Structural Anatomy

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    An analysis of an aberrant circumflex artery originating from the right aortic sinus and its clinical implications.
    (2019-03-05) Mobeen, Misha; Mathew, Ezek; Reeves, Rustin; Nguyen, Minh-Triet (Michael)
    During routine cadaver dissection, a coronary vessel abnormality was discovered in a 71-year old female cadaver. The circumflex artery (CxA), normally a branch from the left coronary artery (LCA), took its origin from the root of the right coronary artery (RCA) instead. It appears to exit the right aortic sinus sharing the same coronary ostium as the RCA. The vessel veered left, taking a retroaortic course between the aorta and left ventricle towards the left side of the heart. Although the female donor’s death was due to chronic hypoxemia and respiratory failure secondary to chronic obstructive pulmonary disease, there was no medical history evidence of pathological conditions due to the variant coronary vessel. The aberrant CxA is rare due to its origin from the RCA. In addition, the normal perfusion area for the CxA appears markedly reduced in this case, possibly due to constriction as it loops posterior to the aorta. Preliminary measurement of the CxA indicated some possible sites of constriction, and overall the diameter of the vessel was small. Furthermore, the RCA and LCA perfusion areas appeared to compensate for the reduction. Surgical case reports implicate the significance of a CxA arising from the right coronary sinus. One such clinical significance for this variant would be an increased difficulty with aortic valve replacement due to the origination site of the CxA.
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    Massive Intracranial Hemorrhage with Subsequent Subfalcine and Transtentorial Herniation: A Case Study
    (2019-03-05) Hubbard, Daniel; Nguyen, Sarah; Ozguc, Fatma; Steinberg, Spencer; Flores, Lesley; Fisher, Cara; Garcia, Laura
    Background: Brain herniation is a progression of pathology due to increased intracranial pressure creating a mass effect. The mass effect created by a large intracranial hemorrhage on one side of the brain often leads to a subfalcine herniation. Subfalcine herniation is a common type of herniation, characterized by displacement of the brain beneath the inferior border of the falx cerebri dural infolding. As the mass effect increases, it can cause further herniations in the brain. In this case study, the posterior brain cavity is affected by a transtentorial herniation which causes compression of the brainstem and the cerebellum. This mass effect can lead to a variety of symptoms including headache, nausea, vomiting, and altered mental status. This case study is a classic presentation of a massive intracranial hemorrhage with resultant cerebral and cerebellar shifts due to mass effect. Case Information: This case report presents a subfalcine herniation secondary to intracranial hemorrhage found during routine dissection in a 63-year-old male cadaver. Cause of death for the subject was listed as: Intracranial hemorrhage with subfalcine herniation, coagulopathy, acute liver failure, ischemia, congestive heart failure, and chronic obstructive pulmonary disease. Photographs of the brain and cranial cavity were obtained as well as cerebellar shift measurements along the transverse axis. Conclusion: This case highlights the pathologies that can develop in severe cases of intracranial hemorrhage, and it emphasizes the comorbidities that may have affected the prognosis as well as the progression of the disease. Consideration of presenting symptoms can be crucial in identifying possible affected areas of the brain at the time of patient presentation. Due to the lack of patient history, we do not have a clear idea of the chronology of the disease. However, there are factors observed during dissection that allow us to concoct a plausible progression of the disease.
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    Ladd’s Band Obstruction in 61 Year Old Physician
    (2019-03-05) Gibson, John Dr.; Williams, Trevor
    Ladd’s Band obstruction and congenital malrotation of the intestines is a rather uncommon anomaly with an incidence of 1 in 500 births and with symptomatic cases only appearing in 1 out of every 6000 births [1], [2]. Malrotation occurs when any part of the normal developmental cycle arrests and prevents the total 270 degrees of counterclockwise rotation. This will orient the caecum, appendix, and colon to the left side of the abdomen and the small bowel to the right. The ligament of treitzis also absent. When malrotation occurs, physiological absorption of primitive mesentery may not hapen1. This forms peritoneal bands that may obstruct the small bowel. These bands are known as Ladd’s bands and were described in 1932 by William Ladd in multiple cases of small bowel obstruction in children. Treatment of acute bowel obstruction secondary to peritoneal bands typically involves surgery to lyse the obstructing band. This procedure is known as the Ladd’s procedure and is usually accompanied with returning the intraabdominal organs to their anatomical position and an appendectomy to avoid future sequela1. This procedure is an open procedure, but can be done laparoscopically Most (40%) affected patients present within the first week of life with the large majority (75–85%) then presenting within the first year [3]. Incidence rates in adults become increasingly small and one estimate shows an occurrence of 0.16% within the adult population [4]. I present a case of a 61 year old man with undiagnosed malrotation who presented with acute small bowel obstruction. This would be one of the oldest patients presenting with a small bowel obstruction from Ladd’s band adhesions.
