Molecular characterization and functionality of rumen-derived extracellular vesicles using a Caenorhabditis elegans animal model.

The rumen fluids contain a wide range of bacteria, protozoa, fungi, and viruses. The various ruminal microorganisms in the rumen provide nutrients by fermenting the forage they eat. During metabolic processes, microorganisms present in the rumen release diverse vesicles during the fermentation process. Therefore, in this study, we confirmed the function of rumen extracellular vesicles (EVs) and their interaction with the host. We confirmed the structure of the rumen EVs by transmission electron microscope (TEM) and the size of the particles using nanoparticle tracking analysis (NTA). Rumen EVs range in size from 100 nm to 400 nm and are composed of microvesicles, microparticles, and ectosomes. Using the Caenorhabditis elegans smart animal model, we verified the interaction between the host and rumen EVs. Exposure of C. elegans to rumen EVs did not significantly enhance longevity, whereas exposure to the pathogenic bacteria Escherichia coli O157:H7 and Staphylococcus aureus significantly increased lifespan. Furthermore, transcriptome analysis showed gene expression alterations in C. elegans exposed to rumen EVs, with significant changes in the metabolic pathway, fatty acid degradation, and biosynthesis of cofactors. Our study describes the effect of rumen EV interactions with the host and provides novel insights for discovering biotherapeutic agents in the animal industry.

Melanin Treatment Effect of Vacuoles-Zinc Oxide Nanoparticles Combined with Ascorbic Acid.

Currently, ascorbic acid (AA) is widely used as a skin whitening material, but, AA, an unstable hydrophilic molecule, cannot penetrate the skin easily, due to the hydrophobic character of the stratum corneum. Therefore, we conjugated AA with hydrated zinc oxide-an inorganic matrix with positive surface charge, to improve the stability of AA. The metal-conjugated-ascorbic acid (ZnAA) was then combined with yeast vacuole through the vacuolar membrane proteins that relate to metal transportation to create an enhanced vacuole that contained ZnAA. The characteristics of vacuole with ZnAA (ZnAA_Vac) were next examined by various tests that included X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray (EDX) analysis. Furthermore, the ability of ZnAA_Vac to degrade melanin was confirmed in both melanoma cell line B16F10, and the artificial human skin MelanoDerm. The results showed that ZnAA_Vac possessed a higher depigmenting effect than the wild-type vacuole or ascorbic acid by reducing 75% of melanin color. Interestingly, ZnAA_Vac was found to be harmless, and did not cause any cytotoxicity to the cells. Overall, ZnAA_Vac is expected to provide a robust, harmless, and effective whitening agent for the skin.

Compound of Cynanchum wilfordii and Humulus lupulus L. Ameliorates Menopausal Symptoms in Ovariectomized Mice.

Cynanchum wilfordii and Humulus lupulus L. have been used for their various pharmacological properties in South Korea as a traditional medicine or health functional food, respectively, and their intake may relieve menopausal symptoms. The purpose of current study was to determine the effect of compound of Cynanchum wilfordii and Humulus lupulus L. (CWHL) in menopausal symptoms of ovariectomized (OVX) mice. OVX mice received CWHL or caudatin (an active ingredient of CWHL) once daily for 7 weeks. Values for hypothalamic serotonin (5-HT), dopamine, norepinephrine, estrogen receptor (ER)-ß, 5-HT1A, and 5-HT2A were significantly enhanced, while value for hypothalamic monoamine oxidase A was reduced in CWHL and caudatin groups compared with the OVX group. CWHL and caudatin significantly reduced tail skin temperature and rectal temperature of OVX mice through partial recovering of the levels of serum estrogen, nitric oxide, follicle-stimulating hormone, luteinizing hormone, and receptor-activator of the NF-κB ligand (RANKL). Moreover, CWHL and caudatin improved bone mineral density via decreasing levels of serum RANKL, tartrate-resistant acid phosphatase, and collagen type 1 cross-linked N-telopeptide and improving levels of serum alkaline phosphatase, osteoprotegerin, and osteocalcin compared with the OVX group without adverse effects such as dyslipidemia. CWHL increased uterine ER-ß levels but did not change uterus and vaginal weights. Taken together, the results indicate that CWHL may relieve menopausal symptoms by controlling depression-, hot flashes-, and osteoporosis-associated biomarkers. Therefore, we propose that CWHL might be a safe and potential candidate for management of menopause as a health functional food.

