ABSTRACT
Objective:To explore the microRNA profile changes in the development of NKT cells.Methods: Differently developmental stage of NKT cells in mouse thymus were sorted by flow cytometry.Total RNA were extracted,reversely transcribed and pre-amplified.TaqMan low density microRNA assay and single real-time PCR were applied to detect the expression changes of microRNAs in the developmental process of NKT cells.Results: There were total 92 microRNAs whose expression changed significantly during the development and maturation of NKT cells.Among them,increasly expressed microRNAs were 71,including 36 microRNAs whose expression continuously increased;decreasly expressed microRNAs were 21,including 12 microRNAs whose expression continuously decreased.In addition,single real-time PCR analysis showed that the expression of Let-7f,miR-150,miR-24,miR-29 increased,while the expression of miR-223 and miR-155 decreased during the development and maturation of NKT cells.Conclusion: NKT development and maturation is accompanied by expression changes of large amount of microRNAs,indicating that specific microRNA regulates NKT development and function.
ABSTRACT
Objective To determine the accuracy of femoral components sizing predicted by standardized digital templating in total knee arthroplasty (TKA).Methods Fifty consecutive patients (50 knees),who underwent primary TKAs for endstage osteoarthritis,were prospectively studied.The intra-operative and radiographic data were collected.All operations were performed by the same surgical techniques with PS type,open box Vanguard Complete Knee System.All patients underwent lateral and AP radiography of the involved knee under fluoroscopy before and after surgery.The distal femoral anteroposterior dimension (DFAP) were measured and the femoral components size were predicted on preoperative radiographs by two different methods:measurement of DFAP did not include (group A) the cartilage thickness of the medial posterior condyle or included that (group B).Cutting errors were corrected gradually,and DFAP was measured consequently.The most appropriate size was chose after each step respectively based on postoperative radiographs.The accuracy of femoral size predicted under different conditions was compared within two groups.Results During correction of cutting errors,the correct rate ranged from 18％ to 44％ in group A and from 26％ to 34％ in group B,the accuracy within one size ranged from 54％ to 84％ in group A and from 58％ to 84％ in group B.The cartilage thickness of medial posterior condylar,external rotation of femoral component,under-resected of anterior condylar,flexion of femoral component,and over-resected of posterior condylar can change the DFAP by 1.97±0.85 mm,1.56±2.06 mm,1.15±1.31 mm,-2.86±1.52 mm,and-0.87±0.77 mm,respectively.Conclusion Variation of intraoperative cutting errors and the cartilage thickness of medial posterior condyles can influence the accuracy of templating to some extent.Standardized digital radiography templating cannot predict femoral sizes accurately.
ABSTRACT
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.
ABSTRACT
Objective To explore the effect of the posterior condylar offset (PCO) on clinical results after total knee arthroplasty (TKA) using a high-flex posterior-stabilized (PS) fixed-bearing prosthesis.Methods Clinical and radiographic materials of 107 consecutive female patients (107 knees),who had undergone primary TKAs for end-stage osteoarthritis was prospectively analyzed.All operations were performed by using the same operative technique.Based on the corrected PCO change,all cases were divided into two groups:66 knees in which the corrected PCO change ≥0 mm (aged 48-73 years,with an average of 61.4 years) and 41 knees in which the corrected PCO change ＜ 0 mm (aged 52-75 years,with an average of 62.2 years).One-year postoperatively,clinical and radiographic variables from the two groups were compared by independent t-test.The associations between the corrected PCO changes and the improvements of clinical variables in all patients were analyzed by Pearson linear correlation.Results The corrected PCO change was 2.49±1.71 mm in the PCO change ≥0 mm group and-1.28±1.41 mm in the PCO change ＜ 0 mm group.One-year postoperatively,the Knee Society scores,the Western Ontario and McMaster Universities Osteoarthritis Index,non-weight-bearing active and passive range of knee flexion,flexion contracture,and their improvements had no statistical differences between the two groups.The corrected PCO change was not significantly correlated with the improvement of any clinical variable.While the PCO change ≥0 mm group (130.40°± 11.63°) demonstrated greater flexion than the PCO change ＜ 0 mm group (123.80°±13.12°) during active weight-bearing one year after TKA,which was significantly different between the two groups (t=2.11,P=0.0401).Conclusion Restoration of PCO plays an important role in the optimization of active knee flexion during weight-bearing conditions after posterior-stabilized TKA,while it had no benefit to non-weight-bearing knee flexion and any other clinical result.