Micro Electromechanical System Navigation Assists Femoral Extramedullary Alignment Osteotomy in Total Knee Arthroplasty: A Single‐Blind Randomizing Study

Objective A micro‐electromechanical system (MEMS) was developed based on spatial alignment and navigation technology to assist femoral extramedullary alignment osteotomy (FEAO) in total knee arthroplasty (TKA). The system can locate and adjust the femoral distal condylar osteotomy (FDCO) to obtain a better femoral prosthesis placement. It is a portable navigation device and provides an innovative approach for FDCO. Methods Sixty patients who suffered from severe knee osteoarthritis who underwent unilateral TKA from May 14, 2021 to May 30, 2022 were randomly divided into a MEMS‐FEAO group and a conventional femoral intramedullary alignment osteotomy (FIAO) group, with 30 cases in each group for a controlled retrospective study. The hip‐knee‐ankle angle (HKAA) of the lower limb was measured before and after surgery, the femoral valgus angle (FVA) was measured preoperatively, and the femoral prosthesis valgus angle (FPVA) and the femoral prosthesis flexion angle (FPFA) were measured postoperatively following computed tomography imaging protocols. Measurement data is statistically described as mean ± standard deviation c. The count data is described by frequency (constituent ratio) using the rank sum test. Result A total of 6.7% (2/30) of FEAO compared to 20.0% (6/30) of FIAO cases were postoperative deviations where the HKAA exceeded ±3° of neutral alignment (p  0.05), and there was no statistical significance between the two groups. Conclusion The MEMS‐FEAO system can improve the accurate alignment and can be utilized as a locator to obtain the best femoral prosthesis placement in TKA and significantly reduce the rate of poor force line of the lower limb

Exogenous damage causes cell DNA damage through mediated reactive oxygen levels

Many anti-tumor drugs can induce tumor apoptosis by increasing intracellular ROS. In the present study, we build a model which did not directly cause DNA damage, but simulated damage products. The model of this injury was transferred into the cell so that the cell’s damage recognition mechanism mistakenly recognized that its own DNA was damaged, which in turn induced a response. Based on this model, the damaged plasmids (exogenous DNA damage) were transferred into the cells and the amount of reactive oxygen in the cells was improved, and DNA damage of the cells was increased. Therefore, exogenous DNA damage can affect the accumulation of damage in cells by affecting the level of reactive oxygen species, which provides a reference for DNA damage repair research

Rad51 stabilizes the ends of two adjacent DSBs in yeast

DNA double-strand breaks (DSBs) are a major form of DNA damage, and its accurate repair is critical for maintaining genomic stability and preventing cancer. Repair of DSBs is mainly through two pathways, homology-directed DNA repair (HDR) and non-homologous end joining (NHEJ). Compared with NHEJ, HDR has higher fidelity, so the study of interrelated factors in homologous recombination pathway is of particularly important. In this paper, we constructed an I-SceI model controlled by a galactose promoter that produces a DSB or two adjacent DSBs on a single chromosome. Rad50 and Rad51 genes are further deleted in these models. Sensitivity experiments show that Rad51 stabilizes the ends of two adjacent DSBs in yeast. Deletion of Rad51 gene causes the sequence between two adjacent DSBs to drop out directly to form a large gap. If this gap is larger, the efficiency of NHEJ will be greatly reduced, resulting in the deaths of the strain. Our research shows that Rad51 stabilizes the ends of two adjacent DSBs in yeast