Exploring the role of anticipatory postural adjustment duration within APA2 subphase as a potential mediator between clinical disease severity and fall risk in Parkinson's disease.

Introduction: People with Parkinson's Disease (PD) often show reduced anticipatory postural adjustments (APAs) before voluntary steps, impacting their stability. The specific subphase within the APA stage contributing significantly to fall risk remains unclear. Methods: We analyzed center of pressure (CoP) trajectory parameters, including duration, length, and velocity, throughout gait initiation. This examination encompassed both the postural phase, referred to as anticipatory postural adjustment (APA) (APA1, APA2a, APA2b), and the subsequent locomotor phases (LOC). Participants were instructed to initiate a step and then stop (initiating a single step). Furthermore, we conducted assessments of clinical disease severity using the Unified Parkinson's Disease Rating Scale (UPDRS) and evaluated fall risk using Tinetti gait and balance scores during off-medication periods. Results: Freezing of gait (FOG) was observed in 18 out of 110 participants during the measurement of CoP trajectories. The Ramer-Douglas-Peucker algorithm successfully identified CoP displacement trajectories in 105 participants (95.5%), while the remaining 5 cases could not be identified due to FOG. Tinetti balance and gait score showed significant associations with levodopa equivalent daily dose, UPDRS total score, disease duration, duration (s) in APA2a (s) and LOC (s), length in APA1 (cm) and APA2b (cm), mediolateral velocity in APA1 (X) (cm/s), APA2a (X) (cm/s), APA2b (X) (cm/s) and LOC (X) (cm/s), and anterior-posterior velocity in APA2a (Z) (cm/s) and APA2b (Z) (cm/s). Multiple linear regression revealed that only duration (s) in APA2a and UPDRS total score was independently associated with Tinetti gait and balance score. Further mediation analysis showed that the duration (s) in APA2a served as a mediator between UPDRS total score and Tinetti balance and gait score (Sobel test, p = 0.047). Conclusion: APA2 subphase duration mediates the link between disease severity and fall risk in PD, suggesting that longer APA2a duration may indicate reduced control during gait initiation, thereby increasing fall risk.

Differential training benefits and motor unit remodeling in wrist force precision tasks following high and low load blood flow restriction exercises under volume-matched conditions.

BACKGROUND: Blood flow restriction (BFR) resistance training has demonstrated efficacy in promoting strength gains beneficial for rehabilitation. Yet, the distinct functional advantages of BFR strength training using high-load and low-load protocols remain unclear. This study explored the behavioral and neurophysiological mechanisms that explain the differing effects after volume-matched high-load and low-load BFR training. METHODS: Twenty-eight healthy participants were randomly assigned to the high-load blood flow restriction (BFR-HL, n = 14) and low-load blood flow restriction (BFR-LL, n = 14) groups. They underwent 3 weeks of BFR training for isometric wrist extension at intensities of 25% or 75% of maximal voluntary contraction (MVC) with matched training volume. Pre- and post-tests included MVC and trapezoidal force-tracking tests (0-75%-0% MVC) with multi-channel surface electromyography (EMG) from the extensor digitorum. RESULTS: The BFR-HL group exhibited a greater strength gain than that of the BFR-LL group after training (BFR_HL: 26.96 ± 16.33% vs. BFR_LL: 11.16 ± 15.34%)(p = 0.020). However, only the BFR-LL group showed improvement in force steadiness for tracking performance in the post-test (p = 0.004), indicated by a smaller normalized change in force fluctuations compared to the BFR-HL group (p = 0.048). After training, the BFR-HL group activated motor units (MUs) with higher recruitment thresholds (p < 0.001) and longer inter-spike intervals (p = 0.002), contrary to the BFR-LL group, who activated MUs with lower recruitment thresholds (p < 0.001) and shorter inter-spike intervals (p < 0.001) during force-tracking. The discharge variability (p < 0.003) and common drive index (p < 0.002) of MUs were consistently reduced with training for the two groups. CONCLUSIONS: BFR-HL training led to greater strength gains, while BFR-LL training better improved force precision control due to activation of MUs with lower recruitment thresholds and higher discharge rates.

