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Background: Microgravity directly disturbs the reorganization of the cytoskeleton, exerting profound effects on the physiological process of macrophages. Although it has been established that macrophage M1/M2 polarization could be manipulated by the surface nanostructure of biomaterial in our previous study under normal gravity, how will inflammatory monocytes (iMos)-derived macrophages respond to diverse nanostructured Ti surfaces under normal gravity or microgravity remains unrevealed. Results: In this study, Cytochalasin D, a cytoskeleton relaxant, was employed to establish the simulated microgravity (SMG) environment. Our results showed that human iMos polarized into M2c macrophages on NT5 surface but M1 type on NT20 surface with divergent inflammatory phenotypes according to the profile of macrophage polarization featured molecules under normal gravity. However, such manipulative effects of NTs surfaces on iMos-derived macrophages were strikingly weakened by SMG, characterized by the altered macrophage morphology, changed cytokine secretion profile, and decreased cell polarization capacity. Conclusions: To our knowledge, this is the first metallic implantable material study focusing on the functions of specific monocyte subsets and its crucial role of the cytoskeleton in materials-mediated host immune response, which enriches our mechanism knowledge about the crosstalk between immunocytes and biomaterials. The results obtained in the present study may also provide potential targets and strategies for biomaterial development and clinical treatment via precise immune-regulation under normal gravity and microgravity. [ABSTRACT FROM AUTHOR]

Background: An effective vaccine that prevents disease caused by hantaviruses is a global public health priority, but up to now, no vaccine has been approved for worldwide use. Therefore, novel vaccines with high prophylaxis efficacy are urgently needed. Methods: Herein, we designed and synthesized Hantaan virus (HTNV) linear multi-epitope peptide consisting of HLA-A*02-restricted HTNV cytotoxic T cell (CTL) epitope and pan HLA-DR-binding epitope (PADRE), and evaluated the immunogenicity, as well as effectiveness, of multi-epitope peptides in HLA-A2.1/Kb transgenic mice with interferon (IFN)-γ enzyme-linked immunospot assay, cytotoxic mediator detection, proliferation assay and HTNV-challenge test. Results: The results showed that a much higher frequency of specific IFN-γ-secreting CTLs, high levels of granzyme B production, and a strong proliferation capacity of specific CTLs were observed in splenocytes of mice immunized with multi-epitope peptide than in those of a single CTL epitope. Moreover, pre-immunization of multi-epitope peptide could reduce the levels of HTNV RNA loads in the liver, spleen and kidneys of mice, indicating that specific CTL responses induced by multi-epitope peptide could reduce HTNV RNA loads in vivo. Conclusions: This study may provide an important foundation for the development of novel peptide vaccines for HTNV prophylaxis. [ABSTRACT FROM AUTHOR]

Background: Screw fixation is a typical technique for the isolated subtalar joint. However, no consensus has been reached on how to select the most suitable insertion position and direction. This study aims to find the ideal screw insertion and then explore its influence on the clinical efficacy of subtalar fusion by analyzing the effects of different cannulated screw insertions on the stress distribution, anti-rotary strength, and anti-inversion/eversion strength of the subtalar joint. Methods: In this study, we investigated three cannulated screw insertions for subtalar fusion: screw insertion with the most uniform stress distribution (group A), lateral-medial parallel screw insertion (group B), and traditional longitudinally parallel screw insertion (group C). The effects of these three insertions on the loading stress of the subtalar joint (including stress distribution, anti-inversion/eversion strength, and anti-rotary strength) were comparatively analyzed with the three-dimensional finite element method to screen the ideal screw insertion. Moreover, a prospective study was conducted to analyze the influence of the ideal screw insertion on subtalar fusion, including the fusion rate, fusion time, and clinical efficacy (VAS score, AOFAS score, and complications). Results: Group B was worse than group A with respect to the stress distribution uniformity, but slightly better than group C, and better than both groups A and C in terms of the anti-rotary strength and anti-inversion/eversion strength. The screw insertion based on the most uniform stress distribution is not feasible in surgery. Therefore, the lateral-medial antiparallel screw insertion is the ideal insertion. From January 2012 to June 2016, 48 cases were treated by subtalar fusion with the ideal screw insertion, and then followed up for 30.6 months (12–48 months). The fusion was proved in all 48 cases with a fusion rate of 100% by X-ray or CT scan. The mean time of fusion was 12.8 weeks (12–16 weeks). The VAS score decreased from 6.00 before operation to 1.03 on the last visit (P < 0.05), and the AOFAS score increased from 57.0 to 85.6 (P < 0.05), with a good and excellent rate of 95.8%. Conclusions: The lateral-medial parallel screw insertion not only demonstrates a good stress distribution profile of the subtalar joint but also has advantages such as easy localization and operation during surgery, as well as a high fusion rate and few complications after surgery. Therefore, it is a safe, accurate, and effective fixation mode that is worthy of being popularized clinically. [ABSTRACT FROM AUTHOR]

