Paracoccus benzoatiresistens sp. nov., a benzoate resistance and selenite reduction bacterium isolated from wetland.

A Gram-stain-negative, aerobic, non-motile, catalase- and oxidase-positive, pale orange, rod-shaped strain EF6T, was isolated from a natural wetland reserve in Hebei province, China. The strain grew at 25-37 °C (optimum, 30 °C), pH 5-9 (optimum, pH 7), and in the presence of 1.0-4.0% (w/v) NaCl (optimum, 2%). A phylogenetic analysis based on 16S rRNA gene sequence revealed that strain EF6T belongs to the genus Paracoccus, and the closest members were Paracoccus shandongensis wg2T with 98.1% similarity, Paracoccus fontiphilus MVW-1 T (97.9%), Paracoccus everestensis S8-55 T (97.7%), Paracoccus subflavus GY0581T (97.6%), Paracoccus sediminis CMB17T (97.3%), Paracoccus caeni MJ17T (97.0%), and Paracoccus angustae E6T (97.0%). The genome size of strain EF6T was 4.88 Mb, and the DNA G + C content was 65.3%. The digital DNA-DNA hybridization, average nucleotide identity, and average amino acid identity values between strain EF6T and the reference strains were all below the threshold limit for species delineation (< 32.8%, < 88.0%, and < 86.7%, respectively). The major fatty acids (≥ 5.0%) were summed feature 8 (86.3%, C18:1 ω6c and/or C18:1 ω7c) and C18:1 (5.0%) and the only isoprenoid quinone was Q-10. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids, five unidentified phospholipids, and an unidentified aminolipid. Strain EF6T displays notable resistance to benzoate and selenite, with higher tolerance levels (25 g/L for benzoate and 150 mM for selenite) compared to the closely related species. Genomic analysis identified six benzoate resistance genes (acdA, pcaF, fadA, pcaC, purB, and catA) and twenty selenite resistance and reduction-related genes (iscR, ssuB, ssuD, selA, selD and so on). Additionally, EF6T possesses unique genes (catA, ssuB, and ssuC) absent in the closely related species for benzoate and selenite resistance. Its robust resistance to benzoate and selenite, coupled with its genomic makeup, make EF6T a promising candidate for the remediation of both organic and inorganic pollutants. It is worth noting that the specific resistance phenotypes described above were not reported in other novel species in Paracoccus. Based on the results of biochemical, physiological, phylogenetic, and chemotaxonomic analyses, combined with comparisons of the 16S rRNA gene sequence and the whole genome sequence, strain EF6T is considered to represent a novel species of the genus Paracoccus within the family Rhodobacteraceae, for which the name Paracoccus benzoatiresistens sp. nov. is proposed. The type strain is EF6T (= GDMCC 1.3400 T = JCM 35642 T = MCCC 1K08702T).

Mariniradius sediminis sp. nov., a multi-xenobiotics degrading genes harbouring bacterium isolated from sediment of river.

A Gram-stain-negative, strictly aerobic, non-motile, catalase- and oxidase-positive, pink and rod-shaped strain, designated RY-2T, was isolated from sediment of Fuyang River located in Wuqiang County, Hengshui City, Hebei Province, PR China. The strain grew at 25-45 °C (optimum, 37 °C), pH 7.0-8.0 (optimum, pH 7.0) and in the presence of 0-1.5 % (w/v) NaCl (optimum, 1 %). From the phylogenetic analysis of the 16S rRNA gene sequence, strain RY-2T was affiliated to the genus Mariniradius, and had the highest 16S rRNA gene sequence similarity to Mariniradius saccharolyticus JCM 17389T (98.3 %) and the similarity values between strain RY-2T and other type strains was all below 89.3 %. The genome size of strain RY-2T was 4.75 Mb and the DNA G+C content was 46.6 %. Values of digital DNA-DNA hybridization and average nucleotide identity between strain RY-2T and the reference strain were 63.2 and 95.5 %, respectively. The major fatty acids (≥5.0 %) were iso-C15 : 0 (37.9 %), summed feature 9 (8.4 %, iso-C17 : 1 ω9c and/or C16 : 010-methyl), anteiso-C15 : 0 (8.2 %), iso-C17 : 0 3-OH (7.6 %) and summed feature 4 (5.2 %, iso-C17 : 1 I and/or anteiso-C17 : 1 B) and its sole menaquinone was MK-7. The polar lipids consisted of phosphatidylethanolamine, an unknown phosphoglycolipid, an unidentified phospholipid, two unidentified aminolipids, three unidentified glycolipids and nine unidentified lipids. Based on the results of biochemical, physiological, phylogenomic and chemotaxonomic analyses, strain RY-2T is considered to represent a novel species of the genus Mariniradius within the family Cyclobacteriaceae, for which the name Mariniradius sediminis sp. nov. is proposed. The type strain is RY-2T (=GDMCC 1.2781T=JCM 35631T).

Flavihumibacter fluminis sp. nov., a novel thermotolerant bacterium isolated from river silt.

