Conclusions

Patients undergoing TKA while on chronic anticoagulation have worse outcomes within 1 year postoperatively than patients not on chronic anticoagulation. Further studies are needed to validate these findings and to identify sources of the increased risk of complications in this population, as well as identify factors that may mitigate this risk.

Analysis of the causes of poor incision healing after hip and knee surgery and review of the literature

OBJECTIVE

A retrospective study was conducted to analyze the specific causes and literature review of patients who developed poor incision healing problems after hip and knee surgery.

METHODS

This was a retrospective analysis of 250 patients admitted to the Department of Orthopedics and Traumatology of the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine from October 1, 2022 to August 14, 2023 for hip and knee surgery. Among them, patients, 27 males and 39 females, were found to have poor incision healing after surgery; their ages ranged from 22 - 79 years, with an average of 58.71 years; and the patients developed symptoms of poor surgical incision healing from 1 - 8 months after surgery, with an average of 2.3 months. The causes of poor incision healing after hip and knee surgery were analyzed with reference to previously documented clinical data and relevant literature.

RESULTS

According to this data, it was concluded that the surgeon's inexperience in surgical incision suturing, unskilled suturing technique, inaccurate suture selection, etc., led to the occurrence of surgical incision healing problems, which accounted for 77.28% of the cases. The patient's age, lifestyle habits, BMI, and other underlying diseases (e.g., diabetes mellitus, rheumatoid arthritis, etc.) caused poor postoperative incision healing in 22.73% of cases.

CONCLUSION

Poor intraoperative suturing by the surgeon was the main cause of poor incision healing after hip and knee arthroplasty, which can be avoided by good suturing and strict postoperative dressing changes and nursing care.

The Comparison of Aspirin and Direct Oral Anticoagulant as Thromboprophylaxis Following Total Knee Replacement: A Retrospective Study

Objective  Venous thromboembolism (VTE) is still a major challenge after major orthopaedic surgery, including total knee replacement (TKR). The aim of this study was to estimate the risk of VTE with aspirin-only pharmacologic prophylaxis following primary TKR surgery versus direct oral anticoagulant (DOAC). Methods  The study included 476 patients who underwent primary TKR from 2016 to 2020. All patients received thromboprophylaxis with DOAC (DOAC group) ( n  = 267) or aspirin (aspirin group) ( n  = 209). Clinical outcomes were evaluated and compared between those who received DOAC and aspirin. The primary outcome was the incidence of VTE. The secondary outcome was wound complications. Result  Aspirin and DOAC were comparable in preventing VTE in patients who underwent primary TKR. The incidence of deep vein thrombosis was similar in the aspirin (10%) and factor Xa inhibitor groups (10.1%), ( p  = 0.98) with zero case of pulmonary emboli in both groups. There was no significant difference between the aspirin (1.4%) and DOAC groups (1.5%) regarding wound complication ( p  = 0.95). Conclusion  Postoperative thromboprophylaxis with aspirin only was not associated with a higher risk of postoperative VTE compared with DOAC following TKR. Considering the wide availability and cost-effectiveness, aspirin may serve as a promising alternative to DOAC for VTE prophylaxis.

The Use of Aspirin for Venous Thromboembolism Prophylaxis in Patients Who Have Morbid Obesity Undergoing Primary and Revision Total Joint Arthroplasty

BACKGROUND

Venous thromboembolism (VTE) poses a major clinical concern due to its life-threatening nature, and obese and morbidly obese patients are thought to be at an increased risk for VTE. The aims of this study were twofold; first, to explore VTE rates in patients who have a body mass index (BMI) > 40 undergoing primary and revision total joint arthroplasty, and second, to investigate aspirin (ASA) efficacy and safety.

METHODS

We identified all patients (n = 4,672) who had a BMI > 40 who underwent primary and revision total joint arthroplasty from 2016 to 2022 at a single academic tertiary care center. Patients were stratified by BMI groups: 40 to 44.9 (n = 3,462), 45 to 49.9 (n = 935), and 50+ (n = 275). The primary outcome was any VTE event within 90 days postoperatively. The secondary outcome consisted of wound complications within 90 days postoperatively.

