Norepinephrine weaning guided by the Hypotension Prediction Index in vasoplegic shock after cardiac surgery: protocol for a single-centre, open-label randomised controlled trial - the NORAHPI study.

INTRODUCTION: Norepinephrine (NE) is the first-line recommended vasopressor for restoring mean arterial pressure (MAP) in vasoplegic syndrome (vs) following cardiac surgery with cardiopulmonary bypass. However, solely focusing on target MAP values can lead to acute hypotension episodes during NE weaning. The Hypotension Prediction Index (HPI) is a machine learning algorithm embedded in the Acumen IQ device, capable of detecting hypotensive episodes before their clinical manifestation. This study evaluates the clinical benefits of an NE weaning strategy guided by the HPI. MATERIAL AND ANALYSIS: The Norahpi trial is a prospective, open-label, single-centre study that randomises 142 patients. Inclusion criteria encompass adult patients scheduled for on-pump cardiac surgery with postsurgical NE administration for vs patient randomisation occurs once they achieve haemodynamic stability (MAP>65 mm Hg) for at least 4 hours on NE. Patients will be allocated to the intervention group (n=71) or the control group (n=71). In the intervention group, the NE weaning protocol is based on MAP>65 mmHg and HPI<80 and solely on MAP>65 mm Hg in the control group. Successful NE weaning is defined as achieving NE weaning within 72 hours of inclusion. An intention-to-treat analysis will be performed. The primary endpoint will compare the duration of NE administration between the two groups. The secondary endpoints will include the prevalence, frequency and time of arterial hypotensive events monitored by the Acumen IQ device. Additionally, we will assess cumulative diuresis, the total dose of NE, and the number of protocol weaning failures. We also aim to evaluate the occurrence of postoperative complications, the length of stay and all-cause mortality at 30 days. ETHICS AND DISSEMINATION: Ethical approval has been secured from the Institutional Review Board (IRB) at the University Hospital of Amiens (IRB-ID:2023-A01058-37). The findings will be shared through peer-reviewed publications and presentations at national and international conferences. TRIAL REGISTRATION NUMBER: NCT05922982.

S erratus anterior plane block alone, paravertebral block alone and their combination in video-assisted thoracoscopic surgery: the THORACOSOPIC double-blind, randomized trial.

OBJECTIVES: Serratus anterior plane block (SAPB) and paravertebral block (PVB) are well known to reduce pain levels after video-assisted thoracoscopic surgery (VATS). However, the relative efficacies of each block and a combination of the 2 have not been fully characterized. The objective of the present study was to assess the efficacy of PVB alone, SAPB alone and the combination of PVB and SAPB with regard to the occurrence and intensity of pain after VATS. METHODS: We conducted the THORACOSOPIC single-centre, double-blind, randomized trial in adult patients due to undergo elective VATS lung resection. The participants were randomized to PVB only, SAPB only and PVB + SAPB groups. The primary end-point was pain on coughing on admission to the postanaesthesia care unit. The secondary end-points were postoperative pain at rest and on coughing at other time points and the cumulative opioid consumption. Pain was scored on a visual analogue scale. RESULTS: One-hundred and fifty-six patients (52 in each group) were included. On admission to the postanaesthesia care unit, the 3 groups did not differ significantly with regard to the pain on coughing: the visual analogue scale score was 3 (0-6), 4 (0-8) and 2 (0-6) in the PVB, SAPB and PVB + SAPB groups, respectively (P = 0.204). During postoperative care, the overall pain score was significantly lower in the SABP + PVP group at rest and on cough. CONCLUSIONS: The combination of SABP + PVB could be beneficial for pain management in VATS in comparison to SABP or PVB alone.

Opioid-free anaesthesia with dexmedetomidine and lidocaine versus remifentanil-based anaesthesia in cardiac surgery: study protocol of a French randomised, multicentre and single-blinded OFACS trial.