A yellow, Gram-stain-positive, strictly aerobic, thermotolerant, non-motile and rod-shaped bacterial strain, designated RY-1T, was isolated from a silt sample of Fuyang River, Wuqiang County, Hengshui City, Hebei Province, PR China. Cells showed oxidase- and catalase-positive activities. Growth occurred at 20-45 °C (optimum, 37 °C) and pH 6.0-8.0 (optimum, pH 7.0), and in the presence of 0-1.5 % (w/v) NaCl (optimum, 0%). A phylogenetic tree based on 16S rRNA gene sequences revealed that strain RY-1T formed a phylogenetic lineage with Flavihumibacter members within the family Chitinophagaceae. A comparison of 16S rRNA gene sequences showed that strain RY-1T was most closely related to Flavihumibacter cheonanensis WS16T (98.6 %), Flavihumibacter sediminis CJ663T (97.7 %) and Flavihumibacter solisilvae 3-3T (97.6 %). The genome size of strain RY-1T was 4.71 Mb, and the DNA G+C content was 44.3  %. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values between strain RY-1T and reference strains were all lower than the threshold values for species delineation. Strain RY-1T contained menaquinone-7 and iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1G as the sole respiratory isoprenoid quinone and major cellular fatty acids (≥5 %), respectively. The major polar lipids consisted of phosphatidylethanolamine, three unidentified aminolipids and four unidentified lipids. According to the results of phenotypic, phylogenetic and chemotaxonomic characteristics, strain RY-1T represents a novel species of the genus Flavihumibacter, for which the name Flavihumibacter fluminis sp. nov. is proposed. The type strain is RY-1T (=GDMCC 1.2775T=JCM 34870T).

Flavobacterium potami sp. nov., a multi-metal resistance genes harbouring bacterium isolated from shallow river silt.

Environmental pollution by heavy metals is becoming an increasing problem and has become a matter of great concern due to the adverse effects worldwide. In this study, we report a novel strain of multi-metal resistant bacteria. A Gram-stain-negative, strictly aerobic, non-motile, yellow, rod-shaped strain 17AT, was isolated from the shallow silt of Fuyang River located in Longdian town, Hengshui city, Hebei province, China. Strain 17AT grew at 20-35 °C (optimum, 30 °C), pH 5-10 (optimum, pH 7) and 0-2% (w/v) NaCl (optimum, 1%). Phylogenetic analyses of 16S rRNA gene sequences showed that strain 17AT was closely related to members of the genus Flavobacterium, and had the highest 16S rRNA gene sequence similarity with 'Flavobacterium panacis' DCY106T (97.5%), followed by Flavobacterium johnsoniae subsp. johnsoniae UW101T (97.3%), Flavobacterium cutihirudinis E89T (97.2%), Flavobacterium limi THG-AG6.4T (97.2%), Flavobacterium hibisci THG-HG1.4T (97.2%) and Flavobacterium johnsoniae subsp. aurantiacum DSM 6792T (97.1%). The genome size of strain 17AT was 5.4 Mb and the DNA G + C content was 34.0%. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values among strain 17AT and reference strains were in the ranges of 79.8-86.1%, 24.1-31.4% and 80.5-88.6%, respectively, lower than the threshold values for species delineation. Strain 17AT contained iso-C15:0 and C16:0 3-OH as the predominant fatty acids (≥ 10%). The main isoprenoid quinone of strain 17AT was identified as MK-6. The polar lipids consisted of phosphatidylethanolamine, three unidentified aminolipids, two unidentified aminophospholipids and six unidentified lipids. Comparative genomics analysis between strain 17AT and its reference type strains revealed that there are a number of metal-resistant genes in strain 17AT, which are located in 15 gene clusters responsible for the copper homeostasis, cobalt-zinc-cadmium resistance, copper resistance, and arsenic/antimony resistance, with the copper resistance protein NlpE being unique to 17AT. Combined data from phenotypic, phylogenetic and chemotaxonomic studies demonstrated that strain 17AT is a representative of a novel species within the genus Flavobacterium, for which the name Flavobacterium potami sp. nov. is proposed. The type strain is 17AT (= GDMCC 1.2723T = JCM 34833T).

Combined approach versus single Henry approach for fixation of die-punch distal radius fractures: a retrospective study.

