Establishing biosynthetic pathway for the production of p-hydroxyacetophenone and its glucoside in Escherichia coli.

p-Hydroxyacetophenone (p-HAP) and its glucoside picein are plant-derived natural products that have been extensively used in chemical, pharmaceutical and cosmetic industries owing to their antioxidant, antibacterial and antiseptic activities. However, the natural biosynthetic pathways for p-HAP and picein have yet been resolved so far, limiting their biosynthesis in microorganisms. In this study, we design and construct a biosynthetic pathway for de novo production of p-HAP and picein from glucose in E. coli. First, screening and characterizing pathway enzymes enable us to successfully establish functional biosynthetic pathway for p-HAP production. Then, the rate-limiting step in the pathway caused by a reversible alcohol dehydrogenase is completely eliminated by modulating intracellular redox cofactors. Subsequent host strain engineering via systematic increase of precursor supplies enables production enhancement of p-HAP with a titer of 1445.3 mg/L under fed-batch conditions. Finally, a novel p-HAP glucosyltransferase capable of generating picein from p-HAP is identified and characterized from a series of glycosyltransferases. On this basis, de novo biosynthesis of picein from glucose is achieved with a titer of 210.7 mg/L under fed-batch conditions. This work not only demonstrates a microbial platform for p-HAP and picein synthesis, but also represents a generalizable pathway design strategy to produce value-added compounds.

Inhibition of fibroblast activation protein ameliorates cartilage matrix degradation and osteoarthritis progression.

Fibroblast activation protein (Fap) is a serine protease that degrades denatured type I collagen, α2-antiplasmin and FGF21. Fap is highly expressed in bone marrow stromal cells and functions as an osteogenic suppressor and can be inhibited by the bone growth factor Osteolectin (Oln). Fap is also expressed in synovial fibroblasts and positively correlated with the severity of rheumatoid arthritis (RA). However, whether Fap plays a critical role in osteoarthritis (OA) remains poorly understood. Here, we found that Fap is significantly elevated in osteoarthritic synovium, while the genetic deletion or pharmacological inhibition of Fap significantly ameliorated posttraumatic OA in mice. Mechanistically, we found that Fap degrades denatured type II collagen (Col II) and Mmp13-cleaved native Col II. Intra-articular injection of rFap significantly accelerated Col II degradation and OA progression. In contrast, Oln is expressed in the superficial layer of articular cartilage and is significantly downregulated in OA. Genetic deletion of Oln significantly exacerbated OA progression, which was partially rescued by Fap deletion or inhibition. Intra-articular injection of rOln significantly ameliorated OA progression. Taken together, these findings identify Fap as a critical pathogenic factor in OA that could be targeted by both synthetic and endogenous inhibitors to ameliorate articular cartilage degradation.

Exosome modification to better alleviates endoplasmic reticulum stress induced chondrocyte apoptosis and osteoarthritis.

Osteoarthritis (OA) is characterized by cartilage matrix degeneration and chondrocyte apoptosis. Prolonged endoplasmic reticulum (ER) stress participates in chondrocyte apoptosis and cartilage degeneration in OA progression. miR-486-5p could suppress the apoptosis of nucleus pulposus cells and cardiomyocyte, yet whether miR-486-5p modified exosomes could modulate ER stress and apoptosis of chondrocytes remain unknown. We validated the increased inflammation and ER stress in OA synovium and cartilage, and the inhibition of ER stress could attenuate the IL-1ß induced chondrocyte apoptosis. Administration of exogenous miR-486-5p could inhibit the ER stress, alleviate chondrocytes apoptosis and promote matrix regeneration. In comparison with direct administration of miR-486-5p and miR-486-5p overexpressing ADSCs, miR-486-5p modified exosomes indicated a better effect in modulating chondrocyte homeostasis. MiR-486-5p containing exosomes could also regulate macrophage polarization. Our IVIS imaging data validated that intraarticular injection of miR-486-5p containing exosomes could sustain for at least 7 days. MiR-486-5p containing exosomes showed a better effect on alleviating rats OA compared with direct administration of miR-486-5p and miR-486-5p overexpressing ADSCs. Our data demonstrated that miR-486-5p modified exosomes have a better effect on alleviating chondrocyte apoptosis and osteoarthritis. This study provides evidence of this efficient strategy of exosomal miRNA delivery and the miRNA-based therapy for OA.

