Citations

Despite advances in imaging, instrumentation, surgical techniques, and postoperative care, outcomes for certain peripheral nerve procedures remain consistently disappointing. In this article, we describe five surgical scenarios--adult pan-brachial plexus injuries, peroneal nerve injury after knee dislocation, sciatic nerve injury after total hip arthroplasty, radiation-induced brachial plexopathy, and lower trunk injury after cardiac surgery--that, in our experience and review of the literature, frequently lead to limited and consistently poor functional recovery after nerve surgery. These challenging cases reflect not only technical and anatomical complexity but the profound biological limitations of nerve regeneration in specific contexts. By critically analyzing these five procedures, we aim to promote more realistic patient counseling, support timely and individualized decision-making, and foster a more nuanced understanding of when and what type of surgical intervention may or may not be beneficial.

Abstract Carpal fractures are uncommon, representing a small proportion of hand fractures. This study aimed to determine the incidence, injury mechanisms, treatment patterns, and complication rates of carpal fractures in Olmsted County, Minnesota, United States. A retrospective review was performed using the Rochester Epidemiology Project registry to identify carpal fractures between 2013 and 2023. Fractures were confirmed by radiographs, computed tomography, or radiology reports. Demographic data, injury mechanism, fracture laterality, and fracture characteristics were recorded. A total of 699 carpal fractures were identified. Most patients were men (57%) with a mean age of 43 years. The most common fracture was the scaphoid (44%), followed by the triquetrum (31%), hamate (9%), and trapezium (3%). The overall incidence was 53.6 per 100,000 person-years. Concomitant wrist fractures occurred in 22%, and multiple ipsilateral carpal fractures in 4.6%. Patients with triquetrum fractures had the highest mean age (54 years) and low surgical rates (2%), whereas hamate and trapezoid fractures occurred at younger ages (39 and 38 years) and had the highest surgical rates (28 and 33%, respectively). The most common injury mechanism was a fall onto an outstretched hand (n = 438). Overall, 14% (n = 98) of patients underwent surgery, of whom 77% were men. The highest nonunion rate was seen in hamate fractures (10.9%), followed by scaphoid waist and proximal pole fractures (10.5%). Nonscaphoid carpal fractures occur more frequently than previously reported and demonstrate variable age distribution, treatment rates, and nonunion risks. Understanding these patterns can improve diagnosis, guide treatment planning, and inform patient expectations. IV.

Abstract Introduction: Epoxy fatty acid (EpFA) mechanisms of hormone therapy resistance (HTR) in ER+HER2- breast cancer (BC) are poorly understood. EETs are EpFAs that contribute to BC progression and HTR by promoting oxidative phosphorylation (OXPHOS). However, it remains unclear how EETs contribute to HTR. In this study, two fulvestrant resistant (FR) subclones of the letrozole resistant (LR) MCF-7AC1 line were isolated (termed LR/FR) and were incidentally resistant to the CDKi palbociclib (PR) (termed MCF-7AC1 LR/FR/PR or multiply resistant - MCF-7AC1 MR). These HTR cell lines exhibited CYP3A4 upregulation (2.3- to 4.3-fold) and increased cellular (±)14,15-EET levels, which were suppressed by biguanide treatment (P<0.05). Structure activity studies led to the design of hexyl cuban-1-yl biguanide (HCB) and fluorinated HCB derivatives C5F2-HCB and C6F3-HCB, which inhibited CYP3A4-mediated EET biosynthesis and growth of the HTR lines. HCB fluorination improved pharmacokinetics (PK) and toxicity. Methods: HCB and fluorinated HCBs were tested for impact on EET biosynthesis, OXPHOS, PK, and growth inhibition and reversal of hypoxia in the MCF-7AC1 MR tumor model. Results: Fulvestrant selection for MCF-7AC1 MR cell lines resulted in undetectable cyclin D1 and estrogen receptor (ERα) expression, while cyclin E1, CDK4, CDK6, CYP3A4, and c-MYC were upregulated (P<0.001). MCF-7 MR cells demonstrated 1.8, 1.4, and 1.2- fold higher levels of (±)8,9, (±)11,12, and (±)14,15-EET compared to parental MCF-7 cells (P<0.05). The most potent fluorinated HCB, C6F3-HCB, suppressed cellular levels of (±)8,9-EET, (±)11,12-EET, and (±)14,15-EET by 53-60% (P<0.029). The MCF-7AC1 MR cells were more potently inhibited by HCBs and fluorinated derivatives compared to the MCF-7 cell line. Comparing an MCF-7 MR line vs. MCF-7, HCB exhibited IC50 values of 4.1 vs. 7.0 uM, C5F2-HCB 10 vs. 25 uM, and C6F3-HCB 5.4 vs. 12 uM (P values all <0.05). C5F2-HCB exhibited the best PK and treatment of the MCF-7AC1 MR xenograft model showed reversal of hypoxia (P<0.05) and transient inhibition by C5F2-HCB (P=0.025 at 20 days). P/F also transiently inhibited this model (P=0.006 at 20 days). C5F2-HCB and P/F showed synergy in vitro (CI=0.46) leading to testing of C5F2-HCB/P/F in vivo enabled by acceptable toxicity of the triplet in mice. This combination showed synergy in vivo vs. standard of care palbociclib/fulvestrant by nonparametric statistical tests (Mann Whitney; P=0.0389; Kolmogorov-Smirnov; P=0.0473), providing a pathway for possible clinical development of the combination. Conclusions: MR BC cell lines exhibit upregulation of CYP3A4 and biosynthesis of EETs, indicating a role for EETs in HTR. The C5F2-HCB/P/F exhibits activity against the highly resistant MCF-7 MR xenograft with acceptable toxicity indicating an avenue for clinical development. Citation Format: Zhijun Guo, Jianxun Lei, Christian T. Wells, Allison M. Makovec, Andrew C. Yates, Swaathi Jayaraman, John R. Hawse, Joshua A. McCarra, Qing Cao, Michael J. Pryzbilla, Brenda L. Koniar, Beverly J. Norris, Craig M. Florey, Robert J. Schumacher, Michael A. Farrar, Kaylee L. Schwertfeger, Elizabeth A. Ambrose, Henry Wong, Gunda I. Georg, Antonino D'Assoro, Matthew P. Goetz, David A. Potter. Fluorinated cuban-1-yl biguanides overcome hormone therapy resistance to standard of care fulvestrant, and palbociclib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(8_Suppl):Abstract nr LB196.

