Occurrence of hemodynamic changes following administration of rocuronium in a dog presenting for an ophthalmic procedure.

A 10-year-old, neutered male, Golden Retriever dog presented for surgical correction of a descemetocele. Acepromazine (0.02 mg/kg) and methadone (0.5 mg/kg) were administered intramuscularly for sedation, propofol (2 mg/kg) and midazolam (0.2 mg/kg) were administered intravenously for anaesthetic induction and isoflurane in oxygen was utilised for anaesthetic maintenance. Rocuronium (0.5 mg/kg), a neuromuscular blocking agent, was administered intravenously to facilitate central positioning of the eye for surgery. Within 10 min of rocuronium administration, the dog became tachycardic and hypotensive. Hemodynamic aberrations did not resolve with initial interventions but were successfully mitigated with the administration of diphenhydramine (0.8 mg/kg) intravenously. The dog remained stable throughout the remainder of the procedure and experienced a smooth and uneventful recovery. While it is difficult to confirm that the hemodynamic changes observed in this clinical case resulted solely from administration of rocuronium, the observance of the cardiovascular changes, timing of events and response to therapy suggest that rocuronium elicited a histamine response that was successfully treated with diphenhydramine.

Immune Hypersensitivity Is Associated With Higher Graft Failure Rate After Osteochondral Allograft Transplantation of the Knee.

Purpose: To analyze the effects of 1 or more patient-reported allergies on clinical outcomes, in particular graft failure rate, and patient-reported outcomes (PROs) following osteochondral allograft transplantation (OCA) of the knee. Methods: Retrospective review of patients who underwent knee OCA from August 2010 to May 2021 with a minimum of 2-year follow-up. Patients were initially divided into 2 cohorts: those with at least 1 allergy and those without any allergies. Clinical outcomes assessed included graft failure, reoperation rates, deep vein thrombosis/pulmonary embolism, and manipulation under anesthesia/lysis of adhesions (MUA/LOA). PROs assessed, including the visual analog scale (VAS) for pain and satisfaction, the Knee injury and Osteoarthritis Outcome Score (KOOS), and return to sport rates, were compared. Results: In total, 285 patients were included with a mean clinical follow-up of 4.8 ± 2.0 years. The allergy cohort had a significantly higher rate of graft failure (P = .008). In a regression analysis controlling for confounding variables, graft failure remained significantly associated with the presence of medication allergies (odds ratio [OR], 3.631; 95% CI, 1.139-11.577; P = .029). Furthermore, an increasing number of allergies were associated with an increased rate of graft failure (OR, 1.644; 95% CI, 1.074-2.515; P = .022). There was no difference in rate of reoperation, complications, infection, and MUA/LOA. Of the 100 patients who completed PROs, there was no difference in VAS satisfaction, pain, and any of the KOOS outcome scores or return to sport. Conclusions: The presence of 1 or more patient-reported allergies was shown to be significantly associated with OCA graft failure. Furthermore, an increasing number of patient-reported allergies were associated with a higher rate of graft failure. However, there were no significant differences in VAS satisfaction or pain, KOOS symptom, quality of life, pain, or return to sport in patients with at least 1 patient-reported allergy and those without allergies. Level of Evidence: Level III, retrospective cohort study.

Energetic and Electronic Properties of UO0/± and UF0/±.

High-level electronic structure calculations were conducted to examine the bonding and spectroscopic properties of the UO0/± and UF0/± diatomic molecules. The low-lying Ω states were described by using multireference SO-CASPT2 calculations. The adiabatic electronic affinity (AEA), adiabatic ionization energy (IE), and bond dissociation energy (BDE) were calculated at the Feller-Peterson-Dixon (FPD) level. The ground state of UO is predicted to be 5I4, and that of UF is 4I9/2. The calculated AEAs of UO and UF are 1.123 and 0.453 eV, respectively, and the corresponding IEs are 5.976 and 6.278 eV. The BDE of UO (749.5 kJ/mol) is predicted to be considerably higher than that of UF (627.2 kJ/mol), and both are higher than those predicted for UB, UC, and UN. NBO calculations show strong ionic character for the ground states of UO and UF and bond orders that range from 2 to 3 and from 1 to 2, respectively. Comparisons of the calculated properties to those of the series comprising UB, UC, and UN diatomic molecules are given.

Oncolytic adenoviral therapy plus pembrolizumab in BCG-unresponsive non-muscle-invasive bladder cancer: the phase 2 CORE-001 trial.

