Anatomical and surgical considerations of the pectoralis muscle.

Introduction: The pectoralis major (PM) muscle is the largest and most superior muscle of the anterior chest wall. The PM plays an important role in flexion, adduction, and internal rotation of the arm. The pectoralis major's size, strength, and anatomical location make it an excellent candidate in transfer surgeries due to its ability to restore balancing forces that may be lost in scapular winging and subscapularis tears. Each of these injuries and pathologies involves the PM muscle in some way, and careful consideration of its anatomy and physiology is necessary. This review article aims to provide a comprehensive overview of the anatomy, physiology, and surgical considerations of the pectoralis muscle with a specific focus on the surgical techniques involving the muscle. Methods: A comprehensive literature search using a combination of the following terms: pectoralis major, rupture, transfer, chronic subscapularis tear, pectoralis surgery, anatomy, scapular winging, and long thoracic nerve anatomy. There were no limitations with regards to article type or publishing date, but article language was limited to only English. Conclusion: The pectoralis muscle is an important muscle when it comes to function of the upper extremity primarily or through transfer procedure. Injuries and impairments of the pectoralis major or other muscles of the upper extremity can significantly impact an individual's quality of life, limiting their ability to perform activities of daily living. A thorough understanding of anatomical, functional, and surgical purposes of the pectoralis muscle is crucial for achieving optimal outcomes and avoiding complications.

Pediatric Axial Ewing Sarcoma: A Retrospective Population-Based Survival Analysis.

INTRODUCTION: Ewing sarcomas of the axial skeleton represent a notable challenge for clinicians because of their aggressive presentation and tendency to obstruct neurovascular structures; however, little data exist regarding axial tumors in children. This study is the first population-based analysis assessing treatment regimens for axial Ewing sarcomas and their effects on cancer-specific survival and overall survival (OS). METHODS: Data from 2004 to 2019 were collected for all patients aged 1 to 24 years from the Surveillance, Epidemiology, and End Results (SEER) database. Primary groups included pelvic tumors, thoracic tumors, and vertebral tumors. Chi-squared and Kaplan-Meier tests were used to assess associations between demographic variables, clinical and treatment characteristics, and patient survival. RESULTS: Pelvic tumors were most common, and 49.7% received chemotherapy/radiation. Vertebral tumors were least common, and 56.7% received chemotherapy/surgery/radiation. 53.5% of thoracic tumors received chemotherapy/surgery. Surgery was most common for thoracic tumors (80.2%) and rare for pelvic tumors (38.9%). Radiation therapy was most common for vertebral tumors (83.6%) and least common for thoracic tumors (36.0%). Pelvic tumors exhibited the lowest OS (1-year, 5-year, and 10-year OS: 96%, 70%, and 59%), followed by thoracic tumors (1-year, 5-year, and 10-year OS: 97%, 79%, and 66%) and vertebral tumors (1-year, 5-year, and 10-year OS: 92%, 77%, and 68%). CONCLUSION: This study underpins the importance of both early detection and chemotherapy-based multimodal therapy in the treatment of axial Ewing sarcoma in a pediatric population. A comparatively large decline in OS was observed between 5 and 10 years for patients with thoracic tumors, and this cohort's 10-year OS has not improved when compared with a similar SEER cohort from 1973 to 2011. Despite a growing body of research supporting definitive radiation therapy, a notable portion of patients with pelvic Ewing sarcoma did not receive radiation, representing an unmet need for this population.

A Prefixed Four-Trunk Brachial Plexus with Anomalous Anatomy of All Subsequent Divisions, Cords, and Terminal Branches: A Cadaveric Case Report.

BACKGROUND The brachial plexus is a complex neural structure providing motor and sensory innervation to structures of the arm, shoulder, and upper chest. The anatomical structure is typically divided into roots, trunks, divisions, and cords. Due to the presence of multiple nerve roots and branches, anatomical variations are common. Awareness of variations from normal anatomy is important in imaging, administration of nerve blocks, and surgical procedures of the neck and shoulder region. CASE REPORT We present a case of multiple anatomic variations of the right brachial plexus identified in a cadaver during routine dissection. To summarize, we identified a prefixed plexus with anomalous contributions from the C4 nerve root. Nerve roots C4 and C5 emerged anterior to the anterior scalene muscle. Furthermore, 4 trunks, rather than the typical 3, gave rise to multiple anomalies in the branching pattern of the distal divisions and cords. To the best of our knowledge, this is the first such case reported in the published literature. CONCLUSIONS The current case report presents a combination of brachial plexus anomalies not previously described in the medical literature - specifically, a prefixed (C4-T1) brachial plexus positioned anterior to the anterior scalene muscle with anomalies of the trunks, divisions, cords, and terminal branches. The variations presented have implications in neurogenic compression, interscalene blocks, and trauma to the upper limb. Knowledge of these anomalies may better equip anatomists and clinicians to understand pathology and intervention of the upper limb.