The C. elegans regulatory factor X (RFX) DAF-19M module: A shift from general ciliogenesis to cell-specific ciliary and behavioral specialization.

Cilia are important for the interaction with environments and the proper function of tissues. While the basic structure of cilia is well conserved, ciliated cells have various functions. To understand the distinctive identities of ciliated cells, the identification of cell-specific proteins and its regulation is essential. Here, we report the mechanism that confers a specific identity on IL2 neurons in Caenorhabditis elegans, neurons important for the dauer larva-specific nictation behavior. We show that DAF-19M, an isoform of the sole C. elegans RFX transcription factor DAF-19, heads a regulatory subroutine, regulating target genes through an X-box motif variant under the control of terminal selector proteins UNC-86 and CFI-1 in IL2 neurons. Considering the conservation of DAF-19M module in IL2 neurons for nictation and in male-specific neurons for mating behavior, we propose the existence of an evolutionarily adaptable, hard-wired genetic module for distinct behaviors that share the feature "recognizing the environment."

Renoprotective Effect of KLF2 on Glomerular Endothelial Dysfunction in Hypertensive Nephropathy.

Kruppel-like factor 2 (KLF2) regulates endothelial cell metabolism; endothelial dysfunction is associated with hypertension and is a predictor of atherosclerosis development and cardiovascular events. Here, we investigated the role of KLF2 in hypertensive nephropathy by regulating KLF2 expression in human primary glomerular endothelial cells (hPGECs) and evaluating this expression in the kidney tissues of a 5/6 nephrectomy mouse model as well as patients with hypertension. Hypertension-mimicking devices and KLF2 siRNA were used to downregulate KLF2 expression, while the expression of KLF2 was upregulated by administering simvastatin. After 4 mmHg of pressure was applied on hPGECs for 48 h, KLF2 mRNA expression decreased, while alpha-smooth muscle actin (αSMA) mRNA expression increased. Apoptosis and fibrosis rates were increased under pressure, and these phenomena were aggravated following KLF2 knockdown, but were alleviated after simvastatin treatment; additionally, these changes were observed in angiotensin II, angiotensin type-1 receptor (AT1R) mRNA, and interleukin-18 (IL-18), but not in angiotensin type-2 receptor mRNA. Reduced expression of KLF2 in glomerular endothelial cells due to hypertension was found in both 5/6 nephrectomy mice and patients with hypertensive nephropathy. Thus, our study demonstrates that the pressure-induced apoptosis and fibrosis of glomerular endothelial cells result from angiotensin II, AT1R activation, and KLF2 inhibition, and are associated with IL-18.

The patient-rated tennis elbow evaluation questionnaire was successfully translated to Korean.

INTRODUCTION: Lateral epicondylitis is a common tendinopathy of the elbow. An adequately validated questionnaire is essential to compare the various treatment options, because there is still controversy regarding the best treatment for lateral epicondylitis. PURPOSE OF THE STUDY: The patient-rated tennis elbow evaluation (PRTEE) was introduced to measure the degree of symptoms and the limitation of function in these patients. This English questionnaire was previously translated into several languages and validated; however, it has not been translated into Korean. The aim of this study was to translate and cross-culturally adapt the PRTEE questionnaire into Korean, and to assess the reliability and validity of the translated questionnaire. METHODS: Eighty-three patients were asked to complete the Korean version of the PRTEE and other questionnaires related to the upper extremity or to the general health condition (the Disabilities of Arm, Shoulder, and Hand questionnaire, Short Form-12, and EQ-5D). The PRTEE responses were recorded twice to evaluate test-retest reliability. Internal consistency, test-retest reliability, concurrent validity, and ceiling and flooring effects were evaluated. RESULTS: The Korean version of the PRTEE showed high internal consistency (Cronbach's alpha = 0.968). The overall test-retest reliability was good (intra-class correlation score = 0.94). High correlation efficiencies between the PRTEE and other questionnaires were observed, supporting high concurrent validity (Spearman's correlation = 0.83 for the Disabilities of Arm, Shoulder, and Hand questionnaire; -0.73 for Short Form-12; and -0.57 for EQ-5D). Ceiling and floor effects were not observed on this test. CONCLUSION: We successfully translated the PRTEE into the Korean language; this version of the PRTEE showed good reliability and construct validity in Korean-speaking patients with lateral epicondylitis.

