[Comparative study of short-term effectiveness of three surgical methods for ulnar styloid base fracture complicated with triangular fibrocartilage complex injury].

Objective: To compare the short-term effectiveness of arthroscopic suture of triangular fibrocartilage complex (TFCC), arthroscopic suture of TFCC combined with open reduction and internal fixation, and simple open reduction and internal fixation in the treatment of distal radius fractures combined with ulnar styloid base fractures and TFCC injury. Methods: A clinical data of 97 patients with distal radius fractures combined with ulnar styloid base fracture and TFCC injury, who were admitted between September 2019 and September 2022 and met the selective criteria, was retrospectively analyzed. After reduction and internal fixation of distal radius fractures, 37 cases underwent arthroscopic suture of TFCC (TFCC group), 31 cases underwent arthroscopic suture of TFCC combined with open reduction and internal fixation of ulnar styloid base fractures (combination group), and 29 cases underwent simple open reduction and internal fixation of ulnar styloid base fractures (internal fixation group). There was no significant difference in baseline data between groups ( P>0.05), such as gender, age, injury side, time from injury to operation, and preoperative radius height, palm inclination, ulnar deviation, grip strength, wrist range of motion (ROM) in rotation, ulnar-radial deviation, and flexion-extension. The differences (change value) in radius height, metacarpal inclination angle, ulnar deviation angle, grip strength, and wrist ROM in rotation, ulnar-radial deviation, and flexion-extension between preoperative and 12 months after operation in 3 groups were compared. The effectiveness was evaluated according to the modified Gartland-Werley score at 12 months after operation. Results: All incisions healed by first intention. All patients were followed up 12-18 months (mean, 14 months). X-ray films showed that there were 4 patients with non-union of ulnar styloid base fracture in TFCC group, and the remaining patients had fracture healing at 3 months after operation. The radius height, palm inclination, and ulnar deviation of 3 groups at 12 months after operation were significantly better than those before operation ( P<0.05); however, the differences in the change values of the above indexes between groups was not significant ( P>0.05). At 12 months after operation, the change values of wrist ROM in rotation, ulnar-radial deviation, and flexion-extension in the TFCC group and the combination group were significantly greater than those in the internal fixation group ( P<0.05), and there was no significant difference between the TFCC group and the combination group ( P>0.05). The change values of grip strength was significantly greater in the combination group than in the internal fixation group ( P<0.05); there was no significant difference between the other groups ( P>0.05). The excellent and good rates according to the modified Gartland-Werley score were 91.89% (34/37), 93.54% (29/31), and 72.41% (21/29) in the TFCC group, the combination group, and the internal fixation group, respectively. The excellent and good rates of the TFCC group and the combination group were significantly higher than that of the internal fixation group ( P<0.05); there was no significant difference between the TFCC group and the combination group ( P>0.05). Conclusion: For ulnar styloid base fractures with TFCC injury, compared with simple open reduction and internal fixation, arthroscopic suture of TFCC or suture TFCC combined with internal fixation treatment are both beneficial for wrist function recovery, and their short-term effectiveness are similar. Therefore, arthroscopic suture of TFCC may be a better choice.

Band 40/41 Surface Acoustic Wave Filters on 42°YX-Lithium Tantalate Substrate with Suppression of Transverse Leakage.

The transverse leakage of leaky surface acoustic waves (LSAWs) occurs on 42°YX-lithium tantalate substrates (42LT), which increases the insertion loss, narrows the bandwidth and flattens the roll-off of band 40/41 SAW filters and duplexers. In this work, LSAW characteristics with different metal materials and thicknesses are calculated by the finite element method (FEM), which determines the IDT material and thickness used for band 40/41 SAW filter design. To deeply understand transverse leakage and suppress it, the effects of different gap and dummy lengths on transverse leakage are simulated and discussed. Then, a new technique of using a wider dummy without any additional lithographic or depositing processes is proposed to suppress the leakage. Its effectiveness is validated by both simulations and experiments. Then, the technique is extended to applications of band 40 and 41 SAW filters. The experimental results show that with the wider dummy structure, the band 40 and 41 SAW filters achieve a more than 0.2 dB improvement in the insertion loss, a wider bandwidth and a steeper roll-off characteristic. This technique may also be extended to the other band SAW filter applications.

Optimization of Surface Acoustic Wave Resonators on 42°Y-X LiTaO3/SiO2/Poly-Si/Si Substrate for Improved Performance and Transverse Mode Suppression.

SAW devices with a multi-layered piezoelectric substrate have excellent performance due to advantages such as a high quality factor, Q, low loss insertion, large bandwidth, etc. Prior to manufacturing, a comprehensive analysis and proper design are essential to evaluating the device's key performance indicators, including the Bode Q value, bandwidth, and transverse mode suppression. This study explored the performance of SAW resonators employing a 42°Y-X LiTaO3 (LT) thin-plate-based multi-layered piezoelectric substrate. The thicknesses for each layer of the 42°Y-X LT/SiO2/poly-Si/Si substrate were optimized according to the index of phase velocity, Bode Q value, and bandwidth. The effect of the device structure parameters on the dispersion curve and slowness curve was studied, and a flat slowness curve was found to be favorable for transverse mode suppression. In addition, the design of the dummy configuration was also optimized for the suppression of spurious waves. Based on the optimized design, a one-port resonator on the 42°Y-X LT/SiO2/poly-Si/Si substrate was fabricated. The simulation results and measurements are presented and compared, which provides guidelines for the design of new types of SAW devices configured with complex structures.