Rhizobial secretion of truncated exopolysaccharides severely impairs the Mesorhizobium-Lotus symbiosis.

The symbiosis between Mesorhizobium japonicum R7A and Lotus japonicus Gifu is an important model system for investigating the role of bacterial exopolysaccharides (EPS) in plant-microbe interactions. Previously we showed that R7A exoB mutants that are affected at an early stage of EPS synthesis and in lipopolysaccharide (LPS) synthesis induce effective nodules on L. japonicus Gifu after a delay, whereas exoU mutants affected in the biosynthesis of the EPS side chain induce small uninfected nodule primordia and are impaired in infection. The presence of a halo around the exoU mutant when grown on Calcofluor-containing media suggested the mutant secreted a truncated version of R7A EPS. A non-polar ΔexoA mutant defective in the addition of the first glucose residue to the EPS backbone was also severely impaired symbiotically. Here we used a suppressor screen to show that the severe symbiotic phenotype of the exoU mutant was due to secretion of an acetylated pentasaccharide, as both monomers and oligomers, by the same Wzx/Wzy system that transports wild-type exopolysaccharide. We also present evidence that the ΔexoA mutant secretes an oligosaccharide by the same transport system, contributing to its symbiotic phenotype. In contrast, ΔexoYF, and polar exoA and exoL mutants have a similar phenotype to exoB mutants, forming effective nodules after a delay. These studies provide substantial evidence that secreted incompatible EPS is perceived by the plant leading to abrogation of the infection process.

Implementation of an Enhanced Recovery After Surgery Protocol for Cranial Vault Remodeling Procedures.

BACKGROUND: Enhanced recovery after surgery (ERAS) protocols have been implemented across surgical disciplines, including cranial vault remodeling for craniosynostosis. The authors aim to describe the implementation of an ERAS protocol for cranial vault remodeling procedures performed for patients with craniosynostosis at a tertiary care hospital. DESCRIPTION: Institutional review board approval was received. All patients undergoing a cranial remodeling procedure for craniosynostosis at the authors' institution over a 10-year period were collected (n = 168). Patient and craniosynostosis demographics were collected as well as operative details. Primary outcome measures were intensive care unit length of stay (ICU LOS) and narcotic usage. Chi squared and independent t-tests were employed to determine significance. A significance value of 0.05 was utilized. RESULTS: During the time examined, there were 168 primary cranial vault remodeling procedures performed at the authors' institution - all of which were included in the analysis. Use of the ERAS protocol was associated with decreased initial 24-hour morphine equivalent usage (p < 0.01) and decreased total morphine equivalent usage (p < 0.01). Patients using the ERAS protocol experienced a shorter ICU LOS (p < 0.01), but the total hospital length of stay was unchanged. CONCLUSION: This study reiterates the benefit of developing and implementing an ERAS protocol for patients undergoing cranial vault remodeling procedures. The protocol resulted in an overall decreased ICU LOS and a decrease in narcotic use. This has implications for ways to maximize hospital reimbursement for these procedures, as well as potentially improve outcomes.

Quantitative source apportionment of faecal indicator bacteria from anthropogenic and zoogenic sources of faecal contamination.

Recreational bathing waters are complex systems with diverse inputs from multiple anthropogenic and zoogenic sources of faecal contamination. Faecal contamination is a substantial threat to water quality and public health. Here we present a comprehensive strategy to estimate the contribution of faecal indicator bacteria (FIB) from different biological sources on two at-risk beaches in Dublin, Ireland. The daily FIB loading rate was determined for three sources of contamination: a sewage-impacted urban stream, dog and wild bird fouling. This comparative analysis determined that the stream contributed the highest daily levels of FIB, followed by dog fouling. Dog fouling may be a significant source of FIB, contributing approximately 20 % of E. coli under certain conditions, whereas wild bird fouling contributed a negligible proportion of FIB (<3 %). This study demonstrates that source-specific quantitative microbial source apportionment (QMSA) strategies are vital to identify primary public health risks and target interventions to mitigate faecal contamination.

Tixagevimab/Cilgavimab does not prevent COVID-19 in patients with multiple sclerosis and related disorders on B-cell depleting therapies.