RESULTS

The total VTE rate was 0.4% (n = 21) and did not differ statistically between the BMI groups (0.4 versus 0.4 versus 0.7%, P = .669). The VTEs consisted of 6 deep venous thromboses (DVTs), 14 pulmonary embolisms, and one concomitant deep venous thrombosis and pulmonary embolism. The VTE rates were not statistically different between patients who received aspirin 325 mg 0.5% (n = 9), aspirin 81 mg 0.2% (n = 1), aspirin + anticoagulant (AC) 0.5% (n = 6), and AC alone 0.4% (n = 5) (P = .954). In addition, wound complications did not differ significantly between patients who received ASA 325 mg, ASA 81mg, ASA + AC, or AC alone (1.6 versus 1.0 versus 1.8 versus 1.1%, P = .351).

CONCLUSIONS

The use of aspirin 325 and 81 mg was found to have similar VTE rates as aspirin + ACs and ACs alone, with no significant increase in wound complications. In patients who have a BMI > 40, the use of aspirin is a safe option for VTE prophylaxis and should be prescribed in the context of the patient who has other risk factors for VTE.

The CRISTAL Study Group. Aspirin or enoxaparin for VTE prophylaxis after primary partial, total or revision hip or knee arthroplasty: A secondary analysis from the CRISTAL cluster randomized trial

BACKGROUND

This study compares aspirin to enoxaparin for symptomatic VTE prophylaxis within 90 days of any type of hip or knee arthroplasty performed for any diagnosis, in patients enrolled in the CRISTAL trial.

MATERIALS AND METHODS

CRISTAL was a cluster-randomised crossover, registry-nested non-inferiority trial across 31 hospitals in Australia. The primary publication was restricted to patients undergoing primary total hip or knee arthroplasty for a diagnosis of osteoarthritis. This report includes all enrolled patients undergoing hip or knee arthroplasty procedures (partial or total, primary or revision) performed for any indication. Hospitals were randomized to administer patients aspirin (100mg daily) or enoxaparin (40mg daily), for 35 days after hip arthroplasty and 14 days after knee arthroplasty. Crossover occurred after the patient enrolment target had been met for the first group. The primary outcome was symptomatic VTE within 90 days. Analyses were performed by randomization group.

RESULTS

Between April 20, 2019 and December 18, 2020, 12384 patients were enrolled (7238 aspirin group and 5146 enoxaparin). Of these, 6901 (95.3%) given aspirin and 4827 (93.8%) given enoxaparin (total 11728, 94.7%) were included in the final analyses. Within 90 days, symptomatic VTE occurred in 226 (3.27%) aspirin patients and 85 (1.76%) enoxaparin patients, significant for the superiority of enoxaparin (estimated treatment difference 1.85%, 95% CI 0.59% to 3.10%, p = 0.004). Joint-related reoperation within 90 days was lower in the enoxaparin group (109/4827 (2.26%) vs 171/6896 (2.47%) with aspirin, estimated difference 0.77%; 95% CI 0.06% to 1.47%, p = 0.03). There were no significant differences in the other secondary outcomes.

CONCLUSION

In patients undergoing hip or knee arthroplasty (of any type, performed for any indication) enrolled in the CRISTAL trial, aspirin compared to enoxaparin resulted in a significantly higher rate of symptomatic VTE and joint-related reoperation within 90 days. These findings extend the applicability of the CRISTAL trial results.

TRIAL REGISTRATION

Anzctr.org.au, identifier: ACTRN12618001879257.

Trends in deep vein thrombosis prophylaxis after total hip arthroplasty: 2016 to 2021

Introduction

Venous thromboembolism (VTE) has long been acknowledged as a potential complication of total hip arthroplasty (THA) contributing to heightened patient morbidity, mortality, and substantial healthcare costs. We aimed to: 1) assess trends in VTE prophylaxis utilization between 2016 and 2021; 2) determine the incidence of postoperative VTE and transfusions; and 3) identify independent risk factors for 90-day VTE and transfusion risks following THA in relation to the use of aspirin, dabigatran, enoxaparin, rivaroxaban, and warfarin.

Methods

A national, all-payer database was queried from January 1, 2016 and December 31, 2022. Use trends for aspirin, enoxaparin, rivaroxaban, dabigatran, and warfarin as thromboprophylaxis following THA was assessed. Incidence of ninety-day postoperative outcomes assessed included rates of 90-day postoperative VTE and transfusion.