Death-Associated Protein 6 (Daxx) Alleviates Liver Fibrosis by Modulating Smad2 Acetylation.

Transforming growth factor-ß (TGF-ß) has been identified as an inducer of hepatocyte epithelial-mesenchymal transition (EMT), which triggers liver fibrosis. Death-associated protein 6 (Daxx) is known to be associated with the TGF-ß-induced apoptotic pathway, but the function of Daxx in liver fibrosis remains unknown. This study aimed to elucidate the role of Daxx in liver fibrosis. We used liver fibrosis tissues from humans and mice to assess Daxx expression. EMT properties and TGF-ß signaling pathway activation were investigated in the Daxx-overexpressing FL83B cell line. The therapeutic effect of Daxx was investigated in a mouse model of liver fibrosis by the hydrodynamic injection of plasmids. The expression of Daxx was markedly decreased in hepatocytes from fibrotic human and mouse livers, as well as in hepatocytes treated with TGF-ß in vitro. The overexpression of Daxx inhibited the EMT process by interfering with the TGF-ß-induced phosphorylation of Smad2. Coimmunoprecipitation analysis confirmed that Daxx reduced the transcriptional activity of Smad2 by binding to its MH1 domain and interfering with Smad2 acetylation. In addition, the therapeutic delivery of Daxx alleviated liver fibrosis in a thioacetamide-induced fibrosis mouse model. Overall, our results indicate that Daxx could be a potential therapeutic target to modulate fibrogenesis, as well as a useful biomarker for liver fibrosis.

Intracellular protein delivery using QRPL - A vacuolar targeting signal on carboxypeptidase Y.

The signal peptide sequence is known to increase transport efficiency to organelles in eukaryotic cells. In this study, we focus on the signal peptide of the vacuolar protein for vacuolar targeting. The signal peptide sequence QRPL of carboxypeptidase Y (CPY) was inserted inside the interest protein that does not locate in the vacuole for vacuolar targeting. We constructed recombinant strains MBTL-Q-DJ1 and MBTL-Q-DJ2 containing QRPL and green florescent protein (GFP) or aldehyde dehydrogenase 6 (ALD6), respectively. The protein location was then confirmed by confocal microscopy. Fascinatingly, the green fluorescent protein that contains QRPL inside the sequence could be expressed faster than its natural form (within 1 h after induction). Also, the aldehyde removal activity of ALD6 protein in the recombinant yeast was then analyzed by measuring the luminescent intensity in Vibrio fischeri. We confirmed that MBTL-Q-DJ2 containing ALD6 protein has the aldehydes-reducing ability, and in particular, the highest efficiency showed at 500 µg/µL of vacuolar enzyme. In summary, the signal peptide QRPL could be used not only to transport proteins accurately to vacuole but also to improve the protein activity and shorten the induction time.

Development of Er3+, Yb3+ Co-Doped Y2O3 NPs According to Yb3+ Concentration by LP-PLA Method: Potential Further Biosensor.

