Extended-duration thromboprophylaxis with enoxaparin after arthroscopic surgery of the anterior cruciate ligament: a prospective, randomized, placebo-controlled study.
OBJECTIVE
To compare the efficacy of extended-duration thromboprophylaxis with enoxaparin for 20 days in the outpatient setting with in-hospital thromboprophylaxis with enoxaparin (3 to 8 days) only in patients who had undergone arthroscopic surgery of the anterior cruciate ligament (ACL).


METHODS
This was a single-center, randomized, double-blind, prospective trial investigating 175 ACL surgery patients. All patients received subcutaneous enoxaparin 40 mg once daily 12 to 18 hours presurgery and 3 to 8 days postsurgery during hospitalization. After discharge, patients were randomized to 40 mg enoxaparin (n = 87) or placebo (n = 88) self-administered once daily subcutaneously for 20 days. The primary efficacy end-points were the incidences of symptomatic and asymptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE). Primary safety endpoints were the incidences of major and minor bleeding.


RESULTS
Thirty-five patients were excluded because of noncompliance with the predefined protocol. No patient had DVT confirmed by magnetic resonance venography (MRV) at discharge. Of 140 patients in the intention-to-treat population, 2 (2.8%) who received postdischarge enoxaparin (n = 72) and 28 (41.2%) who received placebo (n = 68) had DVT confirmed by MRV (P < .001). No patients were diagnosed with PE. No major bleeds occurred. Minor bleeding occurred in 13 (2.5%) out of 513 postdischarge enoxaparin injections and 10 (2.0%) out of 492 placebo injections (P = .595). Risk factors for DVT during the 20 days postdischarge were age >30 years (odds ratio [OR]: 3.241; 95% confidence interval [CI], 1.015 to 10.349) and immobilization before surgery (OR 18.195; 95% CI, 2.046 to 161.837).


CONCLUSIONS
Extended-duration postdischarge thromboprophylaxis for 20 days with enoxaparin in the outpatient setting significantly reduced the incidence of DVT in ACL surgery patients compared with enoxaparin limited to in-hospital thromboprophylaxis without increasing major or minor bleeding.


METHODS
Level I, high-quality randomized controlled trial.
Marlovits
Stefan
S
Department of Traumatology, General Hospital, Medical University of Vienna, Vienna, Austria. stefan.marlovits@meduniwien.ac.at
Striessnig
Gabriele
G
Schuster
Raimund
R
Stocker
Roland
R
Luxl
Monika
M
Trattnig
Siegfried
S
Vécsei
Vilmos
V
D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D001182:Arthroscopy / Q000009:adverse effects / Q000379:methods; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D017984:Enoxaparin / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D007279:Injections, Subcutaneous; D007718:Knee Injuries / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods*; D011446:Prospective Studies; D012307:Risk Factors; D013927:Thrombosis / Q000209:etiology / Q000517:prevention & control*; D016896:Treatment Outcome
D000925:Anticoagulants; D017984:Enoxaparin