A systematic review of posterior pilon variant fractures.

Posterior pilon variant ankle fractures (PPVF) are a unique subtype of posterior malleolar fractures which have been a source of controversy and confusion in recent years. There has not been a thorough literature review previously written on the topic. Database searches of PubMed and Embase were conducted from inception until June 2023. The key words included "pilon variant," "posterior pilon variant," and "posterior pilon" fractures. Outcomes were evaluated by union time, rates of delayed union, nonunion, malunion, and complication. A total of 15 articles relevant to surgical repair of pilon variant fractures were included in the literature review. The unique mechanism of injury has been reported to involve both rotational and axial forces, leading to involvement of the posterior and medial aspects of the distal tibia. Pilon variant fractures can be suspected by several characteristics on radiographs and have a high confirmation rate via CT images. Multiple systems have been proposed to classify this fracture pattern, but there is no consensus on the ideal classification system. Surgically, direct fixation has shown better short-term clinical outcomes versus indirect fixation or no fixation. PPVF have a distinct fracture pattern involving the posterior and medial columns of the distal tibial plafond, and results from a mechanism intermediate to rotational and axial forces. These fractures are more severe than tri-malleolar fractures due to increased rates of articular impaction and incongruity. Future classification systems should focus on joint surface area and the tibial pilon column involved to avoid confusion with less severe posterior malleolar fractures.

Optimization of a translational murine model of closed-head traumatic brain injury.

Traumatic brain injury (TBI) from closed-head trauma is a leading cause of disability, with limited effective interventions. Many TBI models impact brain parenchyma directly, and are limited by the fact that these forces do not recapitulate clinically relevant closed head injury. However, applying clinically relevant injury mechanics to the intact skull may lead to variability and as a result, preclinical modeling TBI remains a challenge. Current models often do not explore sex differences in TBI, which is critically important for translation to clinical practice. We systematically investigated sources of variability in a murine model of closed-head TBI and developed a framework to reduce variability across severity and sex. We manipulated pressure, dwell time, and displacement to determine effects on motor coordination, spatial learning, and neuronal damage in 10-week-old male and female mice. Increasing pressure beyond 70 psi had a ceiling effect on cellular and behavioral outcomes, while manipulating dwell time only affected behavioral performance. Increasing displacement precisely graded injury severity in both sexes across all outcomes. Physical signs of trauma occurred more frequently at higher displacements. Stratifying severity based on day-1 rotarod performance retained histological relationships and separated both sexes into injury severity cohorts with distinct patterns of behavioral recovery. Utilizing this stratification strategy, within-group rotarod variability over 6 days post-injury was reduced by 50%. These results have important implications for translational research in TBI and provide a framework for using this clinically relevant translational injury model in both male and female mice.

Neurosurgery Clerkships in United States Medical Schools: A Survey of Doctor of Medicine-Granting and Doctor of Osteopathic Medicine-Granting Schools.

OBJECTIVE: Exposure to neurosurgery is important for knowledge of neurosurgical conditions that physicians may encounter. The current status of neurosurgery nonsubinternship clerkships in the United States is unknown; this study determined the availability and format of non-subinternship neurosurgery clerkships in DO (Doctor of Osteopathic Medicine)-granting and MD (Doctor of Medicine)-granting U.S. medical schools. METHODS: Association of American Medical Colleges and American Association of Colleges of Osteopathic Medicine websites were used to obtain contact information for all U.S. medical schools. Respondents were asked whether their school offered a non-subinternship neurosurgery clerkship, if it was required, clerkship length, and whether the clerkship was embedded in another clerkship. Nonsubinternship clerkships/electives/selectives were defined as an exploratory neurosurgery rotation. For nonresponding schools, data were collected from school websites. RESULTS: Data were obtained for 180/199 U.S. medical schools; 142 (79%) provided neurosurgery non-subinternships, including 125/150 (83.3%) MD-granting and 17/30 (57%) DO-granting schools. Four MD-granting schools (2.8%) required the clerkship; 87/142 (61%) offered a stand-alone clerkship, 34/142 (24%) an embedded clerkship, and 21/142 (15%) offered both. In total, 200 clerkships were offered across 142 schools. Most were either >1-2 weeks or >3-4 weeks (69/200, 35% and 89/200, 45%, respectively). CONCLUSIONS: Most U.S. medical schools provide elective neurosurgery non-subinternships. Fewer, although still a majority, of DO-granting schools offer a neurosurgery non-subinternship compared with MD-granting schools.