Objective To evaluate the clinical effect of 3D printing-assisted percutaneous screw fixation in treating unstable pelvic fracture.Methods A total of 80 patients with unstable pelvic fractures,who received treatment at the Lianyungang Municipal First People's Hospital of China from January 2022 to January 2023,were enrolled in this study.According to the surgical methods,the patients were divided into percutaneous screw fixation group(n=47,receiving 3D printing-assisted percutaneous screw fixation)and open reduction group(n=33,receiving open reduction with steel plate internal fixation).The intraoperative blood loss,time spent for surgery,total hospitalization time,fracture healing time,levels of serum creatine kinase(CK),myoglobin(Myo),lactate dehydrogenase(LDH)levels,and incidence of surgical complications were compared between the two groups.Results In the percutaneous screw fixation group,the time spent for surgery[(62.96±19.31)min vs(100.07±26.71)min],intraoperative blood loss[(112.71±25.43)mL vs(230.65±30.29)mL],total hospitalization time[(11.04±2.35)days vs(15.16±2.58)days]and fracture healing time[(102.18±9.74)days vs(113.42±11.52)days]were remarkably higher than those in the open reduction group(all P＜0.01);the postoperative 3-month total effective rate was 95.74％,which was significantly higher than 80.00％in the open reduction group(P＜0.05);and the excellent rate of fracture reduction quality was higher than that in the open reduction group(P＜0.05).The postoperative one-,3-and 6-month Majeed scores in the percutaneous screw fixation group were strikingly higher than those in the open reduction group(all P＜0.05).No statistically significant differences in the preoperative levels of CK,Myo and LHD existed between the two groups(all P＞0.05),while the postoperative levels of CK,Myo and LHD in the percutaneous screw fixation group were prominently lower than those in the open reduction group(all P＜0.05).The difference in the incidence of postoperative complications between the two groups was not statistically significant(P＞0.05).Conclusion For the treatment of unstable pelvic fracture,3D printing-assisted percutaneous screw fixation is superior to open reduction with plate internal fixation in achieving better clinical results,reducing surgical injury,and shortening postoperative recovery time.

Background: Tigecycline, eravacycline, and omadacycline are recently developed tetracyclines. Susceptibility of microbes to these tetracyclines and their molecular mechanisms have not been well elucidated. We investigated the susceptibility of Moraxella catarrhalis to tigecycline, eravacycline, and omadacycline and its resistance mechanisms against these tetracyclines. Methods: A total of 207 non-duplicate M. catarrhalis isolates were collected from different inpatients. The minimum inhibitory concentrations (MICs) of the tetracyclines were determined by broth microdilution. Tigecycline-, eravacycline-, or omadacycline-resistant isolates were induced under In Vitro pressure. The tet genes and mutations in the 16S rRNA was detected by PCR and sequencing. Results: Eravacycline had a lower MIC50 (0.06 mg/L) than tigecycline (0.125 mg/L) or omadacycline (0.125 mg/L) against M. catarrhalis isolates. We found that 136 isolates (65.7%) had the tetB gene, and 15 (7.2%) isolates were positive for tetL; however, their presence was not correlated with high tigecycline, eravacycline, or omadacycline ( ≥ 1 mg/L) MICs.Compared with the initial MIC after 160 days of induction, the MICs of tigecycline or eravacycline against three M. catarrhalis isolates increased ≥ eight-fold, while those of omadacycline against two M. catarrhalis isolates increased 64-fold. Mutations in the 16S rRNA genes (C1036T and/or G460A) were observed in omadacycline-induced resistant isolates, and increased RR (the genes encoding 16SrRNA (four copies, RR1-RR4) copy number of 16S rRNA genes with mutations was associated with increased resistance to omadacycline. Conclusions Tigecycline, eravacycline, and omadacycline exhibited robust antimicrobial effects against M. catarrhalis. Mutations in the 16S rRNA genes contributed to omadacycline resistance in M. catarrhalis.