Wound Discharge After Pharmacological Thromboprophylaxis in Lower Limb Arthroplasty

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.

Administration of Prophylactic Enoxaparin on the Morning of Surgery Does Not Increase Risk of Blood Transfusion or Wound Drainage Following Internal Fixation of Geriatric Femur Fractures

BACKGROUND

Despite standard use of chemoprophylaxis, 30-day incidence of venous thromboembolism after geriatric, those older than 60 years, femur fracture surgery is reported to be up to 10%. Missing one dose of enoxaparin has been proven to increase the risk of developing venous thromboembolism. It is commonplace to hold preoperative chemoprophylaxis the morning of surgery because of concern for intraoperative bleeding or wound drainage. We sought to determine whether administration of prophylactic enoxaparin the morning of surgery resulted in an increased rate of blood transfusion or wound drainage in geriatric patients undergoing femur fracture treatment.

METHODS

We retrospectively reviewed patients older than 60 years who underwent internal fixation of an isolated femur fracture, including femoral neck, intertrochanteric, subtrochanteric, femoral shaft, and distal femur fractures, at a Level 1 trauma center. Medical records, hospital billing data, and radiographs were reviewed to determine patient characteristics such as Charlson Comorbidity Index, enoxaparin dosing, packed red blood cell transfusion, and persistent wound drainage, defined as any drainage requiring utilization of closed incision negative pressure wound therapy. Thirty-day mortality served as the secondary outcome measure.

RESULTS

Five hundred seven patients were included. One hundred sixty-four (32%) received enoxaparin on the morning of surgery, whereas 343 (68%) did not. 27% of patients received PRBC transfusion, and this did not differ between groups (27% vs. 28%, P = 0.72). Subgroup analysis of fixation strategies revealed no difference in the frequency of blood transfusion for any fixation type as related to the timing of enoxaparin dosage. Utilization of closed incision negative pressure wound therapy for the treatment of postoperative wound drainage did not differ between dosing groups. No difference was observed in thirty-day mortality between groups (2.4% vs. 2.7%, P = 0.9).

DISCUSSION

Administration of a prophylactic dose of enoxaparin on the morning of surgery does not seem to increase the rate of postoperative blood transfusion or wound drainage after fixation of geriatric femur fracture.

LEVEL OF EVIDENCE

Level III, therapeutic.

Quality evaluation of clinical practice guidelines for thromboprophylaxis in orthopaedic trauma based on AGREE II and AGREE-REX: a systematic review protocol

INTRODUCTION

Orthopaedic trauma patients are at high risk of venous thromboembolism (VTE). As VTE prophylaxis has gradually raised public concerns, guidelines related to this topic have increased over time. However, the existing recommendations of thromboprophylaxis guidelines in orthopaedic trauma patients are still inconsistent, and the quality of the guidelines and recommendations for the topic still lacks comprehensive assessments. This review aims to critically appraise clinical practice guidelines for thromboprophylaxis in orthopaedic trauma patients.

METHODS AND ANALYSIS

We will conduct a comprehensive literature search up to 31 October 2022 in databases (PubMed, EMBASE, CINAHL, Web of Science, the Cochrane Library, etc), academic websites and guideline repositories. The quality of the guidelines and recommendations will be assessed by five reviewers independently using the Appraisal of Guidelines Research and Evaluation II instrument (AGREE-II) and the AGREE - Recommendation EXcellence (AGREE-REX). We will summarise the characteristics of the guidelines and compare the differences between these recommendations.

ETHICS AND DISSEMINATION

This study will follow the Declaration of Helsinki and has received approval from the Ethics Committee on Biomedical Research, West China Hospital, Sichuan University (ethics approval no. 2021-989). The results will be summarised as a paper, disseminated through peer-reviewed journals, and will help guide further research in the future.

PROTOCOL REGISTRATION NUMBER

CRD42021273405.

The draining surgical wound post total hip and knee arthroplasty: what are my options? A narrative review

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are successful orthopaedic procedures with an ever-increasing demand annually worldwide, and persistent wound drainage (PWD) is a well-known complication following these procedures. Despite many definitions for PWD having been proposed, a validated description remains elusive.

PWD is a risk factor for periprosthetic joint infection (PJI). PJI is a devastating complication of THA and TKA, and a leading cause of revision surgery with dramatic morbidity and mortality and a significant burden on health socioeconomics.

Prevention of PJI has become an essential focus in THA and TKA. Understanding the pathophysiology, risk factors and subsequent management of PWD may aid in decreasing the rate of PJI.

Risk factors of PWD can be divided into modifiable and non-modifiable patient risk factors, pharmacological and surgical risk factors. No gold standard treatment protocol to address PWD exists; however, non-operative options progressing to surgical interventions have been described.

The aim of this study was to review the current literature regarding PWD and consolidate the risk factors and management strategies available.

