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BMC Biology Aug 2021The origin of powered avian flight was a locomotor innovation that expanded the ecological potential of maniraptoran dinosaurs, leading to remarkable variation in modern...
BACKGROUND
The origin of powered avian flight was a locomotor innovation that expanded the ecological potential of maniraptoran dinosaurs, leading to remarkable variation in modern birds (Neornithes). The avian sternum is the anchor for the major flight muscles and, despite varying widely in morphology, has not been extensively studied from evolutionary or functional perspectives. We quantify sternal variation across a broad phylogenetic scope of birds using 3D geometric morphometrics methods. Using this comprehensive dataset, we apply phylogenetically informed regression approaches to test hypotheses of sternum size allometry and the correlation of sternal shape with both size and locomotory capabilities, including flightlessness and the highly varying flight and swimming styles of Neornithes.
RESULTS
We find evidence for isometry of sternal size relative to body mass and document significant allometry of sternal shape alongside important correlations with locomotory capability, reflecting the effects of both body shape and musculoskeletal variation. Among these, we show that a large sternum with a deep or cranially projected sternal keel is necessary for powered flight in modern birds, that deeper sternal keels are correlated with slower but stronger flight, robust caudal sternal borders are associated with faster flapping styles, and that narrower sterna are associated with running abilities. Correlations between shape and locomotion are significant but show weak explanatory power, indicating that although sternal shape is broadly associated with locomotory ecology, other unexplored factors are also important.
CONCLUSIONS
These results display the ecological importance of the avian sternum for flight and locomotion by providing a novel understanding of sternum form and function in Neornithes. Our study lays the groundwork for estimating the locomotory abilities of paravian dinosaurs, the ancestors to Neornithes, by highlighting the importance of this critical element for avian flight, and will be useful for future work on the origin of flight along the dinosaur-bird lineage.
Topics: Animals; Biological Evolution; Birds; Dinosaurs; Locomotion; Phylogeny; Sternum
PubMed: 34412636
DOI: 10.1186/s12915-021-01105-1 -
Jornal Brasileiro de Pneumologia :... 2007Among the deformities of the thoracic wall,pectus carinatum has not received the same attention as has pectus excavatum. Few pulmonologists, pediatricians, and thoracic... (Review)
Review
Among the deformities of the thoracic wall,pectus carinatum has not received the same attention as has pectus excavatum. Few pulmonologists, pediatricians, and thoracic surgeons are aware of the approaches to treating this condition. As a consequence, patients with pectus carinatum are not referred for treatment. This deformity, with an incidence of 1:1000 teenagers, is oligosymptomatic. However, for aesthetic and emotional reasons, it accounts for a large number of medical appointments. Such patients are introverted and do not engage in physical activities, since they are unwilling to expose their chest, which also discourages them from going to the beach or to swimming pools. The diagnosis is clinical and visual, and details are obtained through chest X-rays and computed tomography. The treatment is based on a well-known organogram that summarizes orthopedic and surgical procedures. Dynamic compression, combined with physical exercises, is indicated for teenagers with flexible thorax in inferior and lateral pectus carinatum, with limited indication for those with superior pectus carinatum. For individuals of any age with rigid thorax, surgery is indicated for aesthetic reasons. Among the techniques described, the modified sternum chondroplasty stands out due to the excellent aesthetic results achieved.
Topics: Adolescent; Adult; Child; Cicatrix; Esthetics; Female; Funnel Chest; Humans; Male; Orthopedic Procedures; Sternum; Thoracic Wall
PubMed: 17982540
DOI: 10.1590/s1806-37132007000400017 -
The Journal of Thoracic and... Dec 2018
Topics: Aortic Valve; Heart Valve Prosthesis; Sternotomy; Sternum
PubMed: 30107920
DOI: 10.1016/j.jtcvs.2018.06.076 -
Thorax Sep 1969The deformity of pectus excavatum is caused by a negative pressure in the anterior mediastinum sucking in the body of the sternum. This is usually due to the heart lying...
The deformity of pectus excavatum is caused by a negative pressure in the anterior mediastinum sucking in the body of the sternum. This is usually due to the heart lying on the left side, leaving the mediastinum empty so that the sternum and costal cartilages are sucked in to fill the empty space. The operation consists of excising the deformed cartilages, mobilizing the sternum, and suturing the pericardial sac into a central position which corrects the deformity.
Topics: Adolescent; Adult; Cartilage; Child; Funnel Chest; Heart Defects, Congenital; Humans; Male; Mediastinum; Pericardium; Pressure; Sternum
PubMed: 5348322
DOI: 10.1136/thx.24.5.557 -
Multimedia Manual of Cardiothoracic... Sep 2020Pectus carinatum is a common chest wall anomaly. It occurs five times more frequently in males than females and can be present at birth, although it usually progresses...