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    Patellar Fracture Non-Union with Acquired Patella Baja: A Case Report
    (2019-03-05) Cooley, Daniel; Wagner, MD, Russell; Williams, Trevor
    Fractures of the patella are usually caused by direct forces on the bone such as from a fall on a flexed knee or a dashboard injury and constitute 1% of all fractures 1,9. This injury occurs most commonly in males (2:1 ratio) and may disrupt the extensor mechanism affecting ambulation. On physical exam a patient presenting with a patellar fracture will have significant hemarthrosis with anterior knee pain, inability to perform a straight leg test, and a palpable patellar defect. X-rays of this pathology are best evaluated on lateral x-ray. Operative fixation is commonly performed in order to preserve the patella and maintain full range of motion of the knee. Non-union of patellar fractures following surgical fixation is a rare complication; a recent meta-analysis reported an incidence of 1.3% 1,9. The literature on the treatment of patellar fracture non-unions is limited to small case series. Patellabajais a condition in which the patella lies lower than normal in relation to the tibial tubercle. Diagnosis involves radiographs of the knee and measurement of the patella tendon length in relation to the patella bone length, known as the Insall-Salvatiratio 2,9. This condition is commonly seen following surgery or after trauma. These cause the patellar tendon to lose length, either from scarring or shrinkage of fibers. Symptoms may include anterior knee pain stiffness in addition to weakness the extensor mechanism and restriction of full knee flexion 2,9. Depending on the functional demands of the patient and severity of the symptoms, patients can either be managed non-operatively or with surgery to modify patella positioning or with patellectomy in severe cases. To the best of our knowledge there is no previous literature describing the treatment of a patellar nonunion with significant patella baja. We present the case of a patella fracture nonunion that failed previous surgical fixation and acquired patella baja, which we treated with repeat open reduction internal fixation and tibial tubercle osteotomy.
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    TCOM Anatomical Research: Left Extraacetablar Trochanteric Bursa Abscess
    (2019-03-05) Ewart, Mackenzie; Erickson, Daniel; Platis, Brett; Certeza, Justinne; Powell, Jake; Khan, Fatima; Karnkowska, Basia; Fisher, Cara PhD; Mohammad, Shanzay
    Abstract Background: The connections between diseases and their respective symptoms are unique, and often require the study of a multitude of factors. For a large abscess to persist, both the underlying disease and therapy options must permit the chronic progression. For this reason, studies that focus on condition-disease causalities offer important information as to the disease potential of a given region of the human anatomy. In this anatomical research, we studied a rare extra-acetablar trochanteric abscess (to determine condition-disease causality) discovered during the dissection of the left sub-ileum pelvic area of a an elderly female donor. Case Information: This case report was based off of the anatomical findings of an anonymous female donor. The donor’s body presented with an isolated Left Extra-acetabular Trochanteric Bursa Abscess. We hypothesized that: “the extra-acetabular trochanteric bursa abscess may elucidate condition-disease causality of this rare anatomical finding, given the donor’s past medical history and histological findings.” Dissection of the abscess and subsequent histological processing provided insight into a condition that was clearly chronic, unmanaged, and pathological nature. Correlating symptoms were swelling, immobilization at the joint, and severe pain. Conclusions: The anatomical anomaly of an isolated left extra-acetabular trochanteric bursa abscess was confirmed through dissection and histological processing. Numerous studies have confirmed a significant correlation between middle-aged or elderly females and trochanteric bursae. This may be due to the wider pelvis, or to hormonal effects in females. These findings are in accordance with our hypothesis that the prevalence of a rare anatomic bursitis may be explained by a deeper disease causality. A medical history and thorough examination are enough to diagnose trochanteric abscesses, yet it is a diagnosis that is commonly missed - especially in elderly patients. Thus, the data presented in this report provides evidence for the presence of a plausible disease-condition causality to this rare anatomical anomaly, but does not imperially quantify such a finding to the general population. More experiments are required to determine the cause, identity, and prevalence of the extra-acetabular trochanteric bursa abscess in humans. Is your abstract for competition or not for competition? No Research Area Structural Anatomy Presentation Type Poster
