Finite element analysis of a customized coronoid prosthesis for traumatic coronoid deficiency.

BACKGROUND: Traumatic coronoid deficiency with persistent elbow instability is a challenging condition. Autologous bone graft reconstruction is often associated with a range of additional clinical problems and the outcome is often unpredictable. The purpose of this study was to design a prosthetic device that can reconstruct coronoid deficiency of any height and to evaluate its mechanical properties using finite element analysis. MATERIALS AND METHODS: A customized coronoid prosthesis was designed based on image registration, automatic measurement, and computer-aided design. After pilot study and sample size calculation, image data collected from 6 patients who underwent bilateral complete upper extremity CT scans were reconstructed. The test was divided into 3 groups: coronoid intact, prosthesis and autograft. Regan-Morrey type II and autologous olecranon osteotomy models were established. The prosthesis and autogenous olecranon were assembled to the coronoid base. Stress was applied axially along the proximal humeral diaphysis and implant micromotion and contact mechanics of the humeroulnar joint were measured at 30°, 45°, 60° and 90° of joint flexion respectively. RESULTS: At all flexion angles, the maximum stress on the coronoid articular surface was significantly reduced in the prosthesis and autograft groups, with the reduction being more significant in the latter (P < .001). With increasing flexion, the maximum stress at the coronoid articular surface increased significantly after autograft reconstruction (7.2 to 68 MPa, P < .001), whereas the humeroulnar joint obtained a similar contact mechanics pattern to that of the control group after prosthetic reconstruction. As the flexion angle increased, the relative micromotion of both the prosthesis and autograft increased significantly (0.5-1.6 vs. 0.2-1.2, Pmeasure time < 0.001, Pgroups < 0.001). Contact pressure and center-of-force paths of the humeroulnar joint experience abrupt stress changes at approximately 60° of flexion. CONCLUSION: The contact stress pattern in the humeroulnar joint is similar in prosthesis and intact coronoid groups. Autograft reconstruction increases contact stresses at the articular surface and alters the joint center-of-force path. The "stress surge phenomenon" in the humeroulnar joint surface before and after 60° of flexion may be one of the mechanisms of traumatic elbow degeneration.

Halbach array assisted assembly of orderly aligned nickel nanowire networks as transparent conductive films.

The aspect ratio and arrangement of nanowires play an important role in achieving excellent optoelectronic performance for metal nanowire-based transparent conductive films (TCFs). However, limited to the technology and material properties, studies are always focused on only one of the issues. Here, a novel strategy for manipulating the relative aspect ratio and arrangement of nickel nanowires (NiNWs) at nanoscale by Halbach array assisted assembly technology is introduced. Head-to-tail nickel nanowire chains as large as hundreds of micrometers are formed as a result of the dipole-dipole interactions of wire-wire. The arrangement of nickel nanowires can be preciously controlled by layer-by-layer deposition. Notably, the alignment create a significant improvement on the optoelectronic performance of nickel nanowire TCFs. The optimized orderly aligned NiNWs TCFs demonstrate super optoelectronic performance (90 Ω sq-1, 86%) than disordered NiNW TCFs (200 Ω sq-1, 80%). Moreover, NiNW-based TCFs exhibit outstanding long-term oxidation stability at 80 °C over 30 d as well as high-temperature oxidization stability even up to 300 °C, that is the most stable metal nanowire-based TCFs in air as far as we know. The low-cost, good optoelectronic performance and excellent oxidation resistance of aligned NiNWs will make them as attractive alternatives to silver nanowires for TCFs application.

Head-to-head comparison of [68Ga]Ga-FAPI PET and [18F]FDG PET in the detection of bone and lymph node metastasis in various cancers: A systematic review and meta-analysis.

PURPOSE: The aim of our meta-analysis and systematic review was to contrast the positivity rates of [68Ga]Ga-FAPI PET and [18F]FDG PET in detecting bone and lymph node metastases across diverse cancer types. METHODS: We conducted a comprehensive search for eligible articles up until August 2023, utilizing databases including PubMed, Embase, and Web of Science. Studies focusing on the positivity rate of [68Ga]Ga-FAPI PET vs. [18F]FDG PET for bone and lymph metastasis were included. Using random-effect model, the positivity rate for [68Ga]Ga-FAPI PET and [18F]FDG PET were generated. In order to gauge the heterogeneity among aggregated studies, we utilized the I2 statistic. Additionally, we applied the Quality Assessment of Diagnostic Performance Studies (QUADAS-2) methodology to evaluate the caliber of the studies encompassed in our analysis. RESULTS: A total of 430 publications were initially identified in the search. Eventually, 25 studies, involving 779 patients, met the inclusion criteria. In terms of bone metastasis, the findings indicate no statistically significant difference between the use of [68Ga]Ga-FAPI PET and [18F]FDG PET (P = 0.34). However, concerning lymph node metastasis, the results demonstrate significant difference between the two imaging agents (P = 0.04). CONCLUSIONS: This systematic review suggests that [68Ga]Ga-FAPI PET appears to outperform [18F]FDG PET in detecting lymph node metastases. However, when it comes to bone metastasis, no statistically significant difference was observed. It is crucial to acknowledge that the insights concerning bone metastasis stem from studies with comparatively modest sample sizes. Consequently, there is a pressing demand for further, expansive prospective studies in this field.

