Distal arthrogryposis type I (DA1) is a disorder characterized by congenital contractures of the hands and feet for which few genes have been identified. Here we describe a five-generation family with DA1 segregating as an autosomal dominant disorder with complete penetrance. Genome-wide linkage analysis using Affymetrix GeneChip Mapping 10K data from 12 affected members of this family revealed a multipoint LOD(max) of 3.27 on chromosome 12q. Sequencing of the slow-twitch skeletal muscle myosin binding protein C1 (MYBPC1), located within the linkage interval, revealed a missense mutation (c.706T>C) that segregated with disease in this family and causes a W236R amino acid substitution. A second MYBPC1 missense mutation was identified (c.2566T>C)(Y856H) in another family with DA1, accounting for an MYBPC1 mutation frequency of 13% (two of 15). Skeletal muscle biopsies from affected patients showed type I (slow-twitch) fibers were smaller than type II fibers. Expression of a green fluorescent protein (GFP)-tagged MYBPC1 construct containing WT and DA1 mutations in mouse skeletal muscle revealed robust sarcomeric localization. In contrast, a more diffuse localization was seen when non-fused GFP and MYBPC1 proteins containing corresponding MYBPC3 amino acid substitutions (R326Q, E334K) that cause hypertrophic cardiomyopathy were expressed. These findings reveal that the MYBPC1 is a novel gene responsible for DA1, though the mechanism of disease may differ from how some cardiac MYBPC3 mutations cause hypertrophic cardiomyopathy.

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The objective of this article is to highlight the salient points of preoperative planning, intraoperative considerations for fracture reduction methods, and implant fixation when treating distal diaphyseal or diametaphyseal tibia fractures with an intramedullary nail. Through review of the necessary preoperative considerations, techniques available to hold and maintain a reduction, and lastly how to maximize the selected implant of intramedullary nail, we hope to assist the treating surgeon in simplifying these sometimes complex fractures into manageable injuries that can be treated successfully with an intramedullary implant.

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ImportanceRacial disparities in treatment benchmarks have been documented among older patients with hip fractures. However, these studies were limited to patient-level evaluations.ObjectiveTo assess whether disparities in meeting fracture care time-to-surgery benchmarks exist at the patient level or at the hospital or institutional level using high-quality multicenter prospectively collected data; the study hypothesis was that disparities at the hospital-level reflecting structural health systems issues would be detected.Design, Setting, and ParticipantsThis cohort study was a secondary analysis of prospectively collected data in the PREP-IT (Program of Randomized trials to Evaluate Preoperative antiseptic skin solutions in orthopaedic Trauma) program from 23 sites throughout North America. The PREP-IT trials enrolled patients from 2018 to 2021, and patients were followed for 1-year. All patients with hip and femur fractures enrolled in the PREP-IT program were included in analysis. Data were analyzed April to September 2022.ExposuresPatient-level and hospital-level race, ethnicity, and insurance status.Main Outcomes and MeasuresPrimary outcome measure was time to surgery based on 24-hour time-to-surgery benchmarks. Multilevel multivariate regression models were used to evaluate the association of race, ethnicity, and insurance status with time to surgery. The reported odds ratios (ORs) were per 10% change in insurance coverage or racial composition at the hospital level.ResultsA total of 2565 patients with a mean (SD) age of 64.5 (20.4) years (1129 [44.0%] men; mean [SD] body mass index, 27.3 [14.9]; 83 [3.2%] Asian, 343 [13.4%] Black, 2112 [82.3%] White, 28 [1.1%] other) were included in analysis. Of these patients, 834 (32.5%) were employed and 2367 (92.2%) had insurance; 1015 (39.6%) had sustained a femur fracture, with a mean (SD) injury severity score of 10.4 (5.8). Five hundred ninety-six patients (23.2%) did not meet the 24-hour time-to-operating-room benchmark. After controlling for patient-level characteristics, there was an independent association between missing the 24-hour benchmark and hospital population insurance coverage (OR, 0.94; 95% CI, 0.89-0.98; P = .005) and the interaction term between hospital population insurance coverage and racial composition (OR, 1.03; 95% CI, 1.01-1.05; P = .03). There was no association between patient race and delay beyond 24-hour benchmarks (OR, 0.96; 95% CI, 0.72-1.29; P = .79).Conclusions and RelevanceIn this cohort study, patients who sought care from an institution with a greater proportion of patients with racial or ethnic minority status or who were uninsured were more likely to experience delays greater than the 24-hour benchmarks regardless of the individual patient race; institutions that treat a less diverse patient population appeared to be more resilient to the mix of insurance status in their patient population and were more likely to meet time-to-surgery benchmarks, regardless of patient insurance status or population-based insurance mix. While it is unsurprising that increased delays were associated with underfunded institutions, the association between institutional-level racial disparity and surgical delays implies structural health systems bias.