Cretostimogene grenadenorepvec is a serotype-5 oncolytic adenovirus designed to selectively replicate in cancer cells with retinoblastoma pathway alterations, previously tested as monotherapy in bacillus Calmette-Guérin (BCG)-experienced non-muscle-invasive bladder cancer. In this phase 2 study, we assessed the potential synergistic efficacy between intravesical cretostimogene and systemic pembrolizumab in patients with BCG-unresponsive non-muscle-invasive bladder cancer with carcinoma in situ (CIS). Thirty-five patients were treated with intravesical cretostimogene with systemic pembrolizumab. Induction cretostimogene was administered weekly for 6 weeks followed by three weekly maintenance infusions at months 3, 6, 9, 12 and 18 in patients maintaining complete response (CR). Patients with persistent CIS/high-grade Ta at the 3-month assessment were eligible for re-induction. Pembrolizumab was administered for up to 24 months. The primary endpoint was CR at 12 months as assessed by cystoscopy, urine cytology, cross-sectional imaging and mandatory bladder mapping biopsies. Secondary endpoints included CR at any time, duration of response, progression-free survival and safety. The CR rate in the intention-to-treat population at 12 months was 57.1% (20 out of 35, 95% confidence interval (CI) 40.7-73.5%), meeting the primary endpoint. A total of 29 out of 35 patients (82.9%, 95% CI 70.4-95.3%) derived a CR at 3 months. With a median follow-up of 26.5 months, the median duration of response has not been reached (95% CI 15.7 to not reached). The CR rate at 24 months was 51.4% (18 out of 35) (95% CI 34.9-68.0%). No patient progressed to muscle-invasive bladder cancer in this trial. Adverse events attributed to cretostimogene were low grade, self-limiting and predominantly limited to bladder-related symptoms. A total of 5 out of 35 patients (14.3%) developed grade 3 treatment-related adverse effects. There was no evidence of overlapping or synergistic toxicities. Combination intravesical cretostimogene and systemic pembrolizumab demonstrated enduring efficacy. With a toxicity profile similar to its monotherapy components, this combination may shift the benefit-to-risk ratio for patients with BCG-unresponsive CIS. ClinicalTrials.gov Identifier: NCT04387461 .

Neural network denoising of x-ray images from high-energy-density experiments.

Noise is a consistent problem for x-ray transmission images of High-Energy-Density (HED) experiments because it can significantly affect the accuracy of inferring quantitative physical properties from these images. We consider experiments that use x-ray area backlighting to image a thin layer of opaque material within a physics package to observe its hydrodynamic evolution. The spatial variance of the x-ray transmission across the system due to changing opacity serves as an analog for measuring density in this evolving layer. The noise in these images adds nonphysical variations in measured intensity, which can significantly reduce the accuracy of our inferred densities, particularly at small spatial scales. Denoising these images is thus necessary to improve our quantitative analysis, but any denoising method also affects the underlying information in the image. In this paper, we present a method for denoising HED x-ray images via a deep convolutional neural network model with a modified DenseNet architecture. In our denoising framework, we estimate the noise present in the real (data) images of interest and apply the inferred noise distribution to a set of natural images. These synthetic noisy images are then used to train a neural network model to recognize and remove noise of that character. We show that our trained denoiser network significantly reduces the noise in our experimental images while retaining important physical features.

Inhibition of the Eukaryotic Initiation Factor-2-α Kinase PERK Decreases Risk of Autoimmune Diabetes in Mice.

Preventing the onset of autoimmune type 1 diabetes (T1D) is feasible through pharmacological interventions that target molecular stress-responsive mechanisms. Cellular stresses, such as nutrient deficiency, viral infection, or unfolded proteins, trigger the integrated stress response (ISR), which curtails protein synthesis by phosphorylating eIF2α. In T1D, maladaptive unfolded protein response (UPR) in insulin-producing ß cells renders these cells susceptible to autoimmunity. We show that inhibition of the eIF2α kinase PERK, a common component of the UPR and ISR, reverses the mRNA translation block in stressed human islets and delays the onset of diabetes, reduces islet inflammation, and preserves ß cell mass in T1D-susceptible mice. Single-cell RNA sequencing of islets from PERK-inhibited mice shows reductions in the UPR and PERK signaling pathways and alterations in antigen processing and presentation pathways in ß cells. Spatial proteomics of islets from these mice shows an increase in the immune checkpoint protein PD-L1 in ß cells. Golgi membrane protein 1, whose levels increase following PERK inhibition in human islets and EndoC-ßH1 human ß cells, interacts with and stabilizes PD-L1. Collectively, our studies show that PERK activity enhances ß cell immunogenicity, and inhibition of PERK may offer a strategy to prevent or delay the development of T1D.