A Miniaturized Piezoelectric MEMS Accelerometer with Polygon Topological Cantilever Structure.

This work proposes a miniaturized piezoelectric MEMS accelerometer based on polygonal topology with an area of only 868 × 833 µm2. The device consists of six trapezoidal cantilever beams with shorter fixed sides. Meanwhile, a device with larger fixed sides is also designed for comparison. The theoretical and finite element models are established to analyze the effect of the beam's effective stiffness on the output voltage and natural frequency. As the stiffness of the device decreases, the natural frequency of the device decreases while the output signal increases. The proposed polygonal topology with shorter fixed sides has higher voltage sensitivity than the larger fixed one based on finite element simulations. The piezoelectric accelerometers are fabricated using Cavity-SOI substrates with a core piezoelectric film of aluminum nitride (AlN) of about 928 nm. The fabricated piezoelectric MEMS accelerometers have good linearity (0.99996) at accelerations less than 2 g. The measured natural frequency of the accelerometer with shorter fixed sides is 98 kHz, and the sensitivity, resolution, and minimum detectable signal at 400 Hz are 1.553 mV/g, 1 mg, and 2 mg, respectively. Compared with the traditional trapezoidal cantilever with the same diaphragm area, its output voltage sensitivity is increased by 22.48%.

Home Range and Activity Patterns of Free-Ranging Cats: A Case Study from a Chinese University Campus.

Human activities and the available resources influence the home range and activity patterns of free-ranging cats. Our objective in this study was to determine sex and breeding season vs. non-breeding season home range size, as well as activity patterns for unowned free-ranging cats at a university campus in China. Twenty-nine adult cats (fifteen males and fourteen females) were tracked with attached GPS units from October 2018 to June 2020. We considered the effects of sex and breeding status on the home range size of free-ranging cats. Male cats had larger home ranges (95% KDE: 12.60 ± 2.61 ha) than female cats (95% KDE: 5.02 ± 1.34 ha) in the breeding season. There was a seasonal effect on the home range size of male cats; for example, during the non-breeding season, the home range (95% KDE: 6.68 ± 1.22 ha) was smaller than that during the breeding season (95% KDE: 12.60 ± 2.61 ha), while female cats tended to have larger home ranges in the non-breeding season (95% KDE: 7.73 ± 2.77 ha) than in the breeding season (95% KDE: 5.02 ± 1.34 ha). We used the number of activity steps to measure the activity intensity of cats to explore their activity patterns. The mean (±SE) number of steps a cat takes per day was 19,863.96 ± 1627.21. There were two peak periods of activity in a day, 6:00-10:00 and 17:00-21:00. Our study provided a case study of the home range and activity patterns of free-ranging cats living on a Chinese university campus, and the results show that the home range of free-ranging cats is affected by the breeding status and sex, and free-ranging cats have more intense activities at twilight and relatively lower activity intensity in the afternoon. The results provided theoretical support for the management and conservation implications of free-ranging cats in cities.

Clinical effect of arthroscopic long head of biceps transfer and tenodesis on irreparable rotator cuff tear.