BACKGROUND: Distal radius fracture (DRF) is one of the most common orthopaedic-related traumas. DRF patients with die-punch fractures have a higher risk of loss of reduction, poorer functional outcomes, and increased risk of complications even after open reduction and internal fixation (ORIF). According to the three-column theory, the lunate fossa is an important part of the intermediate column for load bearing. When the distal radius fracture involves the lunate fossa, adequate anatomical reduction can have an important impact on the prognosis of wrist function. Herein, we used the combined volar and dorsal approach, and the dorsal approach was used to assist in bone grafting or dorsal plate fixation in reducing fractures. We compare the combined approach versus the Henry approach for the fixation of die-punch distal radius fractures. METHODS: We reviewed patients who were admitted for surgery for die-punch fractures from January 2016 to June 2021. The patients were followed-up after surgery to measure and evaluate their Gartland-Werley wrist score, wrist range of motion (ROM), and follow-up imaging data. RESULTS: There were 21 patients in the volar locking plate (VLP) group and 10 patients in the combined approach group. The majority of fractures in the VLP and combined approach groups were AO B and C fractures, respectively. The cause of injury and AO fracture classification showed significant differences between the two groups, and there was no difference in age or sex between the two groups. There was no significant difference in ROM between the two groups, but the VLP group presented a better Gartland-Werley score and volar tilt angle, and the combined group presented better maintenance in radial height and articular congruity. CONCLUSIONS: Reduction through the combined palmar and dorsal approach supplemented by bone grafting or dorsal plate fixation is an effective method for the treatment of die-punch distal radius fractures, which provides a new option for the treatment of die-punch fractures.

Magnetic Resonance Imaging Manifestations of Annular Ligament Injuries in Children With Monteggia Fractures.

BACKGROUND: Magnetic resonance imaging (MRI) is commonly performed in children with elbow injuries to visualize soft tissues such as the annular ligament. Herein, we investigated the MRI manifestations of annular ligament injuries in children with Monteggia fractures following attempted closed reduction. METHODS: The clinical and imaging data of 88 children with acute Monteggia fractures treated at our hospital between 2015 and 2019 were analyzed. Clinically and radiographically, 67 patients achieved radiologic reduction of the radial head at the time of MRI, whereas 21 patients had a failed closed reduction. Annular ligament injury and superior radioulnar joint congruency were analyzed qualitatively, and the maximum superior radioulnar joint gap distance was measured. RESULTS: MRI manifestations of annular ligament injury were primarily characterized as varying degrees of annular ligament displacement, as follows: I degree (10 patients), the annular ligament encircled the radial head without displacement; II degree (5 patients), the annular ligament was partially displaced but visibly encircled the radial head at the level of the radial notch; and III degree (73 patients), the annular ligament was completely displaced. In 15 patients with I and II degrees annular ligament injuries, the annular ligament encircled the radial head (maximum superior radioulnar joint gap distance, 1.2±0.3 mm), showing good congruency of the superior radioulnar joint. In 73 patients with III degree annular ligament injury, the annular ligament was displaced and did not encircle the radial head (maximum superior radioulnar joint gap distance, 3.3±2.7 mm; P <0.05), showing good congruency of the superior radioulnar joint in 25 of 73 patients, and significantly poor congruency in 48 of 73 patients ( P <0.05). CONCLUSIONS: Annular ligament injuries in children with Monteggia fractures exhibit different degrees of displacement of the annular ligament. In I and II degree annular ligament injuries, the annular ligament still encircles the radial head. In III degree annular ligament injuries, the annular ligament is displaced away and is no longer around the radial head. Without the annular ligament restraining the radial head, the superior radioulnar joint is more likely to exhibit poor congruency and increased gap distance. LEVEL OF EVIDENCE: Level II.

Lysobacter selenitireducens sp. nov., isolated from river sediment.

A Gram-stain-negative, yellow-pigmented, motile, flagellated and rod-shaped bacterium, designated as 13AT, was isolated from a river sediment sample of Fuyang River in Hengshui City, Hebei Province, PR China. Strain 13AT grew at 10-37 °C (optimum, 30 °C), at pH 5.0-11.0 (optimum, pH 7.0) and at 0-7 % (w/v) NaCl concentration (optimum, 0 %). Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain 13AT belongs to the genus Lysobacter, and was most closely related to Lysobacter spongiicola DSM 21749T (97.8 %), Lysobacter concretionis DSM 16239T (97.5 %), Lysobacter daejeonensis GIM 1.690T (97.3 %) and Lysobacter arseniciresistens CGMCC 1.10752T (96.9 %). Meanwhile, the type species Lysobacter enzymogenes ATCC 29487T was selected as a reference strain (95.2 %). The genomic size of strain 13AT was 3.0 Mb and the DNA G+C content was 69.0 %. The average nucleotide identity values between strain 13AT and each of the reference type strains L. spongiicola DSM 21749T, L. concretionis DSM 16239T, L. daejeonensis GIM 1.690T, L. arseniciresistens CGMCC 1.10752T and L. enzymogenes ATCC 29487T were 75.9, 76.1, 77.7, 78.0 and 73.2 %, respectively. The digital DNA-DNA hybridization values between strain 13AT and each of the reference type strains were 21.7, 22.2, 21.9, 22.7 and 23.2 %, respectively. The average amino acid identity values between strain 13AT and each of the reference type strains were 72.5, 72.9, 72.3, 75.0 and 69.2 %, respectively. The major fatty acids were iso-C15 : 0, iso-C16 : 0 and summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl). The sole respiratory quinone was identified as ubiquinone-8. The polar lipid profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid, an unidentified lipid, four unidentified phospholipids and two unidentified glycolipids. Based on the phenotypic, physiological, phylogenetic and chemotaxonomic data, strain 13AT represents a novel species of the genus Lysobacter, for which the name Lysobacter selenitireducens sp. nov. is proposed. The type strain is 13AT (=JCM 34786T=GDMCC 1.2722T).