INTRODUCTION: Intraoperative opioids have been used for decades to reduce negative responses to nociception. However, opioids may have several, and sometimes serious, adverse effects. Cardiac surgery exposes patients to a high risk of postoperative complications, some of which are common to those caused by opioids: acute respiratory failure, postoperative cognitive dysfunction, postoperative ileus (POI) or death. An opioid-free anaesthesia (OFA) strategy, based on the use of dexmedetomidine and lidocaine, may limit these adverse effects, but no randomised trials on this issue have been published in cardiac surgery.We hypothesised that OFA versus opioid-based anaesthesia (OBA) may reduce the incidence of major opioid-related complications after cardiac surgery. METHODS AND ANALYSIS: Multicentre, randomised, parallel and single-blinded clinical trial in four cardiac surgical centres in France, including 268 patients scheduled for coronary artery bypass grafting under cardiac bypass, with or without aortic valve replacement. Patients will be randomised to either a control OBA protocol using remifentanil or an OFA protocol using dexmedetomidine/lidocaine. The primary composite endpoint is the occurrence of at least one of the following: (1) postoperative cognitive disorder evaluated by the Confusion Assessment Method for the Intensive Care Unit test, (2) POI, (3) acute respiratory distress or (4) death within the first 48 postoperative hours. Secondary endpoints are postoperative pain, morphine consumption, nausea-vomiting, shock, acute kidney injury, atrioventricular block, pneumonia and length of hospital stay. ETHICS AND DISSEMINATION: This trial has been approved by an independent ethics committee (Comité de Protection des Personnes Ouest III-Angers on 23 February 2021). Results will be submitted in international journals for peer reviewing. TRIAL REGISTRATION NUMBER: NCT04940689, EudraCT 2020-002126-90.

Effect of non-steroidal anti-inflammatory drugs on the management of postoperative pain after cardiac surgery: a multicenter, randomized, controlled, double-blind trial (KETOPAIN Study).

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) are recommended for the management of acute postoperative pain as part of a multimodal strategy to reduce opioid use, relieve pain, and reduce chronic pain in non-cardiac surgery. However, significant concerns arise in cardiac surgery due to the potential adverse effects of NSAID including increased bleeding and acute kidney injury (AKI). We hypothesized that NSAIDs are effective against pain and safe in the early postoperative period following cardiac surgery, taking contraindications into account. METHODS: The KETOPAIN trial is a prospective, double blind, 1:1 ratio, versus placebo multicentric trial, randomizing 238 patients scheduled for cardiac surgery. Written consent will be obtained for all participants. The inclusion criterion is patients more than 18 years old undergoing for elective cardiac surgery under cardiopulmonary bypass (CPB). Patients will be allocated to the intervention (ketoprofen) group (n = 119) or the control (placebo) group (n = 119). In the intervention group, in addition to the standard treatment, patients will receive NSAIDs (ketoprofen) at a dose of 100 mg each 12 h 48 h after. The control group, in addition to the standard treatment, will receive a placebo of NSAIDs every 12 h for 48 h after surgery. An intention-to-treat analysis will be performed. The primary endpoint will be the intensity of acute postoperative pain at rest at 24 h from the end of surgery. Pain will be assessed using the numerous rating scale. The secondary endpoints will be postoperative pain on coughing during chest physiotherapy, postoperative pain until day 7, the pain trajectory between day 3 and day 7, cumulative opioid consumption within 48 h after surgery, nausea and vomiting, the occurrence of postoperative pulmonary complications within the first 7 days after surgery, neuropathic pain at 3 months, and quality of life at 3 months. DISCUSSION: NSAIDs function as non-selective, reversible inhibitors of the cyclooxygenase enzyme and play a role in a multimodal pain management approach. While there are recommendations supporting the use of NSAIDs in major non-cardiac surgery, recent guidelines do not favor their use in cardiac surgery. However, this is based on low-quality evidence. Major concerns regarding NSAID use in cardiac surgery patients are potential increase in postoperative bleeding or AKI. However, few studies support the possible use of NSAIDs without the risk of bleeding and/or AKI. Also, in a recent French survey, many anesthesiologists reported using NSAIDs in cardiac surgery. To date, no large randomized study has been conducted to evaluate the efficacy of NSAIDs in the management of postoperative pain in cardiac surgery. The expected outcome of this study is an improvement in the management of acute postoperative pain in cardiac surgery with a multimodal strategy including the use of NSAIDs. TRIAL REGISTRATION: ClinicalTrials.gov NCT06381063. Registered on April 24, 2024.

N-truncated amyloid ß (Aß) 4-42 forms stable aggregates and induces acute and long-lasting behavioral deficits.