Release of ATP in the Lung Evoked by Inhalation of Irritant Gases in Rats.

Adenosine triphosphate (ATP) can be released into the extracellular milieu from various types of cells in response to a wide range of physical or chemical stresses. In the respiratory tract, extracellular ATP is recognized as an important signal molecule and trigger of airway inflammation. Chlorine (Cl2), sulfur dioxide (SO2), and ammonia (NH3) are potent irritant gases and common industrial air pollutants due to their widespread uses as chemical agents. This study was carried out to determine if acute inhalation challenges of these irritant gases, at the concentration and duration simulating the accidental exposures to these chemical gases in industrial operations, triggered the release of ATP in the rat respiratory tract; and if so, whether the level of ATP in bronchoalveolar lavage fluid (BALF) evoked by inhalation challenge of a given irritant gas was elevated by chronic allergic airway inflammation. Our results showed: 1) Inhalation of these irritant gases caused significant increases in the ATP level in BALF, and the magnitude of evoked ATP release was in the order of Cl2 > SO2 > NH3. 2) Chronic airway inflammation induced by ovalbumin-sensitization markedly elevated the ATP level in BALF during baseline (breathing room air) but did not potentiate the release of ATP in the lung triggered by inhalation challenges of these irritant gases. These findings suggested a possible involvement of the ATP release in the lung in the regulation of overall airway responses to acute inhalation of irritant gases and the pathogenesis of chronic allergic airway inflammation.

Human platelet lysate-cultured adipose-derived stem cell sheets promote angiogenesis and accelerate wound healing via CCL5 modulation.

BACKGROUND: A rising population faces challenges with healing-impaired cutaneous wounds, often leading to physical disabilities. Adipose-derived stem cells (ASCs), specifically in the cell sheet format, have emerged as a promising remedy for impaired wound healing. Human platelet lysate (HPL) provides an attractive alternative to fetal bovine serum (FBS) for culturing clinical-grade ASCs. However, the potential of HPL sheets in promoting wound healing has not been fully investigated. This study aimed to explore the anti-fibrotic and pro-angiogenic capabilities of HPL-cultured ASC sheets and delve into the molecular mechanism. METHODS: A rat burn model was utilized to evaluate the efficacy of HPL-cultured ASC sheets in promoting wound healing. ASC sheets were fabricated with HPL, and those with FBS were included for comparison. Various analyses were conducted to assess the impact of HPL sheets on wound healing. Histological examination of wound tissues provided insights into aspects such as wound closure, collagen deposition, and overall tissue regeneration. Immunofluorescence was employed to assess the presence and distribution of transplanted ASCs after treatment. Further in vitro studies were conducted to decipher the specific factors in HPL sheets contributing to angiogenesis. RESULTS: HPL-cultured ASC sheets significantly accelerated wound closure, fostering ample and organized collagen deposition in the neo-dermis. Significantly more retained ASCs were observed in wound tissues treated with HPL sheets compared to the FBS counterparts. Moreover, HPL sheets mitigated macrophage recruitment and decreased subsequent wound tissue fibrosis in vivo. Immunohistochemistry also indicated enhanced angiogenesis in the HPL sheet group. The in vitro analyses showed upregulation of C-C motif chemokine ligand 5 (CCL5) and angiogenin in HPL sheets, including both gene expression and protein secretion. Culturing endothelial cells in the conditioned media compared to media supplemented with CCL5 or angiogenin suggested a correlation between CCL5 and the pro-angiogenic effect of HPL sheets. Additionally, through neutralizing antibody experiments, we further validated the crucial role of CCL5 in HPL sheet-mediated angiogenesis in vitro. CONCLUSIONS: The present study underscores CCL5 as an essential factor in the pro-angiogenic effect of HPL-cultured ASC sheets during the wound healing process. These findings highlight the potential of HPL-cultured ASC sheets as a promising therapeutic option for healing-impaired cutaneous wounds in clinical settings. Furthermore, the mechanism exploration yields valuable information for optimizing regenerative strategies with ASC products. BRIEF ACKNOWLEDGMENT: This research was supported by the National Science and Technology Council, Taiwan (NSTC112-2321-B-002-018), National Taiwan University Hospital (111C-007), and E-Da Hospital-National Taiwan University Hospital Joint Research Program (111-EDN0001, 112-EDN0002).

