Low frequency of symptomatic venous thromboembolism after multiligamentous knee reconstruction with thromboprophylaxis

Background: Reconstruction of the multiligament-injured knee often involves extended surgical and tourniquet use times and often is performed in patients who have sustained concomitant fractures as well as vascular injuries, all of which would appear to predispose the patient to the potentially serious complications of deep vein thrombosis and perhaps pulmonary embolism, yet little is known about the frequency of venous thromboembolic (VTE) events after multiligamentous knee reconstruction. Questions/purposes: The purposes of this study were to (1) determine the frequency of symptomatic VTE after multiligamentous knee reconstruction at a single institution; and (2) to determine associated risk factors for VTE in these patients. Methods: The records of 134 (63% of the 213 consented individuals in our longitudinal database) patients who underwent primary (129 [96%]) or revision (five [4%]) multiligamentous knee reconstruction at a single institution between 1992 and 2013 were retrospectively reviewed. With two patients undergoing procedures bilaterally, this resulted in a total of 136 multiligamentous knee reconstructions. VTE for which clinical symptoms were evident and confirmed by imaging within 3 months after the reconstructive procedure was noted. Pre- and perioperative data were collected with respect to demographics, associated injuries, medical history, smoking status, and surgical data. Standard rehabilitation and thromboprophylaxis protocols were used in all patients. Results: Three cases of symptomatic VTE (three deep vein thromboses) occurred after the 136 reconstructions (2%; 95% confidence interval, 0.53%-7.3%). Two of the three patients were obese and the remaining patient smoked and abused alcohol. However, as a result of a low frequency of VTE, no risk factors could be identified in this series. Conclusions: Symptomatic VTE occurred in 2% of multiligamentous knee reconstructions at our institution while receiving thromboprophylaxis. This is similar to rates documented after anterior cruciate ligament reconstruction without thromboprophylaxis. Further multicenter research is required to identify the true frequency of and risk factors for developing VTE in patients undergoing multiligamentous knee reconstruction after knee dislocation. Level of Evidence: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.