Results

From 2016 to 2021, aspirin (n = 36,346) was the most used agent for VTE prophylaxis after THA, followed by dabigatran (n = 13,065), rivaroxaban (n = 11,790), enoxaparin (n = 11,380), and warfarin (n = 6326). Independent risk factors for 90-day VTE included CKD, COPD, CHF, obesity, dabigatran, enoxaparin, rivaroxaban, and warfarin (all p < 0.05).

Conclusion

Aspirin was used with increasing frequency and demonstrated lower rates of VTE and transfusion following THA, compared to dabigatran, enoxaparin, rivaroxaban, and warfarin. These findings seem to indicate that the increasing use of aspirin in VTE prophylaxis has been accomplished in appropriately selected patients.

Aspirin is a safe and effective thromboembolic prophylaxis after total knee arthroplasty: a systematic review and meta-analysis

PURPOSE

Patients undergoing total knee arthroplasty (TKA) are at high risk for thromboembolic events compared to non-surgical patients. Both anticoagulants and antiplatelet agents are used as antithrombotic prophylaxis in TKA. The aim of this review is to understand the role of aspirin in the prevention of thromboembolic events and to compare its efficacy and safety with the main anticoagulants used in antithromboembolic prophylaxis in TKA.

METHODS

A systematic review and meta-analysis was performed according to the PRISMA guidelines. An electronic systematic search was conducted using PubMed, Scopus, and the Cochrane Central Registry to evaluate studies that compared aspirin with other anticoagulants, in terms of deep venous thrombosis and pulmonary embolism after TKA. The meta-analysis compared the rate of complications between aspirin and other anticoagulants.

RESULTS

Thirteen studies were included in the systematic review for a total of 163,983 patients, and 10 studies were included in the meta-analysis. The meta-analysis demonstrated no statistically significant differences between aspirin and other anticoagulants in terms of the rate of deep venous thrombosis (OR 0.93, 95% CI 0.81-1.08, p = 0.35) and pulmonary embolism (OR 0.89, 95% CI 0.56-1.41, p = 0.61).

CONCLUSION

Aspirin is safe, effective, and not inferior to other main anticoagulants in preventing thromboembolic events following TKA.

Is Enoxaparin Associated With a Higher Risk of Persistent Wound Drainage Than Aspirin? A Secondary Analysis of Data From the CRISTAL Randomized Trial

BACKGROUND

Owing to its association with prosthetic joint infection, persistent wound drainage has become an important clinical entity after THA or TKA. The association between venous thromboembolism (VTE) prophylaxis and persistent wound drainage has not been extensively reported before but has potentially important clinical implications.

QUESTIONS/PURPOSES

(1) Is the type of VTE prophylaxis (enoxaparin or aspirin) used after hip arthroplasty or knee arthroplasty associated with a higher risk of persistent wound drainage? (2) In patients who experience persistent wound drainage, is the type of VTE prophylaxis associated with a longer time taken to achieve a dry wound? (3) Is type of VTE prophylaxis associated with a higher risk of joint-related reoperation within 6 months?

METHODS

This was a secondary analysis of data from an earlier cluster-randomized trial conducted through the Australian Orthopaedic Association National Joint Replacement Registry; data were drawn from two participating hospitals from that study. According to the trial's allocation sequence, the two participating hospitals were randomized to administer aspirin (100 mg daily) or enoxaparin (40 mg daily) as VTE prophylaxis to all patients undergoing hip arthroplasty for 35 days after the procedure and for all patients undergoing knee arthroplasty for 14 days afterwards. Crossover to the alternate prophylaxis group occurred after the patient enrollment target had been met for the first arm. Between April 2019 and December 2020, 1339 of 1679 eligible patients were included in this study; 82% (707 of 861) of eligible patients were allocated to the enoxaparin group and 77% (632 of 818) of eligible patients we allocated to the aspirin group. The mean age in both groups was 67 ± 10 years and the mean BMI was 32 ± 7 kg/m 2 . There was a higher proportion of male patients (43% [302 of 707] versus 36% [227 of 632]; p = 0.01), hip arthroplasties (36% [254 of 707] versus 29% [182 of 632]; p = 0.006), and patients receiving subcuticular closure (62% [441 of 707] versus 33% [208 of 631]; p < 0.001) in the enoxaparin group than in the aspirin group. Patients were monitored for wound drainage on each postoperative day until discharge, and this was recorded in the medical record once per day. Assessors were not blinded to the type of prophylaxis each patient received. Persistent wound drainage was defined as any wound drainage beyond Postoperative Day 3. For patients who experienced persistent wound drainage, the time taken to achieve a dry wound was defined as the number of days beyond Postoperative Day 3 for the wound to become dry. Logistic regression was used to determine whether the prophylaxis type was associated with persistent wound drainage. For patients with persistent wound drainage, the median time of drainage was compared between groups using the Kruskal-Wallis test. The number of patients undergoing a joint-related reoperation within 6 months was identified through data linkage to the Australian Orthopaedic Association National Joint Replacement Registry and electronic record review, and was compared using a Fisher exact test.