Background: The study aimed to introduce the isolated talonavicular and talonavicular-cuneiform arthrodesis for the stage III and IV Müller-Weiss disease and analyze their clinical outcomes., Methods: Thirty patients of stage III and IV Müller-Weiss disease were divided into the talonavicular (TN) arthrodesis group and the talonavicular-cuneiform (TNC) arthrodesis group according to the perinavicular osteoarthritis by MRI scans. For the isolated talonavicular arthrodesis group, 16 patients underwent talonavicular arthrodesis with two 4.0 mm hollow headless compression screws. For the TNC arthrodesis group, 14 patients were received the TNC arthrodesis with reverse "V" shape osteotomy and autoallergic iliac bone graft. All patients were followed up at 3, 6, 9, and 12 months, and per 6 months after 1 year, by the AOFAS ankle-midfoot scores, and evaluated by radiographic measurements., Results: All of them were followed up in two groups and all patients were satisfied with their clinical results. At the TN arthrodesis group, the patients' mean was 39.8 months (range, 11-66 months) follow-up. The mean AOFAS ankle and hindfoot scores had improved from 38.3 ± 5.1 preoperatively to 88.9 ± 1.9 at the last postoperative assessment. At the TNC arthrodesis group, the mean follow-up was 51.7 months (range, 12-90 months). The mean AOFAS ankle and hindfoot scores were 40.1 ± 7.9 preoperatively to 90.1 ± 2.0 at the last postoperative. All of the cases were solid fusion on the radiograph., Conclusions: According to MRI evaluation, either TN or TNC arthrodesis for stage III or IV Müller-Weiss disease have the good clinical outcomes with solid fusion rate and obvious improvement of the quality of life of patients.

Background: Screw fixation is a typical technique for isolated talonavicular arthrodesis (TNA), however, no consensus has been reached on how to select most suitable inserted position and direction. The study aimed to present a new fixation technique and to evaluate the clinical outcome of individual headless compression screws (HCSs) applied with three-dimensional (3D) image processing technology to isolated TNA., Methods: From 2007 to 2014, 69 patients underwent isolated TNA by using double Acutrak HCSs. The preoperative three-dimensional (3D) insertion model of double HCSs was applied by Mimics, Catia, and SolidWorks reconstruction software. One HCS oriented antegradely from the edge of dorsal navicular tail where intersected interspace between the first and the second cuneiform into the talus body along the talus axis, and the other one paralleled the first screw oriented from the dorsal-medial navicular where intersected at the medial plane of the first cuneiform. The anteroposterior and lateral X-ray examinations certified that the double HCSs were placed along the longitudinal axis of the talus. Postoperative assessment included the American Orthopaedic Foot & Ankle Society hindfoot (AOFAS), the visual analogue scale (VAS) score, satisfaction score, imaging assessments, and complications., Results: At the mean 44-months follow-up, all patients exhibited good articular congruity and solid bone fusion at an average of 11.26 ± 0.85 weeks (range, 10 ~ 13 weeks) without screw loosening, shifting, or breakage. The overall fusion rates were 100%. The average AOFAS score increased from 46.62 ± 4.6 (range, 37 ~ 56) preoperatively to 74.77 ± 5.4 (range, 64-88) at the final follow-up (95% CI: -30.86 ~ -27.34; p < 0.001). The mean VAS score decreased from 7.01 ± 1.2 (range, 4 ~ 9) to 1.93 ± 1.3 (range, 0 ~ 4) (95% CI: 4.69 ~ 5.48; p < 0.001). One cases (1.45%) and three cases (4.35%) experienced wound infection and adjacent arthritis respectively. The postoperative satisfaction score including pain relief, activities of daily living, and return to recreational activities were good to excellent in 62 (89.9%) cases., Conclusions: Individual 3D reconstruction of HCSs insertion model can be designed with three-dimensional image processing technology in TNA. The technology is safe, effective, and reliable to isolated TNA method with high bone fusion rates, low incidences of complications.