Pectus carinatum is a common chest wall anomaly. It occurs five times more frequently in males than females and can be present at birth, although it usually progresses during adolescence. The correction of chest wall anomalies offers patients significant improvements in quality of life and it should never be regarded as an entirely cosmetic issue. Most patients with pectus carinatum can be corrected with a brace. When bracing is not an option, good results can be obtained by surgery using the Ravitch method. In this method a midline incision is made over the sternum and costal cartilage is resected. In some patients the sternum protrudes and an osteotomy is necessary for optimal correction.
Topics: Costal Cartilage; Humans; Osteotomy; Pectus Carinatum; Postoperative Care; Sternotomy; Sternum
PubMed: 33000923
DOI: 10.1510/mmcts.2020.050 -
The Journal of Thoracic and... Mar 2020
Topics: Aorta; Bone Plates; Sternum
PubMed: 31630842
DOI: 10.1016/j.jtcvs.2019.08.098 -
BMJ Case Reports Oct 2014The spine, pelvic bones and long bones of the lower extremities are common sites for insufficiency fractures. Cases of sternum insufficiency fractures have rarely been...
The spine, pelvic bones and long bones of the lower extremities are common sites for insufficiency fractures. Cases of sternum insufficiency fractures have rarely been reported among elderly patients. Insufficiency fractures tend to occur in bones with decreased mechanical strength especially among elderly patients, in postmenopausal women and patients with underlying diseases. We describe a case of spontaneous sternum insufficiency fracture in a healthy man, with no known risk factors to fracture, or previous history of fractures. Sternum insufficiency fracture is a rare cause of chest pain. This case serves to remind the emergency physician to remain vigilant for other non-cardiac, non-pulmonary and non-traumatic causes of chest pain, especially among patients with known risk factors such as osteoporosis, chronic obstructive pulmonary disease, rheumatoid arthritis, systemic lupus erythematosus and patients on long-term steroid treatment. If diagnosed correctly, these patients can be discharged and treated as outpatients as this case emphasises.
Topics: Aged; Diagnosis, Differential; Follow-Up Studies; Fractures, Spontaneous; Fractures, Stress; Humans; Male; Sternum; Tomography, X-Ray Computed
PubMed: 25326566
DOI: 10.1136/bcr-2014-206683 -
Interactive Cardiovascular and Thoracic... Jun 2012Pectus excavatum and pectus carinatum represent the most frequent chest wall deformations. However, the pathogenesis is still poorly understood and research results... (Review)
Review
Pectus excavatum and pectus carinatum represent the most frequent chest wall deformations. However, the pathogenesis is still poorly understood and research results remain inconsistent. To focus on the recent state of knowledge, we summarize and critically discuss the pathological concepts based on the history of these entities, beginning with the first description in the sixteenth century. Based on the early clinical descriptions, we review and discuss the different pathogenetic hypotheses. To open new perspectives for the potential pathomechanisms, the embryonic and foetal development of the ribs and the sternum is highlighted following the understanding that the origin of these deformities is given by the disruption in the maturation of the parasternal region. In the second, different therapeutical techniques are highlighted and based on the pathogenetic hypotheses and the embryological knowledge potential new biomaterial-based perspectives with interesting insights for tissue engineering-based treatment options are presented.
Topics: Funnel Chest; History, 16th Century; History, 19th Century; History, 20th Century; Humans; Incidence; Risk Factors; Sternum; Thoracic Surgical Procedures; Treatment Outcome
PubMed: 22394989
DOI: 10.1093/icvts/ivs045 -
International Orthopaedics Dec 2023The purpose of this study is to present a classification of thoracic spine fractures based on anatomical and biomechanical characteristics. (Review)
Review
PURPOSE
The purpose of this study is to present a classification of thoracic spine fractures based on anatomical and biomechanical characteristics.
METHODS
This is a narrative review of the literature.
RESULTS
The classification is based on the relationship between movement and common forces acting on the spine. A mechanistic concept is incorporated into the classification, which considers both movements and the application of forces, leading to pathomorphological characteristics. A hierarchical ranking determines the severity of fractures within the thoracic spine, and treatment recommendations are presented in each category. The fourth column of the spine is incorporated into the classification through direct and indirect mechanisms.
CONCLUSIONS
The proposed classification accommodates several advantages, such as simplicity and practicality, that make this classification helpful in daily practice. The dynamic relationship between movement and force provides a better understanding of the fracture mechanism. Finally, incorporating the fourth column will strengthen the indication for surgical management. To the best of our knowledge, this classification is the first classification developed uniquely for the thoracic spine fractures and will help to address a critical gap in the literature.
Topics: Humans; Spinal Fractures; Sternum; Thoracic Vertebrae; Fractures, Bone; Thoracic Injuries
PubMed: 36943457
DOI: 10.1007/s00264-023-05778-x -
Proceedings of the Royal Society of... Mar 1970
Topics: Adult; Chronic Disease; Humans; Male; Melioidosis; Penicillins; Sternum; Sulfamethoxazole
PubMed: 5445578
DOI: No ID Found