Flavobacterium selenitireducens sp. nov., isolated from rhizosphere soil of ancient mulberry.

A Gram-stain-negative, non-motile, aerobic, yellow, convex, rod-shaped mesophilic bacterial strain, designated strain D33T, was isolated from rhizosphere soil of ancient mulberry in Dezhou city, Shandong province, PR China. The strain grew at 8-37 °C (optimum, 30 °C), pH 4-9 (optimum, pH 7) and growth occurred at 0.5-5.5 % (w/v) NaCl (optimally at 1 %). The results of the phylogenetic analyses of 16S rRNA gene and whole genome sequences indicated that D33T was closely related to members of the genus Flavobacterium and had the highest 16S rRNA gene sequence similarity with 'Flavobacterium agri' KACC 19300 (95.4 %), Flavobacterium ichthyis NST-5T (94.6 %), Flavobacterium ahnfeltiae KCTC 32467T (93.6 %) and Flavobacterium longum JCM 19141T (93.6 %). The genome size of D33T was 3.8 Mb and the DNA G+C content was 48.0 mol%. The average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH) and average amino acid identity (AAI) values among D33T and reference strains were lower than the threshold values for species delineation. The only respiratory quinone of D33T was menaquinone 6 (MK-6). The predominant fatty acids (>5 %) were C15:0, C16 : 0, C18 : 0, iso-C15:0, iso-C17 : 0 3-OH, anteiso-C15 : 0 and summed feature 9 . The polar lipid profile contained phosphatidylethanolamine, two unidentified aminophospholipids, three unidentified aminolipids and two unidentified lipids. Combined data from phenotypic, phylogenetic and chemotaxonomic studies indicated that D33T is a representative of a novel species of the genus Flavobacterium, for which the name Flavobacterium selenitireducens sp. nov. is proposed. The type strain is D33T (=GDMCC 1.1946T=KACC 22131T).

A combination of the K-L and S-P approaches for treating acetabular posterior wall factures accompanied by femoral head fractures with open reduction and internal fixation.

BACKGROUND: In clinical practice, acetabular posterior wall fracture combined with femoral head fracture is rare. However, with the increasing number of engineering and traffic accidents, such fractures, have increased significantly in recent years. This paper aims to explore the clinical efficiency of the Kocher-Langenbeck (K-L) and Smith-Petersen (S-P) combined approaches for open reduction and internal fixation (ORIF) of acetabular posterior wall fractures accompanied by femoral head fractures (Pipkin type IV fractures). METHODS: A retrospective study was conducted on 8 patients who underwent open reduction and internal fixation (ORIF) of Pipkin type IV fractures through the K-L combined with S-P approach in our hospital from January 2015 to January 2020. All 8 patients were successfully operated on without serious complications, such as important blood vessel and nerve damage, with an operation time of 143.8 ± 44.38 min and intraoperative blood loss of 225 ± 70.71 ml. Perioperative data were recorded. The Harris score was used to evaluate the clinical effect. Fracture reduction quality was evaluated according to the Matta radiological standard. The grade of ectopic ossification was evaluated by the Brooker grading method, and the stage of femoral head necrosis was evaluated by Ficat-Arlet staging. RESULTS: The Harris score increased significantly from 57.38 ± 4.779 at 3 months, to 76.13 ± 3.682 at 6 months, 88.25 ± 3.495 at 12 months, and 92.13 ± 2.232 at 36 months postoperatively. After statistical analysis, compared with the previous observation time point, the data comparison differences between the groups were statistically significant. P < 0.001, P < 0.001, P < 0.05). By the time of the latest follow-up, 6 of the 8 patients had recovered to the level of pre-injury sports capacity. In contrast, the other 2 patients remained below the level of pre-injury sports capacity. In terms of imaging evaluation, the quality of fracture reduction on radiographs was graded as excellent in 6 patients and good in 2 patients according to Matta's criteria. At the last follow-up, no heterotopic ossification or femoral head necrosis was found in of all the images. In addition, the hip joint space was normal in 6 cases, mildly narrowed in 1 case, and clearly narrowed in 1 case. CONCLUSIONS: The K-L combined with S-P approach provides effective exposure for the reduction and fixation of Pipkin type IV fractures and achieves satisfactory clinical outcomes.

Finite element analysis of infra-acetabular screw fixation for the treatment of acetabular posterior column fracture.

