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Periprosthetic femoral fractures (PPFFs) following total hip arthroplasty (THA) present a significant clinical challenge due to their increasing incidence with an aging population and evolving surgical practices. Historically, classifications were primarily based on anatomical fracture location, the stability of the implant, and bone quality surrounding the implant. We critically analyzed 25 classification systems, highlighting the emergence and adaptations of key systems such as the Vancouver classification system (VCS) and the Unified classification system (UCS), which are lauded for their simplicity and effectiveness yet require further refinement. VCS, developed in 1995, categorizes fractures based on the site, implant stability, and bone quality, and remains widely used due to its robust applicability across different clinical settings. Introduced in 2014, UCS expands the VCS to encompass all periprosthetic fractures with additional fracture types, aiming for a universal application. Despite their widespread adoption, these systems exhibit shortcomings, including the incomplete inclusion of all PPFF types and the imprecise assessment of implant stability and surrounding bone loss. These gaps can result in misclassification and suboptimal treatment outcomes. This paper suggests the necessity for ongoing improvements in classification systems to include emerging fracture types and refined diagnostic criteria, ensuring that they remain relevant to contemporary orthopedic practices and continue to facilitate the precise tailoring of treatment to patient‐specific circumstances. This comprehensive historical review serves as a foundation for future innovations in classification systems, ultimately aiming to standardize PPFF treatment and improve patient prognosis.

Abstract To investigate the clinical effects of specific Unified Classification System B (UCS B)-lesser trochanter periprosthetic fractures and determine whether they occur only with non-cemented stems. A retrospective analysis of 28 patients with specific UCS B2 fractures who underwent two surgical treatments, longer stem revision and internal fixation (LSRIF) and open reduction and internal fixation (ORIF), was performed. The patients were assessed at 1, 3, 6, 12, and 24 months and annually thereafter. Fracture healing, complications, Harris Hip Score (HHS), and the Short Form Health Survey questionnaire (SF-36) quality of life score were assessed at each follow-up. At the time of the last follow-up, seven patients had been lost: three were lost to contact, two died, and two were hospitalised elsewhere and unavailable for follow-up. The remaining 21 patients were followed for an average of 49.3 ± 15.4 (range: 24–74.4) months. Their average fracture healing time was 13.5 ± 1.1 (12–15.4) weeks. Complications included three cases (10.71%) of thrombus, one (3.57%) of heart failure, and one (3.57%) of pulmonary infection. There were no revisions due to prosthesis loosening, subsidence, or infection. At the last follow-up, the HHS, SF-36 mental score, and SF-36 physical score were recorded, LSRIF vs. ORIF (82.9 ± 6.6 vs. 74.7 ± 3.9, p = 0.059; 50.9 ± 7.6 vs. 38 ± 1.4, p = 0.012, and 51.7 ± 8.4 vs. 39.7 ± 3.4, p = 0.032, respectively). Specific UCS B2 fractures mostly occur with non-cemented stems. LSRIF with cables is the main treatment, while ORIF is an option for those elderly in poor condition.

Objective The isolated second metacarpal base fracture‐dislocations in adults are rare, and the traditional main treatments include closed reduction with the plaster or splint and open reduction with internal fixation (ORIF). However, closed reduction with the plaster or splint is not solid enough and ORIF can damage the surrounding important tissues. The purpose of this study was to explore the clinical outcomes of closed reduction and external fixation (CREF) for the treatment of isolated second metacarpal base fracture‐dislocations. Methods Ten patients who suffered isolated second metacarpal base fracture‐dislocations between January 1, 2010, and February 1, 2020, were reviewed. All of the patients were treated by CREF. Radiographs and computed tomography scans were performed regularly after the operation. The grip and pinch strength, visual analog scale (VAS) pain score, American Society for Surgery of the Hand total active movement (TAM) and total active flexion (TAF) scores, Cooney score, Sollerman hand function test (SHFT) score, QuickDASH score, and range of motion of the index finger were recorded at the last follow‐up visit to evaluate functional recovery; the injured and healthy hands were compared and we also recorded postoperative complications. The paired samples t‐test was used to compare the healthy and injured sides. Results The patients were followed up for a median of 29.50 ± 4.2 months. There were no significant differences in the grip strength, pinch strength, angle of proximal interphalangeal joint (PIPJ) flexion, or angle of distal interphalangeal joint (DIPJ) flexion between the injured and healthy sides at the final follow‐up visit (all p > 0.05). The mean TAM (268.20 ± 4.21) and TAF scores (270.60 ± 4.17) on injured side were significantly lower than those on healthy side (all p

