Elsevier

The Knee

Volume 13, Issue 2, March 2006, Pages 118-121
The Knee

Evaluation of wound healing after total knee arthroplasty in a randomized prospective trial comparing fondaparinux with enoxaparin

https://doi.org/10.1016/j.knee.2005.08.010Get rights and content

Abstract

Background

Fondaparinux, a new synthetic pentasaccharide has proven to be a more potent thromboprophylactic drug compared to enoxaparin after major orthopaedic surgery. However, the safety of fondaparinux regarding wound healing has not yet been investigated.

Methods

We performed a single-centre prospective clinical trial, in which patients undergoing total knee arthroplasty or revision of at least one of the components of a previous knee arthroplasty were randomly assigned to thromboprophylaxis with fondaparinux or enoxaparin. The trial included 109 patients and wound discharge was compared. Secondary outcome measures were the amount of blood in the suction drain, postoperative transfusion rate, change in haemoglobin levels, haematocrit, intervention rate, time to regain flexion and rate of symptomatic thromboembolic events.

Results

55 patients were treated with fondaparinux and 54 with enoxaparin. Base-line characteristics were similar. In both groups wound dressings remained dry after five (5.17 ± 2.5 and 5.19 ± 3) days postoperatively. There were no significant differences in any of our outcome measures.

Conclusions

We did not find any significant difference in wound healing with fondaparinux after major knee surgery. Post hoc analyses suggested the study should have had a sample size of 155 in each group. We believe this trial should be used as a pilot study for further investigations concerning the safety of thromboprophylaxis.

Introduction

Total knee arthroplasty (TKA) is now a common treatment for disabling osteoarthritis of the knee. It successfully alleviates pain and restores function. Nevertheless it is still not without risks. Based on the results of contrast venography deep vein thrombosis occurs in 50% of patients after major knee surgery without prophylaxis [1]. The rates of venous thromboembolism (VTE) in patients receiving low-molecular weight heparins (LMWH), still one of the reference thromboprophylactic drugs, range between 15% and 33%. Recent studies proved fondaparinux, a new synthetic pentasaccharide, to be more effective. In the Pentamax trial fondaparinux reduced the rates of VTE by 55% compared to enoxaparine [2]. Since this new drug is more effective, one would expect more bleeding and wound problems. In the first studies [2], [3], [4], [5], [6], [7], [8] no significant increase in major adverse effects was found. We designed a prospective randomized trial to investigate whether there was a significant difference in wound healing. To our knowledge this is the first prospective randomized trial that assesses the safety of thromboprophylaxis regarding the surgical wound. We think that delayed wound healing can have an adverse effect on the general outcome after TKA.

Section snippets

Materials and methods

This single-centre, open-label, randomized, prospective clinical trial was approved by the head of the department for a limited period. All patients who satisfied the inclusion criteria and did not meet any of the exclusion criteria were offered enrolment between September 2003 and March 2004.

Patient population

Between September 2003 and March 2004, 202 patients underwent TKA or revision of at least one of the metal components of a previous TKA. Eighty-two (40.6%) of them did not fully meet our criteria or did not give consent for the trial. One hundred and twenty patients underwent randomisation and 11 (9.2%) of them had to be withdrawn from the trial due to difficult insertion of the epidural catheter. Analyses were performed on 109 patients (55 in the fondaparinux group, 54 in the enoxaparin group)

Interpretation

In this randomized comparison of fondaparinux with enoxaparin for thromboprophylaxis in patients requiring TKA or revision of at least one of the metal components of a previous TKA, surgical wound healing was not significantly different.

Since patients had regular contacts with nurses and members of the surgical team, follow-up throughout the study period of six weeks was 100%. Thus all events were meticulously recorded.

A drawback we should mention is the difference between the first dose of

Conflict of interest

The first author designed the study, interpreted the data and wrote the article, with the help of the two other authors. The first author is independent; the other authors do not have a significant financial interest in any company. We had to stop our trial in March 2004 due to a change in the anaesthetic protocol. The anaesthesiology department then started a trial involving fondaparinux and was sponsored by Sanofi-Synthelabo.

Acknowledgement

We would like to thank Mr. G. Tuerlinckx for his dedication and follow-up of the information charts and also special thanks to Mr. J. Nijs for his help with the statistical analysis of our data.

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