Multiscale brain age prediction reveals region-specific accelerated brain aging in Parkinson's disease.

Brain biological age, which measures the aging process in the brain using neuroimaging data, has been used to assess advanced brain aging in neurodegenerative diseases, including Parkinson disease (PD). However, assuming that whole brain degeneration is uniform may not be sufficient for assessing the complex neurodegenerative processes in PD. In this study we constructed a multiscale brain age prediction models based on structural MRI of 1240 healthy participants. To assess the brain aging patterns using the brain age prediction model, 93 PD patients and 91 healthy controls matching for sex and age were included. We found increased global and regional brain age in PD patients. The advanced aging regions were predominantly noted in the frontal and temporal cortices, limbic system, basal ganglia, thalamus, and cerebellum. Furthermore, region-level rather than global brain age in PD patients was associated with disease severity. Our multiscale brain age prediction model could aid in the development of objective image-based biomarkers to detect advanced brain aging in neurodegenerative diseases.

Rosmarinic acid Ameliorates neuronal regeneration in the bridging silicone rubber conduits of the sciatic nerve in taxol-treated rats.

Background and aim: Taxol modulates local inflammatory conditions in peripheral nerves, which may impair their regeneration and recovery when injured. This study aimed to determine the effects of rosmarinic acid (RA, a polyphenol constituent of many culinary herbs) on the regeneration of the sciatic nerves in the bridging conduits. Experimental procedure: In the cell study, RA decreased nuclear factor (NF)-κB activity induced by taxol in a dose dependency. In the animal model, taxol-treated rats were divided into 3 groups (n = 10/group): taxol (2 mg/kg body weight for 4 times) and taxol + RA (3 times/week for 4 weeks at 20 and 40 mg/kg body weight) groups. Macrophage infiltration, calcitonin gene-related peptide (CGRP) expression levels, neuronal connectivity, animal behavior, and neuronal electrophysiology were evaluated. Results and conclusion: At the end of 4 weeks, macrophage density, CGRP expression level, and axon number significantly increased in the RA group compared with the taxol group. The RA administration unaffected heat, cold plate licking latencies, and motor coordination. Moreover, the 40 mg/kg RA group had significantly larger nerve conduction velocity and less latency compared to the taxol group. This study suggested that RA could ameliorate local inflammatory conditions to augment the recovery of regenerating nerves by accelerating their regrowth and improving electrophysiological function in taxol-treated peripheral nerve injury repaired with the silicone rubber conduit.

Reduced Tolerogenic Program Death-Ligand 1-Expressing Conventional Type 1 Dendritic Cells Are Associated with Rapid Decline in Chronic Obstructive Pulmonary Disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized, at least in part, by autoimmunity through amplified T helper 1 and 17 (Th1 and Th17) immune responses. The loss of immune tolerance controlled by programmed death-ligand 1 (PD-L1) may contribute to this. OBJECTIVES: We studied the tolerogenic role of PD-L1+ dendritic cells (DCs) and their subtypes in relation to specific T cell immunity and the clinical phenotypes of COPD. METHODS: We used flow cytometry to analyze PD-L1 expression by the DCs and their subtypes in the peripheral blood mononuclear cells (PBMCs) from normal participants and those with COPD. T cell proliferation and the signature cytokines of T cell subtypes stimulated with elastin as autoantigens were measured using flow cytometry and enzyme-linked immunosorbent assays (ELISA), respectively. MEASUREMENT AND MAIN RESULTS: A total of 83 participants were enrolled (normal, n = 29; COPD, n = 54). A reduced PD-L1+ conventional dendritic cell 1 (cDC1) ratio in the PBMCs of the patients with COPD was shown (13.7 ± 13.7%, p = 0.03). The decrease in the PD-L1+ cDC1 ratio was associated with a rapid decline in COPD (p = 0.02) and correlated with the CD4+ T cells (r = -0.33, p = 0.02). This is supported by the NCBI GEO database accession number GSE56766, the researchers of which found that the gene expressions of PD-L1 and CD4, but not CD8 were negatively correlated from PBMC in COPD patients (r = -0.43, p = 0.002). Functionally, the PD-L1 blockade enhanced CD4+ T cell proliferation stimulated by CD3/elastin (31.2 ± 22.3%, p = 0.04) and interleukin (IL)-17A production stimulated by both CD3 (156.3 ± 54.7, p = 0.03) and CD3/elastin (148 ± 64.9, p = 0.03) from the normal PBMCs. The PD-L1 blockade failed to increase IL-17A production in the cDC1-depleted PBMCs. By contrast, there was no significant change in interferon (IFN)-γ, IL-4, or IL-10 after the PD-L1 blockade. Again, these findings were supported by the NCBI GEO database accession number GSE56766, the researchers of which found that only the expression of RORC, a master transcription factor driving the Th17 cells, was significantly negatively correlated to PD-L1 (r = -0.33, p = 0.02). CONCLUSIONS: Circulating PD-L1+ cDC1 was reduced in the patients with COPD, and the tolerogenic role was suppressed with susceptibility to self-antigens and linked to rapid decline caused by Th17-skewed chronic inflammation.