As diagnostic biosensors for analyzing fluids from the human body, the development of inorganic NPs is of increasing concern. For one, nanoceramic phosphors have been studied to meet the increasing requirements for biological, imaging, and diagnostic applications. In this study, Y2O3 NPs co-doped with trivalent rare earths (erbium and ytterbium) were obtained using a liquid phase-pulsed laser ablation (LP-PLA) method after getting high density Er, Yb:Y2O3 ceramic targets by Spark plasma sintering (SPS). Most NPs are under 50 nm in diameter and show high crystallinity of cubic Y2O3 structure, containing (222), (440), and (332) planes via HR-TEM. Excitation under a 980 nm laser to a nanoparticle solution showed 525 and 565 nm green, and 660 nm red emissions. The green emission intensity increased and decreased with increasing Yb3+ additive concentration, when the red spectrum continuously strengthened. Utilizing this study's outcome, we suggest developing technology to mark invisible biomolecules dissolved in a solvent using UC luminescence of Er3+, Yb3+ co-doped Y2O3 NPs by LP-PLA. The LP-PLA method has a potential ability for the fabrication of UC NPs for biosensors with uniform size distribution by laser parameters.

Evaluation of Probiotic Characteristics of Newly Isolated Lactic Acid Bacteria from Dry-Aged Hanwoo Beef.

Dry aging is a traditional method that improves meat quality, and diverse microbial communities are changed during the process. Lactic acid bacteria (LAB) are widely present in fermented foods and has many beneficial effects, such as immune enhancement and maintenance of intestinal homeostasis. In this study, we conducted metagenomic analysis to evaluate the changes in the microbial composition of dry-aged beef. We found that lactic acid bacterial strains were abundant in dry-aged beef including Lactobacillus sakei and Enterococcus faecalis. We investigated their abilities in acid and bile tolerance, adhesion to the host, antibiotic resistance, and antimicrobial activity as potential probiotics, confirming that L. sakei and E. faecalis strains had remarkable capability as probiotics. The isolates from dry-aged beef showed at least 70% survival under acidic conditions in addition to an increase in the survival level under bile conditions. Antibiotic susceptibility and antibacterial activity assays further verified their effectiveness in inhibiting all pathogenic bacteria tested, and most of them had low resistance to antibiotics. Finally, we used the Caenorhabditis elegans model to confirm their life extension and influence on host resistance. In the model system, 12D26 and 20D48 strains had great abilities to extend the nematode lifespan and to improve host resistance, respectively. These results suggest the potential use of newly isolated LAB strains from dry-aged beef as probiotic candidates for production of fermented meat.

Preferential Expression of Programmed Death Ligand 1 Protein in Tumor-Associated Macrophages and Its Potential Role in Immunotherapy for Hepatocellular Carcinoma.

A predictive biomarker of immune checkpoint inhibitor (ICI)-based treatments in hepatocellular carcinoma (HCC) has not been clearly demonstrated. In this study, we focused on the infiltration and programmed death ligand 1 (PD-L1) expression of tumor-associated macrophages (TAMs) in the tumor microenvironment of HCC. Immunohistochemistry demonstrated that PD-L1 was preferentially expressed on CD68+ macrophages in the tumor microenvironment of HCC, suggestive of its expression in TAMs rather than in T cells or tumor cells (P < 0.05). A co-culture experiment using activated T cells and M2 macrophages confirmed a significant increase in T cell functionality after the pretreatment of M2 macrophages with anti-PD-L1. Syngeneic mouse model experiments demonstrated that TAMs expressed PD-L1 and tumors treated with anti-PD-L1 showed smaller diameters than those treated with IgG. In these mice, anti-PD-L1 treatment increased activation markers in intratumoral CD8+ T cells and reduced the size of the TAM population. Regarding nivolumab-treated patients, three of eight patients responded to the anti-PD-1 treatment. The percentage of Ki-67-positive CD4+ and CD8+ T cells was higher in responders than non-responders after nivolumab. Overall, PD-L1 expression on TAMs may be targeted by immune-based HCC treatment, and ICI treatment results in the reinvigoration of exhausted CD8+ T cells in HCC.

Poor Prognostic Factors in Patients With Rotator Cuff Retear.