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    Virtual Dissection of Complex Masticatory Muscles with DiceCT
    (2019-03-05) Saavedra, Richard; Menegaz, Rachel A.; Kile, Ranger
    Purpose: Weaning is a critical stage in the life history of altricial mammals, with far-reaching impacts on growth trajectories and survival. Post-weaning diet(s) are known to affect craniofacial skeletal morphology as well as masticatory muscle volumes, physiological cross-sectional areas (PCSA), and fiber type ratios. These muscles and their subparts can be functionally grouped into vertical elevators, protractors, and retractors. However, the extent to which these functional groups differ in their responses to dietary changes is currently underappreciated, particularly where they are difficult to isolate through traditional dissection methods. Here we use diffusible iodine-based contrast-enhanced computed tomography (diceCT) to perform digital dissections of small, complex masticatory muscles to assess the effects of longitudinal variation in diet on the growth of functional groups of these muscles. Methods: Sprague-Dawley rats were raised from weaning (21 days) to adulthood (16 weeks), and randomly sorted into hard and/or soft dietary treatment groups. Post-sacrifice, cranial tissues were fixed in 4% PFM for 36 hours and stored in 70% EA at 4℃. Specimens were stained in 11.25% Lugol’s solution (I2KI) for 48 hours before microCT scanning. In 3D Slicer, muscles were manually segmented every 10 slices, the “Fill Between Slices” function was applied, and volumes were quantified. Volumetric measurements were compared using Kruskall-Wallis tests and pairwise Mann-Whitney U-tests (α = 0.05). Results: Contrary to our expectations, preliminary results suggest a trend for animals raised on softer diets to have larger temporalis and superficial masseter muscles than those raised on hard diets. However, no statistically significant differences were observed among or between treatments likely due to small sample size (n Conclusions: DiceCT is a promising method for soft tissue analysis that complements CT analyses of bone. Volumetric data can be obtained for small and/or complex musculature where limitations exist for traditional dissection methods.
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    Variation in maxillary sinus anatomy: Implications of ostium positioning on health disparities in sinusitis
    (2019-03-05) Butaric, Lauren; Rosales, Armando; Maddux, Scott D.; Kim, Suhhyun
    Purpose - Over 30 million people were diagnosed with sinusitis in 2017, yet potential anatomical etiologies behind sinus infections remain poorly understood. Previous research has suggested regional differences in maxillary sinus (MS) size and shape as possible contributors to sinusitis susceptibility. Paranasal sinuses drainage is mediated by mucociliary transport and gravity, but the human orthograde posture and the superior positioning of the MS ostia result in a heavy reliance on the mucociliary system. The purpose of this study was to examine the anatomical relationships between MS and the MS ostium among different ancestral groups to assess potential impacts on drainage and infection risks. Methods - By utilizing CT scans (n=49) of crania from Europe, East Asia, and Sub-Saharan Africa, we collected 93 3D coordinate landmarks from which 34 linear measurements of MS and surrounding facial features were calculated. ANOVA and Tukey-Kramer tests were employed to test for statistically significant differences between groups. Results - ANOVA and Tukey-Kramer test results indicate that Asians have significantly taller MS compared to Europeans and Africans (F=9.4, p=0.0003) and a greater distance from the floor of MS to the ostium (F=8.4, p=0.0007). Further, the ratio of these two variables indicates that the ostium is more superiorly positioned among Asians (at 66% of MS height) than Europeans (61%) or Africans (60%). Conclusions From this data, we tested and support the hypothesis that MS size, shape, and ostium position differ between regional groups. Although limited by small sample size, these results suggest that MS and ostium structure may differentially influence mucus and pathogen clearance from the sinus among individuals of Asian ancestry relative to those of European or African ancestry. Additional research into the prevalence of MS sinusitis in these populations is warranted to evaluate potential contributions to health disparities.