N-truncated Aß4-42 is highly abundant in Alzheimer disease (AD) brain and was the first Aß peptide discovered in AD plaques. However, a possible role in AD aetiology has largely been neglected. In the present report, we demonstrate that Aß4-42 rapidly forms aggregates possessing a high aggregation propensity in terms of monomer consumption and oligomer formation. Short-term treatment of primary cortical neurons indicated that Aß4-42 is as toxic as pyroglutamate Aß3-42 and Aß1-42. In line with these findings, treatment of wildtype mice using intraventricular Aß injection induced significant working memory deficits with Aß4-42, pyroglutamate Aß3-42 and Aß1-42. Transgenic mice expressing Aß4-42 (Tg4-42 transgenic line) developed a massive CA1 pyramidal neuron loss in the hippocampus. The hippocampus-specific expression of Aß4-42 correlates well with age-dependent spatial reference memory deficits assessed by the Morris water maze test. Our findings indicate that N-truncated Aß4-42 triggers acute and long-lasting behavioral deficits comparable to AD typical memory dysfunction.

Prognostic value of right ventricular dilatation on computed tomography pulmonary angiogram for predicting adverse clinical events in severe COVID-19 pneumonia.

Background: Right ventricle dilatation (RVD) is a common complication of non-intubated COVID-19 pneumonia caused by pro-thrombotic pneumonitis, intra-pulmonary shunting, and pulmonary vascular dysfunction. In several pulmonary diseases, RVD is routinely measured on computed tomography pulmonary angiogram (CTPA) by the right ventricle-to-left ventricle (LV) diameter ratio > 1 for predicting adverse events. Objective: The aim of the study was to evaluate the association between RVD and the occurrence of adverse events in a cohort of critically ill non-intubated COVID-19 patients. Methods: Between February 2020 and February 2022, non-intubated patients admitted to the Amiens University Hospital intensive care unit for COVID-19 pneumonia with CTPA performed within 48 h of admission were included. RVD was defined by an RV/LV diameter ratio greater than one measured on CTPA. The primary outcome was the occurrence of an adverse event (renal replacement therapy, extracorporeal membrane oxygenation, 30-day mortality after ICU admission). Results: Among 181 patients, 62% (n = 112/181) presented RVD. The RV/LV ratio was 1.10 [1.05-1.18] in the RVD group and 0.88 [0.84-0.96] in the non-RVD group (p = 0.001). Adverse clinical events were 30% and identical in the two groups (p = 0.73). In Receiving operative curves (ROC) analysis, the RV/LV ratio measurement failed to identify patients with adverse events. On multivariable Cox analysis, RVD was not associated with adverse events to the contrary to chest tomography severity score > 10 (hazards ratio = 1.70, 95% CI [1.03-2.94]; p = 0.04) and cardiovascular component (> 2) of the SOFA score (HR = 2.93, 95% CI [1.44-5.95], p = 0.003). Conclusion: Right ventricle (RV) dilatation assessed by RV/LV ratio was a common CTPA finding in non-intubated critical patients with COVID-19 pneumonia and was not associated with the occurrence of clinical adverse events.

N-glycans of Phaeodactylum tricornutum diatom and functional characterization of its N-acetylglucosaminyltransferase I enzyme.

N-glycosylation, a major co- and post-translational event in the synthesis of proteins in eukaryotes, is unknown in aquatic photosynthetic microalgae. In this paper, we describe the N-glycosylation pathway in the diatom Phaeodactylum tricornutum. Bio-informatic analysis of its genome revealed the presence of a complete set of sequences potentially encoding for proteins involved in the synthesis of the lipid-linked Glc(3)Man(9)GlcNAc(2)-PP-dolichol N-glycan, some subunits of the oligosaccharyltransferase complex, as well as endoplasmic reticulum glucosidases and chaperones required for protein quality control and, finally, the α-mannosidase I involved in the trimming of the N-glycan precursor into Man-5 N-glycan. Moreover, one N-acetylglucosaminyltransferase I, a Golgi glycosyltransferase that initiates the synthesis of complex type N-glycans, was predicted in the P. tricornutum genome. We demonstrated that this gene encodes for an active N-acetylglucosaminyltransferase I, which is able to restore complex type N-glycans maturation in the Chinese hamster ovary Lec1 mutant, defective in its endogeneous N-acetylglucosaminyltransferase I. Consistent with these data, the structural analyses of N-linked glycans demonstrated that P. tricornutum proteins carry mainly high mannose type N-glycans ranging from Man-5 to Man-9. Although representing a minor glycan population, paucimannose N-glycans were also detected, suggesting the occurrence of an N-acetylglucosaminyltransferase I-dependent maturation of N-glycans in this diatom.

Impact and Persistence of Serratia marcescens in Tenebrio molitor Larvae and Feed under Optimal and Stressed Mass Rearing Conditions.