BACKGROUND: The treatment for retears after arthroscopic rotator cuff repair (ARCR) has long been a challenge. PURPOSE: This study aimed to (1) summarize the characteristics of patients with a retear after primary ARCR and (2) determine the risk factors for poor clinical outcomes after a retear. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: We collected the data of patients with a retear after primary ARCR between January 2011 and December 2016. There were 45 patients with retears included (19 men [42.2%] and 26 women [57.8%]; mean ± SD age, 63.11 ± 8.87 years). Initially, the demographic and outcome data of patients with a retear were analyzed. Patients were classified into good and poor outcome groups according to their overall satisfaction at final follow-up. Univariable and multivariable logistic regression analyses were performed to determine the factors for poor clinical outcomes after a retear. RESULTS: A total of 31 patients were classified into the good outcome group, and 14 patients were classified into the poor outcome group. Both the good and the poor outcome groups showed that clinical scores significantly improved at the time of the retear diagnosis, but the final scores were maintained or worse compared with scores at the time of the retear diagnosis. Final range of motion (ROM), except external rotation in the good outcome group, was worse or had no significant change compared with ROM at the time of the retear diagnosis. On multivariable logistic regression analysis, current smoking (odds ratio [OR], 45.580 [95% CI, 3.014-689.274]; P = .006), female sex (OR, 32.774 [95% CI, 2.433-441.575]; P = .009), and retears of the same or larger size than the initial tear (OR, 10.261 [95% CI, 1.544-68.202]; P = .016) showed a higher OR for poor clinical outcomes after a retear. CONCLUSION: Smoking, female sex, and retears of the same or larger size than the initial tear were independent risk factors for poor clinical outcomes after a rotator cuff retear. Final clinical scores and ROM were similar or worse compared with the scores and ROM at the time of the retear diagnosis. Therefore, revision surgery should be actively considered in female patients or those who smoke with poor clinical outcomes and a larger retear size than the preoperative tear size at the time of the retear diagnosis.

The relationship between rotator cuff integrity and acromiohumeral distance following open and arthroscopic rotator cuff repair.

BACKGROUND: Acromiohumeral distance (AHD) has become both a diagnostic and prognostic parameter related to rotator cuff pathology which is always measured in a 2-dimensional plane. The purposes of this study were (1) to evaluate the regional AHD with MRI following open and arthroscopic rotator cuff repair and, (2) to investigate its association to the rotator cuff integrity following medium to large size rotator cuff repair with open and arthroscopic manner. METHODS: A retrospective review of 112 patients who were treated for full-thickness medium to large size rotator cuff tears either by open repair (open group) or arthroscopic repair (arthroscopic group) was done. All patients included in the study are those with at least 12 and 18 months for the post-operative MRI and clinical follow-up. Propensity score matching was used to select controls matched for age, sex, body mass index, tear size, and affected site. There were 56 patients in each group with a mean age of 63.3 years (range, 50 to 77 years). The post-operative functional and radiologic outcomes for both groups were compared. AHD was measured at three regions of interest (ROI) with MRI and compared pre-and post-operatively. RESULTS: AHD was significantly greater in the open group when measured at the anterior third of the lateral acromion border compare to the arthroscopic group (p = 0.005). The re-tear rate was affected by AHD at the anterior third of the lateral border of the acromion for the arthroscopic and open group (p = 0.021, p = 0.029). The AHD measured at the anterior and middle third of lateral acromion border were significantly greater in healed compared to the re-tear rotator cuff group (p = 0.019, p = 0.022). CONCLUSIONS: Open rotator cuff repair showed greater AHD at the anterior third of the lateral border of the acromion. Regional AHD measured at anterior third of the lateral border of acromion significantly associated with rotator cuff integrity following repair. LEVEL OF EVIDENCE: propensity-matched case-control (Level II).

Role of inferomedial supporting screws for secondary varus deformity in non-osteoporotic proximal humerus fracture: A biomechanical study.