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    Novel Presentation of Hepatic and Foregut Vasculature: A Case Study
    (2019-03-05) Hubbard, Daniel; Mebane, Nova; Nguyen, Sarah; Ozguc, Fatma; Menegaz, Rachel A.; Garcia, Laura
    Background: In the most typical presentation, the foregut (abdominal esophagus, stomach, and first and second parts of the duodenum), pancreas, spleen, and liver are supplied by branches of the celiac trunk. The celiac trunk arises from the superior abdominal aorta and branches into the splenic artery, left gastric artery, and the common hepatic artery. The common hepatic artery further branches into the gastroduodenal artery and the proper hepatic artery, which gives rise to the left and right hepatic arteries near the hilum of the liver. The superior mesenteric artery arises from the abdominal aorta just inferiorly to the celiac trunk and supplies the midgut (third part of the duodenum through the splenic flexure of the colon). While this is the typical “textbook” arrangement, variations in branching patterns are not uncommon. In this case study, we describe a novel case of the hepatic foregut vasculature not matched in the current literature. Case Information: The novel variant in the arterial supply of the liver was encountered during the routine cadaveric dissection of a 63-year-old Caucasian male. The common hepatic artery is absent as per its accepted definition. The gastroduodenal artery is a branch of the celiac trunk, while the proper hepatic artery emerges from the superior mesenteric artery. At the hepatic hilum, the proper hepatic artery gives rise to left and right hepatic arteries. Additionally, an accessory left hepatic artery is present branching from the left gastric artery. Conclusions: Variations in hepatic arterial supply are common, and it is important for surgeons to be aware of these variations when performing surgical procedures such as liver transplants, cholecystectomies, and other abdominal procedures. Patients are at risk of hemorrhage, ischemia, or other surgical complications if these variations are not discovered and precautionary steps taken to avoid damaging or accidentally ligating the vessels. Appropriate imaging techniques, such as contrast-enhanced computed tomography (CE-CT), should be used to document patient-specific vasculature branching patterns from the celiac trunk and superior mesenteric when developing surgical approaches involving the foregut and liver.
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    Two Cases of the Psoas Quartus Muscle Variant
    (2019-03-05) Wickramage, Pavithra; Lewis, Daeija; Owens, Matthew; Fisher, Cara; Mahan, Jedidiah
    Background: The psoas major muscle originates from the thoracic and lumbar vertebrae, joins with the iliacus along the iliac crest, and attaches to the femur at the lesser trochanter. The iliopsoas muscle, formed from the joining of the psoas and iliacus muscles, acts as a powerful hip flexor. An additional psoas muscle, psoas minor, is commonly found in up to half of the population. Although rare, several other variations in this muscle have been reported that could influence the surrounding structures. Case Information: During routine dissections of 31 cadavers, two cadavers showed a variant of the psoas muscle that attaches superior to the iliac crest. A bilateral variant on a 71-year-old female cadaver and a unilateral variant on an 80-year-old female cadaver were discovered. Similar variants have previously described as the psoas quartus muscles. After reviewing the literature, this case appears to represent the third reported psoas quartus muscle, the first reported psoas quartus muscle without the presence of a psoas tertius variant, and the second reported bilateral psoas quartus muscle. Conclusion: Clinicians should consider the possibility of a muscle variant during surgical procedures, radiological interpretations, or evaluations of pain, especially in relation to the displacement of the femoral nerve.
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    Acute Torsion of an Extralobar Sequestration: Case Report
    (2019-03-05) Mitts, Matthew; Knott, Marty; Kindt, Lexy
    Background Pulmonary sequestration is a congenital formation that involves the growth of non-functional lung tissue that is not perfused by the lung arterial blood supply. There are two types of pulmonary sequestrations, intralobar and extralobar. Intralobar sequestrations are more common and usually present in adults as recurrent pneumonia. Extralobar sequestrations are less common, asymptomatic, and usually are found incidentally on prenatal ultrasound. Presentations of symptomatic extralobar sequestrations are very rare and are most commonly diagnosed postoperatively. Case Information: We describe a case of a 6-year-old boy who presented with a three-day history of acute abdominal pain, tachypnea, and a right pleural effusion. A tube thoracostomy was performed to drain his effusion in attempts to improve his symptoms. Computed tomography revealed a right posterior mediastinal mass that was concerning for malignancy. The decision was made to proceed with surgical excision versus biopsy. The patient was found to have a necrotic extralobar sequestration due to torsion. Thoracoscopic resection was performed and the patient was discharged without complication. Conclusions: There are only 10 previously reported pediatric cases of an extralobar sequestration with torsion and only 1 reported on the right side. Extralobar sequestrations appear on imaging as posterior mediastinal masses which elicit a broad range of differential diagnoses in children and are often neoplastic. A review of the pediatric literature demonstrates a common radiographic, pathologic, operative and clinical vignette to maintain a high suspicion of extralobar sequestration for the differential of a paraspinal mass.