BACKGROUND: Infra-acetabular screws have been described to increase the fixation strength of acetabular fractures with separation of the columns. Previous studies were based on the simulation of the anterior column fractures without modelling the biomechanical effect of the screw in the posterior column fractures. The purpose of this study was to compare the stability of different internal fixation models of posterior column fracture and to provide a theoretical basis for the clinical application of infra-acetabular screws. METHODS: Five internal fixation models of acetabular posterior column fracture were simulated using five implants, including one reconstruction plate (PCP model), one posterior column screw (PCS model), one infra-acetabular screw (PIS model), one infra-acetabular screw and one reconstruction plate (PIS + PCP model), and one infra-acetabular screw and one posterior column screw (PIS + PCS model). After meshing, material parameter, and boundary condition settings, a vertical downward load of 500 N was applied on the surface of the sacrum. To evaluate the biomechanical properties, the stress distribution and von Mises peak stress were recorded and analyzed, and the displacement distributions of the upper and lower fracture surfaces were compared. RESULTS: In model PCP, the maximum stress of the plate is 71.952 MPa; in model PCS, the maximum stress of the screw is 52.740 MPa; in model PIS, the maximum stress of the screw is 68.985 MPa; in model PIS + PCP, the maximum stress of the plate is 64.695 MPa and the maximum stress of the screw is 39.679 MPa; and in model PIS + PCS, the maximum stress of the posterior column screw is 48.197 MPa and the maximum stress of the infra-acetabular screw is 65.201 MPa. The maximum stresses of implants are all located on the fracture surfaces. The average displacement differences of the upper and lower fracture surfaces are compared as follows: model PIS + PCS (0.03503 mm) < model PIS + PCP (0.08205 mm) < model PCP (0.10096 mm) < model PCS (0.19007 mm) < model PIS (0.23546 mm). CONCLUSION: With sufficient biomechanical stability, infra-acetabular screws can be used as a supplementary fixation for the treatment of acetabular posterior column fractures. It is recommended to fix the fracture by the combined application of the infra-acetabular screw and posterior column screw.

Effect of fibroblast growth factor 2 on degenerative endplate chondrocyte: From anabolism to catabolism.

BACKGROUND: Endplate degeneration is characterized by an unbalance between the anabolism and catabolism of endplate chondrocyte (CH). Fibroblast growth factor 2 (FGF2) has been shown to promote cartilage repair by increasing articular CH anabolic activity. We aimed to explore the effect of FGF2 on the metabolism of endplate CH to elucidate whether FGF2 could be used as a therapy to delay the endplate degeneration. METHODS: We collected the endplate tissue from the patients and tested the collagen II mRNA level as the anabolic marker and the MMP-13 and TIMP-4 expression as the catabolic markers. The FGF2, FGF receptor 1 (FGFR1), and FGFR3 mRNA expression of the endplate tissue were also analyzed. Besides, we treated the CHs with exogenic FGF2 protein, measured the markers mentioned above, the proliferation and the apoptosis of the CHs. To compare the effect of FGF2 on the CHs with or without degeneration, we also induced CHs degeneration by interleukin-1ß (IL-1ß) stimulation and used the FGF2 protein to treat the degenerative CHs. RESULTS: Severely degenerative endplate had a lower collagen II and TIMP-4 mRNA level, but it expressed a more massive amount of MMP-13, FGF2, and FGFR1. FGF2 supplement upregulated the FGFR1/FGFR3, TIMP-4, collagen II expression, and promoted the CHs proliferation. In the first 24 h of IL-1ß treatment, the FGF2 mRNA expression was suppressed, but it significantly increased 48 h later. Meanwhile, the FGFR1 was upregulated, and FGFR3 was inhibited by IL-1ß treatment. Interestingly, the FGF2 protein supplement accelerated the degenerative CHs catabolism by decreasing collagen II and TIPM-4 expression but increasing MMP-13. However, the FGF2 could promote the anabolism process in case of the blocking of FGFR1. The FGF2 supplement could also promote the proliferation and inhibited the apoptosis of degenerative CHs, which could be magnified by FGFR1 blocking. CONCLUSIONS: The results demonstrate that FGF2 is upregulated in the highly degenerative endplate. The supplement of FGF2 contributes to the anabolism in the early phase of endplate degeneration. In the later stage of endplate degeneration, FGF2 turns to accelerate the catabolism, which can be rejected by the reasonable use of FGFR1 inhibitors.

The largest secure corridor of the infra-acetabular screw-a 3-D axial perspective analysis.

BACKGROUND: The infra-acetabular screw which is placed from the pubis to the ischium can be used as a special positional screw of the posterior column of the acetabulum. This study was performed to simulate the surgical procedure and obtain the ideal insertion point, diameter, length and angle of the screw through the method of axial perspective in Chinese patients. METHODS: We randomly collected the pelvic computed tomography (CT) scans of 200 adults. DICOM-formatted CT-scan images were imported into Mimics software to establish the 3D digital model of the right semi-pelvic was established. A virtual cylinder representing the screw was placed from the pubis to the ischium to fix the posterior column. The largest secure diameter and length of the virtual screw were measured and the position of the insertion point and the directions of the screw were also researched. RESULTS: The screw insertion safe zone exhibits an irregular shape of "tear drop" in the reconstructed pelvic model. The mean maximum diameter of screws was 5.01 ± 1.28 mm, and the mean maximum length of screws was 93.99 ± 8.92 mm. The screw insertion corridor with the least diameter 3.5 mm was found in 94 of 100 males (94%) and 86 of 100 females (86%). We found gender-dependent differences for the mean maximum diameter and the maximum length of the screw. There was statistically significant difference between genders in the position of insertion point. CONCLUSIONS: In this study, we suggest an individual preoperative 3D reconstruction simulation to develop better screw placement plans, which provides a valuable guideline for seeking the largest secure corridor of infra-acetabular screw. Further biomechanical studies are needed to verify the function of the screw.