OBJECTIVE: To explore the clinical effect of arthroscopic long head of biceps transfer and tenodesis for on irreparable rotator cuff tear. METHODS: A total of 18 patients with irreparable rotator cuff tear who were treated in the Dongfang Hospital Affiliated to Tongji University School of Medicine from April 2018 to March 2020 were included in this study. They all underwent arthroscopic long head of biceps transfer and tenodesis. Shoulder joint motions (forward flexion, abduction, and external rotation angle) and magnetic resonance imaging (MRI) were performed. Moreover, visual analogue scale (VAS) and university of California Los Angeles (UCLA) score were conducted during follow-up. RESULTS: Preoperative symptoms lasted from 3 to 16 months, with an average duration of 10 months. All patients healed in the first stage without obvious complications were included. All patients were followed up for 4 to 14 months after the surgery, with an average duration of 11.1 months. The range of shoulder joint motions, including forward flexion (80.52° ± 31.19° vs. 149.47° ± 28.36°), abduction (65.13° ± 37.59° vs. 152.46° ± 28.64°) and lateral rotation (30.17° ± 15.15° vs. 71.49° ± 11.42°) was significantly improved after operation (P < 0.05). The VAS score was notably decreased after operation (8.46 ± 0.80 vs. 1.55 ± 0.70), but the UCLA score was markedly increased (15.27 ± 2.89 vs. 31.17 ± 2.36). MRI imaging showed that 15 patients had good tissue healing, with a healing rate of 83.3% (15/18). CONCLUSION: Arthroscopy of the biceps long head tendon transposition can significantly relieve pain in patients with large rotator cuff tears, improve joint mobility, and restore joint function.

CRISPR-based metabolic engineering in non-model microorganisms.

Non-model microorganisms possess unique and versatile metabolic characteristics, offering great opportunities as cell factories for biosynthesis of target products. However, lack of efficient genetic tools for pathway engineering represents a big challenge to unlock the full production potential of these microbes. Over the past years, CRISPR systems have been extensively developed and applied to domesticate non-model microorganisms. In this paper, we summarize the current significant advances in designing and constructing CRISPR-mediated genetic modification systems in non-model microorganisms, such as bacteria, fungi and cyanobacteria. We particularly put emphasis on reviewing some successful implementations in metabolic pathway engineering via CRISPR-based genome editing tools. Moreover, the current barriers and future perspectives on improving the editing efficiency of CRISPR systems in non-model microorganisms are also discussed.

Genistein loaded into microporous surface of nano tantalum/PEEK composite with antibacterial effect regulating cellular response in vitro, and promoting osseointegration in vivo.

Poly(ether-ether-ketone) (PEEK) with good biocompatibility exhibits high mechanical strengths but bioinert. In addition, tantalum (Ta) possesses outstanding osteogenesis but high density and elastic modulus, and cost. In this study, by blending Ta nanoparticles with PEEK, Ta/PEEK composite (TP) was prepared, which was then treated by concentrated sulfuric acid to form a microporous surface containing Ta particles on TP (TPS). Moreover, genistein (GS) with antibacterial property was loaded into the microporous surface of TPS (TPSG). Compared with TP, the surface properties (e.g., surface roughness and hydrophilicity) of TPS was obviously improved because of the microporous surface including Ta nanoparticles. Moreover, TPS showed low antibacterial properties because of presence of sulfonic group while TPSG exhibited excellent antibacterial properties due to GS loaded into the microporous surface. Furthermore, compared with TP, TPS obviously promoted attachment and proliferation of MG63 cells, while TPSG with GS remarkably inducing osteogenic differentiation of the cells compared with TPS in vitro. Moreover, in comparison with TP, TPS with optimized surface properties promoted new bone regeneration and osseointegration, while TPSG loading GS further enhanced bone regeneration as well as osseointegration in vivo. In summary, the GS loaded into microporous surface including Ta nanoparticles of TPSG exhibited antibacterial and osteogenic activity, which would have great potential for bone tissue repair.

Adipose-derived stem cell exosomes facilitate rotator cuff repair by mediating tendon-derived stem cells.

Aim: To evaluate the potential capability of adipose-derived stem cell exosomes (ADSC-exos) on rotator cuff repair by mediating the tendon-derived stem cells (TDSCs) and explored the mechanism. Methods: First, we investigated the growth, survival and migration of TDSCs in the presence of ADSC-exos in vitro. Using a rat rotator cuff injury model to analyze the ability of the ADSC-exos to promote rotator cuff healing in vivo. Results: The hydrogel with ADSC-exos significantly improved the osteogenic and adipogenesis differentiation and enhanced the expression of RUNX2, Sox-9, TNMD, TNC and Scx and the mechanical properties of the articular portion. Conclusion: The ADSC-exos have the potential to promote the rotator cuff repair by mediating the TDSCs.