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    Novel Investigation of the Deep Band of the Lateral Plantar Aponeurosis and Its Relationship with the Lateral Plantar Nerve
    (2019-03-05) Dickerson, Austin; Kadado, Kevin; Cohen, Zach; Holcomb, Jenna; Fisher, Cara; Beck, Cameron
    Purpose: The plantar foot is separated into medial, central and lateral compartments by the plantar aponeurosis (PA). The PA functions to support the arch of the foot and transmit forces during the gait cycle. A recent dissection of a cadaveric foot uncovered a fascial band arising from the medial aspect of the lateral PA and diving deep into the foot. A branch of the lateral plantar nerve passed deep to this fascial band. A review of current literature turned up limited and outdated sources, while some of the most commonly used anatomy textbooks and atlases failed to describe or depict this band. As such, our study objectives were twofold. First, determine the frequency among cadavers that possess this fascial band. Second, determine the location where the lateral plantar nerve passed deep to it. Methods: 50 pairs of cadaveric feet were dissected by removing the skin and superficial fascia on the plantar foot. If the medial portion of the lateral PA was present, the fascial band was dissected further to determine if it dove deep to the central PA and the tendons of the flexor digitorum brevis and longus muscles to insert on the plantar plates of the 3rd and 4th metatarsophalangeal joints. Images were taken when the lateral plantar nerve passed deep to the band. ImageJ was used to take two measurements assessing the relationship of the tuberosity at the base of the 5th metatarsal to where the nerve crossed deep to the fascial band. Measurements were also taken from the great toe to the heel to assess foot length. Results: The fascial band was found unilaterally in 10 pairs and bilaterally in 14 pairs. Therefore, 38% of feet possessed the deep band of the lateral PA. On average, the point at which the lateral plantar nerve passed deep to the fascial band was 2.0037 cm medial and 1.6637 cm anterior to the tuberosity at the base of the 5th metatarsal. When separated by sex, both distances were not significantly different (p Conclusion: Based on results, the deep band of the lateral PA should be included in textbooks and atlases because of the frequency at which it was discovered and its relationship to the lateral plantar nerve. The clinical implications of this study should be applied to the care of podiatry patients.
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    Evaluating Energetic Demands on the Human Nose Within a Regional Sample
    (2019-03-05) Kelly, Alexa; Maddux, Scott D.; Prazak, Patrick
    Purpose: It is widely recognized that the primary function of the nose is to warm, humidify, and filter air in preparation for entry into the lungs. Accordingly, geographic variability in nasal anatomy has long been attributed to climatic adaptation. However, as the human nose is also the primary respiratory conduit during normal breathing, it must facilitate a sufficient intake of oxygen to meet metabolic demands. Thus, given that body size also exhibits considerable geographic-mediated variation, it has long been argued that metabolism may represent a confounding influence on human nasal morphology. In particular, given its critical role in air-conditioning, it has been hypothesized nasal passage breadth should most strongly correlate with climate. Conversely, it has been suggested that nasal height and length dimensions may represent compensatory mechanisms for ensuring that a sufficient volume of oxygen can be inspired to meet body size/metabolic demands. Methods: To test these hypotheses, we obtained CT scan data for 35 modern human crania from the Bronze-Age archaeological site of Tepe Hissar, Iran. CT dicom images for each cranium were initially processed using the 3D Slicer software program, rendering a 3D digital model which was subsequently oriented in the Frankfurt Horizontal position to permit anthropometry. A total of 61 craniofacial landmarks were then placed on each 3D model, from which 15 linear measurements of nasal morphology were ultimately calculated using the Euclidean distance formula. These 15 nasal measurements were then employed in conjunction with body size/stature estimations (i.e., metabolic proxies) derived from associated post-cranial measurements, to assess the relationship between body size and nasal anatomy. Results:Following theoretical expectations, our results indicate that, within this one geographic sample (i.e., holding climate constant), no measure of nasal passage breadth was significantly correlated with body size (all p-values [greater than] 0.06). Conversely, all height and length measurements of the nasal aperture and internal cavity were found to be significantly correlated with body size (all r-values=0.48-0.62, all p-values Conclusions: Collectively, these results support the assertion that airway height and length dimensions reflect metabolic demands for sufficient intake of oxygen, while nasal breadth dimensions are more likely driven by climatic factors.
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    Craniofacial Bone Mineral Density in Mice with Osteogenesis Imperfecta (OI)
    (2019-03-05) Ladd, Summer; Organ, Jason; Menegaz, Rachel A.; McBride, Alexandra H.
