Objective To investigate the biomechanical characteristics of Salto Talaris tibial components with different heights at the bone-prosthesis interface during different gait support phases after total ankle replacement.Methods An ankle joint model was reconstructed using a weight-bearing CT from a 61-year-old female patient with ankle arthritis,and Salto Talaris tibial components with different heights(5,7,9,11 mm)were modelled to simulate the loading of the tibial-prosthesis during four gait support phases,and to analyse the micromotion and stresses at the bone-prosthesis interface.Results The 11 mm and 9 mm models had a poorer prosthesis stability,with the peak micromotion exceeding 50 μm and the peak internal tibial stresses of 30.75 MPa and 29.86 MPa,respectively,which exceeded the yield stress of the cancellous bone.The tibial stresses of the 7 mm and 5 mm models were within reasonable ranges and the average peak micromotions were only 42.66 μm and 40.32 μm.In contrast,the initial stability of the 5 mm model prosthesis was the best.Conclusions For total ankle replacement with Salto prosthesis,the height of the tibial component should be chosen appropriately,and the optimal height was about 5 mm.Excessive flexion and extension activities of the ankle joint should be avoided to maintain the stability of the prosthesis after surgery.This study provides a theoretical basis for the improvement of the structural parameters of the Salto prosthesis,which is valuable for the selection of clinical surgical prostheses and helps to improve the results of total ankle replacement.

Objective To investigate the biomechanical characteristics of Salto Talaris tibial components with different heights at the bone-prosthesis interface during different gait support phases after total ankle replacement.Methods An ankle joint model was reconstructed using a weight-bearing CT from a 61-year-old female patient with ankle arthritis,and Salto Talaris tibial components with different heights(5,7,9,11 mm)were modelled to simulate the loading of the tibial-prosthesis during four gait support phases,and to analyse the micromotion and stresses at the bone-prosthesis interface.Results The 11 mm and 9 mm models had a poorer prosthesis stability,with the peak micromotion exceeding 50 μm and the peak internal tibial stresses of 30.75 MPa and 29.86 MPa,respectively,which exceeded the yield stress of the cancellous bone.The tibial stresses of the 7 mm and 5 mm models were within reasonable ranges and the average peak micromotions were only 42.66 μm and 40.32 μm.In contrast,the initial stability of the 5 mm model prosthesis was the best.Conclusions For total ankle replacement with Salto prosthesis,the height of the tibial component should be chosen appropriately,and the optimal height was about 5 mm.Excessive flexion and extension activities of the ankle joint should be avoided to maintain the stability of the prosthesis after surgery.This study provides a theoretical basis for the improvement of the structural parameters of the Salto prosthesis,which is valuable for the selection of clinical surgical prostheses and helps to improve the results of total ankle replacement.

Objective:To evaluate the efficacy of preoperative neoadjuvant chemoradiotherapy for low and locally advanced rectal cancer.Methods:Clinical data of 46 patients with low rectal tumors located within 6 cm from the edge of anal admitted to our hospital between February 2014 and December 2018 were retrospectively analyzed. SIB-IMRT technique was adopted for preoperative radiotherapy. Rectal tumors and positive lymph nodes were irradiated with a dose of 58.75 Gy in 25 fractions (2.35 Gy/fraction), and pelvic lymphatic drainage area was given with 50 Gy in 25 fractions (2.0 Gy/fraction). Oral administration of capecitabine was delivered for concurrent chemotherapy. Radical surgery for rectal cancer was performed at 6 to 12 weeks after the end of chemoradiotherapy. The overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), local recurrence-free survival (LRFS) and metastasis-free survival (MFS) were calculated by using Kaplan- Meier method. Univariate analysis was conducted by log-rank test, and multivariate analysis was performed by Cox’s regression model. Results:After a median follow-up of 47 months, local recurrence occurred in 3 patients and distant metastasis in 6 patients. The ypCR rate was 26%(12/46), the sphincter-preservation rate was 74%(34/46), the R 0 resection rate was 100%(44/44), the overall tumor response TN down staging rate was 87%(40/46), and the postoperative complication rate was 13%(6/46). The 3-year OS, DFS, and PFS were 93%, 91% and 87%, respectively. In univariate analysis, ypN staging was an important factor affecting OS, DFS, PFS, LRFS and MFS (all P<0.05). In multivariate analysis, ypN staging was significantly correlated with DFS, PFS, LRFS and MFS (all P<0.05). Conclusions:Preoperative SIB-IMRT 58.75 Gy in 25 fractions combined with capecitabine chemotherapy is a safe and efficacious treatment for patients with low and locally advanced rectal cancer, which improves the ypCR rate and quality of life, and yields tolerable adverse reactions. Nevertheless, the long-term survival benefits remain to be validated.

