Summary

We investigated the incidence of deep venous thrombosis (DVT) and pulmonary embolism after arthroscopically assisted anterior cruciate ligament reconstruction using ultrasonography and contrast enhanced computed tomography, and identified the risk factors for DVT.

Abstract

Introduction

Arthroscopically assisted anterior cruciate ligament reconstruction (ACLR) is commonly performed for the treatment of anterior cruciate ligament (ACL) injury. Deep venous thrombosis (DVT) and pulmonary embolism (PE) are potential life-threatening complications following ACLR. However, the incidence of the DVT and PE, and the risk factors for DVT are unclear. The objective of this study was to investigate the incidence of DVT and PE after ACLR using ultrasonography (US) and contrast enhanced computed tomography (CT), and to identify the risk factors for DVT.

Methods

Between April 2017 and August 2018, 53 ACLRs of 53 consecutive patients, including 10 revision surgeries, were performed at our hospital. Twenty-seven females and Twenty-six males were enrolled. None had a previous history of DVT or PE. All of the ACLRs were performed by the same surgeon; under general anesthesia with femoral and sciatic nerve blocks, and tourniquet use. ACLs were reconstructed using single bundle hamstring autograft. Postoperatively, knee immobilization was used for one day for patients without meniscus repair, and for five days for patients with meniscus repair. On the seventh postoperative day, full weight bearing was started. Although none received pharmacological prophylaxis, compression stockings were used. US of the leg veins was performed preoperatively and on the seventh postoperative day, to detect DVT. If the patient was diagnosed as having DVT on the seventh postoperative day, contrast enhanced CT was conducted to detect PE. US was performed by a well-experienced vascular surgeon. Clinical and surgical data including age, body mass index (BMI), preoperative Lysholm score, time interval from injury to ACLR, operative time, tourniquet time, and meniscus repair were recorded, and compared between the patients with and without DVT.

Results

Among all the patients, the mean age, BMI and preoperative Lysholm score were 30.3 years, 22.6 kg/m2 and 71.5, respectively. The time interval from injury to ACLR was more than 3 months in 33 of 53 patients. The mean operative and tourniquet times were 81.2 min and 68.7 min, respectively. Meniscus repair was performed in 19 of 53 patients. Although no DVT was detected before the ACLR, distal DVT was detected in 9 patients (17.0%) postoperatively. Of the 9 patients, 4 patients (7.5%) had PE. All of the patients with DVT and PE were asymptomatic. When comparing patients with and without DVT, the age was significantly higher in patients with DVT (p<0.001). The mean age of the patients with and without DVT were 41.9 years and 27.9 years, respectively.

Discussion

In our study, the incidence of DVT and PE were 17.0% and 7.5% respectively. It was unexpectedly high suggesting a need for thromboprophylaxis. Pharmacological prophylaxis such as low-molecular-weight heparin is effective for reducing DVT after knee arthroscopy. However, routine pharmacologic prophylaxis remains controversial. Since the age was identified as risk factor for DVT in this study, the patients with the risk factor should be considered for pharmacological prophylaxis after ACLR.