Background: Tibiotalocalcaneal arthrodesis with headless compression screws has not been previously reported. We hypothesized that these screws could be suitable for tibiotalocalcaneal arthrodesis because of their special design. This study aimed to evaluate the clinical outcomes of patients undergoing tibiotalocalcaneal arthrodesis with headless compression screws for the treatment of severe arthropathy of the ankle and subtalar joint., Methods: From 2010 to 2015, 23 patients with severe ankle and subtalar arthropathy underwent tibiotalocalcaneal arthrodesis. All surgeries were completed by a senior surgeon in the same hospital. These patients were 18~76 years (mean 54.6 years) old; the duration of their disease was 9~38 months (mean 13.2 months). The study population included 12 males and 11 females; 12 patients underwent surgery on the left and 11 on the right. Indications for surgery included avascular necrosis of the talus (n = 14), severe posttraumatic arthritis (n = 4), osteoarthritis (n = 2), terminal tuberculous arthritis (n = 1), rheumatoid arthritis (n = 1) and Charcot neuroarthropathy (n = 1). A lateral oblique incision was performed to expose the subtalar joint, and an anteromedial longitudinal incision was used to expose the ankle joint. After the articular surfaces were removed, the tibia, talus and calcaneus were carefully aligned and fixed with two headless compression screws. Patients were followed up at 6 weeks and 3, 6 and 9 months after surgery; they were evaluated by Roles and Maudsley patient satisfaction scores, the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot Score, visual analogue scale (VAS) score and radiographic evaluation., Results: Seventeen patients were studied, with a mean follow-up time of 6.5 months (range 5-24). The mean Roles and Maudsley patient satisfaction score was 1.41 at the last follow-up; most of the patients were satisfied with the surgery results. The mean preoperative AOFAS Ankle-Hindfoot Score was 29.6 (range 18-37), while the mean last follow-up AOFAS Ankle-Hindfoot Score was 68.5 (range 61-80). The VAS score for preoperative functional pain was 6.95 (range 3-10) compared to 1.56 (range 0-3) postoperatively (P < 0.001). The mean surgical duration was 57 (range 42-125) min. The mean time to union was 3.8 months (range 3-12 months); fusion of the ankle and subtalar joint was successful in all patients. One patient experienced delayed wound healing., Conclusions: Tibiotalocalcaneal arthrodesis with headless compression screws for the treatment of severe arthropathy of the ankle and subtalar joint is an effective treatment that is minimally invasive and is associated with a short operation time, high fusion rate, low incidence of complications and good postoperative recovery.

Background: There are many existing operative approaches for subtalar fusion; however, no optional strategy of operative approach has been developed yet. This study aimed to analyze the differential clinical efficacy of subtalar fusion with three operative approaches., Methods: The clinical data of 102 patients from April 2008 to April 2012 were analyzed prospectively. These patients were divided into three groups with the random number table: group A, group B, and group C. The following parameters were compared among three groups: effective exposure area and exposure time of subtalar joint, intraoperative bleeding volume, postoperative complications, fusion time, fusion rate, AOFAS score and VAS score before and after operation., Results: In the exposure area score, there was no statistically significant difference between group A and group C (P > 0.05) ,but with a statistically significant difference between group A/C and group B (P < 0.05). In exposure time and intraoperative bleeding volume, there was no statistically significant difference between group A and group B (P > 0.05) but with a statistically significant difference between group A/B and group C (P < 0.05). In three groups, there was a statistically significant difference in both AOFAS score and VAS score before operation and at 6 months/12 months/last visit after operation (P < 0.05). The incidence of complications in the three groups was 8.8%, 12.5% and 19.4%. No statistically significant differences in fusion rate and fusion time were observed among the three groups (P > 0.05)., Conclusion: Three operative approaches have different indications, All the three operative approaches do not influence the fusion rate and fusion time of subtalar joint. The lateral tarsal sinus approach is inferior to the posterior-lateral L approach and the approach from the inferior tip of fibula to the basilar part of the fourth metatarsal bone in the exposure area, while the lateral tarsal sinus approach and the approach from the inferior tip of fibula to the basilar part of the fourth metatarsal bone are superior to the posterior-lateral L approach in the exposure time, intraoperative bleeding volume, and incidence of complications.