Inhibition of the eukaryotic initiation factor-2-α kinase PERK decreases risk of autoimmune diabetes in mice.

Preventing the onset of autoimmune type 1 diabetes (T1D) is feasible through pharmacological interventions that target molecular stress-responsive mechanisms. Cellular stresses, such as nutrient deficiency, viral infection, or unfolded proteins, trigger the integrated stress response (ISR), which curtails protein synthesis by phosphorylating eIF2α. In T1D, maladaptive unfolded protein response (UPR) in insulin-producing beta cells renders these cells susceptible to autoimmunity. We found that inhibition of the eIF2α kinase PERK, a common component of the UPR and ISR, reversed the mRNA translation block in stressed human islets and delayed the onset of diabetes, reduced islet inflammation, and preserved ß cell mass in T1D-susceptible mice. Single-cell RNA sequencing of islets from PERK-inhibited mice showed reductions in the UPR and PERK signaling pathways and alterations in antigen processing and presentation pathways in ß cells. Spatial proteomics of islets from these mice showed an increase in the immune checkpoint protein PD-L1 in ß cells. Golgi membrane protein 1, whose levels increased following PERK inhibition in human islets and EndoC-ßH1 human ß cells, interacted with and stabilized PD-L1. Collectively, our studies show that PERK activity enhances ß cell immunogenicity, and inhibition of PERK may offer a strategy to prevent or delay the development of T1D.

Comparable Clinical and Functional Outcomes Between Osteochondral Allograft Transplantation and Autologous Chondrocyte Implantation for Articular Cartilage Lesions in the Patellofemoral Joint at a Mean Follow-up of 5 Years.

PURPOSE: To assess clinical outcomes and return to sport (RTS) rates among patients who undergo osteochondral allograft (OCA) transplantation and autologous chondrocyte implantation (ACI) or matrix-induced autologous chondrocyte implantation (MACI), for patellofemoral articular cartilage defects. METHODS: A retrospective review of patients who underwent an OCA or ACI/MACI from 2010 to 2020 was conducted. Patient-reported outcomes collected included visual analog scale for pain/satisfaction, Knee Injury and Osteoarthritis Outcome Score (KOOS), and RTS. The percentage of patients that met the patient acceptable symptom state for KOOS was recorded. Logistic regression was used to identify predictors of worse outcomes. RESULTS: A total of 95 patients were included (78% follow-up) with ACI or MACI performed in 55 cases (57.9%) and OCA in 40 (42.1%). A tibial tubercle osteotomy was the most common concomitant procedure for OCA (66%) and ACI/MACI (98%). Overall, KOOS pain was significantly poorer in OCA than ACI/MACI (74.7, 95% confidence interval 68.1-81.1 vs 83.6, 95% confidence interval 81.3, 88.4, P = .012), whereas the remaining KOOS subscores were nonsignificantly different (all P > .05). Overall, RTS rate was 54%, with no significant difference in return between OCA or ACI/MACI (52% vs 58%, P = .738). There were 26 (27%) reoperations and 5 (5%) graft failures in the entire group. Increasing age was associated with lower satisfaction in OCA and poorer outcomes in ACI/MACI, whereas larger lesion area was associated with lower satisfaction and poorer outcomes in ACI/MACI. CONCLUSIONS: Clinical and functional outcomes were similar in patients who underwent OCA or ACI/MACI for patellofemoral articular cartilage defects at a mean follow-up of 5 years. Patients who received OCA had a greater proportion of degenerative cartilage lesions and, among those with trochlear lesions, reported greater pain at final follow-up than their ACI/MACI counterparts. Overall, increasing age and a larger lesion size were associated with worse patient-reported outcomes. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Asymmetric preservation of choroidal pigmentation simulating choroidal nevus in two siblings with Waardenburg syndrome type 2A.

