Objective:To study the effects of ascorbic acid on BMP-2 mRNA expression of osteoblast cell sheets.Methods:Rat os-teoblasts were primaryly cultured and identified;osteoblast cell sheets were built by physical scraping method in vitro;the osteoblast cell sheets were cultured with 1 5,50 and 85 mg/L ascorbic acid for 1 and 2 weeks respectively,and the expression of BMP-2 mRNA of the cell sheets was detected by RT-qPCR.Results:The obtained cells were conformed to be osteoblasts.The osteoblast cell sheets could be rolled into tube in vitro.The expression of BMP-2 mRNA of osteoblast cell sheets in experiment group,whether in week one or week two was higher than that in control group,50 mg/L group showed the highest expression(first week P <0.05;second week P>0.05);the expression of any group in week two was higher than that in week one(P <0.05).Conclusion:Ascorbic acid may pro-mote the expression of BMP-2 mRNA in osteoblast cell sheets.

Objective: To investigate the clinical efficacy of tight suturing for shortening healing scar tissues in repair of Myerson type III old rupture of Achilles tendon. Methods: A retrospective case series study was performed to analyze the clinical data of 16 patients with Myerson III type chronic Achilles tendon ruptures admitted to Sports Hospital Affiliated to Chengdu Sport University from January 2015 to December 2017. All of the patients were males with sports injuries, aged 19-71 years (mean, 40.6 years). The Achilles tendon defect was 5-7 centimeter (mean, 5.2 centimeter). The patients received tight suturing and shortening healing scar tissue for the repair. The operation time and surgical wound size were recorded. The clinical efficacy was evaluated by Amer-Lindholm standard and American 0rthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score. Meanwhile, the complications such as wound infection, Achilles tendon re-rupture, heel lifting weakness, muscle strength decline, ankle dysfunction, lameness and symptoms of sural nerve injury were recorded. Results: All patients were followed up for 11-41 months, with an average of 26 months. The operation time ranged from 25-51 minutes, with an average of 37 minutes. The incision was 4-12 cm, averaging 7 cm. According to the Amer-Lindholm standard, 14 patients were graded as excellent and two were graded as good, with the excellent and good rate of 100%. AOFAS ankle-hindfoot score increased from (42.7±6.8)points before operation to (95.1±4.9)points at the last follow-up (P<0.05). During the follow-up, there were no complications such as infection, Achilles tendon rupture, heel lifting weakness, muscle strength decline, ankle joint dysfunction, lameness and gastrocnemial nerve injury. Conclusion For Myerson type III old rupture of Achilles tendon, tight suturing for shortening healing scar tissue can increase the postoperative function scores without wound infection or complications.