Digital anatomical study and clinical application of screw placement for quadrilateral plate fractures in the danger zone.

BACKGROUND: Direct screw placement for quadrilateral plate fractures in the danger zone of the acetabulum is very difficult. This study was performed to simulate the surgical procedure and try to obtain effective and safe screw angles through the middle window of the ilioinguinal approach in Chinese patients. METHODS: We randomly collected the pelvic computed tomography (CT) scans of 100 adults. DICOM-formatted CT-scan images were imported into Mimics software. The three-dimensional reconstruction (3D) digital model of the semi-pelvis was established. A 3.5 mm cylinder was used to simulate the pathway of the screw from the designated insertion point. The angles of insertion and intersex differences were explored by statistical analyses. RESULTS: The screws could be inserted via three angles: medial inclination, anterior inclination and posterior inclination. The mean minimum medial inclination angle (MIMIA) of insertion point A was 4.96° ± 1.11° in males and 8.66° ± 3.40° in females, and the intersex difference was significant. The mean minimum medial inclination angle (MIMIA) of insertion point B was - 5.31° ± 3.69° in males and 1.75° ± 8.95° in females, and the intersex difference was significant. There were no differences between any of the angles for males and females at insertion point O. CONCLUSIONS: Preoperative measurement and calculation by digital tools before screw placement for quadrilateral plate fractures of the acetabulum are feasible. Double cortical screws could be placed safely in the danger zone through the middle window of the ilioinguinal approach to increase the stability of the acetabulum.

Treatment of post-traumatic chronic osteomyelitis of lower limbs by bone transport technique using mono-lateral external fixator: Follow-up study of 18 cases.

PURPOSE: To review the results of the treatment of post-traumatic chronic osteomyelitis of lower limbs by bone transport technique using mono-lateral external fixator. PATIENTS AND METHODS: A total of 18 patients with post-traumatic chronic osteomyelitis of lower limbs were treated by bone transport technique using mono-lateral external fixator in this study. Seven cases (patients No. 1-7) were performed early BGPO (autologous ilium bone grafting and plate osteosynthesis) intervention after BT (bone transport). The end results were assessed by the criteria of ASAMI and Paley et al. Some data between the cases with and without the intervention of early BGPO were subjected to statistical analysis of Student's t-test. RESULTS: The overall average time for union was 10.8 months. The average union time of the non-early BGPO cases was 52.27 ± 7.82 weeks while the early BGPO cases took a shorter time of 36.86 ± 5.34 weeks (P < 0.001). The overall average duration from bone transport to removal of external fixator was 10.0 months. The average duration from bone transport to removal of external fixator in the non-early BGPO cases was 51.55 ± 7.45 weeks while the early BGPO cases took a shorter time of 29.29 ± 5.47 weeks (P < 0.001). The overall average of BHI was 1.77 months cm(-1). The average of BHI in the non-early BGPO cases was 2.25 ± 0.25 months cm(-1) and the average BHI of the early BGPO cases was 1.22 ± 0.114 months cm(-1) (P < 0.001). There were 31 additional surgeries and 38 complications in total after bone transport treatment. The bone results were excellent in 15 cases, good in 3 cases. The functional results were excellent in 9 cases, good in 6 cases and fair in 3 cases. CONCLUSIONS: 1. Bone transport technique using mono-lateral external fixator is an effective method for the treatment of post-traumatic chronic osteomyelitis. 2. Early BGPO intervention after bone transport is a feasible method to shorten the external fixation time and the total duration of treatment.

Minimally Invasive Sinus Tarsi Approach With Cannulated Screw Fixation Combined With Vacuum-Assisted Closure for Treatment of Severe Open Calcaneal Fractures With Medial Wounds.

The aim of our prospective study was to investigate the clinical results and advantages of a minimally invasive sinus tarsi approach with cannulated screw fixation combined with vacuum-assisted closure for the treatment of severe open calcaneal fractures with medial wounds. A total of 31 patients (32 feet) with open calcaneal fractures who were admitted to our hospital from January 2008 to May 2013 were selected for the study and randomly divided into 2 groups: the cannulated screw group (n = 16 patients, 16 feet) and the plate group (n = 15 patients, 16 feet). The Böhler and Gissane angles were compared before and after surgery. The clinical results were evaluated using according to the American Orthopaedic Foot and Ankle Society ankle-hindfoot scale and the rate of infection. The follow-up duration for all patients ranged from 10 to 36 (mean 24) months. No statistically significant differences were found in the radiologic indicators, incidence of early postoperative complications, or American Orthopaedic Foot and Ankle Society ankle-hindfoot scores (p > .05) between the 2 groups. However, a statistically significant difference was seen in the duration of hospitalization (p < .05) between the 2 groups. A minimally invasive sinus tarsi approach with cannulated screw fixation combined with vacuum-assisted closure is an effective method for the treatment of severe open calcaneal fractures with medial wounds. It provides good reduction and requires fewer days of hospitalization.