Lateral to medial fibro-adipogenic degeneration are greater in infraspinatus than supraspinatus following nerve and tendon injury of murine rotator cuff.

Small animal models of massive tears of the rotator cuff (RC) were introduced a decade ago and have been extensively used to study the pathophysiology of chronically injured RC. Transection of rodent suprascapular nerve and RC tendon results in progressive muscle atrophy, fibrosis and fat accumulation and affect the infraspinatus and supraspinatus muscles similarly to that seen in the setting of massive RC tears in humans. The purpose of this study was to perform a comprehensive and detailed analysis of the kinetics of fibrotic scar and adipose tissue development comparing phenotypic differences between chronically injured infraspinatus and supraspinatus. Automatic mosaic imaging was used to create large image of whole infraspinatus or supraspinatus sectioned area for quantification of spatial heterogeneity of muscle damage. Pathologic changes advanced from the lateral site of transection to the medial region far from the transection site. A prominent, accelerated muscle fibrosis and fat accumulation was measured in injured infraspinatus compared to supraspinatus. Furthermore, adipose tissue occupied significantly larger area than that of fibrotic tissue in both muscles but was greater in infraspinatus within 6 weeks post induction of injury. Our findings confirm that infraspinatus is more susceptible to accelerated chronic degeneration and can be used to identify the physiological functions that distinguish between the response of infraspinatus and supraspinatus in the setting of massive tears. Whether these pathologic differences observed in mice are reflected in humans is one key aspect that awaits clarification.

Metal Organic Framework@Polysilsesequioxane Core/Shell-Structured Nanoplatform for Drug Delivery.

Modern pharmaceutics requires novel drug loading platforms with high drug loading capacity, controlled release, high stability, and good biocompacity. Metal-organic frameworks (MOFs) show promising applications in biomedicine owing to their extraordinarily high surface area, tunable pore size, and adjustable internal surface properties. However, MOFs have low stability due to weak coordinate bonding and limited biocompatibility, limiting their bioapplication. In this study, we fabricated MOFs/polysilsesquioxane (PSQ) nanocomposites and utilized them as drug carriers. Amine-functionalized MOF (UiO-66-NH2) nanoparticles were synthesized and encapsulated with epoxy-functionalized polysilsesquioxane layer on the surface via a facile process. MOFs possessed high surface area and regular micropores, and PSQs offered stability, inertness, and functionality. The obtained UiO-66-NH2@EPSQ nanocomposites were utilized as carriers for ibuprofen, a drug with carboxylic groups on the surface, and demonstrated high drug loading capacity and well-controlled release property. The UiO-66-NH2@EPSQ nanocomposite exhibited low cytotoxicity to HeLa cells within a wide concentration range of 10-100 µg/mL, as estimated by the MTT method. The UiO-66-NH2@EPSQ drug release system could be a potential platform in the field of controlled drug delivery.

Mercapto-Functionalized Porous Organosilica Monoliths Loaded with Gold Nanoparticles for Catalytic Application.

Porous organosilica monoliths have attracted much attention from both the academic and industrial fields due to their porous structure; excellent mechanical property and easily functionalized surface. A new mercapto-functionalized silicone monolith from a precursor mixture containing methyltrimethoxysilane; 3-mercaptopropyltrimethoxysilane; and 3-mercaptopropyl(dimethoxy)methylsilane prepared via a two-step acid/base hydrolysis-polycondensation process was reported. Silane precursor ratios and surfactant type were varied to control the networks of porous monolithic gels. Gold nanoparticles were loaded onto the surface of the porous organosilica monolith (POM). Versatile characterization techniques were utilized to investigate the properties of the synthesized materials with and without gold nanoparticles. Scanning electron microscopy was used to investigate the morphology of the as-synthesized porous monolith materials. Fourier transform infrared spectroscopy was applied to confirm the surface chemistry. 29Si nuclear magnetic resonance was used to investigate the hydrolysis and polycondensation of organosilane precursors. Transmission electron microscopy was carried out to prove the existence of well-dispersed gold nanoparticles on the porous materials. Ultraviolet-visible spectroscopy was utilized to evaluate the high catalytic performance of the as-synthesized Au/POM particles.