Spiders of the genus Pholcus were collected for the first time during an expedition to the Lüliang Mountains in Shanxi Province, North China. Phylogenetic analyses of DNA sequence data from COI, H3, wnt, and 28S genes allowed us to group them into nine well-supported clades. We used morphology and four methods of molecular species delimitation, namely Automatic Barcode Gap Discovery (ABGD), the Generalized Mixed Yule Coalescent (GMYC), Bayesian Poisson Tree Processes (bPTP), and Bayesian Phylogenetics and Phylogeography (BPP), to investigate species boundaries. These integrative taxonomic analyses identified the nine clades as nine distinct species, comprising Pholcus luya Peng & Zhang, 2013 and eight other species new to science: Pholcus jiaocheng sp. nov., Pholcus linfen sp. nov., Pholcus lishi sp. nov., Pholcus luliang sp. nov., Pholcus wenshui sp. nov., Pholcus xiangfen sp. nov., Pholcus xuanzhong sp. nov., and Pholcus zhongyang sp. nov. The species occur in geographic proximity and show many morphological similarities. All of them belong to the P. phungiformes species group. The records from the Lüliang Mountains represent the westernmost distribution limit of this species group.

In the article, the authors present their study which examined the uneven distribution pattern of spiders in Eurasia, particularly in Europe and China, by analyzing 35 species of the Pholcus phungiformes species group from China's Yanshan-Taihang Mountains. Based on the results, there could be more species of spiders in China than Europe due to their higher survival in China's mountainous landscape than the glacial ice features in northern Europe.

The corrosion properties of γ'-strengthened CoxNi-Al-W-Cr (where x = 15, 20, 25, and 30 at.%) superalloys were investigated in the mixture of 75 wt.% Na2SO4 + 25 wt.% NaCl at 900°C. The results showed that the corrosion behavior is associated with both sulfuration and oxidation processes. It was demonstrated that increasing the addition of Ni effectively promoted the formation of continuous Al2O3 scales, so that the hot corrosion resistance could be improved. When Ni content is more than 20 at.%, a large amount of Ni3S2 precipitates during the corrosion process. Sulfuration can destroy the integrity of the corrosion layer and increase the activity of oxygen. In this way, the internal oxidation of the alloys becomes more serious. Therefore, it is recommended that the optimum Ni addition is about 20 at.% for new type Co-Ni-Al-W-Cr superalloys. [ABSTRACT FROM AUTHOR]

Abstract  A vibration model for the stator of traveling wave type ultrasonic motors has been presented using Kirchhoff plate theory. In this model, the vibration equation influenced by electric field is established based on the geometric equations, the constitutive equations and the balanced equations for the structure. This electric field distribution is assumed based on Maxwell equation. Shearing deformation, rotary inertia and damping of the piezoelectric ceramic are been taken into account. Firstly, the dynamics of the stator is discussed. The mode of the stator is derived and validated by comparing the resonant frequencies and modal shapes with those by finite element analysis. Then, the effect of the piezoelectric ceramic damping is also discussed. Finally, The friction layer is simplified as the axial spring. Using modal shapes as the weight function, the analytic solution under the forced vibration for the stator is computed by Galerkin method. The theoretical model and its analytic solution in this paper contribute to simplifying the model for the parametric study and understanding the vibration between the stator and the rotor. [ABSTRACT FROM AUTHOR]

Linear ultrasonic motor (LUSM) is a new type of driver. LUSM has many advantages, so it is taken seriously in aeronautics and astronautics. But, because of the deficiency of studies on the performance of LUSM in abnormal temperature, it's necessary to do research on the performance of LUSM in different ambient temperature, to confirm whether it can work under abnormal temperature and how it works. In this research, we use V type LUSM (VLUSM) as the test object, owing to that VLUSM is one basic type of linear ultrasonic motor. When doing research, we pay close attention to the moment of force and the rotation rate of VLUSM, to discover how much they change in abnormal temperature environment. This research compares all datum partitioned by different temperature, and uses figures to show the tendency of those mechanical properties in abnormal temperature. At the same time, we explain the changing by means of theories. Finally, through detailed experimental demonstration, we believe that as the temperature rises, both moment of force and rotation rate of VLUSM increase, and we can also conclude that VLUSM can work normally under abnormal temperature environment. [ABSTRACT FROM AUTHOR]