INTRODUCTION: In addition to sensorineural hearing loss, Waardenburg Syndrome (WS) may present with variable pigmentation of skin and choroid, which may simulate other life-threating conditions (e.g. melanoma). CASE REPORT: Two siblings ostensibly presented with unilateral choroidal pigmentary abnormalities concerning for choroidal tumour. Serial ophthalmic examination documented no lesion growth (base or height) whilst the apparent syndromic features (i.e. iris hypochromia, profound sensorineural hearing loss, SNHL), family history (autosomal dominant inheritance) and positive genetic testing (pathogenic MITF variant) led to a revised diagnosis of Waardenburg Syndrome type 2A. CONCLUSION: Sectoral preservation of choroidal pigmentation in WS is rarely associated with choroidal malignancy. Awareness of syndromic features (e.g. SNHL) and access to genetic testing may facilitate early accurate diagnosis (i.e. allay concern for malignancy), enable treatment of modifiable features (e.g. SNHL) and identify other affected relatives.

Owner survey suggests cats may be undertreated for pain compared to dogs after an elective ovariohysterectomy or orchiectomy.

OBJECTIVE: To investigate differences in pain management between dogs and cats after surgical sterilization. We hypothesized that dogs would be more likely to be discharged with analgesics after sterilization compared to cats and that owner compliance would be better in dogs. ANIMALS: 175 respondents owning 92 dogs and 83 cats from a high-volume, low-cost veterinary clinic in Michigan during August 2022. METHODS: Owners received an online survey designed to assess their pet's postoperative analgesic care. They were asked demographic information about themselves and their pets. Additionally, they were asked if their pet was discharged with analgesics, if they were administered as prescribed, and if their pet was painful at home. Dogs and cats were included if they were sterilized within 6 months of survey completion and in the owner's care at the time of the procedure. RESULTS: The survey was distributed to 5,241 owners and received 227 responses, a response rate of 4.4%. Analgesics were prescribed for 19 of 162 (12%) pets: 14 of 88 (16%) dogs and 5 of 74 (6.7%) cats. There was no difference in the prescription of analgesics between dogs and cats after ovariohysterectomy (P = .09) or orchiectomy (P = .73). 15 of 19 owners reported their compliance in administering analgesics at 78.9%. Owners' subjective assessments showed that 24 of 86 (28%) dogs and 12 of 68 (17%) cats appeared painful at home. CLINICAL RELEVANCE: Postoperative pain in cats may not be appropriately managed.

Cytokine Receptor-like Factor 1 (CRLF1) and Its Role in Osteochondral Repair.

BACKGROUND: Since cytokine receptor-like factor 1 (CRLF1) has been implicated in tissue regeneration, we hypothesized that CRLF1 released by mesenchymal stem cells can promote the repair of osteochondral defects. METHODS: The degree of a femoral osteochondral defect repair in rabbits after intra-articular injections of bone marrow-derived mesenchymal stem cells (BMSCs) that were transduced with empty adeno-associated virus (AAV) or AAV containing CRLF1 was determined by morphological, histological, and micro computer tomography (CT) analyses. The effects of CRLF1 on chondrogenic differentiation of BMSCs or catabolic events of interleukin-1beta-treated chondrocyte cell line TC28a2 were determined by alcian blue staining, gene expression levels of cartilage and catabolic marker genes using real-time PCR analysis, and immunoblot analysis of Smad2/3 and STAT3 signaling. RESULTS: Intra-articular injections of BMSCs overexpressing CRLF1 markedly improved repair of a rabbit femoral osteochondral defect. Overexpression of CRLF1 in BMSCs resulted in the release of a homodimeric CRLF1 complex that stimulated chondrogenic differentiation of BMSCs via enhancing Smad2/3 signaling, whereas the suppression of CRLF1 expression inhibited chondrogenic differentiation. In addition, CRLF1 inhibited catabolic events in TC28a2 cells cultured in an inflammatory environment, while a heterodimeric complex of CRLF1 and cardiotrophin-like Cytokine (CLC) stimulated catabolic events via STAT3 activation. CONCLUSION: A homodimeric CRLF1 complex released by BMSCs enhanced the repair of osteochondral defects via the inhibition of catabolic events in chondrocytes and the stimulation of chondrogenic differentiation of precursor cells.

Survival of transfused red blood cells from a donor with alpha-thalassemia trait in a recipient with sickle cell disease.