Trichosporon asahii infection after total knee arthroplasty: A case report and review of the literature.

Reports of fungal infection after total knee arthroplasty are extremely rare. In most reports, the infecting organism is a Candida species. The present report describes a case involving a 73-year-old immunocompetent woman who underwent total knee arthroplasty and presented one month later with signs of prosthetic infection. She underwent joint debridement and the fluid was sent for culture and sensitivity testing. The culture showed growth of Trichosporon asahii. The patient was administered intravenous and intra-articular injections of amphotericin B, followed by antifungal treatment with voriconazole for one year. At 26 months of follow-up, there was no evidence of infection and the patient was ambulating with a walker. To the authors' knowledge, the present case is the first report of T asahii infection following knee replacement. Early detection, prompt institution of the appropriate antibiotics and regular follow-up are recommended.

Les rapports d'infection fongique sont d'une extrême rareté après une arthroplastie totale du genou. Dans la plupart des rapports, l'organisme infectant fait partie des espèces à Candida. Le présent rapport décrit le cas d'une femme immunocompétente de 73 ans qui a subi une arthroplastie totale du genou et qui, un mois plus tard, a consulté en raison de signes d'infection prosthétique. Elle a subi un débridement articulaire, et le liquide a été envoyé pour mise en culture et test de sensibilité. La culture a révélé une croissance de Trichosporon asahii. La femme a reçu des injections intraveineuses et intra-articulaires d'amphotéricine B, puis un traitement antifongique au voriconazole pendant un an. Après 26 mois de suivi, elle n'avait plus de traces d'infection et pouvait se déplacer avec un déambulateur. En autant que le sache les auteurs, ce cas est le premier rapport d'infection à T asahii après une arthroplastie du genou. Ils recommandent le dépistage précoce, l'amorce rapide des antibiotiques pertinents et un suivi régulier.

Methacrylated gelatin and platelet-rich plasma based hydrogels promote regeneration of critical-sized bone defects.

Physiological repair of large-sized bone defects requires instructive scaffolds with appropriate mechanical properties, biocompatibility, biodegradability, vasculogenic ability and osteo-inductivity. The objective of this study was to fabricate in situ injectable hydrogels using platelet-rich plasma (PRP)-loaded gelatin methacrylate (GM) and employ them for the regeneration of large-sized bone defects. We performed various biological assays as well as assessed the mechanical properties of GM@PRP hydrogels alongside evaluating the release kinetics of growth factors (GFs) from hydrogels. The GM@PRP hydrogels manifested sufficient mechanical properties to support the filling of the tissue defects. For biofunction assay, the GM@PRP hydrogels significantly improved cell migration and angiogenesis. Especially, transcriptome RNA sequencing of human umbilical vein endothelial cells and bone marrow-derived stem cells were performed to delineate vascularization and biomineralization abilities of GM@PRP hydrogels. The GM@PRP hydrogels were subcutaneously implanted in rats for up to 4 weeks for preliminary biocompatibility followed by their transplantation into a tibial defect model for up to 8 weeks in rats. Tibial defects treated with GM@PRP hydrogels manifested significant bone regeneration as well as angiogenesis, biomineralization, and collagen deposition. Based on the biocompatibility and biological function of GM@PRP hydrogels, a new strategy is provided for the regenerative repair of large-size bone defects.

An evaluation of three-dimensional image-guided technologies in percutaneous pelvic and acetabular lag screw placement.

