ABSTRACT
In the past 4 decades, many articles have reported on the effects of the piezoelectric effect on bone formation and the research progress of piezoelectric biomaterials in orthopedics. The purpose of this study is to comprehensively evaluate all existing research and latest developments in the field of bone piezoelectricity, and to explore potential research directions in this area. To assess the overall trend in this field over the past 40 years, this study comprehensively collected literature reviews in this field using a literature retrieval program, applied bibliometric methods and visual analysis using CiteSpace and R language, and identified and investigated publications based on publication year (1984-2022), type of literature, language, country, institution, author, journal, keywords, and citation counts. The results show that the most productive countries in this field are China, the United States, and Italy. The journal with the most publications in the field of bone piezoelectricity is the International Journal of Oral & Maxillofacial Implants, followed by Implant Dentistry. The most productive authors are Lanceros-Méndez S, followed by Sohn D.S. Further research on the results obtained leads to the conclusion that the research direction of this field mainly includes piezoelectric surgery, piezoelectric bone tissue engineering scaffold, manufacturing artificial cochleae for hearing loss patients, among which the piezoelectric bone tissue engineering scaffold is the main research direction in this field. The piezoelectric materials involved in this direction mainly include polyhydroxybutyrate valerate, PVDF, and BaTiO3.
ABSTRACT
In recent years, perovskite has received increasing attention in the medical field. However, there has been a lack of related bibliometric analysis in this research field. This study aims to analyse the research status and hot topics of perovskite in the medical field from a bibliometric perspective and explore the research direction of perovskite. This study collected 1852 records of perovskite research in the medical field from 1983 to 2022 in the Web of Science (WOS) database. The country, institution, journal, cited references, and keywords were analysed using CiteSpace, VOS viewer, and Bibliometrix software. The number of articles related to perovskite research in the medical field has been increasing every year. China and USA have published the most papers and are the main forces in this research field. The University of London Imperial College of Science, Technology, and Medicine is the most active institution and has contributed the most publications. ACS Applied Materials & Interfaces is the most prolific journal in this field. "Medical electronic devices", "X-rays", and "piezoelectric materials" are the most researched directions of perovskite in the medical field. "Performance", "perovskite", and "solar cells" are the most frequently used keywords in this field. Advanced Materials is the most relevant and academically influential journal for perovskite research. Halide perovskites have been a hot topic in this field in recent years and will be a future research trend. X-ray, electronic medical equipment, and medical stents are the main research directions.
ABSTRACT
OBJECTIVE: Post-operative femoral shaft fractures are often accompanied by a residual varus/valgus deformity, which can result in osteoarthritis in severe cases. The purpose of this study was to investigate the biomechanical effects of residual varus/valgus deformities after middle and lower femoral fracture on the stress distribution and contact area of knee joint. METHODS: Thin-slice CT scanning of lower extremities and MRI imaging of knee joints were obtained from a healthy adult male to establish normal lower limb model (neutral position). Then, the models of 3°, 5°, and 10° of varus/valgus were established respectively by modifying middle and lower femur of normal model. To validate the modifying, a patient-specific model, whose BMI was same to former and had 10° of varus deformity of tibia, was built and simulated under the same boundary conditions. RESULT: The contact area and maximum stress of modified models were similar to those of patient-specific model. The contact area and maximum stress of medial tibial cartilage in normal neutral position were 244.36 mm2 and 0.64 MPa, while those of lateral were 196.25 mm2 and 0.76 MPa. From 10° of valgus neutral position to 10° of varus, the contact area and maximum stress of medial tibial cartilage increased, and the lateral gradually decreased. The contact area and maximum stress of medial meniscus in normal neutral position were 110.91 mm2 and 3.24 MPa, while those of lateral were 135.83 mm2 and 3.45 MPa. The maximum stress of medial tibia subchondral bone in normal neutral position was 1.47 MPa, while that of lateral was 0.65 MPa. The variation trend of medial/lateral meniscus and subchondral bone was consistent with that of tibial plateau cartilage in the contact area and maximum stress. CONCLUSION: This study suggested that varus/valgus deformity of femur had an obvious effect on the contact area and stress distribution of knee joint, providing biomechanical evidence and deepening understanding when performing orthopedic trauma surgery or surgical correction of the already existing varus/valgus deformity.