Industrial insect mass rearing aims to produce quality insects under safe sanitary conditions which can be compromised by pathogens and abiotic stressors. Therefore, knowledge on pathogen persistence, virulence and means of detection is of importance. This study focuses on the opportunistic pathogen Serratia marcescens (Sm) as a possible candidate to reveal sanitary issues in Tenebrio molitor (Tm) breeding. A screening test was performed to assess the impact of abiotic stressors (starvation, density and sieving) in presence and absence of Sm. Two Sm detection methods were conducted, and the kinetics of Sm persistence were investigated. Our results show that (i) the presence of Sm had a low but significant effect on Tm mortality, (ii) a short temporary starvation period had a negative impact on larval growth, (iii) the detection of Sm by q-PCR was sensitive but less convenient than a specific Sm growth media, (iv) the kinetics of persistence showed that Sm declined but survived for nine days in the feed and in the feces for three weeks. Both the relatively low virulence and the persistence in the environment suggest that Sm could be used as an indicator for the sanitary status of mealworm production.

Pituitary adenylate cyclase-activating polypeptide (PACAP) stimulates the expression and the release of tissue plasminogen activator (tPA) in neuronal cells: involvement of tPA in the neuroprotective effect of PACAP.

Pituitary adenylate cyclase-activating polypeptide (PACAP) and tissue plasminogen activator (tPA) play important roles in neuronal migration and survival. However, a direct link between the neurotrophic effects of PACAP and tPA has never been investigated. In this study, we show that, in PC12 cells, PACAP induced a 9.85-fold increase in tPA gene expression through activation of the protein kinase A- and protein kinase C-dependent signaling pathways. In immature cerebellar granule neurons (CGN), PACAP stimulated tPA mRNA expression and release of proteolytically active tPA. Immunocytochemical labeling revealed the presence of tPA in the cytoplasm and processes of cultured CGN. The inhibitory effect of PACAP on CGN motility was not affected by the tPA substrate plasminogen or the tPA inhibitor plasminogen activator inhibitor-1. In contrast, plasminogen activator inhibitor-1 significantly reduced the stimulatory effect of PACAP on CGN survival. Altogether, these data indicate that tPA gene expression is activated by PACAP in both tumoral and normal neuronal cells. The present study also demonstrates that PACAP stimulates the release of tPA which promotes CGN survival by a mechanism dependent of its proteolytic activity.

Impact of Early Weightbearing After Ankle Arthroscopy and Bone Marrow Stimulation for Osteochondral Lesions of the Talus.

BACKGROUND: Osteochondral lesion of the talus (OLT) may be caused by osteochondritis dissecans, osteochondral fractures, avascular necrosis, or focal arthritic changes. For certain focal cartilage defects, bone marrow stimulation (BMS) has been a widely used technique to restore a fibrocartilage substitute overlying the defect. There are various postoperative weightbearing protocols for this procedure, with no single gold standard method. PURPOSE: To retrospectively review the outcomes of patients undergoing ankle arthroscopy with concomitant BMS to determine outcomes based on postoperative weightbearing status. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: We retrospectively reviewed the records of patients who underwent ankle arthroscopy with BMS for OLTs between 2015 and 2018. Patients were placed into 2 cohorts based on postoperative immobilization status: the nonweightbearing (NWB) group and the weightbearing-as-tolerated (WBAT) group. Patient characteristics obtained included age, sex, comorbidities, and etiology of talar pathology. Outcomes included the pain visual analog scale (VAS), range of motion (ROM), complications, time to first weightbearing, and the method and length of immobilization. Patients who were lost to follow-up before 30 days were excluded. The chi-square test was used to compare categorical variables between cohorts, and the t test was used for continuous variables. RESULTS: A total of 69 patients met the inclusion criteria for this study, 18 in the WBAT group and 51 in the NWB group. The mean lesion size was 9.48 × 9.21 mm (range, 3-15 mm × 2-20 mm) for the NWB group and 9.36 × 9.72 mm (range, 5-14 mm × 6-20 mm) for the WBAT group (P > .05). The VAS scores improved from 4.40 to 0.67 for the WBAT group and from 6.33 to 2.55 for the NWB group, with the difference in final values reaching statistical significance (P = .0002). Postoperative ROM was not significantly different between the groups. There were 4 repeat operations within the NWB cohort. CONCLUSION: The surgical management of OLTs can be challenging, and the postoperative weightbearing protocol can be an extra obstacle for the patient to navigate. We found no difference in pain, ROM, or complications when allowing immediate, full WBAT.

Chromosome-scale assembly of the yellow mealworm genome.