Functional Metal Organic Framework/SiO2 Nanocomposites: From Versatile Synthesis to Advanced Applications.

Metal organic frameworks (MOFs), also called porous coordination polymers, have attracted extensive attention as molecular-level organic-inorganic hybrid supramolecular solid materials bridged by metal ions/clusters and organic ligands. Given their advantages, such as their high specific surface area, high porosity, and open active metal sites, MOFs offer great potential for gas storage, adsorption, catalysis, pollute removal, and biomedicine. However, the relatively weak stability and poor mechanical property of most MOFs have limited the practical application of such materials. Recently, the combination of MOFs with inorganic materials has been found to provide a possible strategy to solve such limitations. Silica, which has excellent chemical stability and mechanical properties, shows great advantages in compounding with MOFs to improve their properties and performance. It not only provides structured support for MOF materials but also improves the stability of materials through hydrophobic interaction or covalent bonding. This review summarizes the fabrication strategy, structural characteristics, and applications of MOF/silica composites, focusing on their application in chromatographic column separation, catalysis, biomedicine, and adsorption. The challenges of the application of MOF/SiO2 composites are addressed, and future developments are prospected.

Raspberry-Like Polysilsesquioxane Particles with Hollow-Spheres-on-Sphere Structure: Rational Design, Controllable Synthesis, and Catalytic Application.

Raspberry-like hollow-spheres-on-sphere (HSOS) particles with reactive surfaces, uniform sizes and monodisperse properties were rational designed and fabricated to immobilize gold nanoparticles for the catalytic reduction of 4-nitrophenol. HSOS polysilsesquioxane (PSQ) particles were constructed by an organic alkali catalyzed sol-gel process from trialkoxysilane precursors with stabilized polystyrene (PS) nanoparticles as both a sacrifice template and a Pickering emulsifier. The PSQ particles were fabricated in an ice bath with methyltrimethoxysilane and mercaptopropyltrimethoxysiane as a co-precursor, tetramethylammonium hydroxide (TMAH) as a catalyst, polyvinylpyrrolidone (PVP) and sodium lignosulfonat as co-stabilizers and PS latex as a hard template. The formation mechanism of the hierarchical particles was investigated in detail by the time study through imaging the particles at regular time intervals during the reaction process. Various effect factors on the morphology were studied systematically which showed that the precursor composition, the content of PS, TMAH and PVP are the most important factors. The hierarchical structure combined with the mercaptopropyl groups on both the surface and the skeleton to make it possible to adsorb guest molecules. Au nanoparticles were immobilized on the particles for the catalytic reduction of 4-nitrophenol to 4-aminophenol. The unique PSQ colloids with hollow-spheres-on-sphere extended the family of the hierarchical structures and has shown the potential applications in separations, drug delivery and heterogeneous catalysts.

Magnetic Resonance Imaging and Biomechanical Analysis of Adipose-derived Stromal Vascular Fraction Applied on Rotator Cuff Repair in Rabbits.

