ObjectiveTo explore the effects of cryopreservation on the cell survival rate, cell viability, early apoptosis, migration ability, and tendon-related marker expression of tendon-derived stem cells (TDSCs) in rat patellar tendons.MethodsThe patellar tendon tissues were harvested from 12 4-month-old male Sprague Dawley rats; 12 patellar tendon tissues from 6 rats were cryopreserved (the experimental group), and the other 12 patellar tendon tissues were not treated (the control group). The patellar tendons were digested with 0.3% type I collagenase to obtain nucleated cells. The survival rate of nucleated cells was detected by trypan blue exclusion assay, and colony-forming ability by crystal violet staining. TDSCs were isolated and cultured to passage 3 (P3). The cell viability of TDSCs was detected by Alamar Blue method, the early apoptosis by Annexin V-FITC/PI assay, the cell migration ability by Transwell method, and the mRNA expressions of tendon-related markers [collagen type I (Col1α1), scleraxis (Scx), and tenomodulin (Tnmd)] by real-time quantitative PCR.ResultsThe survival rate of nucleated cells was 91.00%±3.63% in the control group, and was 61.65%±4.76% in the experimental group, showing significant difference (t=12.010, P=0.000). The formation of the primary nucleated cell clones was observed in 2 groups. At 12 days, the number of colonies forming of the experimental group [(8.41±0.33)/1 000 nucleated cells] was significantly lower than that of the control group [(15.19±0.47)/1 000 nucleated cells] (t=28.910, P=0.000). The percentage of TDSCs in the active nucleated cells in the experimental group (1.37%±0.09%) was significantly lower than that in the control group (1.67%±0.10%) (t=5.508, P=0.003). The growth trend of TDSCs (P3) in the 2 groups was consistent within 14 days. There was no significant difference in absorbance (A) value between 2 groups at each time point (P>0.05). The early apoptotic rate of TDSCs was 1.67%±0.06% in the experimental group and was 1.63%±0.06% in the control group, showing no significant difference (t=0.707, P=0.519). Under microscope, TDSCs adhered to the lower chamber of the Transwell chamber; the number of cells was 445.00±9.70 in the experimental group and was 451.50±12.66 in the control group, showing no significant difference (t=0.998, P=0.342). The relative mRNA expressions of Col1α1, Scx, and Tnmd were 3.498±0.065, 0.062±0.002, and (4.211±0.211)×10–5 in the experimental group and were 3.499±0.113, 0.062±0.001, and (4.341±0.274)×10–5 in the con-trol group, showing no significant difference (t=0.013, P=0.991; t=0.042, P=0.969; t=0.653, P=0.549).ConclusionThe survival rate of nucleated cells in cryopreserved rat tendon tissues is lower, but a large number of active TDSCs, and its cell viability, early apoptosis rate, migration ability in vitro, and cell tenogenic differentiation ability are remained.
ObjectiveTo analyze the risk factors for postoperative mortality of the elderly patients with femoral neck fracture undergoing hemiarthroplasty.MethodsPatients who underwent hemiarthroplasty for femoral neck fractures between January 2011 and December 2015 were enrolled as object. One hundred and nine patients who met the selection criteria were included in the study, and the clinical data were collected, including gender, age, time from admission to surgery, comorbidities, and preoperative hemoglobin level and nutritional status. Univariate analysis and Cox proportional hazard regression model were used to screen the risk factors for postoperative mortality.ResultsThe 1-year and 2-year mortalities were 6.4% (7/109) and 17.4% (19/109), respectively. Univariate analysis showed that the age, preoperative hemoglobin level and nutritional status were the influencing factors of postoperative mortality in the elderly patients with femoral neck fractures treated with hemiarthroplasty (P<0.05). Multivariate analysis showed that the age≥80 years and malnutrition were the independent risk factors for postoperative mortality (P<0.05).ConclusionTo improve the clinical outcomes, perioperative risk should be comprehensively evaluated by multidisciplinary and perioperative management should be strengthened in the elderly patients with femoral neck fracture, especially those with advanced age and malnutrition, for the high postoperative mortality.
ObjectiveTo analyze the risk factors for postoperative mortality of elder patients with intertrochanteric fractures.MethodsPatients with intertrochanteric fractures who underwent proximal femoral interlocking intramedullary nail fixation between January 2014 and December 2015 were enrolled in the study. Among them, 135 patients who met the selection criteria were included in the study, and the clinical data were collected, including gender, age, time from admission to surgery, comorbidities, and preoperative hemoglobin, albumin, and total lymphocyte count (TLC), and nutritional status. Univariate analysis and Cox proportional hazards regression model were used to screen the risk factors for postoperative mortality.ResultsTwenty-seven patients (20.0%) died within 2 years after surgery, and 16 (11.9%) died within 1 year after surgery. Univariate analysis showed that age, coronary atherosclerotic heart disease, number of comorbidities, preoperative hemoglobin and albumin levels were the influencing factors of postoperative mortality in elder patients with intertrochanteric fractures treated with proximal femoral interlocking intramedullary nail fixation (P<0.05). Multivariate analysis showed that age (≥80 years), combined more than 2 medical diseases, and preoperative albumin (<35 g/L) were the independent risk factors for postoperative mortality (P<0.05).ConclusionTo improve the clinical outcomes, perioperative risk should be comprehensively evaluated and perioperative management strengthened in the elder patients with intertrochanteric fractures, especially those with advanced age, more combined diseases, and low albumin, for the high postoperative mortality.