Evaluating effectiveness of cadaveric arthroscopic training for orthopaedic residents: A comparison of joints and training levels.

Purpose: This study aimed to evaluate the effects and interactions of training level and different joints on the outcomes of cadaveric arthroscopic training courses for orthopaedic residents. Methods: This prospective study enrolled 16 orthopaedic residents who voluntarily participated in a cadaveric training programme involving the shoulder, elbow, wrist, knee and ankle joints. Outcomes were quantitatively assessed using task-specific checklists and the Arthroscopic Surgery Skill Evaluation Tool. Two-way analysis of variance (ANOVA) was conducted to determine the significance of the interactions between joint and years of training. Results: Resident scores significantly increased after the dedicated lectures in all five joints (p = 0.003 for the shoulder module, p < 0.001 for the other joints). Two-way ANOVA revealed that the progress made after the dedicated lectures was significantly impacted by the joint (p = 0.006) and training level × joint interaction (p = 0.005) but not by the training level (p = 0.47). The simple effect of the joint was examined using Sidak's multiple comparison test. Among junior residents, the dedicated lectures resulted in more substantial progress in elbow and wrist arthroscopy when compared to shoulder arthroscopy (p = 0.020 and p = 0.043, respectively). Conclusions: The results suggest that, in cadaveric arthroscopic training courses for orthopaedic residents, training outcomes are primarily impacted by the specific joint being trained rather than the training level. Specifically, junior residents demonstrated greater improvement with training in procedures that are less commonly encountered during on-the-job training, such as elbow and wrist arthroscopy. Clinical Relevance: These findings suggest the need to prioritise wrist and elbow arthroscopic training for junior residents to optimise educational outcomes. Level of Evidence: Level III.

Biomechanical Comparisons of All-Suture Suspensory Button versus Interference Screw for Inlay Subpectoral Bicep tenodesis.

BACKGROUND: All-suture buttons (ASB) and interference screw (IS) are commonly utilized in the inlay subpectoral biceps tendon tenodesis. However, the biomechanical characteristics of these two methods have not been compared directly. The aim of present study was to compare the biomechanical properties of ASB versus IS for inlay subpectoral biceps tendon tenodesis in a human cadaveric model. METHODS: Sixteen fresh-frozen human cadaveric shoulders were randomly divided into two experimental inlay biceps tenodesis groups: ASB or IS. After tenodesis, every specimen was preloaded at 5 N for 2 minutes, followed with a cyclic loading test from 5 to 70 N for 500 load cycles. Then the load-to-failure test was performed. Afterwards, the humerus was placed in a cylinder tube and secured with anchoring cement. Lastly, a two-point bending test was performed to determine the strength of the humerus. Destructive axial force was applied, and the failure strength and displacement were recorded. RESULTS: No difference in stiffness was observed between the two groups (ASB=27.4 ± 3.5 N/mm vs IS= 29.7 ± 3.0 N/mm; P=.270). Cyclic displacement was significantly greater in the ASB group (6.8 ± 2.6 mm) than the IS group (3.8 ± 1.1 mm; P=.021). In terms of failure load, there were no statistical differences among the two groups (P=.234). The ASB group was able to withstand significantly greater displacement (11.9 ± 1.6 mm) before failure than the IS group (7.8 ± 1.5mm; P=.001). During the humeral bending test, the ASB group exhibited significantly greater maximal load (2354.8 ± 285.1 N vs 2086.4 ± 296.1 N; P=.046) and larger displacement (17.8 ± 2.8mm vs 14.1± 2.8 mm; P=.027) before fracture. CONCLUSIONS: In inlay subpectoral bicep tenodesis, ASB fixation appears to offer comparable stiffness and failure load to that of IS fixation. Additionally, the ASB group exhibited greater resistance to load and displacement before humeral fracture. However, the ASB group did demonstrate increased cyclic displacement compared to IS group.