    Purpose: Osteogenesis imperfecta (OI) is a rare genetic disorder characterized by the abnormal synthesis and assembly of type I collagen (Col1), a major organic component of bone. Clinical manifestations of the severe OI type III include small body size, limb deformities, and low bone mineral density (BMD) within the post-cranial skeleton. OI type III often co-occurs with craniofacial defects, such as dentinogenesis imperfecta (DI). The goals of this study are: (1) to examine whether Col1 defects, as seen in OI type III, affect BMD within the craniofacial skeleton; (2) to examine whether craniofacial BMD covaries with diet-related biomechanical loading. Methods: The homozygous recessive murine mouse (OIM-/-) is a model for OI Type III. Similar to human OI patients, OIM-/- mice exhibit low post-cranial BMD, smaller body size, and DI. OIM-/- mice and WT littermates were weaned at 21 days and raised on either hard (high loading) or soft (low loading) diets. This resulted in four genotype x diet treatment groups: OIM-hard (n=6), OIM-soft (n=3), WT-hard (n=9), and WT-soft (n=3). Micro-CT scans were collected at 16 weeks (skeletal maturity). BMD was measured using Bruker CTAnalyzer software for eight regions of interest (ROIs) within the mandible (TMJ, corpus at the second molar, and symphysis), facial skeleton (nasal bone, maxilla at the second molar, premaxilla at the incisor), and cranial vault (frontal and parietal bones). Pairwise Mann-Whitney U tests were used to statistically compare BMD between treatments (α = 0.05). Results: At all ROIs except for the frontal bone, WT-hard mice had significantly (p p = 0.052) with the current sample sizes. Similarly, at the mandibular and cranial vault ROIs, WT-soft mice tended to have higher BMD than OIM-hard and/or OIM-soft mice (p Conclusions: These results suggest that craniofacial BMD is generally lower in individuals with Col1 defects, consistent with the postcranial presentation. WT mice raised on a hard diet were observed to have the highest BMD measurements across the craniofacial skeleton, however no significant differences were observed between OIM-/- mice raised on hard versus soft diets. While diet-associated loading may influence craniofacial BMD, in this study Col1 status appears to be the primary determinant of BMD.
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    Bilateral variation of the suboccipital region musculature
    (2019-03-05) Fisher, Cara Ph.D.; Dickerson, Austin
    Background: This case report documents bilateral anatomic muscular variation observed in a detailed dissection of the suboccipital region of an 81-year-old male cadaver. The suboccipital muscle group consists of four paired muscles located inferior to the occipital bone. The muscles in this group include the rectus capitis posterior major muscle, rectus capitis posterior minor muscle, obliquus capitis superior muscle, and obliquus capitis inferior muscle. They are innervated by the suboccipital nerve and lie deep to the trapezius muscle and the semispinalis capitis muscle. In this case report, the rectus capitis posterior major muscles were doubled bilaterally. Accessory muscles were also noted bilaterally, immediately superficial to the suboccipital muscles. The two sets of anatomical variants described have little to no previous documentation. Doubling, or division, of the rectus capitis posterior major muscle has been reported, but mentions of a bilateral doubling of the muscle are infrequent. Accessory muscles have been discovered in this area before, but none with the same attachments or morphology as the ones noted here. Case Information: Two accessory muscles lying deep to the semispinalis capitis muscle on each side were observed, as well as a bilateral doubling of the rectus capitis posterior major muscle. The accessory muscles ran from fascial attachments to the nuchal ligament at the level of the second and third cervical vertebrae to insert on the occipital bone below the superior nuchal line. In addition, the left greater occipital nerve was split in two by the medial band of the left accessory muscle. The nerve traveled in two separate parts around the muscle belly, and converged immediately cranial to the accessory muscle to continue its course to innervate the skin of the posterior scalp. Conclusions: The suboccipital region contains neurologic and vascular structures that have been implicated in the etiology of cervicogenic pain, chronic headaches, and occipital neuralgia. Variations in the musculature, like those observed in this case report, have the potential to create structural interactions causing pain or other symptoms. Anatomic variation should be considered in the diagnosis and treatment of pain and other conditions of the suboccipital region.