Background: The yellow mealworm beetle, Tenebrio molitor, is a promising alternative protein source for animal and human nutrition and its farming involves relatively low environmental costs. For these reasons, its industrial scale production started this century. However, to optimize and breed sustainable new T. molitor lines, the access to its genome remains essential. Methods: By combining Oxford Nanopore and Illumina Hi-C data, we constructed a high-quality chromosome-scale assembly of T. molitor. Then, we combined RNA-seq data and available coleoptera proteomes for gene prediction with GMOVE. Results: We produced a high-quality genome with a N50 = 21.9Mb with a completeness of 99.5% and predicted 21,435 genes with a median size of 1,780 bp. Gene orthology between T. molitor and Tribolium castaneum showed a highly conserved synteny between the two coleoptera and paralogs search revealed an expansion of histones in the T. molitor genome. Conclusions: The present genome will greatly help fundamental and applied research such as genetic breeding and will contribute to the sustainable production of the yellow mealworm.

Paradoxical effect of ethanol on potassium channel currents and cell survival in cerebellar granule neurons.

Transient exposure to ethanol (EtOH) results in a massive neurodegeneration in the developing brain leading to behavioral and cognitive deficits observed in fetal alcohol syndrome. There is now compelling evidence that K+ channels play an important role in the control of programmed cell death. The aim of the present work was to investigate the involvement of K+ channels in the EtOH-induced cerebellar granule cell death and/or survival. At low and high concentrations, EtOH evoked membrane depolarization and hyperpolarization, respectively. Bath perfusion of EtOH (10 mM) depressed the I(A) (transient K+ current) potassium current whereas EtOH (400 mM) provoked a marked potentiation of the specific I(K) (delayed rectifier K+ current) current. Pipette dialysis with GTPgammaS or GDPbetaS did not modify the effects of EtOH (400 mM) on both membrane potential and I(K) current. In contrast, the reversible depolarization and slowly recovering inhibition of I(A) induced by EtOH (10 mM) became irreversible in the presence of GTPgammaS. EtOH (400 mM) induced prodeath responses whereas EtOH (10 mM) and K+ channel blockers promoted cell survival. Altogether, these results indicate that in cerebellar granule cells, EtOH mediates a dual effect on K+ currents partly involved in the control of granule cell death.

Replacing Fish Meal with Defatted Insect Meal (Yellow Mealworm Tenebrio molitor) Improves the Growth and Immunity of Pacific White Shrimp (Litopenaeus vannamei).

Recently, ecological and economic issues have affected fish meal (FM) supply, the main source of protein for shrimp. This triggered a search for alternative dietary protein sources for shrimp production. We studied the consequences of replacing FM with a defatted insect meal, ŸnMealTM (YM), comprised of yellow mealworm (Tenebrio molitor). Growth and immune parameters of juvenile Pacific white shrimp (Litopenaeus vannanmei) were compared after an eight-week feeding trial. Shrimp were kept in aquaria with densities of 60 and 40 shrimp/m2 and fed one of five diets in which a proportion of FM was replaced by YM. All diets were isoproteic, isoenergetic, and balanced in lysine and methionine. After the feeding trial, shrimp were challenged with pathogenic bacteria (Vibrio parahaemolyticus). Growth and feed conversion parameters improved when YM was included in shrimp diets; with the highest weight gain and best food conversion ratio (FCR) achieved when 50% of FM was replaced by YM versus the control diet that contained no YM (initial weight: 1.60 g/shrimp; growth: 5.27 vs. 3.94 g/shrimp; FCR 1.20 vs. 1.59). In challenged shrimp, mortality rates were significantly less among groups that received YM, with a 76.9% lower mortality rate in the 50% FM replacement group versus the control.

From speciation to introgressive hybridization: the phylogeographic structure of an island subspecies of termite, Reticulitermes lucifugus corsicus.