Factors associated with reparability of rotator cuff tears: a systematic review and meta-analysis.

BACKGROUND: To identify and quantify the factors associated with the reparability of rotator cuff tears (RCTs). METHODS: PubMed, Scopus, and Web of Science databases were searched for clinical studies published in English focusing on RCT reparability by using the keywords "rotator cuff tear" and "reparability". A meta-analysis was conducted if ≥3 studies examined the same factor and provided enough data to assess RCT reparability. Quality assessment was completed using the quality assessment of diagnostic accuracy studies tool. RESULTS: Eighteen studies (2700 patients) were enrolled and 26 factors were included in the meta-analysis. The dichotomous variables associated with irreparability were Patte stage 3 (odds ratio (OR): 8.0, 95% confidence interval [CI]: 4.3-14.9), massive tear vs. large tear (OR: 3.1, 95% CI: 1.3-7.2), Goutallier stage for each tendon, and tangent sign (OR: 11.1, 95% CI: 4.3-28.4). The continuous variables associated with irreparability were age (mean difference (MD): 3.25, 95% CI: 1.4-5.1), mediolateral tear size (MD: 12.3, 95% CI: 5.8-18.9), anteroposterior tear size (MD: 10.4, 95% CI: 5.2-15.6), acromiohumeral distance on X-ray (MD: -2.3, 95% CI: -3.0 to -1.6) and magnetic resonance imaging (MD: -1.8, 95% CI: -2.8 to -0.9), and inferior glenohumeral distance on magnetic resonance imaging (MD: 2.2, 95% CI: 1.4-3.0). CONCLUSION: This study revealed that older age, larger tear size, severe fatty infiltration, muscle atrophy, and advanced superior migration of the humeral head were strongly associated with irreparable RCTs. Conversely, clinical symptoms provided limited information for predicting reparability. Additionally, the tangent sign emerged as a powerful and simple tool for individual prediction, and several quantitative scoring systems also proved useful.

Predicting osteoporosis from kidney-ureter-bladder radiographs utilizing deep convolutional neural networks.

Osteoporosis is a common condition that can lead to fractures, mobility issues, and death. Although dual-energy X-ray absorptiometry (DXA) is the gold standard for osteoporosis, it is expensive and not widely available. In contrast, kidney-ureter-bladder (KUB) radiographs are inexpensive and frequently ordered in clinical practice. Thus, it is a potential screening tool for osteoporosis. In this study, we explored the possibility of predicting the bone mineral density (BMD) and classifying high-risk patient groups using KUB radiographs. We proposed DeepDXA-KUB, a deep learning model that predicts the BMD values of the left hip and lumbar vertebrae from an input KUB image. The datasets were obtained from Taiwanese medical centers between 2006 and 2019, using 8913 pairs of KUB radiographs and DXA examinations performed within 6 months. The images were randomly divided into training and validation sets in a 4:1 ratio. To evaluate the model's performance, we computed a confusion matrix and evaluated the sensitivity, specificity, accuracy, precision, positive predictive value, negative predictive value, F1 score, and area under the receiver operating curve (AUROC). Moderate correlations were observed between the predicted and DXA-measured BMD values, with a correlation coefficient of 0.858 for the lumbar vertebrae and 0.87 for the left hip. The model demonstrated an osteoporosis detection accuracy, sensitivity, and specificity of 84.7 %, 81.6 %, and 86.6 % for the lumbar vertebrae and 84.2 %, 91.2 %, and 81 % for the left hip, respectively. The AUROC was 0.939 for the lumbar vertebrae and 0.947 for the left hip, indicating a satisfactory performance in osteoporosis screening. The present study is the first to develop a deep learning model based on KUB radiographs to predict lumbar spine and femoral BMD. Our model demonstrated a promising correlation between the predicted and DXA-measured BMD in both the lumbar vertebrae and hip, showing great potential for the opportunistic screening of osteoporosis.