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    Shoulder Balance Outcomes After Spinal Fusion
    (2019-03-05) LaMont, Lauren; Section, Jarren
    Purpose: The purpose of our study is to assess short and long term effects of posterior spinal fusion on shoulder balance and determine the correlation between osseous and soft tissue radiographic parameters utilizing a larger sample size than previously studied. This information could potentially guide patient counseling of expectations regarding postoperative outcome and assist surgeons in optimizing shoulder balance correction during arthrodesis. Methods: This study will be a retrospective, chart review of patients treated for adolescent idiopathic scoliosis with spinal fusion at a single center. We will be collecting radiographic measurements to assess pre- and postoperative spinal, thoracic, and shoulder alignments. Research team members will individually collect data each patient’s imaging with at minimum 2 years of postoperative radiographic assessment. Data will be stored in REDCap. Results: Conclusions:
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    Pericardial Cyst: A Case Report
    (2019-03-05) Philip, Sarah MS; Javed, Madeeha; Lachowsky, Parker; Karagoli, Mustafa; Hutton, Sarah; Le, Minh; Jung, Esther MS; Kao, Jeremy; Fisher, Cara L.
    Abstract Background: Pericardial cysts are usually benign, congenital or idiopathic anomalies with an occurence of 1:100,000 and are commonly noted in the right (70%) or left (22%) cardiophrenic angle and are rarely found in other locations of the pericardium, such as the anterior or posterior superior mediastinum (8%). The aortopulmonary window is the small space between the aortic arch and the pulmonary artery that holds the ligamentum arteriosum, recurrent laryngeal nerve, and lymph nodes. It is a common location for lymphadenopathies, but is a less common location for tumors, cysts, or aneurysms, further signifying the rarity of our findings. Case Information: During a routine dissection of a 91-year-old female cadaver, a pericardial cyst was noted in the aortopulmonary window, an unusual location for such cysts. Conclusion: This case report serves to expand knowledge on the anatomical aspects of rare pericardial cyst locations. Pericardial cysts are often asymptomatic and incidental findings, but some patients may present with complications consisting of dyspnea, cough, and hemoptysis secondary to the compression of structures surrounding the cyst. Knowledge of rare pericardial cyst locations is necessary for clinicians and surgeons during diagnostic and therapeutic procedures, and as a result, current clinical guidelines should take rare variants into consideration.
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    Unilateral Variant Psoas Major with Split Femoral Nerve
    (2019-03-05) Momin, Shahana; Perez, Aaron; Motina, Marina; Mickle, Rebecca; Nyguyen, Peter; Parikh, Tiraj; Fisher, Cara; Parry, Caleb
    Background: The psoas major muscle originates from the transverse processes of lumbar vertebrae 1-5 and inserts into the lesser trochanter of the femur. The femoral nerve arises from ventral rami of lumbar spinal nerves 2-4 and passes through the psoas major in an inferolateral direction until it emerges on the lateral border of the muscle. Variations of the psoas major muscle are rare and can have clinical significance. Here we describe a novel variation of the psoas major muscle. Case Information: During a routine anatomical dissection of a 75-year-old female cadaver, a unilateral variant of the psoas major muscle was found amongst 30 donated bodies. The variant was observed on the left side as an accessory muscle to the psoas major. The variant lies posterior to and runs in parallel with the normal psoas muscle fibers. An anomaly of the femoral nerve was also noted. The femoral nerve arises from fibers that course both anterior and posterior to the variant muscle. These fibers recombine on the lateral border of the psoas major to make the femoral nerve. An additional peripheral neurovascular bundle to the accessory muscle was not observed during the course of dissection. Conclusions: The psoas major variant described has a number of clinically important features. An accessory psoas can result in issues with a lateral interbody fusion procedure. Its implication in femoral nerve injury is variable, and thus neurosurgeons must take particular caution when performing this procedure on patients with this variant. It has been suggested that variant psoas major muscles underlie neuropathies such as nerve entrapment and are often described as disrupting the course of the femoral nerve. Here the femoral nerve was divided by the variant psoas muscle. Such a division could cause compression of the femoral nerve leading to neuropathies and could explain these clinical pathologies. This condition can postulate hip pain. African-American men tend to have a thicker psoas than average, hence extra precautions should be taken for those with this variation in terms of risk of femoral nerve compression.