BACKGROUND: Patients with MS and related disorders (pwMSARD) on B-cell depleting treatments have attenuated immune responses to vaccination and were eligible to receive tixagevimab/cilgavimab. OBJECTIVES: Understand incidence and severity of COVID-19 in pwMSARD on B-cell depleting therapies who received tixagevimab/cilgavimab compared to an untreated group. METHODS: We conducted a retrospective medical records review of adult pwMSARD on B-cell depleting treatments who received tixagevimab/cilgavimab between 1/2022-1/2023. PwMSARD on B-cell depleting treatments who did not served as a control group (CG). We compared COVID-19 incidence and severity within 6 months of tixagevimab/cilgavimab or rituximab/ocrelizumab infusion for the CG. RESULTS: 210 patients were identified, 135 in the treatment group (TG) and 75 in the CG. In the TG, 24 (17.8 %) developed COVID-19 compared to 12 (16 %) in the CG. There was no difference in the odds of developing COVID-19 in an unadjusted logistic regression model (OR=1.14; 95 % CI: 0.53, 2.42; p = 0.74) or after adjusting for age and disease duration (OR=1.05; 95 % CI: 0.47, 2.37; p = 0.91). There was also no difference in COVID-19 severity between groups. CONCLUSIONS: There was no difference in COVID-19 infection rates or severity in pwMSARD on B-cell depleting treatments who received tixagevimab/cilgavimab compared to those who remained untreated.

Echocardiographic predictors of cardiovascular outcome in heart failure with preserved ejection fraction.

AIMS: The optimal echocardiographic predictors of cardiovascular outcome in heart failure (HF) with preserved ejection fraction (HFpEF) are unknown. We aimed to identify independent echocardiographic predictors of cardiovascular outcome in patients with HFpEF. METHODS AND RESULTS: Systematic literature search of three electronic databases was conducted from date of inception until November 2022. Hazard ratios (HRs) and their 95% confidence intervals (CIs) for echocardiographic variables from multivariate prediction models for the composite primary endpoint of cardiovascular death and HF hospitalization were pooled using a random effects meta-analysis. Specific subgroup analyses were conducted for studies that enrolled patients with acute versus chronic HF, and for those studies that included E/e', pulmonary artery systolic pressure (PASP), renal function, natriuretic peptides and diuretic use in multivariate models. Forty-six studies totalling 20 056 patients with HFpEF were included. Three echocardiographic parameters emerged as independent predictors in all subgroup analyses: decreased left ventricular (LV) global longitudinal strain (HR 1.24, 95% CI 1.10-1.39 per 5% decrease), decreased left atrial (LA) reservoir strain (HR 1.30, 95% CI 1.13-1.1.50 per 5% decrease) and lower tricuspid annular plane systolic excursion (TAPSE) to PASP ratio (HR 1.17, 95% CI 1.07-1.25 per 0.1 unit decrease). Other independent echocardiographic predictors of the primary endpoint were a higher E/e', moderate to severe tricuspid regurgitation, LV mass index and LA ejection fraction, although these variables were less robust. CONCLUSIONS: Impaired LV global longitudinal strain, lower LA reservoir strain and lower TAPSE/PASP ratio predict cardiovascular death and HF hospitalization in HFpEF and are independent of filling pressures, clinical characteristics and natriuretic peptides. These echocardiographic parameters reflect key functional changes in HFpEF, and should be incorporated in future prospective risk prediction models.

The Complete Genome Sequences of 12 Species of Enteromius (Cyprinidae, Cypriniformes, Actinopteri).

We present the complete genome sequences of 12 species of Enteromius. Illumina sequencing was performed on genetic material from museum specimens. The reads were assembled using a de novo method followed by a finishing step. The raw and assembled data are publicly available via Genbank.

ChatGPT-4 Can Help Hand Surgeons Communicate Better With Patients.

The American Society for Surgery of the Hand and British Society for Surgery of the Hand produce patient-focused information above the sixth-grade readability recommended by the American Medical Association. To promote health equity, patient-focused content should be aimed at an appropriate level of health literacy. Artificial intelligence-driven large language models may be able to assist hand surgery societies in improving the readability of the information provided to patients. The readability was calculated for all the articles written in English on the American Society for Surgery of the Hand and British Society for Surgery of the Hand websites, in terms of seven of the commonest readability formulas. Chat Generative Pre-Trained Transformer version 4 (ChatGPT-4) was then asked to rewrite each article at a sixth-grade readability level. The readability for each response was calculated and compared with the unedited articles. Chat Generative Pre-Trained Transformer version 4 was able to improve the readability across all chosen readability formulas and was successful in achieving a mean sixth-grade readability level in terms of the Flesch Kincaid Grade Level and Simple Measure of Gobbledygook calculations. It increased the mean Flesch Reading Ease score, with higher scores representing more readable material. This study demonstrated that ChatGPT-4 can be used to improve the readability of patient-focused material in hand surgery. However, ChatGPT-4 is interested primarily in sounding natural, and not in seeking truth, and hence, each response must be evaluated by the surgeon to ensure that information accuracy is not being sacrificed for the sake of readability by this powerful tool.