BACKGROUND: Post-transfusion survival of donor red blood cells (RBCs) is important for effective chronic transfusion therapy in conditions including sickle cell disease (SCD). Biotin labeling RBCs allows direct in vivo measurement of multiple donor RBC units simultaneously post-transfusion. STUDY DESIGN AND METHODS: In an observational trial of patients with SCD receiving monthly chronic transfusion therapy, aliquots of RBCs from one transfusion episode were biotin-labeled and infused along with the unlabeled RBC units. Serial blood samples were obtained to measure RBC survival. Donor units were tested for RBC indices, hemoglobin fractionation, and glucose-6-phosphate dehydrogenase (G6PD) enzyme activity. For microcytic donor RBCs (MCV < 70 fL), HBA1 and HBA2 genetic testing was performed on whole blood. RESULTS: We present one recipient, a pediatric patient with SCD and splenectomy who received two RBC units with aliquots from each unit labeled at distinct biotin densities (2 and 18 µg/mL biotin). One donor unit was identified to have microcytosis (MCV 68.5 fL after biotinylation); whole blood sample obtained at a subsequent donation showed 2-gene deletion alpha-thalassemia trait (ɑ-3.7kb/ɑ-3.7kb) and normal serum ferritin. G6PD activity was >60% of normal mean for both. The RBCs with alpha-thalassemia RBC had accelerated clearance and increased surface phosphatidylserine post-transfusion, as compared with the normocytic RBC (half life 65 vs. 86 days, respectively). DISCUSSION: Post-transfusion RBC survival may be lower for units from donors with alpha-thalassemia trait, although the impact of thalassemia trait donors on transfusion efficacy requires further study.

3-[18F]Fluoro-para-hydroxyphenethylguanidine (3-[18F]pHPG) PET-A Novel Imaging Modality for Paraganglioma.

Context: Functional positron emission tomography (PET) imaging for the characterization of pheochromocytoma and paraganglioma (PCC/PGL) and for detection of metastases in malignant disease, offers valuable clinical insights that can significantly guide patient treatment. Objective: This work aimed to evaluate a novel PET radiotracer, 3-[18F]fluoro-para-hydroxyphenethylguanidine (3-[18F]pHPG), a norepinephrine analogue, for its ability to localize PCC/PGL. Methods: 3-[18F]pHPG PET/CT whole-body scans were performed on 16 patients (8 male:8 female; mean age 47.6 ± 17.6 years; range, 19-74 years) with pathologically confirmed or clinically diagnosed PCC/PGL. After intravenous administration of 304 to 475 MBq (8.2-12.8 mCi) of 3-[18F]pHPG, whole-body PET scans were performed at 90 minutes in all patients. 3-[18F]pHPG PET was interpreted for abnormal findings consistent with primary tumor or metastasis, and biodistribution in normal organs recorded. Standardized uptake value (SUV) measurements were obtained for target lesions and physiological organ distributions. Results: 3-[18F]pHPG PET showed high radiotracer uptake and trapping in primary tumors, and metastatic tumor lesions that included bone, lymph nodes, and other solid organ sites. Physiological biodistribution was universally present in salivary glands (parotid, submandibular, sublingual), thyroid, heart, liver, adrenals, kidneys, and bladder. Comparison [68Ga]DOTATATE PET/CT was available in 10 patients and in all cases showed concordant distribution. Comparison [123I]meta-iodobenzylguanidine [123I]mIBG planar scintigraphy and SPECT/CT scans were available for 4 patients, with 3-[18F]pHPG showing a greater number of metastatic lesions. Conclusion: We found the kinetic profile of 3-[18F]pHPG PET affords high activity retention within benign and metastatic PCC/PGL. Therefore, 3-[18F]pHPG PET imaging provides a novel modality for functional imaging and staging of malignant paraganglioma with advantages of high lesion affinity, whole-body coregistered computed tomography, and rapid same-day imaging.

The Safety, Tolerability, and Preliminary Efficacy of a Gemcitabine-releasing Intravesical System (TAR-200) in American Urological Association-defined Intermediate-risk Non-muscle-invasive Bladder Cancer Patients: A Phase 1b Study.