RESULTS

We found no difference between the enoxaparin and aspirin groups in terms of the percentage of patients who had persistent wound drainage (9% [65 of 707] versus 8% [49 of 632], odds ratio 1.2 [95% confidence interval 0.8 to 1.8]; p = 0.40). For patients receiving subcuticular closure, after controlling for other potentially confounding variables, including age, sex, BMI, preoperative anticoagulant use, and type of arthroplasty, enoxaparin was associated with a higher risk of persistent wound drainage than aspirin (OR 3.6 [95% CI 1.5 to 10.6]; p = 0.009). For patients receiving a skin staple closure, after controlling for the same variables above, we found enoxaparin was not associated with a higher risk of persistent wound drainage (OR 1.1 [95% CI 0.7 to 1.9]; p = 0.66). For patients who experienced persistent wound drainage patients (114: 65 in the enoxaparin group and 49 in the aspirin group), there was no difference in the median (interquartile range) time taken to achieve a dry wound (enoxaparin: 1 day [IQR 1 to 2 days], aspirin: 1 day [IQR 1 to 3 days]; p = 0.22). There was no difference in the risk of joint-related reoperation within 6 months between enoxaparin (2.4% [17 of 707]) and aspirin (2.2% [14 of 632], OR 1.1 [95% CI 0.5 to 2.4]; p = 0.86).

CONCLUSION

Enoxaparin was not associated with an increased risk of persistent wound drainage compared with aspirin for all patients included in this study. Enoxaparin may be associated with a higher risk of drainage for patients receiving subcuticular closure. However, this finding should be interpreted cautiously, given the small sample size in this analysis. The duration of drainage was short regardless of the prophylaxis used, and enoxaparin was not associated with an increased risk of joint-related reoperation. These findings should not deter clinicians from using enoxaparin for VTE prophylaxis after hip or knee arthroplasty.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Prevention of surgical site infection: a ten-step approach

Surgical site infection (SSI) is a common cause of morbidity and mortality in patients undergoing surgery. Similarly, periprosthetic joint infection (PJI), is a major cause of failure after total joint arthroplasty (TJA). As the annual volume of TJA procedures is projected to rise, so will the rate of subsequent SSI and PJI. Currently, prevention has been identified as the single most important strategy for combating SSI/PJI. Hence, the present article will serve as a summary of an evidence-based ten-step approach for SSI/PJI prevention that may help orthopedic surgeons with their infection prevention strategies.

Incidence of Symptomatic Venous Thromboembolism (VTE) in 8,885 Elective Total Hip Arthroplasty Patients Receiving Post-operative Aspirin VTE Prophylaxis

BACKGROUND

Venous thromboembolism (VTE) is a potentially reducible cause of morbidity and mortality in patients undergoing elective hip arthroplasty surgery. The balance of post-operative VTE prophylaxis and risk of post-operative haemorrhage remains at the forefront of surgeon's mind. The National Institute for Health and Care Excellence (NICE) published updated guidelines in 2018 which recommend the use of both mechanical and pharmacological methods in patients undergoing elective total hip arthroplasty (THA).

OBJECTIVES

The aim of this study was to present the symptomatic VTE incidence in 8,885 patients who underwent THA between January 1998 and March 2018 with Aspirin as the primary agent for pharmacological thromboprophylaxis. Intermittent calf compression stockings are routinely used from the time of surgery until mobilization (usually the following day) with prophylactic doses of low molecular weight heparin (LMWH) during inpatient stay (from 2005 onwards) and then Aspirin 150mg once daily for six weeks on hospital discharge (or Aspirin only prior to 2005), with use of other therapies occasionally as required.