Cardiac Substrate Utilization and Relationship to Invasive Exercise Hemodynamic Parameters in HFpEF.

The authors conducted transcardiac blood sampling in healthy subjects and subjects with heart failure with preserved ejection fraction (HFpEF) to compare cardiac metabolite and lipid substrate use. We demonstrate that fatty acids are less used by HFpEF hearts and that lipid extraction is influenced by hemodynamic factors including pulmonary pressures and cardiac index. The release of many products of protein catabolism is apparent in HFpEF compared to healthy myocardium. In subgroup analyses, differences in energy substrate use between female and male hearts were identified.

Agricultural and urban practices are correlated to changes in the resistome of riverine systems.

The objective of this study was to comprehensively characterise the resistome, the collective set of antimicrobial resistance genes in a given environment, of two rivers, from their source to discharge into the sea, as these flow through areas of different land use. Our findings reveal significant differences in the riverine resistome composition in areas of different land uses, with increased abundance and diversity of AMR in downstream agricultural and urban locations, with the resistome in urban areas more similar to the resistome in wastewater. The changes in resistome were accompanied by changes in microbial communities, with a reduction in microbial diversity in downstream agricultural and urban affected areas, driven mostly by increased relative abundance in the phyla, Bacteroidetes and Proteobacteria. These results provide insight into how pollution associated with agricultural and urban activities affects microbial communities and influences AMR in aquatic water bodies. These results add valuable insights to form effective strategies for mitigating and preserving aquatic ecosystems. Overall, our study highlights the critical role of the environment in the development and dissemination of AMR and underscores the importance of adopting a One Health approach to address this global public health threat.

Hippocampal resting-state connectivity is associated with posterior-cortical cognitive impairment in Parkinson's disease.

AIM: Frontal and posterior-cortical cognitive subtypes in Parkinson's disease (PD) present with executive/attention and memory/visuospatial deficits, respectively. As the posterior-cortical subtype is predicted to progress rapidly toward dementia, the present study aimed to explore biological markers of this group using resting-state functional magnetic resonance imaging (rs-fMRI). METHODS: K-means cluster analysis delineated subtypes (cognitively intact, frontal, posterior-cortical, and globally impaired) among 85 people with PD. A subset of PD participants (N = 42) and 20 healthy controls (HCs) underwent rs-fMRI. Connectivity of bilateral hippocampi with regions of interest was compared between posterior-cortical, cognitively intact, and HC participants using seed-based analysis, controlling for age. Exploratory correlations were performed between areas of interest from the group analysis and a series of cognitive tests. RESULTS: The posterior-cortical subtype (N = 19) showed weaker connectivity between the left hippocampus and right anterior temporal fusiform cortex compared to the cognitively intact (N = 11) group, p-false discovery rate (FDR) = .01, and weaker connectivity between bilateral hippocampi and most fusiform regions compared to HCs (N = 20). No differences were found between HCs and cognitively intact PD. Exploratory analyses revealed strongest associations between connectivity of the right anterior temporal fusiform cortex and left hippocampus with category fluency (p-FDR = .01). CONCLUSION: Results suggest that weakened connectivity between the hippocampus and fusiform region is a unique characteristic of posterior-cortical cognitive deficits in PD. Further exploration of hippocampal and fusiform functional integrity as a marker of cognitive decline in PD is warranted.

Bacterial proximity effects on the transfer of antibiotic resistance genes within the alimentary tract of yellow mealworm larvae.