BACKGROUND: Although much research has been carried out into European Reticulitermes taxonomy in recent years, there is still much discussion about phylogenetic relationships. This study investigated the evolution from intra- to interspecific phylogeny in the island subspecies Reticulitermes lucifugus corsicus and threw new light on this phenomenon. An integrative approach based on microsatellites and mitochondrial and nuclear DNA sequences was used to analyze samples taken from a wide area around the Tyrrhenian sea and showed how the subspecies evolved from its origins to its most recent form on continental coasts. RESULTS: According to mitochondrial phylogeny and molecular clock calculations, island and continental taxa diverged significantly by vicariance in the Pleistocene glacial period. However, more recently, numerous migrations, certainly human-mediated, affected the structure of the populations. This study provided evidence of direct hybridization and multiple introgressions which occurred in several hybrid areas. Analysis using STRUCTURE based on microsatellite data identified a population in Provence (France) which differed considerably (Fst = 0.477) from populations on the island of Corsica and in Tuscany in the Italian peninsula. This new population, principally distributed in urban areas, is highly heterogeneous especially within the ITS2 regions where homogenization by concerted evolution does not appear to have been completed. CONCLUSION: This study provides an unusual picture of genetic interaction between termite populations in the Tyrrhenian area and suggests that more attention should be paid to the role of introgression and human impact on the recent evolution of European termites.

Effect of GABA A receptor activation on UT-coupled signaling pathways in rat cortical astrocytes.

Cultured rat cortical astrocytes express two types of urotensin II (UII) binding sites: a high affinity site corresponding to the UT (GPR14) receptor and a low affinity site that has not been fully characterized. Activation of the high affinity site in astroglial cells stimulates polyphosphoinositide (PIP) turnover and provokes an increase in intracellular calcium concentration. We have hypothesized that the existence of distinct affinity sites for UII in rat cortical astrocytes could be accounted for by a possible cross-talk between UT and the ligand-gated ion channel GABA(A) receptor (GABA A R). Exposure of cultured astrocytes to UII provoked a bell-shaped increase in cAMP production, with an EC50 stimulating value of 0.83+/-0.04 pM, that was totally blocked in the presence of the adenylyl cyclase inhibitor SQ 22,536. In contrast, UII was found to inhibit forskolin-induced cAMP formation. In the presence of the specific PKA inhibitor H89, UII provoked a sustained stimulation of cAMP formation. Inhibition of PKA by H89 strongly reduced the stimulatory effect of UII on PIP metabolism. GABA and the GABA A R agonist isoguvacine provoked a marked inhibition of UII-induced cAMP synthesis and a significant reduction of UII-evoked PIP turnover. These data suggest that functional interaction between UT and GABA(A)R negatively regulates coupling of UT to the classical PLC/IP(3) signaling cascade as well as to the adenylyl cyclase/PKA pathway.

Adjustable-Loop Femoral Cortical Suspensory Fixation for Patellar Tendon Anterior Cruciate Ligament Reconstruction: A Time Zero Biomechanical Comparison With Interference Screw Fixation.

BACKGROUND: Adjustable-loop cortical buttons for femoral fixation of bone-tendon-bone grafts have potential advantages over interference screw fixation; however, these devices have not been benchmarked biomechanically against interference screws. Purpose/Hypothesis: The purpose was to compare the time zero biomechanical properties of commercially available, adjustable-loop cortical button and metallic interference screws for femoral fixation of bone-tendon-bone grafts. It was hypothesized that no significant differences would be found in biomechanical properties between fixation techniques. STUDY DESIGN: Controlled laboratory study. METHODS: Adjustable-loop cortical buttons (n = 8) and metallic interference screws (n = 8) were used to fix matched pairs of human bone-tendon-bone allografts in porcine distal femurs. These constructs were preconditioned (10 N to 50 N at 1 Hz, 10 cycles), subjected to cyclic loading (50 N to 250 N at 1 Hz, 500 cycles), and then pulled to failure at 20 mm/min. RESULTS: The loads to failure (mean ± SD, 700 ± 256 N vs 688 ± 215 N, P = .92) and linear stiffnesses (219 ± 48 N/mm vs 218 ± 49 N/mm, P = .97) for the adjustable-loop cortical button and metallic interference screws, respectively, were not significantly different. Cyclic displacement was higher in the adjustable-loop cortical button group (2.1 ± 0.6 mm vs 1.3 ± 0.4 mm, P = .01). The mechanism of failure was different between groups, with bone block slippage occurring most commonly in the interference screw group (n = 5) and fracture of the bone block through the suture hole occurring most commonly in the adjustable-loop cortical button group (n = 6). CONCLUSION: Adjustable-loop cortical buttons and interference screws have similar time zero failure loads, although cyclic displacement was higher with the adjustable-loop cortical buttons. The mean difference in displacement was less than 1 mm compared with the interference screw. CLINICAL RELEVANCE: Adjustable-loop cortical buttons may be an acceptable alternative to an interference screw for femoral fixation of bone-tendon-bone grafts in anterior cruciate ligament reconstruction. The clinical relevance of the observed differences in cyclic displacement is unknown and should be evaluated in future studies.