BACKGROUND: Adipose-derived stromal vascular fraction (ADSVF) can be applied to repair tendon and ligament tears. ADSVF treatment has a better therapeutic potential than adipose stem cells alone in promoting the healing of connective tissue injury in rabbit models. Magnetic resonance imaging (MRI) and biomechanical testing were used in this study to evaluate the efficiency of SVF in the healing of tendon-bone interface of a rotator cuff injury after reattachment. METHODS: A total of 36 rabbits were studied between March and June 2016, 18 rabbits received the SVF-fibrin glue (SVF-FG) treatment and the other 18 formed the control group. ADSVF was isolated from each rabbit. A bilateral amputation of the supraspinatus tendon and parallel reconstruction was also performed on all the 36 rabbits. Then, a mixture of SVF and FG was injected into the tendon-bone interface of the SVF-FG group, whereas the control group only received FG. The animals were randomly sacrificed at 4, 8, and 12 weeks after surgery (n = 6 per group), respectively. The shoulders were prepared for MRI scanning and analysis of biomechanical properties. Analyses of variance were performed using SPSS 13.0. RESULTS: MRI scanning showed that the signal-to-noise quotient of the SVF-FG group was not significantly higher than that of the control group at either 4 (20.1 ± 3.6 vs. 18.2 ± 3.4, F = 1.570, P = 0.232) or 8 weeks (20.7 ± 3.3 vs. 18.0 ± 3.0, F = 2.162, P = 0.117) posttreatment, and only became significant after 12 weeks (27.5 ± 4.6 vs. 22.1 ± 1.9, F = 4.968, P = 0.009). Biomechanical properties such as the maximum load, maximum strength, and the stiffness for the SVF-FG group were significantly greater than that for the control group at 8 weeks' posttreatment (maximum load: 166.89 ± 11.62 N vs. 99.40 ± 5.70 N, P < 0.001; maximum strength: 8.22 ± 1.90 N/mm vs. 5.82 ±0.68 N/mm, P < 0.010; and the stiffness: 34.85± 3.00 Pa vs. 24.57± 5.72 Pa, P < 0.010). CONCLUSION: Local application of ADSVF might lead to better tendon-bone healing in rabbit models.

Bioinformatics analysis of gene expression profiles in B cells of postmenopausal osteoporosis patients.

OBJECTIVE: The aim of this study was to gain a better understanding of the molecular mechanisms and identify more critical genes associated with the pathogenesis of postmenopausal osteoporosis (PMOP). MATERIALS AND METHODS: Microarray data of GSE13850 were download from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified either in B cells from postmenopausal female nonsmokers with high bone mineral density (BMD) compared with those with low BMD (defined as DEG1 group) or in B cells from postmenopausal female smokers with high BMD compared with postmenopausal female nonsmokers with high BMD (defined as DEG2 group). Gene ontology and immune-related functional enrichment analysis of DEGs were performed. Additionally, the protein-protein interaction network of all DEGs was constructed and subnetworks of the hub genes were extracted. RESULTS: A total of 51 DEGs were identified in the DEG1 group, including 30 up- and 21 downregulated genes. Besides, 86 DEGs were identified in the DEG2 group, of which 46 were upregulated and 40 were downregulated. Immune enrichment analysis showed DEGs were mainly enriched in functions of CD molecules and chemokines and receptor, and the upregulated gene interleukin 4 receptor (IL-4R) was significantly enriched. Moreover, guanine nucleotide-binding protein G (GNAI2), filamin A alpha (FLNA), and transforming growth factor-ß1 (TGFB1) were hub proteins in the protein-protein interaction network. CONCLUSION: IL-4R, GNAI2, FLNA, and TGFB1 may be potential target genes associated with the pathogenesis of PMOP. In particular, FLNA, and TGFB1 may be affected by smoking, a risk factor of PMOP.

Identification of crucial genes related to postmenopausal osteoporosis using gene expression profiling.

BACKGROUND: Postmenopausal osteoporosis is a common bone disease and characterized by low bone mineral density. AIM: This study aimed to reveal key genes associated with postmenopausal osteoporosis (PMO), and provide a theoretical basis for subsequent experiments. METHODS: The dataset GSE7429 was obtained from Gene Expression Omnibus. A total of 20 B cell samples (ten ones, respectively from postmenopausal women with low or high bone mineral density (BMD) were included in this dataset. Following screening of differentially expressed genes (DEGs), coexpression analysis of all genes was performed, and key genes in the coexpression network were screened using the random walk algorithm. Afterwards, functional and pathway analyses were conducted. Additionally, protein-protein interactions (PPIs) between DEGs and key genes were analyzed. RESULTS: A set of 308 DEGs (170 up-regulated ones and 138 down-regulated ones) between low BMD and high BMD samples were identified, and 101 key genes in the coexpression network were screened out. In the coexpression network, some genes had a higher score and degree, such as CSTA. The key genes in the coexpression network were mainly enriched in GO terms of the defense response (e.g., SERPINA1 and CST3), immune response (e.g., IL32 and CLEC7A); while, the DEGs were mainly enriched in structural constituent of cytoskeleton (e.g., CYLC2 and TUBA1B) and membrane-enclosed lumen (e.g., CCNE1 and INTS5). In the PPI network, CCNE1 interacted with REL; and TUBA1B interacted with ESR1. CONCLUSIONS: A series of interactions, such as CSTA/TYROBP, CCNE1/REL and TUBA1B/ESR1 might play pivotal roles in the occurrence and development of PMO.