The arthropod intestinal tract and other anatomical parts naturally carry microorganisms. Some of which are pathogens, secrete toxins, or carry transferable antibiotic-resistance genes. The risks associated with the production and consumption of edible arthropods are dependent on indigenous microbes, as well as microbes introduced during the processes of rearing. This mass arthropod production puts individual arthropods in close proximity, which increases the possibility of their exposure to antibiotic-resistant bacteria carried by bacteria from fellow insects, industry workers, or rearing hardware and substrates. The purpose of this study was to determine if the alimentary tract of the yellow mealworm provided an environment permitting horizontal gene transfer between bacteria. The effect of the concentration of bacterial exposure was also assessed. Antibiotic resistance gene transfer between marker Salmonella Lignières (Enterobacterales: Enterobacteriaceae) and Escherichia coli (Migula) (Enterobacterales: Enterobacteriaceae) introduced into the larval gut demonstrated that the nutrient-rich environment of the yellow mealworm gut provided favorable conditions for the transfer of antibiotic resistance genes. Conjugation frequencies were similar across inoculum concentrations; however, transconjugant production correlated positively to increased exposure concentration. The lowest concentration of bacterial exposure required enrichment to detect and thus may have been approaching a threshold level for the 2 bacteria to colocate within the expanse of the larval gut. While many factors can affect this transfer, the simple factor of the proximity of donor and recipient bacteria, as defined by the concentration of bacteria within the volume of the insect gut, likely primarily contributed to the efficiency of antibiotic gene transfer.

A biologging database of mobulid rays from the Gulf of California, Mexico.

We initiated a tagging program in 2004 to determine the large-scale and long-term movement patterns of three species of Mobulid Ray (Mobula mobular, M. munkiana, M. thurstoni). Between 2004 and 2014 we deployed 48 pop-up archival (PAT) tags that recorded temperature, pressure, and light level. Pressure and light level records were then used to calculate animal depth and geolocation. Transmitted and when available recovered raw data files from successful deployments (n = 45) were auto-ingested from the manufacturer into the United States Animal Telemetry Network's (ATN) Data Assembly Center (DAC). Through the ATN DAC, all necessary metadata were compiled, dataset was prepped for release, and derived geolocation trajectories (n = 43) were visualized within their public facing data portal. These data and the full metadata records are available for download from the ATN portal as well as permanently archived under the DataONE Research Workspace member node.

Feasibility and Acceptability of a Videoconferencing CBT Intervention for Anxiety in People with Parkinson's Disease.

OBJECTIVES: In people with Parkinson's disease (PwPD), non-motor symptoms such as anxiety are common and have negative impacts on their quality of life. There are currently few interventions that address anxiety in PwPD, and access to diagnosis and treatment is often limited for those living in rural areas. The aim of this study was to evaluate the feasibility and acceptability of a telehealth videoconferencing CBT intervention for anxiety in PwPD. METHODS: A pre- and post-test feasibility study (N = 10) was conducted and evaluated utilizing the RE-AIM framework (Reach, Effectiveness, Adoption, Implementation, and Maintenance). RESULTS: Lack of access to the internet and videoconferencing technology were identified as barriers to participation. Physical health issues also impacted recruitment and retention. Non-completers were significantly older and less likely to have a carer involved in the intervention. Clinician adoption of the intervention was low while participant acceptability of videoconferencing technology varied and required carer support. CONCLUSIONS: Providing access to technology and support to overcome technological issues, as well as telehealth training for clinicians, are recommended in future studies to improve recruitment, retention, and implementation. CLINICAL IMPLICATIONS: Identification of barriers and facilitators provides future studies with the knowledge to tailorize their program to better suit PwPD.

A physiotherapy group exercise and self-management approach to improve physical activity in people with mild-moderate Parkinson's disease: a randomized controlled trial.

BACKGROUND: Physical activity levels are low in people with Parkinson's disease (PD) and have proved difficult to increase with exercise programs alone. Intervention approaches that address both the capacity to engage in physical activity and self-management strategies to change and maintain exercise behaviours are needed to address this intractable issue. METHODS: This will be an assessor-blinded, randomized controlled trial performed in Brisbane, Australia. Ninety-two people with mild-moderate PD will be randomly allocated to two groups: usual care, and a physiotherapy-led group exercise program combined with self-management strategies. In the intervention group, twelve, 80-min sessions will be conducted over 4 weeks in groups of up to 4 participants. The intervention will consist of circuit training including treadmill walking to target aerobic fitness, and activities targeting strength, balance, and gait performance. In addition, each session will also incorporate strategies focusing on self-management and behaviour change, augmented by the provision of a fitness activity tracker. Outcome measures will be collected at baseline (T1), immediately post intervention (T2) and at 6 months follow-up (T3). The primary outcome measure is free-living physical activity (average daily step count over 7 days) at pre (T1) and post (T2) intervention measured using an activPAL™ device. Secondary outcome measures captured at all time points include time spent walking, sedentary and in moderate intensity exercise over 7 days; spatiotemporal gait performance (step length, gait speed, endurance); health-related quality of life; and outcome expectations and self-efficacy for exercise. DISCUSSION: Sustainability of gains in physical activity following exercise interventions is a challenge for most populations. Our incorporation of a chronic disease self-management approach into the exercise program including fitness tracking extends previous trials and has potential to significantly improve free-living physical activity in people with PD. TRIAL REGISTRATION: This study has been prospectively registered in Australian and New Zealand Clinical Trial Registry (ACTRN12617001057370), registered on 19/07/2017. Available from www.anzctr.org.au/ACTRN12617001057370.aspx .

