Influence Factors Of Calf Muscular Vein Thrombosis After Total Knee Arthroplasty And Its Prevention And Treatment

Background:With the wide application of ultrasonic examination and orthopedists’ awareness of the lower extremity deep vein thrombosis(DVT) improved, a growing number of orthopedic patients are diagnosed with calf muscular vein thrombosis(CMVT) during perioperative period. CMVT was firstly put forward by British scholars in 1965, but our research on CMVT has just begun. Some foreign scholars think that CMVT may be naturally ablated and rarely cause pulmonary embolism and other serious complications, while another study shows that there are approximately 5%-33% of patients with pulmonary embolism are related with CMVT. Once pulmonary embolism happens, it would seriously endanger the safety of patients. Therefore, orthopedic surgeons should pay enough attention to patients suffering from CMVT and ensure them to go through the perioperative period safely. Calf muscular vein thrombosis((CMVT) is one of the common complications after total knee arthroplasty(TKA), which imposes a serious threat to the lives and health of patients and causes further economic pressure and mental burden for patients. The TKA itself is one high risk factor that causes CMVT, therefore, the identification of such risk factors after TKA surgeries is important. It can guide the measures taken before operations, prevent the occurrence of CMVT, improve the prognosis of patients and enhance the quality of their life. Objective:By way of the retrospective analysis of medical records of patients who had accepted the knee arthroplasty in the department of orthopaedics in Shanxi Dayi Hospital, the objective is to discuss the influencing factors for the causing of lower extremity calf muscular venous thrombosis(CMVT) after total knee arthroplasty, and accordingly put forward possible solutions to clinical prevention and treatment so as to reduce the incidence of CMVT and further prevent the occurrence of pulmonary embolism. Methods:By adopting the method of retrospective analysis, this research has studied the cases of patients who were hospitalized and accepted the knee arthroplasty in the department of orthopaedics in Shanxi Dayi Hospital from November, 2011 to September, 2015. For patients with any suspected symptoms of CMVT after TKA surgery, such as pain in lower legs, swelling, discomfort in walking or Homans’ positive sign in physical examination, both lower extremities are examined via vascular doppler ultrasound to make a definite diagnosis of postoperative CMVT. Statistical analysis software SPSS19.0 and Microsoft Excel2007 are used to check and process the result data. The analysis of risk factors for the causing of CMVT after total knee arthroplasty includes clinical characteristics of the research object, relevant laboratory, auxiliary examination results and related operation index. Also, in the study of risk factors of CMVT occurrence after total knee arthroplasty, enumeration data adopts chi-square test while the measurement data employs t test; Multiple factors analysis uses the unconditioned Logistic regression analysis and either analytical or testing method regards P < 0.05 as the difference which has the standard of statistical significance. Results:The study includes 97 patients, among which 33 are male and 64 are female. Their average age is in the range of(68.04 + 8.541). In the clinical data, it is analyzed that among patients, the age range of 71-80(c2=7.323,OR=6.175,P=0.014), body mass index(BMI) > 25(c2=5.701,OR=2.193,P=0.017), duration time of postoperative indwelling drainage tube >72 hours(c2=13.335,OR=5.063,P=0.001) and serum triglyceride levels≥1.7mmol/L(c2=10.173,OR=6.933,P=0.001)have statistical difference and they are risk factors that cause muscular venous thrombosis after knee arthroplasty. In other general clinical characteristics, gender, smoking or not, combined diabetes mellitus and combined hypertension have no statistical difference(P >0.05). Preoperative blood lipid results show that the total cholesterol level of two groups of patients has statistical difference(c2=6.781, OR=5.192, P=0.009). Other operation indexes, such as the amount of arthroplastic joints and operation time have no statistical difference(P > 0.05). When taking age, body mass index, postoperative indwelling drainage time, triglyceride, total cholesterol level into multiple factors analysis, the results prove that the age range of 71-80(c2=5.64 OR=7.553,P=0.018) and the duration time of postoperative indwelling drainage tube which is over 72 hours(c2=8.79, OR=9.476,P=0.003) are independent risk factors causing muscular venous thrombosis after knee arthroplasty. Conclusions:1. Advanced age of patients and long duration of postoperative indwelling drainage tube are independent risk factors causing CMVT after knee arthroplasty.2. Patients, whose serum triglyceride level and total cholesterol level are a little bit higher than those with normal plasma lipid in preoperative blood lipid test, have higher risks in developing CMVT after TKA surgery. However, higher levels of triglyceride and total cholesterol are not the independent risk factors to cause CMVT.