METHODS

Analysis of prospective data collection from consecutive patients at a single institution undergoing THA was performed with the incidence of symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) occurring within six months of the index operation as the primary outcome measure. Ninety-day all-cause mortality of this cohort of patients was also analysed.

RESULTS

8,885 patients were reviewed. This included 7230 primary, 224 complex primary and 1431 revision cases. The overall incidence of symptomatic VTE after elective THA was 1.11% (99/8885) - with the incidence of symptomatic DVT of 0.59% (52/8885) and the incidence of symptomatic PE of 0.53% (47/8885). There was no significant difference (χ² test, p=0.239) in the symptomatic VTE incidence between primary (1.20% - 89/7230), complex primary (0.89% - 2/224) and revision cases (0.70% - 10/1431). The 90-day all-cause mortality was 0.88% (78/8885). Cardiovascular and respiratory disease were the main causes of death following surgery. Only 0.03% of deaths (n= 3) within 90 days of index surgery were due to PE. There was no significant difference (p=0.327) in length of stay (and hence amount of pharmacologic prophylaxis with LMWH received by patients before commencement of Aspirin) with the average length of stay for those patients who did not suffer a VTE of 6.8 days compared with 7.6 days for those who did suffer a VTE.

CONCLUSION

Our results support the use of aspirin as an effective form of prophylaxis against symptomatic VTE following THA in contradiction to NICE and American Academy of Orthopaedic Surgery (AAOS) recommendations. It is not associated with an increased incidence in symptomatic DVT, PE or death compared to other published studies. The fact that it is inexpensive, readily available, requires no monitoring and does not pose an increased risk of bleeding are other advantages of using aspirin for VTE prophylaxis.

Aspirin thromboprophylaxis following primary total knee arthroplasty is associated with a lower rate of early prosthetic joint infection compared with other agents

BACKGROUND

Patients undergoing total knee arthroplasty (TKA) are at increased risk of venous thromboembolism (VTE). Aspirin has been shown to be effective at reducing rates of VTE. In select patients, more potent thromboprophylaxis is indicated, which has been associated with increased rates of bleeding and wound complications. This study aimed to evaluate the effect of thromboprophylaxis choice on rates of early prosthetic joint infection (PJI) following TKA.

METHODS

A review of 11,547 primary TKA patients from 2013 to 2019 at a single academic orthopaedic hospital was conducted. The primary outcome measure was PJI within 90 days of surgery as measured by Musculoskeletal Infection Society criteria. There were 59 (0.5%) patients diagnosed with early PJI. Chi-square and Welch-Two Sample t-tests were used to determine statistically significant relationships between thromboprophylaxis and demographic variables. Significance was set at p<0.05. Multivariate logistic regression adjusted for age, body mass index, sex, and Charlson comorbidity index was performed to identify and control for independent risk factors for early PJI.

RESULTS

There was a statistically significant difference in the rates of early PJI between the aspirin and non-aspirin group (0.3 vs 0.8%, p<0.001). Multivariate logistic regressions revealed that patients given aspirin thromboprophylaxis had significantly lower odds of PJI (odds ratios (OR)=0.51, 95% Confidence Interval (CI) 0.29 to 0.89, p=0.019) compared to non-aspirin patients.

CONCLUSIONS

The use of aspirin thromboprophylaxis following primary TKA is independently associated with a lower rate of early PJIs. Arthroplasty surgeons should consider aspirin as the gold standard thromboprophylaxis in all patients in which it is deemed medically appropriate and should carefully weigh the morbidity of PJI in patients when non-aspirin thromboprophylaxis is considered.

Comparison of 90-Day Adverse Events Associated With Aspirin and Potent Anticoagulation Use for Venous Thromboembolism Prophylaxis: A Cohort Study of 72,288 Total Knee and 35,142 Total Hip Arthroplasty Patients

BACKGROUND

While aspirin is acceptable for venous thromboembolism (VTE) prophylaxis following total joint arthroplasty in most patients, more potent agents are used in patients considered higher risk for VTE. We evaluated the efficacy and safety of aspirin versus potent anticoagulation agents following total knee arthroplasty (TKA) and total hip arthroplasty (THA).

