BACKGROUND:The greatest risk of osteoporosis in total knee arthroplastyisperioperative and long-term periprosthetic fractures. However, limited by the traditional concept of osteoarthritis patientswhousualy not associated with osteoporosis, domestic clinical trials have not given enough attention to the osteoporosis before total knee arthroplasty.
OBJECTIVE:To analyze the osteoporosis and its relative factors in osteoarthritis patients before total knee arthroplasty.
METHODS:Data of 81 cases (81 knees) of knee osteoarthritiswhounderwenttotal knee arthroplasty in the Department of Joint Surgery of Tianjin People’s Hospital from January 2012 to November 2014 were retrospectively analyzed. They received lumbar spine and hip bone mineral density examination before surgery. The correlation of bone mineral density with age, body mass index, knee motion range,and knee deformity was analyzed before surgery. The independent risk factors for osteoporosis before replacement were analyzed.
RESULTS AND CONCLUSION:(1) Of 81 patients, there were normal bone mineral density in 25 cases (31%), osteopenia in 35 cases (43%),andosteoporosis in 21 cases (26%). Al 10 males had no osteoporosis and 21 in 71 female cases suffered osteoporosis (30%). Theincidence of osteoporosis in females was significantly higher than in male patients (P=0.046). (2) There was a linear correlation of bone mineral density with age and body mass index (correlation coefficientr=-0.230, 0.225). (3) The age of≥65 years and body mass index≥25 kg/m2were independent risk factors of osteoporosis before replacement (P< 0.05). (4) Patients with knee osteoarthritis had higher incidence of osteopenia and osteoporosis before total knee arthroplasty. The degree of osteoporosis was negatively correlated with age, but positively correlated with body mass index. The age of≥65 years and body mass index < 25 kg/m2were independent risk factors for preoperative osteoporosis. Thus, bone mineral density examination is essential for those patients before total knee arthroplasty.

The diagnostic technology of acute stroke by microwave imaging has the advantages of being non-ionizing, fast, small, and low-cost. Therefore, this technology is expected to become an auxiliary or alternative means to CT and MRI technology. As the signal transmitting and receiving device of the microwave imaging system, the antenna has an important influence on the performance of the imaging system. At present, there are many antennas with different performances used in imaging systems, but there is a lack of clear evaluation criteria for them. In this paper, several typical antennas were introduced, their advantages and disadvantages from the perspective of bandwidth and near-field were analyzed, and the common requirements of imaging systems for antennas and the performance indicators of various types of imaging systems were summarized. Moreover, the development trend of antenna technology for microwave imaging was pointed out to provide a reference for the study of stroke microwave imaging technology.

OBJECTIVE: To analyze the correlation of lipoprotein(a) [Lp(a)] with the clinical stability and severity of coronary artery stenosis in patients with coronary artery disease (CAD). METHODS: A total of 531 patients undergoing coronary angiography in Nanfang Hospital between January, 2013 and December, 2016 were enrolled in this study. At the cutoff Lp(a) concentration of 300 mg/L, the patients were divided into high Lp(a) group (=191) and low Lp(a) group (=340). In each group, the patients with an established diagnosis of CAD based on coronary angiography findings were further divided into stable angina pectoris (SAP) group and acute coronary syndrome (ACS) group. The correlation between the severity of coronary artery stenosis and Lp(a) was evaluated. RESULTS: The patients in high and low Lp(a) groups showed no significant differences in age, gender, body mass index, smoking status, hypertension, or diabetes (>0.05). Multivariate logistic regression analysis revealed that age, gender, and serum levels of low-density lipoprotein cholesterol (LDL-C) and Lp(a) were independent risk factors for CAD in these patients. A high Lp(a) level was associated with an increased risk of CAD (OR=2.443, 95%CI: 1.205-4.951, =0.013). The patients with a high Lp(a) level were at a significantly higher risk of CAD than those with a low Lp(a) level irrespective of a low or high level of LDL-C (=0.006 and 0.020). In the patients with CAD, the ACS group had a significantly higher Lp(a) level than the SAP group ( < 0.001); the proportion of the patients with high Gensini scores was significantly greater in high Lp(a) group than in low Lp(a) group (17.3% vs 5.6%, =0.026), and a linear relationship was found between Lp(a) level and Gensini score (R=0.130, =0.006). CONCLUSIONS Serum level of Lp(a) is an independent risk factor for CAD, and an increased Lp(a) is the residual risk for CAD. In patients with CAD, a high Lp(a) level is associated with the clinical instability and severity of coronary artery stenosis.
Acute Coronary Syndrome ; blood ; Angina Pectoris ; blood ; Cholesterol, LDL ; blood ; Coronary Angiography ; Coronary Artery Disease ; blood ; classification ; Coronary Stenosis ; blood ; pathology ; Humans ; Lipoprotein(a) ; blood ; Regression Analysis ; Risk Factors ; Severity of Illness Index