This study is to estimate the risk factors of VTEs after knee arthroscopic surgery, and to identify high-risk groups, helping guide future stratifications of thromboprophylaxis for higher risk patients.
Knee arthroscopy is currently the most common orthopedic procedure, which has increased by nearly 50% in the past decade. However, the venous thromboembolism events (VTEs), including the occurrence of deep venous thrombosis (DTV) and pulmonary embolism (PE), are viewed as a relatively rare complication. Literature-based data on the associated risk of VTEs after knee arthroscopy without thromboprophylaxis are limited and controversial.
Objectives: To estimate the risk factors of VTEs after knee arthroscopic surgery, and to identify high-risk groups, helping guide future stratifications of thromboprophylaxis for higher risk patients.
Patients and Methods: The records of patients who underwent knee arthroscopy at the second affiliated hospital of University of South China between July 2010 and July 2015 were reviewed. Anticoagulant drugs were not routinely used. DVT was considered objectively diagnosed when symptoms and signs were present, such as calf pain or swelling on the operative side, and confirmed by positive color duplex ultrasonography. PE was confirmed by conventional venography ventilation/perfusion lung scan (V/Q scan), or computed tomography scan of the chest with intravenous contrast, and indications for chest imaging included shortness of breath or pleuritic chest pain. Considering some potential bias, a 2:1 matched case-control study was generated to include patients in whom knee arthroscopy was performed by the same surgeon, for nearly same operation time or in the same operative side. Preoperative and intraoperative data were collected including demographic data, medical history, medications, and type of surgical procedure and anesthesia. Considered potential risk factors not only include use of tobacco and alcohol, previous DTV, chronic venous insufficiency, oral contraception or hormone replacement therapy, history of trauma or surgery to the involved lower extremity ,operation time and application of tourniquet, but also with respect to the presence of multiple risk factors in a single patient. Univariate and multivariate analyses were performed.
In total, 168 VTEs patients and 336 controls were included in the analysis, 107(63.9%) patients and 201 (59.7%) controls were women. Ligament reconstructions led to a higher risk (OR 16.2, 95% CI 2.4–132) than meniscal surgery, diagnostic arthroscopy, or chondroplasty (OR 5.5, 95% CI 2.9–8.3). Tourniquet time (=60 min) (OR 12, 95% CI 1.94-73.97) and operation time (=90 min) (OR 0.92 95% CI 0.52-1.61)were risk DTE-related factors. An additionally increased risk was found for combinations potential risk factors (OR 46.6, 95% CI 6.1–353).
Our results showed that there are distinct differences in thrombosis risk per person. Further studies should be aimed at demonstrating the benefits of individualization of prophylactic treatment. Advice the patients in high risk after knee arthroscopy use Chemoprophylaxis, this may reduce thrombosis morbidity.