Should postoperative thromboprophylaxis be used after anterior cruciate ligament reconstruction?

Objectives: Anterior cruciate ligament (ACL) reconstruction is the ligament surgery that is performed most often in France. The French Society of Anesthesia-Resuscitation (SFAR) recommends systematic thromboprophylaxis in the postoperative period. The objective of this study was to evaluate the incidence of symptomatic phlebitis after ACL reconstruction. The hypothesis was that it is the same with or without thromboprophylaxis. Methods: This was a retrospective multicentric, multi-operator, case control study. Of the four operators concerned, two did not prescribe postoperative thromboprophylaxis except in special cases (major risk factors) and two prescribed low molecular weight heparin for ten days. All patients who underwent primary ACL reconstruction surgery between 1 July 2018 and 15 February 2020 were followed up by telephone within a minimum of 3 months. All follow-up letters were also consulted to cross-check information. All patients with a history of thromboembolic events (TE) or those who had undergone multiple ligament surgery were excluded. Results: 249 patients were re-contacted in the anticoagulant free group and 221 in the anticoagulant group. The 2 groups were similar. The mean age was 29 years. 60% were male. There were 2 cases of phlebitis in each group. The initial hypothesis was therefore confirmed with an equivalent incidence of symptomatic phlebitis with or without postoperative anticoagulation. In fact, the incidence of symptomatic TE reported with or without thromboprophylaxis in the different Swedish, American and English registries varied from 0.2 to 0.5%, whereas in studies to identify asymptomatic TE, the incidence was 9 to 14%. Our study has some limitations, notably due to the retrospective nature and the absence of ultrasound analysis. However, loss of information is low given that the study is recent and considering the study population. Furthermore, we identified no risk factors. Conclusion: The incidence of symptomatic phlebitis after ACL reconstruction is equivalent with or without thromboprophylaxis. This raises the question of the need for postoperative thromboprophylaxis, particularly in patients without risk factors. National recommendations could be made based on these findings and those in the international literature.