INTRODUCTION: The purpose of this study was to evaluate the effect of a medial support screw through a proximal humerus fracture. For this purpose, we verified whether the biomechanics are different according to the position of the screw while using the same number of screws. In addition, we tried to verify whether the insertion of additional inferomedial screws would make a difference in stability. MATERIALS AND METHODS: Twenty-four proximal humerus bones were included in the study. A two-part fracture was created and fixed using a locking plate. Cyclic loading and load-to-failure test were applied to three groups: group A (proximal 6 screws + calcar screws), group B (proximal 6 screws), and group C (proximal 4 screws + calcar screws). Interfragmentary gaps were measured following cyclic loading and compared. The failure was defined when the bone breakage or medial gap closing was observed during ultimate failure load applied. The load-to-failure, maximum displacement, stiffness, and yield load were recorded and compared. RESULTS: The interfragmentary gap was differently reduced by 0.29 ± 0.14 mm, 0.73 ± 0.25 mm, and 0.53 ± 0.09 mm following 1000 cyclic loading for groups A, B, and C, respectively. The load-to-failure was 945.22 ± 101.02 N, 941.40 ± 148.90 N, and 940.58 ± 91.78 N in groups A, B, and C, respectively. The stiffness of group A (214.76 ± 34.0 N/mm) was superior when compared to that of group C (171.12 ± 23.0 N/mm; p = 0.025). The maximum displacement prior to failure, yield load, showed no significant difference between comparative groups. CONCLUSION: Our study did not show any additional biomechanical effects with the use of inferomedial supporting screws in non-osteoporotic proximal humerus fracture, besides making the fracture-plate construct stiff. The role of the inferomedial supporting screw was also unclear. However, the groups that used increased screw fixation and inferomedial screw insertion seemed to be more resistant to cyclic loading.

Arthroscopic Excision of Heterotopic Ossification in the Supraspinatus Muscle.

Heterotopic ossification is formation of bone in atypical extra-skeletal tissues and usually occurs spontaneously or following neurologic injury with unknown cause. We report a 46-year-old female with right shoulder pain and restricted range of motion (ROM) for 3 months without history of trauma. Magnetic resonance imaging (MRI) showed a lesion within the rotator cuff supraglenoid. Excisional biopsy from a previous institution revealed a heterotopic ossificans (HO ). Following repeat MRI and bone scan, histopathology from arthroscopic resection confirmed an HO. The patient demonstrated improved pain and ROM at follow-up. Idiopathic HO rarely occurs in the shoulder joint, and resection of HO should be delayed until maturation of the lesion to avoid recurrence. The current case showed that arthroscopic HO resection provides an excellent surgical view to ensure complete lesion removal and minimize soft tissue damage at the supraglenoid area. Furthermore, the minimally invasive procedure of arthroscopy may reduce rehabilitation time and facilitate early return to work.

Navigation-assisted anchor insertion in shoulder arthroscopy: a validity study.

BACKGROUND: This study aimed to compare conventional and navigation-assisted arthroscopic rotator cuff repair in terms of anchor screw insertion. METHODS: The surgical performance of five operators while using the conventional and proposed navigation-assisted systems in a phantom surgical model and cadaveric shoulders were compared. The participating operators were divided into two groups, the expert group (n = 3) and the novice group (n = 2). In the phantom model, the experimental tasks included anchor insertion in the rotator cuff footprint and sutures retrieval. A motion analysis camera system was used to track the surgeons' hand movements. The surgical performance metric included the total path length, number of movements, and surgical duration. In cadaveric experiments, the repeatability and reproducibility of the anchor insertion angle were compared among the three experts, and the feasibility of the navigation-assisted anchor insertion was validated. RESULTS: No significant differences in the total path length, number of movements, and time taken were found between the conventional and proposed systems in the phantom model. In cadaveric experiments, however, the clustering of the anchor insertion angle indicated that the proposed system enabled both novice and expert operators to reproducibly insert the anchor with an angle close to the predetermined target angle, resulting in an angle error of < 2° (P = 0.0002). CONCLUSION: The proposed navigation-assisted system improved the surgical performance from a novice level to an expert level. All the experts achieved high repeatability and reproducibility for anchor insertion. The navigation-assisted system may help surgeons, including those who are inexperienced, easily familiarize themselves to of suture anchors insertion in the right direction by providing better guidance for anchor orientation. LEVEL OF EVIDENCE: A retrospective study (level 2).

