Orthopedic & Muscular System: Current Research
Open Access

Abstract

A Prospective, Active-control, Non-inferiority Study of the Effectiveness of Low Molecular Weight Heparin in the Prophylaxis of Postoperative Thrombotic Events in Patients Undergoing Spinal Surgery

Lunzer Andreas, Vavken Patrick and Grohs Josef Georg

Background: The Incidence of verified thrombotic events after elective spine surgery is 18%. Low-Molecular- Weight-Heparin (LMWH) is routinely given on the day before surgery. A postoperative start of the thrombotic prophylaxis could be an advantage in cases with opening of the spinal canal and for preventing epidural bleeding.
Patient and methods: This active-controlled non-inferiority trial compared the effectiveness and safety of LMWH started pre- or postoperatively in patients undergoing spinal surgery. We analysed the incidence of clinically symptomatic venous thromboembolism.
Results: A total number of 241 patients were followed over 14.6 patient-years. The incidence risk of fatal thromboembolisms was 0.011 (95%CI 0.0003 to 0.06) for the group with preoperative treatment and 0.01 (95% CI 0.0002 to 0.04) for the postoperatively treated group. The crude risk ratio was 1.65 (95%CI 0.10 to 26.03). There was no statistically significant difference in risk across groups (p=0.72). The Poisson regression model including follow-up time showed an incidence rate ratio of 0.67 (95% 0.04 to 10.74, p=0.779). There was no increased risk for complications (p=0.211).
Conclusion: This study demonstrates that the postoperative start of LMWH in the prophylaxis of thrombotic events in patients undergoing spinal surgery does not affect safety or the incidence of complications.