Green Consumer Behavior of Sports Enthusiasts on TikTok-An Analysis of the Moderating Effect of Green Concern.

The short-form video platform TikTok has become highly popular. This study explores how professional sports teams can effectively leverage short-form videos to promote green values such as environmental conservation and sustainable development, thereby capturing user attention and enhancing user engagement. This study primarily aimed to investigate the effects of a green brand image on green word of mouth (WOM), customer stickiness, and consumer purchase intention, with further examination regarding the moderating effect of green concerns on these relationships. Few studies have explored the presence of professional sports teams on TikTok, particularly in the context of green issues. Accordingly, this study adopts a novel method to develop specific and actionable recommendations for professional sports teams who have a presence on social media. Additionally, via the application of the Stimulus-Organism-Response theory, this study explains how the green brand image presented by professional sports teams on TikTok influences the interactive relationships among green WOM, customer stickiness, and consumer purchase intention. This study recruited 600 individuals who were either fans of the Taipei Fubon Braves, which is a team in Taiwan's professional basketball league P.LEAGUE+, or fans of other teams. After a confirmatory factor analysis, structural equation modeling was used to test the hypotheses. The results indicate positive correlations in all tested paths. The green concern of the Taipei Fubon Braves' fans moderated the relationship between green WOM and purchase intention; however, this moderating effect was not identified among the non-Taipei Fubon Braves fans. These findings introduce innovative concepts to the field of marketing, contributing substantially to both practical applications and academic research.

Construction, observation and knowledge abstraction for go endgames on small boards.

A Go endgame database consists of optimal game values and moves for every legal arrangement of no more than S pieces on an N by N board. This paper describes methods for constructing such databases when 1 < N ≤ 5 and S = N 2 . When cycles of plies with lengths greater than 4 are encountered, two rules, one allowing cycles and the other disallowing them, are implemented. Observations and knowledge are obtained for these endgames, which may elucidate the fundamental properties of the popular game Go. First, the optimal game values are different when N is even and odd, regardless of whether the repetition of positions is allowed. When N is odd, the first player can occupy the whole board, while this is not the case when N is even. Second, allowing cycles makes the first and second players equal in strength when N is even, whereas the first player always dominates when N is odd. Using the state-of-the-art open-source deep learning Go engine KataGo to correctly solve a given position as an indicator, factors affecting level of difficulty are found, including the distributions of the optimal game values among all legal plies and the cardinality and values of the true optimal plies. A simple formula is designed that works on more than 10% of the positions so that positions with a given level of difficulty can be found with a high probability.

Epigallocatechin-3-gallate Synergistically Enhanced Arecoline-Induced Cytotoxicity by Redirecting Cycle Arrest to Apoptosis.

Carcinogens, such as arecoline, play a crucial role in cancer progression and continuous gene mutations by generating reactive oxygen species (ROS). Antioxidants can reduce ROS levels and potentially prevent cancer progression but may paradoxically enhance the survival of cancer cells. This study investigated whether epigallocatechin-3-gallate (EGCG), an antioxidant from green tea, could resolve this paradox. Prostate cancer cells (PC-3 cell line) were cultured and treated with arecoline combined with NAC (N-acetylcysteine) or EGCG; the combined effects on intracellular ROS levels and cell viability were examined using the MTT and DCFDA assays, respectively. In addition, apoptosis, cell cycle, and protein expression were investigated using flow cytometry and western blot analysis. Our results showed that EGCG, similar to NAC (N-acetylcysteine), reduced the intracellular ROS levels, which were elevated by arecoline. Moreover, EGCG not only caused cell cycle arrest but also facilitated cell apoptosis in arecoline-treated cells in a synergistic manner. These were evidenced by elevated levels of cyclin B1 and p27, and increased fragmentation of procaspase-3, PARP, and DNA. Our findings highlight the potential use of EGCG for cancer prevention and therapy.