Primary Linked Total Elbow Arthroplasty for Acute Distal Humerus Fracture Management: A Systematic Review of Clinical Outcome.

BACKGROUD: The treatment of distal humerus fractures is often challenging in osteoporotic elderly patients. Total elbow arthroplasty (TEA) is a salvage option for non-reconstructable fractures. The aim of this systematic review was to evaluate the clinical evidence for primary TEA in patients with acute distal humeral fractures. METHODS: Literatures were searched through PubMed, Ovid/Medline, Cochrane, Google Scholar, and Embase databases with the keywords, "distal humerus fracture," "total elbow arthroplasty," and "outcome" according to the MeSH (Medical Subject Headings) index for English-language studies published from April 2009 to April 2019. We performed a systematic review using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. RESULTS: Ten articles with a total of 269 patients were included in the review. The Bryan-Morrey approach was the most common surgical approach (33.7%) with triceps reflecting (42%) for triceps tendon management. The most common implant design used was the Coonrad-Morrey system (83%). The mean postoperative motion arc was 102.3° for flexion-extension and 145.8° for pronation-supination. The average functional outcome score was 89.5 with Mayo Elbow Performance Score (MEPS). An excellent MEPS was found in studies with less than 7 days of average time from injury to surgery. The overall complication rate was 21.5%. CONCLUSIONS: The current review showed favorable outcome of primary linked TEA for acute distal humerus fractures. Despite the promising functional outcomes, the complication rate was still considerably high. This systematic review will give surgeons help in explaining to patients regarding the expected outcome after primary TEA for acute distal humerus fractures.

Systematic Review of the Surgical Outcomes of Elbow Plicae.

BACKGROUND: Surgical resection is usually required for symptomatic elbow plicae that have failed nonoperative therapy. However, evidence of surgical outcomes has not been presented. PURPOSE: To review the surgical outcomes for the treatment of synovial plicae in the radiocapitellar joint. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: We searched the PubMed, Ovid/MEDLINE, Cochrane Library, Google Scholar, and Embase databases using keywords as well as Medical Subject Headings terms and Emtree ([(elbow OR humeroradial joint OR radiohumeral joint) AND (meniscus OR plica)] OR snapping elbow OR snapping triceps OR synovial fold syndrome OR synovial fringe) for English-language studies. We conducted a systematic review using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. RESULTS: A total of 14 articles comprising four level 5 and ten level 4 studies were identified, including 279 patients (284 elbows). The triggering factors reported for 58 patients were heavy labor (29 patients; 50.0%), sporting activities (17 patients; 29.3%), and nonspecific trauma (12 patients; 20.7%). Overall, 92 patients (33.0%) were administered a steroid injection before surgery. Arthroscopic plica resection was performed in 266 patients (95.3%). Intraoperatively, plicae were mostly found in the posterior (44.0%) and posterolateral (28.6%) sites, and chondromalacia of the radial head was observed in 25 patients (9.2%). Of the reported surgical outcomes, 67.7% showed a resolution of symptoms. However, 9.3% of patients had residual symptoms, which were likely associated with pre-existing radial head chondromalacia. The complication rate was reported as 1.8%. CONCLUSION: Symptomatic elbow plicae were mostly treated arthroscopically, with most of the results being favorable. Pre-existing chondromalacia and the underestimation of concomitant intra-articular abnormalities may yield an inferior outcome.

Engineered Cell Sheets for the Effective Delivery of Adipose-Derived Stem Cells for Tendon-to-Bone Healing.