Objective To evaluate the feasibility and clinical efficacy of preoperative simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) combined with neoadjuvant chemotherapy of capecitabine in patients with locally-advanced low rectal cancer.Methods Between 2015 and 2016,26 patients admitted to 301 Hospital who were diagnosed with locally-advanced low rectal cancer,which was located within 5 cm from the anal verge,were enrolled in this investigation.Dose fractionation pattern was delivered:58.75 Gy in 25 fractions (2.35 Gy/fraction) for rectal cancer and lymph node metastasis and 50 Gy in 25 fractions for the pelvic lymphatic drainage area and simultaneously combined with capecitabine chemotherapy (825 mg/m2,bid d 1-5 weekly).One cycle of capecitabine (1 250 mg/m2,twice daily,d 1-14)was given at one week after the completion of chemoradiotherapy (CRT).Total mesorectal excision (TME)was performed at 6 to 8 weeks after the completion of CRT.The primary endpoints included pathological complete response rate (ypCR) and sphincter-preserving rate.The secondary endpoints included acute toxicity,tumor downstaging rate and postoperative complications.Results Twenty-six patients successfully completed neoadjuvant CRT,25 of them underwent surgical resection and one patient failed to receive surgery due to pxrianal edema.Postoperative ypCR rate was 32％ (8/25),the sphincter-preserving rate was 60％ (15/25),the tumor downstaging rate was 92％ (23/25) and the R0 resection rate was 100％.During the period of CRT,grade 1 and 2 adverse events occurred in 24 patients,grade 3 radiation dermatitis was noted in 2 cases.No ≥ grade 4 acute adverse event was observed.Postoperative complications included ureteral injury in one case and intestinal obstruction in one patient.Conclusions Preoperative SIB-IMRT combined with neoadjuvant chemotherapy of capecitabine is a feasible and safe treatment for patients with locallyadvanced low rectal cancer,which yields expected ypCR rate,R0 resection rate and sphincter-preserving rate.Nevertheless,the long-term clinical benefits remain to be elucidated.Clinical Trial Registry Chinese Clinical Trial Registry,registration number:ChiCTR-ONC-12002387.

Objective To investigate the mechanism of Glutathione in the prevention of ventilator-associated lung injury.Methods 30 mechanical ventilation patients who were healthy before were selected and randomly divided into the two groups.Group A was the high tidal volume group:10mL/kg;group B was used the tidal volume plus the injection of Glutathione(2.4g/d).After 48 hours,we collected lavage fluid and use Coomassie brilliant blue to detect the protein content of alveolar lavage fluid of the two groups.Results There was a significant difference (P<0.01)between the two groups.The protein content in group A[(9.90 ±2.25)g/L]was higher than that of group B [(4.17 ±0.39)g/L],and there was statistically significant (P<0.01).Conclusion Glutathione can reduce the incidence of ventilator-associated lung injury and prevent the occurrence of ventilator-associated lung injury.

Objective To investigate the clinical efficacy of noninvasive positive pressure ventilation for eld-erly patients with chronic obstructive pulmonary disease and respiratory failure.Methods A total of 64 elderly patients with chronic obstructive pulmonary disease and respiratory failure were collected.The patients were treated with conventional therapy,while using BiPAP ventilator line through the nose and mouth mask bilevel noninvasive pos-itive pressure ventilation therapy,and to give effective care.After treatment for 3d,the pH,PaO2 ,PaCO2 ,SaO2 index changes,respiration,heart rate changes and APACHE Ⅱ,GCS and accessory muscle score were observed.Adverse reactions were recorded.Results Before treatment the PH value of patient was (7.30 ±0.06),which significantly increased to (7.36 ±0.03 )after treatment,PaO2 values was significantly increased to (43.58 ±5.54)from (84.52 ±8.27),SaO2 value was significantly increased to (94.93 ±5.61)from (74.86 ±7.25),PaCO2 value from (71.69 ±8.48)decreased to (42.55 ±6.23).There was statistically significant before and after treatment (t =5.98,6.35,4.86,7.23,all P <0.05),respiratory rate,heart rate were significantly improved,showing a significant difference (t =4.87,5.32,all P <0.05 ),APACHE Ⅱ,GCS and accessory muscle scores were significantly improved,which APACHEⅡ,accessory muscle score was significantly lower,GCS score was significantly increased, were statistically significant (t =4.09,4.01,4.33,all P <0.05).Conclusion It shows that noninvasive positive pressure ventilation combined with conventional drug therapy can improve elderly patients with chronic obstructive pulmonary disease and respiratory failure in patients with clinical symptoms,increase ventilation and improve hyper-capnia,clinical efficacy is better,with no serious adverse reactions.