Background and objective: Patients with intermediate-risk non-muscle-invasive bladder cancer (IR NMIBC) have a high risk of recurrence and need effective therapies to reduce the risk of disease recurrence or progression. This phase 1b study (NCT02720367) assessed the safety and tolerability of TAR-200, an intravesical drug delivery system, in participants with IR NMIBC. Methods: Participants with recurrent IR NMIBC were eligible. Participants received either two 7-d or two 21-d TAR-200 dosing cycles over a 4-6-wk period in a marker lesion/ablation design. TAR-200 was placed in the window between the cystoscopy showing recurrent papillary disease and the subsequent complete transurethral resection of the bladder tumour. The primary endpoint was TAR-200 safety. The secondary endpoints included TAR-200 tolerability, pharmacokinetics, and preliminary efficacy. Key findings and limitations: Twelve participants received TAR-200 treatment. No TAR-200-related serious or grade ≥ 3 treatment-emergent adverse events (TEAEs) occurred. Nine participants had grade ≤ 2 TAR-200-related TEAEs, with urgency, dysuria, and haematuria being most common. Two participants refused a second dosing cycle due to urinary urgency and frequency. Insertion and removal of TAR-200 was successful in all cases. Plasma gemcitabine concentrations remained below the lower limit of detection. Five participants (42%) had complete response (CR): four had pathological CR and one had CR based on visual assessment. Conclusions and clinical implications: TAR-200 appears to be safe and well tolerated, with encouraging preliminary efficacy in participants with IR NMIBC. This study lays the groundwork for the multiple phase 2 and 3 global studies that are currently on-going for TAR-200. Patient summary: In this study, researchers evaluated the safety of the novel drug delivery system TAR-200 in participants with intermediate-risk non-muscle-invasive bladder cancer. They concluded that TAR-200 was safe and well tolerated with promising antitumour activity.

Segond fracture: an indicator for increased risk of lateral meniscus injury in patients with acute anterior cruciate ligament ruptures.

PURPOSE: The purpose of this study was to investigate the incidence and anatomic distribution of meniscus injury in patients who have sustained acute ACL injuries with and without concomitant Segond fracture. We hypothesized that patients who have sustained a torn ACL with a concomitant Segond fracture would have a higher incidence of lateral meniscal injuries than patients with an isolated ACL injury. METHODS: Patients who underwent ACL reconstruction from 2012 to 2022 were retrospectively reviewed. Segond fractures were identified on knee radiographs. Inclusion criteria were age 18-40, injury during sports activity, and reconstruction within 90 days of injury. Sports activity, anatomic location of meniscus injury, and meniscus treatment were documented. Multivariable regression was used to identify predictors of meniscus injury/treatment. RESULTS: There were 25 of 603 (4.1%) patients who had an ACL tear with concomitant Segond fracture. The incidence of lateral meniscus injury in the Segond group (72%) was significantly higher than in the non-Segond cohort (49%; p = 0.024). A significantly smaller proportion of medial meniscus injuries among patients with Segond fractures were repaired (23.1%) compared to the non-Segond group (54.2%; p = 0.043). Multivariate analysis found patients with Segond fractures to have increased odds of lateral meniscus injury (OR 2.68; [1.09, 6.60], p = 0.032) and were less likely to have medial meniscus injuries repaired (OR 0.35; [0.15, 0.81], p = 0.014). Additionally, males had increased odds of lateral meniscus injury (OR 1.54; [1.08 - 2.91], p = 0.017), which were more likely to require repair (OR 1.48; [1.02, 2.14], p = 0.038). CONCLUSIONS: Among acute ACL injuries, the incidence of lateral meniscus injury is greater among patients with Segond fractures. Patients with Segond fracture were less likely to undergo repair of medial meniscal injuries.

Arthroscopic Bankart repair versus nonoperative management for first-time anterior shoulder instability: A cost-effectiveness analysis.

Purpose: Arthroscopic Bankart repair (ABR) may be more effective than nonoperative management for patients with anterior shoulder instability following first-time dislocation. The purpose of the study was to determine the most cost-effective treatment strategy by evaluating the incremental cost-effectiveness ratio (ICER) for ABR versus nonoperative treatment. Methods: This cost-effectiveness study utilized a Markov decision chain and Monte Carlo simulation. Probabilities, health utility values, and outcome data regarding ABR and nonoperative management of first-time shoulder instability derived from level I/II evidence. Costs were tabulated from Centers for Medicaid & Medicare Services. Probabilistic sensitivity analysis was performed using >100,000 repetitions of the Monte Carlo simulation. A willingness-to-pay (WTP) threshold was set at $50,000. Results: The expected cost for operative management higher than nonoperative management ($32,765 vs $29,343). However, ABR (5.48 quality-adjusted life years (QALYs)) was the more effective treatment strategy compared to nonoperative management (4.61 QALYs). The ICER for ABR was $3943. Probabilistic sensitivity analysis showed that ABR was the most cost-effective strategy in 100% of simulations. Discussion: ABR is more cost-effective than nonoperative management for first-time anterior shoulder dislocation. The threshold analysis demonstrated that when accounting for WTP, ABR was found to be the more cost-effective strategy.