METHODS

A cohort study of 72,288 TKA and 35,142 THA from the Kaiser Permanente Total Joint Replacement Registry was performed (2009 to 2019). Identified medications were aspirin, factor Xa inhibitors, low-molecular-weight heparin (LMWH), and warfarin. A validated VTE risk score was assigned to each patient. Propensity score-weighted logistic regressions were used to evaluate 90-day VTEs. Noninferiority testing was performed with a margin of 1.25 using the upper bound (UB) of the 1-sided 95% CI.

RESULTS

For TKA, aspirin was not inferior to LMWH (odds ratio [OR] = 0.77, UB = 1.09) and warfarin (OR = 0.64, UB = 0.90); there was no evidence to support noninferiority of aspirin compared to factor Xa inhibitors. Findings were consistent for THA (LMWH: OR = 0.59, UB = 0.75; warfarin: OR = 0.69, UB = 0.89). TKA was considered higher risk for VTE, whereas aspirin use demonstrated noninferiority compared to warfarin (OR = 0.54, UB = 0.81), we lacked evidence of noninferiority when compared to LMWH and factor Xa inhibitors. We lacked evidence of noninferiority of aspirin versus any potent anticoagulation in higher-risk THA.

CONCLUSION

Aspirin was found to be effective and safe for VTE prevention in primary total joint arthroplasty, including in patients considered higher risk for VTE.

LEVEL OF EVIDENCE

III.

2022 American Association of Hip and Knee Surgeons Symposium: Periprosthetic Joint Infection

Periprosthetic joint infection (PJI) is the leading cause of failure in patients undergoing total joint arthroplasty. This article is a brief summary of a symposium on PJI that was presented at the annual AAHKS meeting. It will provide an overview of current technqiues in the prevention, diagnosis, and management of PJI. It will also highlight emerging technologies in this setting.

Patient characteristics and procedural variables are associated with length of stay and hospital cost among unilateral primary total hip arthroplasty patients: a single-center retrospective cohort study

BACKGROUND

Total hip arthroplasty (THA) is a successful treatment for many hip diseases. Length of stay (LOS) and hospital cost are crucial parameters to quantify the medical efficacy and quality of unilateral primary THA patients. Clinical variables associated with LOS and hospital costs haven't been investigated thoroughly.

METHODS

The present study retrospectively explored the contributors of LOS and hospital costs among a total of 452 unilateral primary THA patients from January 2019 to January 2020. All patients received conventional in-house rehabilitation services within our institute prior to discharge. Outcome parameters included LOS and hospital cost while clinical variables included patient characteristics and procedural variables. Multivariable linear regression analysis was performed to assess the association between outcome parameters and clinical variables by controlling confounding factors. Moreover, we analyzed patients in two groups according to their diagnosis with femur neck fracture (FNF) (confine THA) or non-FNF (elective THA) separately.

RESULTS

Among all 452 eligible participants (266 females and 186 males; age 57.05 ± 15.99 year-old), 145 (32.08%) patients diagnosed with FNF and 307 (67.92%) diagnosed with non-FNF were analyzed separately. Multivariable linear regression analysis revealed that clinical variables including surgery duration, transfusion, and comorbidity (stroke) among the elective THA patients while the approach and comorbidities (stoke, diabetes mellitus, coronary heart disease) among the confine THA patients were associated with a prolonged LOS (P < 0.05). Variables including the American Society of Anesthesiologists classification (ASA), duration, blood loss, and transfusion among the elective THA while the approach, duration, blood loss, transfusion, catheter, and comorbidities (stoke and coronary heart disease) among the confine THA were associated with higher hospital cost (P < 0.05). The results revealed that variables were associated with LOS and hospital cost at different degrees among both elective and confine THA.

CONCLUSIONS

Specific clinical variables of the patient characteristics and procedural variables are associated the LOS and hospital cost, which may be different between the elective and confine THA patients. The findings may indicate that evaluation and identification of detailed perioperative factors are beneficial in managing perioperative preparation, adjusting patients' anticipation, decreasing LOS, and reducing hospital cost.

Time to Venous Thromboembolism Events Following Total Hip Arthroplasty: A Comparison Between Aspirin and Warfarin

BACKGROUND

The attitude and approach of orthopedic community for minimizing venous thromboembolism (VTE) has evolved over the last decade with the trend toward use of aspirin (and mechanical modalities) in lieu of aggressive anticoagulation. The optimal length of VTE prophylaxis following total hip arthroplasty (THA) still remains unknown. This study aimed to determine the timing of VTE in patients who received aspirin compared to warfarin, and determine if 30 days of prophylaxis remain adequate.