Efficacy and safety of continuous passive motion and physical therapy in recovery from knee arthroplasty: a systematic review and meta-analysis.

BACKGROUND: Continuous passive motion (CPM) is commonly used as a postoperative rehabilitation treatment, along with physical therapy, for postoperative knee rehabilitation. However, the comparison between the two in terms of efficacy in postoperative knee replacement recovery is unclear. PURPOSE: To compare efficacy and safety of combined CPM versus physical therapy alone in postoperative rehabilitation after knee arthroplasty. METHODS: PubMed, Embase, and Web of Science databases were used to retrieve and access clinical studies on the efficacy of CPM compared with physical therapy. Review Manager software was used for study publication bias assessment and data analysis based on inclusion criteria. RESULTS: A total of 6 articles covering 557 patients were included in the study. In terms of range of motion (ROM), passive knee flexion was similar between CPM and physical therapy (PT) (WMD, - 0.17; 95% CI, - 0.98-0.64; p = 0.68). At long-term follow-up, passive knee extension was similar between CPM and physical therapy (PT) (WMD, - 0.28; 95% CI, - 1.47 to - 0.92; I2 = 65%, p =0.65). In addition, CPM generates significantly higher in length of stay (WMD, 0.50; 95% CI, - 0.31 to 0.69; I2 = 3%, p < 0.001). CPM generates significantly higher treatment costs and incurs more care costs relative to physical therapy. CONCLUSION: Compared to PT, combined with CPM failed to significantly improve ROM of the knees and patient's satisfaction. In addition, CPM treatment significantly increased the cost of hospitalization.

Alginate Fiber-Enhanced Poly(vinyl alcohol) Hydrogels with Superior Lubricating Property and Biocompatibility.

The design of a novel interpenetrating network hydrogel inspired by the microscopic architecture of natural cartilage based on a supramolecular sodium alginate (SA) nanofibril network is reported in this paper. The mechanical strength and toughness of the poly(vinyl alcohol) (PVA) hydrogel were significantly improved after being incorporated with the alginate nanofibril network. The multiple hydrogen bonds between PVA chains and alginate fibers provided an efficient energy dissipation, thus leading to a significant increase in the mechanical strength of the PVA/SA/NaCl hydrogel. The PVA/SA/NaCl hydrogel demonstrated superior water-lubrication and load-bearing performance due to noncovalent interactions compared with pure PVA hydrogels. Moreover, the bioactivity of the PVA/SA/NaCl hydrogel was proved by the MC3T3 cell proliferation and viability assays over 7 days. Therefore, alginate fiber-enhanced hydrogels with high strength and low friction properties are expected to be used as novel biomimetic lubrication materials.

The Preparation and Wear Behaviors of Phenol-Formaldehyde Resin/BN Composite Coatings.

Phenolic-matrix composites possess excellent synergistic effects on mechanical and tribological properties and can be used in the aerospace, medical, and automobile industries. In this work, a series of phenol-formaldehyde resin/hexagonal boron nitride nanocomposites (PF/BNs) were in situ synthesized using an easy method. PF/BN coatings (PF/BNCs) on 316L steels were prepared through a spin-casting method. The wear behaviors of these PF/BNCs were investigated by dry sliding with steel balls. The percentage of BN, the thickness of the coating, and the heat treatment temperature affected the coefficients of friction (COFs) and wear rates of these coatings. After heat treatment at 100 °C, the tribological properties of the PF/BNCs were remarkably improved, which might be attributed to both the transformation of carbon on the worn surfaces from C-O/C=O into C=N, carbide, and other chemical bonds and the cross-linking of the prepolymers.

Shape controlled synthesis and photoluminescence properties of Eu3+-doped REVO4 nanophosphors.

Eu3+-doped REVO4 nanphosphors were controllably synthesized by an EDTA-mediated hydrothermal method at 180 degrees C using RE(NO3)3 and Na3VO4 as precursors. The obtained products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectra (XPS), and photoluminescence spectroscopy (PL). The XRD results showed that the products were pure tetragonal structure and no other impurity phase appeared. The PL studies demonstrated Eu3+ ions doping effectively enhanced luminescent properties of LaxRE(1-x)VO4 and YxRE(1-x)VO4 nanoparticles, but EU3+ ions doping did not enhance luminescent properties of CexRE(1-x)VO4 (x not equal 0) nanoparticles. The prepared phosphors showed well-defined red luminescence due to radiative transitions from 5D0 to 7F(J) (J = 1,2) levels of Eu3+ ions, respectively. Furthermore, we reported Eu3+-doped CexRE(1-x)VO4 (x not equal 0) phases represented a new class of optically inactive materials.