Biomechanical comparison of three fixation strategies for radial head fractures: a biomechanical study.

Second-generation headless compression screws (HCSs) are commonly used for the fixation of small bones and articular fractures. However, there is a lack of biomechanical data regarding the application of such screws to radial head fractures. This study evaluated the mechanical properties of the fixation of radial head fractures using a single oblique HCS compared with those obtained using a standard locking radial head plate (LRHP) construct and a double cortical screw (DCS) construct. Radial synbone models were used for biomechanical tests of HCS, LRHP, and DCS constructs. All specimens were first cyclically loaded and then loaded to failure. The stiffness for the LRHP group was significantly higher than that for the other two groups, and that for the HCS group was significantly higher than that for the DCS group. The LRHP group had the greatest strength, followed by the HCS group and then the DCS group. The HCS construct demonstrated greater fixation strength than that of the commonly used cortical screws, although the plate group was the most stable. The present study revealed the feasibility of using a single oblique HCS, which has the advantages of being buried, requiring limited wound exposure, and having relatively easy operation, for treating simple radial head fractures.

Traditional versus Minimally Invasive Spinopelvic Fixation for Sacral Fracture Treatment in Vertically Unstable Pelvic Fractures.

PURPOSE: Numerous different fixation techniques are used to treat vertical shear sacral fractures. We report our experience with spinopelvic fixation using a minimally invasive technique. METHODS: Thirty-eight patients with vertical pelvic and sacral fractures were treated with spinopelvic fixation (traditional open method, n = 21; minimally invasive technique, n = 17). Intergroup comparisons and statistical analysis were performed for intraoperative blood loss, operative time, post-operative radiographic grading, post-operative functional score, and complication rates. RESULTS: Patients treated with the minimally invasive technique had a significantly shorter operative time (-52 min, p = 0.022), reduced blood loss volume (-287 mL, p < 0.001), and better cosmetic appearance (p < 0.05) than those in the traditional open group. There were no significant intergroup differences in post-operative radiographic grading (p = 0.489) or post-operative functional scores (p = 0.072). The complication rate was lower in the minimally invasive group (1/17 patients) than in the traditional open group (2/21 patients). CONCLUSIONS: Minimally invasive spinopelvic fixation is a viable treatment for sacral fractures and can reduce blood loss and operative time.

U-Shaped Optical Fiber Probes Coated with Electrically Doped GQDs for Humidity Measurements.

The influence of the bending radius on the sensitivity of the graphene quantum dots (GQDs)-coated probe is experimentally investigated for a U-shaped probe. The fiber is bent into a U shape using the optic fiber flame heating method, and the optic fiber is enclosed in a glass tube to increase the stability of the probe. The surface of the U-shaped optical fiber was coated with electrospun fibers formed via electrospinning. Polymer materials doped with GQDs are applied to U-shaped optical fiber as humidity sensors. Graphene quantum dot nanofibers on the U-shaped optical fiber sensor to form a network structure of graphene quantum dots U-shape fiber sensor (GQDUS). The polymer network structure absorbs water molecules, which in turn affects the bending radius of the optical fiber, and changes the optical fiber spectrum. Graphene quantum dots provide optical enhancement benefits, which in turn increase the sensitivity of fiber optic sensors. The spectra monitoring system consists of an optical spectrum analyzer (OSA) and an amplified spontaneous emission (ASE). This system can be used to detect humidity changes between 20% RH and 80% RH in the chamber. Our results indicate promising applications for quantum dots probe sensors from electrospun nanofibers increasing sensitive environmental monitoring. As such, it could be of substantial value in optical sensors detection.

Internal Residual Strain Measurements in Carbon Fiber-Reinforced Polymer Laminates Curing Process Using Embedded Tilted Fiber Bragg Grating Sensor.

Carbon fiber reinforced plastics (CFRP) have many mechanical properties that are superior to those of conventional structural materials and are becoming more and more widely used. Monitoring the curing process used to produce such composite material is important to ensure the quality of the process, especially for the characterization of residual strains after the material has been manufactured. In this study, we present a tilted fiber Bragg grating (TFBG) sensor used to monitor the curing of CFRP composite materials. The TFBG sensor was embedded into the layers of CFRP laminates to study the curing residual strain of the laminates. The experimental results showed that the curing residual stress was about -22.25 MPa, the axial residual strain was -281.351 µÎµ, and lateral residual strain of 89.91 µÎµ. The TFBG sensor was found to be sensitive to the curing residual strain of the CFRP, meaning that it has potential for use in applications involving composite curing processes. Moreover, it is indeed possible to improve the properties of composite materials via the optimization and monitoring of their curing parameters.

Conventional plate fixation versus minimally invasive modified pedicle screw-rod fixation for anterior pelvic ring fractures.

There are various methods of fixation for anterior pelvic ring fractures. We report our experience with modified pedicle screw-rod fixation (MPSRF) via a minimally invasive method. Fourteen patients with anterior pelvic ring fracture were treated by internal fixation (conventional plate fixation, n = 7; MPSRF, n = 7). Intraoperative blood loss, operative time, post-operative fracture reduction grading by radiography, and complication rates were compared and statistically analyzed. Patients treated with MPSRF had a shorter operative time (-36 min, P = 0.378) and significantly less blood loss (-264 ml, P = 0.026) than patients in the conventional plate fixation group. Postoperative radiological evaluations were similar between the groups (P > 0.05). The complication rate was lower in the MPSRF group (1/7 patients) than in the plate fixation group (2/7 patients). Modified pedicle screw-rod fixation is a viable treatment for anterior pelvic ring fixation and can reduce blood loss.