OBJECTIVETo investigate the influence of ozonated water on physical and chemical properties of vacuum sealing drainage (VSD) materials.

METHODSVSD materials (foam and sealing membrane) were immersed in 10 µg/ml ozonated water for 1 h twice daily for 8 days. The foam appearance and microscopic structure of the materials were observed, and tensile tests and Raman spectrum scan were performed assess the effect of ozonated water. Simulated VSD devices were prepared and tested for leakproofness under negative pressure after ozonated water treatment.

RESULTSzonated water treatment for 8 days caused no obvious abnormal changes in the foam appearance or microscopic structure of the materials. The maximum tensile load of foam before and after ozonated water treatment was 4.25∓0.73 kgf and 2.44∓0.19 kgf (P=0.000), the momentary distance when the foam torn before and after intervention was 92.54∓12.83 mm and 64.44∓4.60 mm, respectively (P=0.000). The corresponding results for VSD sealing membrane were 0.70∓0.58 kgf and 0.71∓0.08 kgf (P=0.698), and 99.30∓10.27 mm and 100.95∓18.22 mm (P=0.966), respectively. Raman spectroscopy revealed changes in only several wave intensities and no new chemical groups appeared within the scan range of 400-4000 cm(-1). The VSD device was well hermetic after treatment with ozonated water.

CONCLUSIONExcept for a decreased stretch resistance property of the foam, VSD materials display no obvious changes in physical and chemical characteristics after treatment with ozonated water for 8 days.

Biomedical and Dental Materials ; chemistry ; Drainage ; instrumentation ; methods ; Ozone ; Vacuum ; Water ; chemistry

Objective To compare the efficacy between intramedullary nail and plate in the internal fixation for distal tibial shaft fractures in adults.Methods A retrospective analysis was conducted of the 49 patients with distal tibial shaft fracture who had been treated by internal fixation with intramedullary nail or plate at Department of Orthopaedics,The First People's Hospital of Neijiang from September 2014 to September 2018.They were 26 males and 23 females,aged from 19 to 71 years (average,42.3 years).According to the AO/ ASIF classification,there were 34 cases of type 43A1 and 15 cases of type 43A2.There were 7 open and 42 closed fractures.Of them,23 received intramedullary nailing and 26 steel plating.The 2 groups were compared in terms of intraoperative blood loss,operation time,hospitalization time,fracture healing time,The American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score,infection and fracturemalunion.Results The 2 groups were comparable because there were no significant differences in the preoperative general data between them(P ＞ 0.05).The intraoperative blood loss in the intramedullary nail group (160.3 mL ± 15.2 mL) was significantly greater than that in the plate group (110.5 mL ± 13.4 mL) (P ＜ 0.05).There were no significant differences between the 2 groups in operation time,hospitalization time,fracture healing time or AOFAS ankle-hindfoot scores at the final follow-up (P ＞ 0.05).There were no significant differences between the 2 groups either in the rates of malunion,infection or internal fixation failure (P ＞ 0.05).Five cases in the intramedullary nail group reported painful discomfort in the front of the knee joint while 7 cases in the plate group postoperative discomfort due to plate protrusion.Conclusions Both intramedullary nail and plate are effective treatments of adult distal tibial fracture.However,in order to minimize the risk of infection,intraoperative maneuvers should be as careful and gentle as possible,repeated violence be avoided and soft tissues be carefully protected.