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    Anatomical Adaptation to Climate: Patterns of Covariation Between Brain and Nasal Morphology
    (2019-03-05) Maddux, Scott D.; Pineda, Jonathan
    Anatomical adaptation to climate: Patterns of covariation between brain and nasal morphology Jonathan Pineda* & Scott D. Maddux, Ph.D.** *TCOM, **Center for Anatomical Sciences, Dept. of Physiology and Anatomy, UNTHSC PURPOSE: Previous research has shown that the geographic distributions of both brain and nasal shape are highly correlated with climatic variables. Specifically, individuals indigenous to cold-dry environments typically exhibit relatively wider brains (for retention of heat), and taller/longer/narrower nasal passages (for enhanced warming and humidification of respired air) compared to individuals from hot-humid climates. While these ecogeographic patterns of brain and nasal shape are both well established, the spatial interaction of these two structures in relation to climate has not been as rigorously investigated. METHODS: We employed CT scan data collected from a total of 30 human crania from the Arctic Circle (9 female, 6 male) and West Africa (8 female, 7 male). 3D digital models were subsequently rendered for each cranium using the 3D Slicer software program and a total of 35 craniofacial landmarks were then placed on each 3D model, permitting assessment of both linear measurements (i.e., Euclidean distances) and 3D spatial relationships via univariate and multivariate statistical analyses. RESULTS: Largely consistent with previous research, permutational t-test results indicate that individuals from the Arctic Circle possess shorter (p=0.029) and wider (p=0.002) braincases compared to West Africans. Similarly, Arctic natives were also found to possess both taller (p=0.0001) and narrower (p=0.001) nasal passages. While on average the Arctic sample also possessed a longer nasal passage (69.8 mm) compared to the Africans (67.1 mm), this difference was not statistically significant (p=0.097). Moreover, a simultaneous-fit two-block partial least squares (2B-PLS) analysis of 3D coordinate landmarks, reveals a significant pattern of covariation (RV=0.37, p=0.012) between nasal and brain morphology, with the first PLS dimension (46.3% of the total covariation) reflecting a significant association between relative brain width and nasal height, width, and length (r=0.74, p=0.032). CONCLUSIONS: Cumulatively, these results are consistent with previous studies, and support the hypothesis that climate has simultaneously influenced both brain and nasal anatomy. Moreover, our 2B-PLS results suggest that the relative spatial positioning of the nose may actually contribute to overall brain thermoregulation by differentially influencing airflow under the basicranium in different climatic regimes.
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    Absolute and Relative Morphometric Differences in the Craniofacial Skeleton of OIM-/- Mice and Wild-Type Littermates
    (2019-03-05) McBride, Alexandra H.; Organ, Jason; Menegaz, Rachel A.; Ladd, Summer
    Purpose: Osteogenesis Imperfecta (OI, or “Brittle Bone Disease”) is a disorder caused by genetic point mutations in COL1A1/COL1A2 which affect the synthesis of type I collagen (Col1). Humans with the severe type III OI exhibit increased susceptibility to skeletal fractures and shortened stature, as well as cranial dysmorphologies and dental malocclusions. Mouse models of Col1 defects report postcranial phenotypes similar to those seen in humans, with a limited number of studies reporting alterations to cranial and dental integrity. This project tests the hypothesis that the reduced craniofacial dimensions reported in both humans and mice with Col1 defects are linked to an overall reduction in body size. Methods: The homozygous OI murine (OIM-/-) is a mouse strain with a nonlethal recessively inherited mutation of the COL1A2 gene. Wild-type (WT) and OIM-/- littermates were weaned at 21d and raised until adult (16 weeks). 3D morphometric landmarks were collected from serial in-vivo µCT scans at 4, 10, and 16 weeks using etdips software. Past 2.17 software was used to Procrustes-transform (rotate and translate) the landmark data, and to calculate interlandmark distances (ILDs) and centroid sizes. ILDs were scaled against skull/mandible centroid size and skull/mandible length to account for the effect of size. Mann-Whitney U tests (α=0.05) were used to compare centroid sizes and both absolute and relative (scaled) ILDs between the genotypes. Results: When comparing absolute morphometric distances, adult OIM-/- mice have shorter skulls, basicrania, palates, mandibles, and toothrows. However, OIM-/-mice are smaller overall than their WT littermates as measured by both body mass and craniomandibular centroid sizes. When the effects of size are accounted for, the trend for interlandmark distances in WT mice to be greater than those in OIM-/- mice is significantly reduced or even reversed. For example, when scaled to centroid size, no significant difference exists between WT and OIM-/- mice in skull, basicranial, or mandibular length. OIM-/- mice have a relatively short midface, short nasal bones, tall mandibular corpora and long mandibular toothrows. Conclusions: These findings underscore the importance of size and scaling in morphometric analyses. The deleterious effect of Col1 mutations on global skeletal dimensions, in combination with localized morphometric changes, may underlie the facial phenotype seen in human patients with OI type III. Attempts to identify these localized changes should first account for the restricted growth and small body sizes present in individuals with OI.