Abstract Variants of the shoulder are commonly encountered and may occasionally be confused with pathological conditions. Our goal is to provide an overview of common normal variants of the shoulder’s anatomical structures as well as any associated clinical or surgical relevance. Following a literature search of common variants of the shoulder and supporting structures, this review provides a summary of variants related to the scapular body, acromion, glenoid, coracoid, labrum, long head biceps tendon, glenohumeral ligamentous complex, and rotator cuff. The shoulder is composed of the glenohumeral, acromioclavicular, sternoclavicular, and scapulothoracic joints and their associated osseous, ligamentous, cartilaginous, and musculotendinous stabilizers. Anatomic variants about the shoulder, especially in the adolescent and young adult populations, are frequently encountered. An awareness of associated pathological conditions and an understanding of when variants might be clinically significant is important in interpreting radiological exams.

Abstract Respiratory bronchiolitis-associated interstitial lung disease (RB-ILD) and alveolar macrophage pneumonia (AMP) are two rare but closely related conditions within the spectrum of smoking-related interstitial pneumonias. Both share characteristic histopathologic features, including the accumulation of pigmented alveolar macrophages alongside varying degrees of interstitial inflammation and fibrosis. RB-ILD is typically a localized, bronchiolocentric process often found in smokers, whereas AMP represents a more diffuse and clinically significant disease that may arise not only from tobacco smoke but also from other causes such as occupational exposures, autoimmune diseases, and drug reactions. This review highlights the clinical presentation, imaging findings, histopathology, and treatment of both entities, emphasizing their overlapping features as well as key distinctions. We further discuss the pathogenic mechanisms driven by cigarette smoke—including oxidative stress, immune activation, and fibrosis—that underlie these diseases. A clear understanding of the similarities and differences between RB-ILD and AMP is essential for accurate diagnosis, effective management, and prognostication, particularly in patients with a history of smoking and diffuse parenchymal lung involvement.

Abstract Background and Aims Stroke and systemic embolism are recognized but poorly characterized complications of atrial fibrillation (AF) and left atrial flutter (AFL) catheter ablation. Their incidence, outcomes, and procedural associations remain insufficiently defined. Methods Retrospective global registry was initiated by the European Heart Rhythm Association Scientific Committee. A secure database captured data from ablation centres worldwide on general AF and left AFL ablation activity, as well as detailed information on patients with symptomatic embolic events between 2017 and 2024. Results Overall, 204 centres reported 335 743 ablation procedures and 550 embolic events (incidence 0.16%). Centre-level rate ranged from 0% to 3.1%. Most events were cerebral (94%), followed by peripheral (5%), and combined (1%). Coronary air embolism accounted for 62% of all peripheral events. Intraprocedural events occurred in 93 patients (17%), within 72 h in 357 (78%) and beyond 72 h in 100 (22%); 128 cases (23%) were diagnosed after hospital discharge. Nonparoxysmal AF (0.23% vs 0.15%; P < .001), centre experience, and ablation energy source (radiofrequency, 0.16%; cryoballoon, 0.16%; pulsed field ablation, 0.25%; laserballoon, 0.88%; P < .001) were associated with embolic risk. Median NIHSS score after stroke was 4 (interquartile range, 2–9). Three-month follow-up was available for 518 patients with embolism (95%): 181 (35%) had sequelae and 16 (3%) died. Conclusions Symptomatic embolic events are infrequent but associated with significant morbidity and mortality. Most events occur early, though a substantial proportion arise later. Higher event rates were observed with laser and possibly with pulsed field ablation. A greater centre experience was associated with a lower embolism incidence.