BACKGROUND: Efforts are being made to treat rotator cuff tears (RCTs) that exhibit poor healing and high retear rates. Tendon-to-bone healing using mesenchymal stem cells is being explored, but research is needed to establish effective delivery options. PURPOSE: To evaluate the effects of an adipose-derived stem cell (ADSC) sheet on mesenchymal stem cell delivery for tendon-to-bone healing of a chronic RCT in rats and to demonstrate that ADSC sheets enhance tendon-to-bone healing. STUDY DESIGN: Controlled laboratory study. METHODS: Mesenchymal stem cells were obtained from rat adipose tissue, and a cell sheet was prepared using a temperature-responsive dish. To evaluate the efficacy of stem cells produced in a sheet for the lesion, the experiment was conducted with 3 groups: repair group, cell sheet transplantation after repair group, and cell sheet-only group. Histological, biomechanical, and micro-computed tomography (micro-CT) results were compared among the groups. RESULTS: Hematoxylin and eosin staining for histomorphological analysis revealed that the cell sheet transplantation after repair group (5.75 ± 0.95) showed statistically significant higher scores than the repair (2.75 ± 0.50) and cell sheet-only (3.25 ± 0.50) groups (P < .001). On safranin O staining, the cell sheet transplantation after repair group (0.51 ± 0.04 mm2) had a larger fibrocartilage area than the repair (0.31 ± 0.06 mm2) and cell sheet-only (0.32 ± 0.03 mm2) groups (P = .001). On micro-CT, bone volume/total volume values were significantly higher in the cell sheet transplantation after repair group (23.98% ± 1.75%) than in the other groups (P < .039); there was no significant difference in the other values. On the biomechanical test, the cell sheet transplantation after repair group (4 weeks after repair) showed significantly higher results than the other groups (P < .005). CONCLUSION: Our study shows that engineered stem cells are a clinically feasible stem cell delivery tool for rotator cuff repair. CLINICAL RELEVANCE: This laboratory study provides evidence that ADSCs are effective in repairing RCTs, which are common sports injuries.

Do Modern Designs of Metal-Backed Glenoid Components Show Improved Clinical Results in Total Shoulder Arthroplasty? A Systematic Review of the Literature.

BACKGROUND: Despite the increased popularity of reverse total shoulder arthroplasty, total shoulder arthroplasty is the standard treatment for advanced shoulder arthritis in young adult patients. Conventional metal-backed glenoid (MBG) designs result in more loosening and revision surgery compared with cemented polyethylene glenoid components. However, modern MBG designs have been recently devised to overcome such drawbacks. PURPOSE: To compare the radiolucency, loosening, and failure rates of modern MBG designs with those of conventional designs. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A search for relevant articles was carried out using the PubMed, Cochrane Library, and Embase databases using MeSH (Medical Subject Headings) terms and natural keywords. A total of 362 articles were screened. We descriptively analyzed numerical data between the groups and statistically analyzed categorical data, such as the presence of loosening, failure, and revision surgery. The main outcome was the rate of revision surgery or failure. Subgroup analysis according to follow-up duration was performed to reduce heterogeneity. RESULTS: A total of 25 articles (2036 shoulders) were included; 15 articles (1579 shoulders) involved a conventional MBG design, and 10 (457 shoulders) involved a modern design. The mean age of the patients was 64.2 and 66.5 years in the conventional and modern design groups, respectively, with a mean follow-up duration of 102.0 and 56.1 months, a mean gain of forward elevation of 35.1° and 61.7°, and a mean gain of external rotation of 24.2° and 39.2°. The rate of radiolucency was 48.0% and 16.7%, the rate of loosening was 11.2% and 4.9%, and the rate of revision was 15.9% and 2.4%, for the conventional and modern design groups, respectively. Subgroup analysis according to follow-up duration showed that the rates of loosening and revision were significantly lower in the modern design group (P < .001). CONCLUSION: Our findings suggest that modern MBG designs showed significantly lower loosening and failure rates than conventional designs. The overall results of the comparison, including loosening, failure, change in range of motion, and clinical scores, indicate that modern MBG designs are promising. More long-term follow-up studies on modern MBGs should be conducted.