Indole-3-Propionic Acid Protects Against Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a common but poorly understood form of heart failure, characterized by impaired diastolic function. It is highly heterogeneous with multiple comorbidities, including obesity and diabetes, making human studies difficult. METHODS: Metabolomic analyses in a mouse model of HFpEF showed that levels of indole-3-propionic acid (IPA), a metabolite produced by gut bacteria from tryptophan, were reduced in the plasma and heart tissue of HFpEF mice as compared with controls. We then examined the role of IPA in mouse models of HFpEF as well as 2 human HFpEF cohorts. RESULTS: The protective role and therapeutic effects of IPA were confirmed in mouse models of HFpEF using IPA dietary supplementation. IPA attenuated diastolic dysfunction, metabolic remodeling, oxidative stress, inflammation, gut microbiota dysbiosis, and intestinal epithelial barrier damage. In the heart, IPA suppressed the expression of NNMT (nicotinamide N-methyl transferase), restored nicotinamide, NAD+/NADH, and SIRT3 (sirtuin 3) levels. IPA mediates the protective effects on diastolic dysfunction, at least in part, by promoting the expression of SIRT3. SIRT3 regulation was mediated by IPA binding to the aryl hydrocarbon receptor, as Sirt3 knockdown diminished the effects of IPA on diastolic dysfunction in vivo. The role of the nicotinamide adenine dinucleotide circuit in HFpEF was further confirmed by nicotinamide supplementation, Nnmt knockdown, and Nnmt overexpression in vivo. IPA levels were significantly reduced in patients with HFpEF in 2 independent human cohorts, consistent with a protective function in humans, as well as mice. CONCLUSIONS: Our findings reveal that IPA protects against diastolic dysfunction in HFpEF by enhancing the nicotinamide adenine dinucleotide salvage pathway, suggesting the possibility of therapeutic management by either altering the gut microbiome composition or supplementing the diet with IPA.

The first human normative ranges and biomarker performance of dimethylguanidino valeric acid isoforms in fatty liver disease.

We have recently determined dimethylguanidino valeric acid (DMGV) to be a novel biomarker of liver injury in non-alcoholic fatty liver disease (NAFLD) and an independent predictor of incident diabetes over a decade in advance. DMGV consists of two stereo-isomers, asymmetric dimethylguanidino valeric acid (ADGV) and symmetric dimethylguanidino valeric acid (SDGV). Here we report, for the first time, the upper limits of normal of both isomers in humans at the accepted 5.56% liver fat threshold for NAFLD, determined using in vivo magnetic resonance spectroscopy. We performed independent and blinded comparative analyses of ADGV and SDGV levels using two different liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods in (A) our laboratory, and (B) the New South Wales Chemical Pathology state laboratory, using unique columns, LC-MS/MS equipment, extraction protocols and normalisation approaches. Despite these differences, each laboratory reported consistent absolute concentrations across a range of liver fat percentages. We next determined the diagnostic performance of SDGV compared to ADGV in a cohort of 268 individuals with liver fat measurements. In derivation-validation analyses we determined rule-in/rule-out thresholds and the concentration of SDGV that provides optimal performance across sensitivity and specificity for the identification of NAFLD. In conclusion, we have herein determined for the first time the true human plasma reference range of both isoforms of an emerging novel biomarker of NAFLD, at the accepted upper normal threshold of liver fat. We have also identified that SDGV is the isoform with the best diagnostic performance and determined the optimal cut-point for its detection of NAFLD.

Factors affecting successful prosthetic use after hemipelvectomy and hip disarticulation amputations: Five-year experience from a tertiary prosthetic rehabilitation center.

