BACKGROUND: Studies have confirmed that titanium dioxide coating can improve the adhesion of implant surface, promote osteoblast proliferation and other cell functions, and improve the bone integration ability between the surrounding bone and implant. But little has been done in the use of titanium dioxide coating as a coating for internal and external fixation to prevent screw loosening. OBJECTIVE: To prepare titanium dioxide coated titanium screws and to observe the effect of titanium dioxide coated titanium screws used for bone fixation to reduce screw loosening. METHODS: Titanium dioxide coating was prepared on the surface of titanium screw by anodic oxidation. Thirty male New Zealand white rabbits (provided by the Central Laboratory of Shanghai Putuo District Central Hospital in China) were randomly divided into two groups (n=15 per group). Titanium dioxide coated screws were implanted in the right tibia of the rabbits in the experimental group, and ordinary titanium screws were implanted in the right tibia of the rabbits in the control group. Bone tissue around the screw canal was taken at 1 day, 1 and 4 weeks after implantation, and levels of platelet-derived growth factor and vascular endothelial growth factor genes were detected using RT-PCR. Four weeks after implantation, bone tissue around the nail canal was taken for hematoxylin-eosin staining. RESULTS AND CONCLUSION: (1) The results of hematoxylin-eosin staining showed that inflammatory cell infiltration was seen in the screw canal of the control group, and some screw canal threads were destroyed and absorbed. In the experimental group, the screw threads were clear and had no damage or absorption; inflammatory cells in the screw canal were less exuded. (2) RT-PCR analysis revealed no significant difference in the expression of platelet-derived growth factor and vascular endothelial growth factor gene between the two groups at 1 day after implantation (P> 0.05), while the expression of platelet-derived growth factor and vascular endothelial growth factor gene in the experimental group was significantly higher than that in the control group at 1 and 4 weeks after implantation (P < 0.05 or P < 0.01). Therefore, titanium dioxide coated titanium screws are more biocompatible than common titanium screws and can effectively prevent screw loosening when used for internal fixation.

Objective:To investigate the influences of anxiety on postoperative efficacy in elderly patients with complex proximal humerus fractures.Methods:A retrospective case control study was conducted to analyze the clinical data of 297 elderly patients with complex proximal humerus fractures admitted to 5 tertiary hospitals in Shanghai from January 2017 to December 2018. There were 121 males and 176 females, aged 65-85 years [(74.2±8.5)years]. The fracture types included Neer type III in 176 patients and Neer type IV in 121 patients. Two days after admission, patients were analyzed by self-rating anxiety scale (SAS) and anxiety factors questionnaire (participated by Shanghai Mental Health Center) and they were divided into anxiety group (SAS>35) and nonanxiety group (SAS≤35). Anxiety group included 68 patients, among which 7 had conservative treatments. Nonanxiety group contained 229 patients, among which 7 had conservative treatments. Both groups underwent with proximal reduction of humerus fractures accepted the operations. Operative patient in both groups underwent open reduction and plate fixation. The surgery rate and length of hospital stay were compared between groups. After 1 year of follow-up, Constant-Murley score was used to evaluate the effect of shoulder joint and dual-energy X-ray absorptiometry (DXA) was taken to observe the wrist joint bone mineral density. Postoperative complications were recorded.Results:All operative patients were followed up for 10-28 months, with an average of 13.6 months. The surgery rate was 89.7% (61/68) in anxiety group and 96.9% (222/229) in nonanxiety group ( P<0.05). The hospital stay was (6.8±3.4)days for non-surgery patients and (10.2±2.8)days for surgery patients in anxiety group and (4.2±1.6)days for non-surgery patients and (7.4±2.2)days for surgery patients in nonanxiety group ( P<0.05). In anxiety group and nonanxiety group, the excellent and good rate of Constant-Murley score was respective 75.4% (46/61) and 88.3% (196/222) and the wrist joint bone mineral density was respective (-3.1±0.5)SD and (-2.9±0.6)SD (both P<0.05). The incidence of complications was 8.2% (5/61) in anxiety group and 4.5% (10/222) in nonanxiety group ( P>0.05). Conclusions:Anxiety has a significant negative influence on the surgery rate, length of hospital stay, shoulder joint function, wrist joint bone mineral density. Intervention on anxiety in elderly patients with complex proximal humerus fractures should be valued attention by clinical orthopedic surgeons.