Suture Contamination During Arthroscopic Rotator Cuff Repair Is Associated With Significantly Higher Retear Rates in Magnetic Resonance Imaging: A Matched-Pair Analysis.

PURPOSE: To evaluate the correlation between suture contamination and rotator cuff tendon retear after arthroscopic rotator cuff repair. METHODS: Patients undergoing primary arthroscopic rotator cuff repair from April 1, 2020, to September 30, 2022, were enrolled. Those younger than 18 years, with a history of shoulder surgeries or shoulder infection episodes, or who declined participation were excluded. A 5-cm section of the first-cut suture, originating from the anchor eyelet ends, in each rotator cuff repair surgery was subjected to bacteria culture and polymerase chain reaction analysis. Patients with positive culture findings were matched 1:1 to those with negative culture reports based on age, sex, tear size as well as involved tendons, preoperative fatty infiltration grade (Goutallier grade), and preoperative muscle atrophy grade (Warner score). Postoperative rotator cuff tendon retear assessments were conducted at the 6-month mark using the Sugaya classification via magnetic resonance imaging. The Wilcoxon signed-rank test was used for matched-pair comparisons between the groups. RESULTS: A total of 141 patients (60 men and 81 women) with a mean age of 61.0 ± 8 years were finally enrolled. Twenty-six patients (18 men and 8 women) had a positive culture, while 115 patients (42 men and 73 women) had a negative culture. After the propensity score matching process, 24 culture-negative patients (16 men and 8 women) were selected as the culture-negative group. Age, fatty infiltration grade, and muscle atrophy grade were not significantly different between matched groups. The retear grade in the culture-positive group was significantly higher than that in the culture-negative group (P = .020) under the matched-pair comparison. Cutibacterium acnes was the most prevalent bacterial species responsible for suture contamination. CONCLUSIONS: The matched-pair analysis revealed that the presence of bacterial contamination on sutures was associated with a higher risk of retear on magnetic resonance imaging following arthroscopic rotator cuff repair. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Biomechanical Comparison of Coracoclavicular Fixation Using Metallic Versus All-Suture Anchors.

Background: A coracoclavicular (CC) fixation technique using an all-suture anchor with the assistance of fluoroscopy can prevent iatrogenic anterior deltoid detachment from the clavicle; however, soft anchor pullout has been reported as a complication. Purpose: To compare the biomechanical properties of conventional metallic and all-suture anchors for CC suture fixation. Study Design: Controlled laboratory study. Methods: A total of 24 fresh-frozen cadaveric specimens were divided into 2 groups: metal anchor group (group M) and all-suture anchor group (group A). In group M, 5.0-mm metallic suture anchors were used for CC fixation, whereas 2.8-mm all-suture anchors were used in group A. The prepared specimens were mounted on a materials testing machine. After preconditioning at 0 to 20 N for 10 cycles, the specimens were subjected to cyclic loading from 20 to 70 N for 1000 cycles. Finally, all the specimens were loaded to failure. Cyclic elongation, linear stiffness, ultimate load, and failure modes were recorded, and the Mann-Whitney U test was used to compare nonparametric parameters between the 2 groups. Results: All of the specimens completed the cyclic loading test. The elongation after cyclic loading in group M (1.6 ± 0.6 mm) was significantly smaller compared with that in group A (2.5 ± 1.2 mm) (P = .02). No between-group differences were found in linear stiffness (42 ± 17 N/mm in group M and 41 ± 17 N/mm in group A). The ultimate failure load in group M (263 ± 66 N) was significantly greater than that in group A (177 ± 76 N) (P = .02). All specimens failed because of suture anchor pullout. Conclusion: The use of all-suture anchors in CC fixation resulted in significantly greater cyclic displacement and smaller ultimate failure load than that of metallic anchors. Clinical Relevance: Understanding the most biomechanically sound suture anchor may assist in lowering the risk of clinical failure in CC fixation and repair.