Cite this article: EFORT Open Rev 2021;6:872-880. DOI: 10.1302/2058-5241.6.200054

Venous thromboembolism prophylaxis in patients undergoing knee replacements: comparison of real-world outcomes

Background Increasing evidence for the use of the aspirin in patients undergoing an orthopaedic surgery for venous thromboembolism prophylaxis has led to a change in the national guidelines substituting anticoagulants with aspirin. Little is known about the impact of such substitution on real-world outcomes from clinical practice. Objective The study was designed to examine clinical outcomes associated with the use of aspirin and apixaban. Setting Two large-scale general hospitals in West Yorkshire region of England. Method A 1-year observational study among adults who underwent elective knee replacements and received venous thromboembolism prophylaxis within the first 14 days post replacements. Main outcome measure The incidence of postoperative venous thromboembolism, leaking wounds during the hospital stay, and 30-day any readmission for the two drugs. Results A total of 420 patients were included. There was a significant drop in apixaban prescribing (from 80.37 to 10.51%) and increase in aspirin use (from 19.02 to 81.71%) after the implementation of the revised guidelines. There were 52 (12.38%) cases of leaking wound, 16 (3.81%) cases of postoperative venous thromboembolism, 45 (10.71%) cases of 30-day readmission and no case of 30-day major bleeding. The leaking wounds and 30-day readmissions were almost twice more frequent in obese compared to non-obese patients. Multivariate logistic regression found an increased risk of leaking wound with apixaban and postoperative venous thromboembolism and 30-day readmission with aspirin use but the differences were not statistically significant. Conclusion The results suggest aspirin to be as effective as apixaban in preventing venous thromboembolism and readmission. Apixaban usage decreased with a corresponding increase in Aspirin use. The impact of obesity and length of hospital stay need further investigations.

Tissue Adhesive for Wound Closure Reduces Immediate Postoperative Wound Dressing Changes After Primary TKA: A Randomized Controlled Study in Simultaneous Bilateral TKA

BACKGROUND

Prolonged wound drainage after TKA is associated with increased risk of infection. To decrease wound drainage, tissue adhesive has been suggested as an adjunct to wound closure after TKA; however, no studies of which we are aware have investigated the effect of tissue adhesive in a modern fast-track TKA setting.

QUESTIONS/PURPOSES

The purpose of this study was to evaluate the effect of wound closure using a high-viscosity tissue adhesive in simultaneous bilateral TKA with respect to (1) postoperative wound drainage, measured as number of dressing changes in the first 72 hours postoperatively; and (2) wound healing assessed using the ASEPSIS score.

METHODS

Thirty patients undergoing simultaneous bilateral TKA were included in the study. The left knee was randomized to receive either standard three-layer closure with staples or the same closure supplemented with tissue adhesive with the opposite treatment used on the contralateral knee. One patient underwent a constrained TKA and underwent revision 2 days after the index procedure and was therefore excluded leaving 29 patients (58 knees) for analysis. Sixty-two percent (n = 18) were female. Mean age was 64 years (range, 42-78 years). Mean body mass index was 28 kg/m (range, 21-38 kg/m). Postoperative wound drainage was evaluated as drainage resulting in a dressing change. The wound dressing was changed if it was soaked to the borders of the absorbable dressing at any point. The nurses changing the dressing were blinded to treatment allocation up to the first dressing change. The number of dressing changes during the first 72 hours postoperatively was recorded. The secondary study endpoint was the ASEPSIS score, which is a clinical score assessing wound healing. ASEPSIS score, measured by a nurse not involved in the treatment, was compared between the groups at 3 weeks followup.

RESULTS

Knees with tissue adhesive underwent fewer dressing changes (median, 0; interquartile range [IQR], 0-1) compared with the contralateral knee (IQR, 1-2; difference of medians, one dressing change; p = 0.001). A total of 59% of knees in the intervention group did not undergo any dressing changes before discharge, whereas 24% of knees in the control group did not undergo any dressing changes before discharge (p = 0.02). The knees in the intervention group and the control group did not differ with respect to ASEPSIS score at 3 weeks.

CONCLUSIONS

Tissue adhesive as an adjunct to standard wound closure after primary TKA reduced the number of dressing changes after surgery, but did not change the appearance or healing of the wound at 3 weeks based on the ASEPSIS scores. Whether the small differences observed here in terms of the number of dressing changes performed will justify the additional costs associated with using this product or whether there are other differences associated with the use of tissue adhesive that may prove important such as patient preferences or longer term differences in wound healing or infection should be studied in the future.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Low-Dose Aspirin Is Safe and Effective for Venous Thromboembolism Prophylaxis Following Total Knee Arthroplasty

BACKGROUND

Aspirin is an effective prophylaxis for venous thromboembolism (VTE) after total knee arthroplasty (TKA). The optimal prophylactic aspirin dose has not been established. The study aims to compare 2 aspirin regimens with regard to the incidence of (1) symptomatic deep venous thrombosis (DVT), (2) pulmonary embolism (PE), (3) bleeding, and (4) mortality within 90 days after TKA.

METHODS

We retrospectively identified 5666 patients who received aspirin twice daily for 4 to 6 weeks after TKA. A total of 1327 patients received 81-mg BID and 4339 patients received 325-mg BID aspirin. Postoperative complications collected were VTEs (DVT and PE), bleeding (gastrointestinal or wound bleeding), and mortality.

RESULTS

The incidence of VTE was 1.5% in the 325-mg group and 0.7% in the 81-mg group (P = .02). Symptomatic DVT was 1.4% in the 325-mg aspirin compared with 0.3% for the 81-mg aspirin (P = .0009). Regression model showed no correlation between aspirin dose and VTE incidence (odds ratio [OR] = 1.03; 95% confidence interval [95% CI], 0.45-2.36; P = .94) or DVT (OR = 0.50; 95% CI, 0.16-1.55; P = .20). The incidence of PE was 0.2% in the high-aspirin group compared with 0.4% in the low-aspirin group (P = .13). Bleeding was 0.2% in the 325-mg aspirin group and 0.2% in the 81-mg aspirin group (P = .62), and 90-day mortality was similar (0.1%) between the groups (P = .56).

CONCLUSION

Low-dose aspirin was not inferior to high-dose aspirin for the prevention of VTE after TKA. Low-dose aspirin can be considered a safe and effective agent in the prevention of VTE after TKA.