Perioperative Venous Thromboembolism And Postoperative Pulmonary Complications Of Total Joint Arthroplasty

Chapter 1:The incidence of venous thromboembolism following total knee arthroplasty:a prospective study by using computed tomographic pulmonary angiography in combination with bilateral lower limb venography.Purpose:Venous thromboembolism (VTE), presenting as deep vein thrombosis (DVT) and pulmonary embolism (PE), is one of the major complications following total knee arthroplasty (TKA). We conducted this prospective observational study to identify the prevalence of VTE among patients undergoing TKA by using computed tomographic pulmonary angiography (CTPA) in combination with bilateral lower limb venography. Methods:We enrolled consecutive patients admitted to our institution for primary unilateral TKA from September 2013 to July 2014. All participants underwent a standard surgical procedure of TKA. CTPA and bilateral lower limb venography were performed within a week after operation. We compared age, gender, BMI, comorbidities, data of laboratory tests, operation time and thromboprophylaxis between VTE group and non-VTE group to identify the risk factors.Results:A total of 109 patients were enrolled in this study. The incidence of symptomatic DVT, asymptomatic DVT, symptomatic PE and asymptomatic PE following TKA were 4.6%,18.3%,1.8% and 1.8% respectively. Elevated level of D-dimer was significantly associated with postoperative VTE.Conclusions:The incidence of VTE following TKA was high despite thromboprophylaxis, and asymptomatic DVTs accounted for a large proportion of thrombotic events.Chapter 2:The preoperative incidence of deep vein thrombosis (DVT) and its correlation with postoperative DVT in patients undergoing elective surgery for femoral neck fracturesIntroduction:Data on the incidence of preoperative deep vein thrombosis (DVT) in patients, who are waiting for elective hip replacement for femoral neck fractures, are limited. Our primary goal was to determine the prevalence and risk factors of preoperative DVT in acute hip fracture patients awaiting hemi-or total hip arthroplasty using venography. The secondary objective was to find a possible relationship between preoperative and postoperative DVT.Methods:We enrolled 119 consecutive patients with subcapital femoral neck fracture, who were awaiting hip replacement at our institution. All of them received venography before and after surgery. We used univariate analysis and multivariate logistic regression analysis to identify the risk factors for preoperative DVT.Results:Of the patients,35 patients (29.4%) developed DVT in affected limbs before surgery. Both long duration of immobilization and increased level of D-dimer were associated with preoperative DVT independently. Intriguingly,66.7% of patients who were diagnosed with DVT after surgery had thrombus in the same location as they did before surgery.Conclusions:We identified the high incidence and risk factors of preoperative DVT in patients awaiting elective surgery for femoral neck fractures. The majority of patients diagnosed with DVT postoperatively had already had thrombus before surgery.Chapter 3:Metabolic syndrome and deep vein thrombosis following total knee and hip arthroplastyBackground:Metabolic syndrome (MS), defined as obesity, hypertension, hyperglycemia and dyslipidemia, is prevalent among patients undergoing total joint arthroplasty (TJA). MS has proven to promote a proinflammatory and prothrombotic state in patients. Venous thromboembolism (VTE) is one of the major complications of TJA. The purpose of this retrospective study is to identify whether MS and its components increase the risk of deep vein thrombosis (DVT) following TJA.Methods:We retrospectively reviewed 1553 patients undergoing primary unilateral TJA from 2007 to 2014. MS was diagnosed based on the World Health Organization (WHO) criteria. All subjects received venography after operation to screen for DVT. Symptomatic DVT events following TJA were also recorded. Univariate analysis and multivariate logistic regression analysis were used to identify the association of MS and its components with postoperative DVT.Results:The prevalence of MS in patients undergoing TJA was 5.1%(n=79). A total of 335 patients (21.6%) were diagnosed with DVT by venography. Seventy-eight patients (5.0%) developed symptomatic DVT. In the total knee arthroplasty (TKA) group, MS and obesity were related to postoperative DVT. MS alone was found to be associated with symptomatic DVT. In the total hip arthroplasty (THA) group, MS increased the risk of symptomatic DVT. However, Obesity, rather than MS, was associated with total DVT following THA.Conclusions:MS was a significant risk factor for DVT following TJA. Strategies to minimize the adverse effect of MS should be considered for these patients.Chapter 4:Early pulmonary complications following total knee arthroplasty under general anesthesia:a prospective cohort study using CT scanPurpose:Postoperative pulmonary complications (PPCs), including respiratory failure, pneumonia, pleural effusion, atelectasis, pneumothorax and aspiration pneumonitis, are common after major surgeries. However, the number of studies regarding PPCs following total knee arthroplasty (TKA) is limited. The aim of this study was to determine the incidence of early PPCs following TKA by computed tomography (CT) scan and to identify associated risk factors.Methods:Patients, who were diagnosed with osteoarthritis (OA) or rheumatoid arthritis (RA) and underwent primary TKA at our institution between September 2013 and July 2014, were included into this prospective cohort study. Patients received a standard procedure of TKA under general anesthesia. Chest CT scan was performed during 5-7 days after surgery. Univariate analysis and multivariate logistic regression analysis were employed to identify the risk factors.Results:The total incidence of early PPCs following TKA was 45.9%. Rates of pneumonia, pleural effusion, and atelectasis were 14.4%,38.7%, and 12.6%, respectively. Lower body mass index (BMI) and perioperative blood transfusion were independent risk factors for PPCs as a whole and associated with atelectasis. Postoperative acute episode of hypoxemia increased the risk of pneumonia. Blood transfusion alone was related to pleural effusion.Conclusions:The incidence of early PPCs following TKA was high. For patients with relevant risk factors, positive measures should be adopted to prevent PPCs.