METHODS

This is a retrospective study of 18,003 patients undergoing primary and revision THA at a single institution between January 2008 and August 2020. During this time, our institution underwent a transition from the use of warfarin to aspirin as the main method for VTE prophylaxis. Symptomatic deep vein thrombosis and pulmonary embolism occurring within 90 days of surgery were identified from medical records and phone call logs. Aspirin and warfarin cohorts were matched to account for demographic and comorbidity differences. Timing of pulmonary embolism was determined based on either the date of diagnostic imaging or patient-provider phone calls confirming diagnosis.

RESULTS

The cohorts included 46 patients in the warfarin group and 46 in the aspirin group. Time to VTE was significantly shorter in the warfarin group compared to aspirin (P = .021) with a median time to VTE of 3 days (interquartile range 2-14) and 10 days (interquartile range 4-19) respectively. Over 90% of the events occurred within 32 or 30 days of surgery in the warfarin and aspirin groups respectively.

CONCLUSION

Based on the findings, a 30-day aspirin prophylaxis remains appropriate for patients undergoing THA.

Aspirin Administered for Venous Thromboembolism Prophylaxis May Protect Against Stiffness Following Total Knee Arthroplasty

BACKGROUND

Aspirin has become the main agent for venous thromboembolism (VTE) prophylaxis following total knee arthroplasty (TKA). This study assessed whether aspirin is associated with less knee stiffness compared to warfarin and other chemoprophylaxis agents.

METHODS

This is a retrospective review of all primary and revision TKAs performed between January 2009 and October 2020 at a high volume institution. Demographics, comorbidity data, and operative variables were extracted from medical records. VTE prophylaxis administered during this time period included aspirin, warfarin, and "others" (factor Xa, unfractionated heparin, low-molecular-weight heparin, fondaparinux, adenosine diphosphate receptor inhibitor, and direct thrombin inhibitor). The primary outcome assessed was manipulation under anesthesia (MUA) performed within 6 months of index surgery. Secondary outcome included major bleeding events. Univariate followed by multivariate regression analyses were performed.

RESULTS

A total of 15,903 cases were included in the study, of which 531 (3.3%) patients developed stiffness that required MUA. The rates of MUA were 2.7% (251/9223) for patients receiving aspirin, 4.2% (238/5709) for patients receiving warfarin, and 4.3% (42/971) for all others (P's < .001). Multivariate regression analysis confirmed that aspirin is associated with lower rates of VTE compared to warfarin (adjusted odds ratio 1.423, 95% confidence interval 1.158-1.747, P < .001) and compared to other anticoagulation medications (adjusted odds ratio 1.742, 95% confidence interval 1.122-2.704, P = .013). Major bleeding events were also significantly lower in patients who received aspirin compared to the other 2 groups (P's = .001).

CONCLUSION

Aspirin prophylaxis is associated with lower rates of MUA following TKA compared to warfarin and other VTE chemoprophylactic agents when grouped together.

Negative Association of Subclinical Hypothyroidism on Improvement in Patient-Reported Outcomes After Total Knee Arthroplasty

BACKGROUND

The purpose of this study is to analyze the potential influence of subclinical hypothyroidism (SCH) on improvement in patient-reported outcome measures following primary total knee arthroplasty.

METHODS

A prospective, comparative cohort study between 92 SCH and 90 euthyroid patients was performed. Patients were followed up to 5 postoperative years. Patient-reported outcome measure was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. The Knee Society Scores were used for functional evaluation, and 5-point Likert scale for patient satisfaction. The Hospital Anxiety and Depression scale was also used.

RESULTS

All outcome scores significantly improved from preoperative to final follow-up in both groups (P = .001). There were no significant differences between groups in Knee Society Scores (P = .057) at the final follow-up, but Western Ontario and McMaster Universities Osteoarthritis Index scores were significantly lower in the SCH group (P = .015). Likewise, the patient satisfaction rate was significant lower in the SCH group (0.010).

CONCLUSION

SCH patients have a slower functional recovery than euthyroid patients, and trended toward lower improvements in patient-reported scores. Depression was the most important negative factor. The findings of this study can provide the surgeon with an important information for better counseling the SCH patients.