Efficacy of intramedullary bridge fixation for midshaft clavicle fractures: a retrospective analysis of a novel technique.

BACKGROUND: The aim of this study was to explore the efficacy of a novel intramedullary fixation technique using the ortho-bridge system (OBS) for midshaft clavicle fractures. METHODS: A total of 63 patients were included in this study: 35 underwent plate internal fixation (LP group) and 28 underwent OBS intramedullary fixation (OBS group). Surgical time, intraoperative blood loss, incision length, fracture healing time, removal of the internal fixation agent, visual analog scale (VAS) score for shoulder pain, Constant-Murley shoulder score and complication occurrence were compared between the two groups. RESULTS: Preoperative general data, such as sex, age and fracture type, were not significantly different between the two groups (P > 0.05). However, the OBS group exhibited better outcomes than the LP group exhibited in terms of surgical time, intraoperative blood loss and total incision length (P < 0.05). Additionally, the OBS group exhibited a significantly shorter fracture healing time and internal-fixation removal time than the LP group exhibited (P < 0.05). The VAS scores on postoperative day 1, week 1, month 1 and month 3 were lower in the OBS group than in the LP group (P < 0.05). Furthermore, the Constant-Murley shoulder scores at 1, 3, and 6 months postoperatively were higher in the OBS group than in the LP group (P < 0.05), with no significant difference at 1 year after surgery (P > 0.05). None of the patients in the OBS group experienced scarring of the surgical incision, and 6 patients in the LP group experienced scarring of the surgical incision. Finally, the complication incidence in the OBS group was lower than that in the LP group. CONCLUSION: For midshaft clavicle fractures, OBS intramedullary fixation is better than locking-plate internal fixation because it led to less trauma, a faster recovery, better efficacy, and better esthetic outcomes and comfort. Therefore, this technique may have potential as a novel treatment for midshaft clavicle fractures. LEVEL OF EVIDENCE: III, retrospective observational study.

Biomechanical study of the stiffness of the femoral locking compression plate of an external fixator for lower tibial fractures.

BACKGROUND: A locking compression plate (LCP) of the distal femur is used as an external fixator for lower tibial fractures. However, in clinical practice, the technique lacks a standardized approach and a strong biomechanical basis for its stability. METHODS: In this paper, internal tibial LCP fixator (Group IT-44), external tibial LCP fixator (Group ET-44), external distal femoral LCP fixator (Group EF-44, group EF-33, group EF-22), and conventional external fixator (Group CEF-22) frames were used to fix unstable fracture models of the lower tibial segment, and anatomical studies were performed to standardize the operation as well as to assess the biomechanical stability and adjustability of the distal femoral LCP external fixator by biomechanical experiments. RESULTS: It was found that the torsional and flexural stiffnesses of group EF-44 and group EF-33 were higher than those of group IT-44 and group ET-44 (p < 0.05); the flexural stiffness of group EF-22 was similar to that of group IT-44 (p > 0.05); and the compressive stiffness of all three EF groups was higher than that of group ET-44 (p < 0.05). In addition, the flexural and compressive stiffnesses of the three EF groups decreased with the decrease in the number of screws (p < 0.05), while the torsional stiffness of the three groups did not differ significantly between the two adjacent groups (p > 0.05). Group CEF-22 showed the highest stiffnesses, while group ET-44 had the lowest stiffnesses (P < 0.05). CONCLUSIONS: The study shows that the distal femoral LCP has good biomechanical stability and adjustability and is superior to the tibial LCP as an external fixator for distal tibial fractures, as long as the technique is used in a standardized manner according to the anatomical studies in this article.

Hyperthermia properties of hyaluronic acid-coated La0.7Sr0.3-xBaxMnO3 nanoparticles.

In this work, La0.7Sr0.3-xBaxMnO3 (0 ≤x≤ 0.15) magnetic nanoparticles were synthesized using a simple sol-gel method in the presence of polyvinyl alcohol as a chelating agent. Then the nanoparticles are coated by hyaluronic acid as the surfactant via high-energy ball milling for their possible application in biocompatible magnetic fluid hyperthermia. The samples were characterized by X-ray diffraction, vibrating sample magnetometry, scanning electron microscopy, high-resolution transmission electron microscopy, Fourier-transform infrared spectroscopy and high-frequency induction heating studies. It was found that the hyaluronic acid-coated La0.7Sr0.25Ba0.05MnO3 nanoparticles, with a particle diameter of ∼100 nm and a Curie temperature of 67 °C at a concentration of 5 mg mL-1, gave the optimal induction heating results. The saturation heating temperature, the specific absorption rate, and the effective specific absorption rate are 44.1 °C, 60.1 W g-1 and 0.14 W g-1 kHz (kA m-2), respectively. The hyaluronic acid-coated La0.7Sr0.25Ba0.05MnO3 nanoparticles with a suitable saturation heating temperature and a high specific absorption rate can be used as an effective heating source for the hyperthermia treatment of cancer. Their targeting ability towards cancer cells and good biocompatibility were also proved by cell experiments.

Achievement of Diverse Domain Structures in Soft Magnetic Thin Film through Adjusting Intrinsic Magnetocrystalline Anisotropy.

Oriented soft magnetic hcp-Co1 - x Ir x films with a fixed thickness of 120 nm were fabricated. All prepared films exhibit soft magnetic properties but various magnetocrystalline anisotropies with the variation of Ir content. The measured data shows that diverse domain structures including the Néel wall, Bloch wall, and stripe domains present in a fixed film thickness. It is singular for the single-layer soft magnetic film to possess diverse domains in a fixed thickness. This phenomenon was explained by introducing intrinsic magnetocrystalline anisotropy energy into soft magnetic films rather than the structural parameters of the film, inner stress, and microstructure effect.

Enhanced film thickness for Néel wall in soft magnetic film by introducing strong magnetocrystalline anisotropy.

This study investigated the magnetic domain walls in a single-layer soft magnetic film with strong magnetocrystalline anisotropy energy. The soft magnetic film is composed of a highly c-axis-oriented hcp-Co81Ir19 alloy with strong negative magnetocrystalline anisotropy. The domain structure of the soft Co81Ir19 films with thickness ranging from 50-230 nm in a demagnetization state was observed through magnetic force microscopy and Lorentz transmission electron microscopy. Results reveal that the critical transition thickness at which the domain wall changes from Néel type to Bloch type is about 138 nm, which is much larger than the critical value of traditional Fe- and Co-based soft magnetic films with negligible magnetocrystalline anisotropy. Theoretical calculation was also performed and the calculated result agrees well with experimental data.