BACKGROUND: Rehabilitation after hip disarticulation and hemipelvectomy amputations can be challenging, and many opt to forego prosthetic limb use. There is limited evidence on characteristics that result in successful prosthetic use; therefore, our study aimed to identify these to help guide patient expectations. METHODS: A retrospective review was performed on patients seen at a UK tertiary prosthetic center in the past 5 years with hip disarticulation or hemipelvectomy amputations. Details and etiology of amputation, length between assessment and delivery of prosthesis, goals, reasons for abandonment, and outcomes were recorded. Successful prosthetic use was defined as the use of a prosthesis at least 3 times a week. Characteristics were compared using odds ratios and Fisher exact test. RESULTS: Twenty-seven patient notes were analyzed: 42% female, 58% male, and age range 14-90. Thirty percent had a hemipelvectomy, and 70% had a hip disarticulation. Neoplasia accounted for 78% of etiologies followed by trauma 15% and infected endoprosthesis 7%. Sixty-seven percent trialed a walking prosthesis; 33% of these stopped eventually. There were no statistically significant findings of factors increasing odds of successful prosthetic use. However, age significantly increased the odds of being given a trial of a prosthesis. CONCLUSION: Although younger patients are more likely to be given the opportunity to trial a walking prosthesis, age does not seem to affect the overall outcome alone. In cases of neoplasia, there is often a delayed start to rehabilitation and prosthetic use, which may affect eventual success. Further studies are required to define the optimum characteristics for successful prosthetic use at higher amputation levels.

Lessons learnt in the first year of an Australian pediatric cardio oncology clinic.

BACKGROUND: Modern oncological therapies together with chemotherapy and radiotherapy have broadened the agents that can cause cardiac sequelae, which can manifest for pediatric oncology patients while on active treatment. Recommendations for high-risk patients who should be monitored in a pediatric cardio-oncology clinic have previously been developed by expert Delphi consensus by our group. In 2022 we opened our first multidisciplinary pediatric cardio-oncology clinic adhering to these recommendations in surveillance and management. OBJECTIVES: Our pediatric cardio-oncology clinic aimed to: (i) Document cardiovascular toxicities observed within a pediatric cardio-oncology clinic and. (ii) Evaluate the applicability of the Australian and New Zealand Pediatric Cardio-Oncology recommendations. METHODS: Monthly multidisciplinary cardio-oncology clinics were conducted in an Australian tertiary pediatric hospital. Structured standardised approaches to assessment were built into the electronic medical record (EMR). All patients underwent baseline echocardiogram and electrocardiogram assessment together with vital signs in conjunction with standard history and examination. RESULTS: Nineteen (54%) individuals had a documented cardiovascular toxicity or pre-existing risk factor prior to referral. The two most common cardiovascular toxicities documented during clinic review included Left Ventricular Dysfunction (LVD) and hypertension. Of note 3 (8.1%) patients had CTCAE grade III LVD. An additional 10 (27%) patients reviewed in clinic had CTCAE grade I hypertension. None of these patients had hypertension noted within their referral. Cascade testing for cardiac history was warranted in 2 (5.4%) of patients. CONCLUSIONS: Pediatric cardio-oncology clinics are likely beneficial to documenting previously unrecognised cardiotoxicity and relevant cardiac family histories, whilst providing an opportunity to address lifestyle risk factors.

Subacute Ulnar Nerve Compression Neuropathy Following Hand Crush Injury in the Setting of Intracanal Accessory Abductor Digiti Minimi: A Double Crush Phenomenon.

Anatomical variations within Guyon's canal such as an accessory abductor digiti minimi are described as causes of ulnar nerve compression. Here we present a unique case of delayed ulnar neuropathy following treatment of left fourth metacarpal base fracture with percutaneous pinning fixation and an uncomplicated two month postoperative course. He returned with new ulnar sensory loss and motor weakness. EMG demonstrated nerve compression with CT identifying an accessory abductor digiti minimi in Guyon's canal. Following Guyon's canal release with partial accessory muscle resection, there was immediate sensory and progressive motor recovery with resolution of clawing. Delayed compression by an accessory abductor digiti minimi following trauma has not been described, suggestive of double-crush phenomenon. The accessory muscle was an asymptomatic variable (first "crush") and with the second "crush" of post-surgical changes resulting in pathological nerve compression. With delayed onset ulnar neuropathy after trauma, surgeons should consider possible accessory structures.