BACKGROUND: Percutaneous stabilization using three-dimensional (3D) navigation system is a promising treatment for pelvic and acetabular fractures. However, there are still some controversies regarding the use of 3D navigation to treat pelvic and acetabular fractures. The purpose of this study was to compare the Iso-C(3D) fluoroscopic navigation, standard fluoroscopy, and two-dimensional (2D) fluoroscopic navigation in placing percutaneous lag screws in pelvic specimens to better understand the merits of 3D navigation techniques. METHODS: Fifty-four instrumentation procedures were performed in this study using six cadaveric pelvic specimens. Three groups were designated for different procedures and tests: group I, standard fluoroscopy; group II, 2D fluoroscopic navigation; and group III, Iso-C(3D) fluoroscopic navigation. Nine screws were placed in each pelvis, including four screws placed bilaterally through the ilium into S1 and S2 vertebrae, four screws placed bilaterally through anterior and posterior columns of acetabulum, and one screw placed through the pubic symphysis. 3D fluoroscopic techniques were evaluated to determine the accuracy of screw position, instrumentation time, and fluoroscopic time. The data were statistically analyzed using SPSS 13.0. RESULTS: The malposition rate was 38.89%, 22.22%, and 0% in standard fluoroscopy, 2D fluoroscopic navigation, and Iso-C(3D) fluoroscopic navigation groups, respectively. There was no significant difference between standard fluoroscopy and 2D fluoroscopic navigation. Compared with Iso-C(3D) fluoroscopic navigation, there were significant differences (analysis of variance [ANOVA], P < 0.05). The mean instrumentation operating time using Iso-C(3D) fluoroscopic navigation technique was 15.4 ± 4.5 min. There were significant differences compared with standard fluoroscopy (31.5 ± 6.2 min) and 2D fluoroscopic navigation (26.3 ± 7.5 min; ANOVA, post hoc Scheffe, P < 0.01). The mean fluoroscopic time of Iso-C(3D) fluoroscopic navigation was 66 ± 4.8 min. Compared with standard fluoroscopy (132.8 ± 7.3 min) and 2D fluoroscopic navigation (47.7 ± 5.6 min), there were significant differences (ANOVA, post hoc least significant difference, P < 0.01). CONCLUSIONS: In the present study, we compared Iso-C(3D) fluoroscopic navigation, 2D fluoroscopic navigation, and standard fluoroscopy. Iso-C(3D) fluoroscopic navigation showed a higher accuracy rate in positioning and a shorter instrumentation operating time. The fluoroscopic time was longer in Iso-C(3D) fluoroscopic navigation than that in standard fluoroscopy, indicating that radiation exposure can be moderately reduced in Iso-C(3D) fluoroscopic navigation operation, although the fluoroscopic time was the shortest in 2D fluoroscopic navigation.

BMP-2 promotes fracture healing by facilitating osteoblast differentiation and bone defect osteogenesis.

OBJECTIVE: To investigate the role of bone morphogenetic protein-2 (BMP-2) in promoting fracture healing in animal models. METHODS: Mouse models with muscle bag heterotopic osteogenesis (HO) were divided into a HO control group (not implanted with 250 µg rhBMP-2 bone repairing material), and a HO observation group (implanted with 250 µg rhBMP-2 bone repairing material); while rat models with bone defect (BD) were divided into a BD control group (not implanted with 250 µg rhBMP-2 bone repairing material) and a BD observation group (implanted with 250 µg rhBMP-2 bone repairing material). At 4 weeks after HO establishment, the new bone formation at the operation site was observed through visual inspections and X-ray scanning. The content of serum alkaline phosphatase (ALP) was detected by automatic biochemical analyzer. The formation of new bone at the operative sites was observed by Hematoxylin and eosin staining and Masson staining. At 0, 2, 4 and 8 weeks after operation, the growth of the defect area and its surrounding callus were observed by X-ray scanning. At 4 and 8 weeks after bone defect establishment in the mouse models, the histological changes and osteogenesis of the bone defect site were observed. RESULTS: The heterotopic osteogenesis experiment showed that at 4 weeks after operation, the mass at the muscle bag in the HO observation group became larger in contrast to the HO control group. X-ray scanning showed that there was obvious irregular bone shadow at the back muscle bag of mice from the HO observation group. The content of serum ALP in the HO observation group was significantly higher than that in the HO control group (all P<0.05). The muscle pocket in the HO observation group showed higher ectopic osteogenic activity comparing with the HO control group. Histological staining showed that bone tissue structure was visible in the newly regenerated bone, forming bone trabeculae and bone marrow tissue. Under the microscope, a large number of osteoblasts arranged neatly in a cubic shape presented at the edge of the new bone, and there were bone lacunae formed, and the bone tissue was in a relatively mature stage. In the rat bone defect models, X-ray scanning showed that the high-density development area was further increased. There was a large amount of callus formation in the bone defect area of the BD observation group, while the BD control group still had no high-density development. At 8 weeks after operation, the high-density development area decreased, indicating that there was partial absorption of callus, while there was still no high-density development in the BD control group. The callus of the bone defect area in the BD observation group was reduced and the defect area was gradually repaired, while the bone defect in the BD control group was still obvious and the bone repair was not completed. CONCLUSIONS: BMP-2 could promote osteoblast differentiation and bone defect osteogenesis in vivo. Thus, it is worthy of clinical application.

A 12-Port MIMO Antenna System for 5G/WLAN Applications.

In this paper, a 12-port MIMO antenna system for 5G/WLAN applications is proposed. The proposed antenna system consists of two types of antenna modules: an L-shaped antenna module covering the C-band (3.4-3.6 GHz) for 5G mobile applications and a folded monopole module for the 5G/WLAN mobile application band (4.5-5.9 GHz). Each two antennas form a pair, six pairs in total, forming a 12 × 12 MIMO antenna array, and the elements between the antenna pairs can achieve an isolation of 11 dB or more without additional decoupling structures. Experimental results show that the antenna can cover the 3.3-3.6 GHz and 4.5-5.9 GHz bands with an overall efficiency greater than 75% and an envelope correlation coefficient less than 0.04. Finally, the one-hand holding mode and two-hand holding mode are discussed to demonstrate their stability in practical applications, and the results show that they still exhibit good radiation and MIMO performance when operating in both modes.