Arthroscopic transtendinous repair of articular-sided pasta (partial articular supraspinatus tendon avulsion) injury.

OBJECTIVE: To evaluate clinical efficacy of arthroscopic transtendinous repair of partial articular-sided PASTA (partial articular supraspinatus tendon avulsion) injury. METHODS: From February 2011 to July 2014, 12 cases of PASTA, aged 29 to 72 years with an average of 52.9 ± 13.3 years, were treated arthoscopically. To repair PASTA, articular-sided rotator cuff tear was explored, injury site was punctured and labeled with PDS absorbable monofilament suture (Ethicon, Somerville, NJ, USA) suture, subacromial bursa was cleaned up with acromioplasty, and integrity of bursa-side rotator cuff was assessed. Then with arthroscope in glenohumeral joint, footprint of the bursa-side supraspinatus tendon was preserved, rivets were introduced into the joint through supraspinatus tendon, joint-side partial tear was sutured, and anatomical reconstruction of the rotator cuff footprint was established. The patients were followed up post-operatively for 12-36 months, average 22 ± 7.3 months. The clinical outcomes were emulated with ASES (American Shoulder and Elbow Surgeons) Shoulder Score system and UCLA (University of California at Los Angeles) Shoulder rating scale. RESULTS: The post-operative ASES score was 89.7 ± 5.6, higher than the pre-operative one 49.8 ± 9.8 (t = 12.25, P <0.0001). While UCLA scale increased from the pre-operative 17.3, ± 3.3 to the post-operative 30.4 ± 3.2 points (t = 9.87, P <0.0001), with a satisfaction rate of 11/12 (91.7%). CONCLUSION: Trans-tendon repair is ideal for PASTA with advantage of maximal preservation of the normal rotator cuff tissue, anatomical reconstruction of the rotator cuff footprint and stable fixation of tendon-bone interface.

Arthroscopic characteristics of meniscal injuries in osteoarthritic knees.

OBJECTIVE: The aim of this study was to investigate the arthroscopic characteristics of meniscal injuries in osteoarthritic knees and explore their significance in the selection of surgical approach. METHODS: Four original types of meniscal injuries were defined. The study included 87 cases; 12 Type 1, 26 Type 2, 35 Type 3 and 14 in Type 4 meniscal injuries. For Type 1 injuries, 5 cases underwent meniscal suture repair and 7 cases partial meniscal resection. Partial meniscal resection was performed in 22 cases and subtotal resection in 4 cases of Type 2 injury. For Type 3 injury, meniscal debridement was performed in 2, partial resection in 8, subtotal resection in 19 and total resection in 6 cases. For Type 4 injury, 3 cases underwent subtotal resection and 11 underwent total resection. Patients were evaluated with the Lysholm, visual analog scale, and Kellgren-Lawrence scale scores and cartilage lesions stages. RESULTS: Mean follow-up period was 26 (range: 8 to 51) months. Joint swelling or pain was present in 13 cases after fatigue. Twist lock symptom was observed in one Type 3 injury and one Type 4 injury. Joint flexion was limited to 20° in one Type 3 injury and two Type 4 injuries. Total knee joint replacement was performed in two Type 2 and two Type 4 injuries 2 to 3 years and 2 months after surgery. CONCLUSION: The classification of meniscal injuries in osteoarthritic knees was designed to guide arthroscopic surgery and improve the therapeutic efficacy of minimally invasive surgery for knee osteoarthritis.