Cervical ribs in human early life: morphological variability and first identification as a morbidity criterion in a past population.

Despite the medical literature on supernumerary cervical ribs in extant adult samples, little is known about their development and occurrence in early infancy. The documentation of cervical ribs in modern samples of fetuses and neonates is indeed affected by ethical as well as technical limitations. The aim of the present study was to investigate their frequencies and morphological variability in the first known archaeological collection of very young children with this anatomical variant. The study sample comes from the 8B-51 necropolis on the Saï island (Sudan) and dates to the Classic Kerma Period (XVIIIe-XVIe centuries BC). It consists of 64 individuals deceased between 24 weeks of amenorrhoea and 2 years of age. Bilateral or unilateral cervical ribs were found in 27 individuals. A total of 43 cervical ribs were identified, 38 of which are fully preserved. According to these observations, at least 42% of the individuals have unilateral or bilateral cervical ribs, with an average maximum length of < 1 cm. This frequency is very high compared to those observed in contemporary adult samples (up to 3%). First, the comparison of our results with biological and genetic research demonstrating the link between the occurrence of cervical ribs and a reduced chance of survival during infancy allows the first identification of this trait as an indicator of morbidity in an archaeological collection, a morbidity to which a genetic homogeneity or even endogamy could contribute. Second, the number of ribs studied makes it possible to propose a morphological classification based on the general shape and the shape of the articular facets, classification that can be used tos refine the analyses of the trait in future samples.

A case of cervical rib andneurovascular compression inRoman period

The possibility to study axial anomalies directly on a skeletal individual is not very frequent. One well preserved skeletal individual from an Italian site dating to the late antique period (5th -4th centuries CE) was studied. This individual shows some interesting skeletal changes in the vertebrae and ribs. A supernumerary rib was found. It is a cervical rib connected to the 1st thoracic rib, presumably with a fibrous bundle. The presence of cervical ribs can produce neurovascular compression of the brachial plexus and subclavian vessels. Because of this, it is often a cause of thoracic out-let syndrome (TOS). In our case the presence of a cervical rib articulated with the first thoracic rib through a probable fibrous band could have re-stricted the space where the brachial plexus and subclavian vessels pass through, creating a state of neurovascular compression, similar

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Bases ósseas e musculares do corte comercial de pescoço de jacaré-do-pantanal (Caimanyacare Daudin, 1802) / Bone and muscular bases of commercial cut from the neck of Yacare Caiman (Caiman yacare Daudin, 1802)

O jacaré-do-pantanal (Caiman yacare) é uma espécie abundante no ecossistema do Pantanal. Sua exploração comercial está regulamentada desde 1990 e se tornou um agronegócio em expansão. Para atender essa demanda, uma unidade processadora instalada em Mato Grosso, vem comercializando carne de jacaré em diferentes cortes, entre os quais o filé de dorso, oriundo do pescoço, nos últimos quatro anos. O objetivo desta pesquisa foi descrever os músculos e correspondentes bases ósseas desse corte. Para a descrição de ossos, utilizaram-se seis carcaças desossadas de exemplares juvenis de jacaré-do-pantanal, além de um exemplar adulto obtido após morte do animal, por doação, do Zoológico da UFMT. Os ossos foram macerados em água corrente, clareados com solução de água oxigenada a 10 volumes, e seus detalhes anatômicos foram descritos. Para descrever o músculo, 24 exemplares juvenis foram obtidos após abate e esfola, conservados em freezer e descongelados quando utilizados, sem qualquer fixação. Após a evisceração, foram dissecados em ambos os antímeros, para verificação de simetria de ocorrência, fixações musculares, relacões de sintopia, forma e arquitetura muscular. Verificou-se que a coluna cervical em C. yacare apresenta nove vértebras cervicais (VC), associadas com as respectivas costelas, que servem de base principal ao filé de dorso, que é constituído pela musculatura cervical, exceto os músculos intertransversais cervicais e intercostais cervicais externos.

The yacare Caiman (Caiman yacare) is an abundant species in the Pantanal ecosystem. Commercial exploitation was regulated in 1990 and has become a thriving business. In order to fulfill this demand, a processing plant settled in Mato Grosso state, Brazil, has been supplying for the last four years different cuts of Pantanal Caiman meat, including the "filé de dorso" (back sirloin) obtained from the neck. The aim of this study was to describe the muscles and corresponding bones related to this cut. To describe the bones, we used six boned carcasses from juvenile yacare Caiman, as well as an adult specimen obtained after animal death, by donation from the Federal University of Mato Grosso Zoo. The bones were macerated in water, bleached with 10 volume-hydrogen-peroxide solution, and their anatomical details were recorded. In order to describe the muscles, 24 juvenile specimens were obtained after slaughter and skinning, preserved in a freezer at -20oC, and thawed at the time of use, without any fixation. After evisceration, the specimens were dissected on both sides to verify symmetry of structures, muscle attachments, sintopy relations, shape, and muscular architecture. The cervical spine of C. yacare features nine cervical vertebrae (CV) associated to their ribs, serving as the main base for the back sirloin cut, which is formed by neck muscles, except for the intertransverse cervical and external intercostal cervical muscles.

Fusión de 2 costillas como causa de trombosis venosa profunda de miembro superior / Fusion of 2 ribs as the cause of deep vein thrombosis in the arm

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Torsion and bending in the neck and tail of sauropod dinosaurs and the function of cervical ribs: insights from functional morphology and biomechanics.

The long necks of sauropods have been subject to many studies regarding their posture and flexibility. Length of the neck varies among groups. Here, we investigate neck posture and morphology in several clades from a mechanical viewpoint. Emphasis is put on comparing sauropod necks and tails with structures in living archosaurs and mammals. Differences in the use made of necks and tails lead to clear-cut differences in the mechanical loads occurring in the same models. Ways of sustaining loads are identified by theoretical considerations. If the observed skeletal structures are suited to resist the estimated loading in a particular posture, this concordance is taken as an argument that this posture or movement was of importance during the life of the individual. Apart from the often-discussed bending in side view, we analyze the often overlooked torsion. Because torsional stresses in a homogenous element concentrate near the periphery, a cylindrical cross section gives greatest strength, and the direction of forces is oblique. In a vertebrate neck, during e.g. shaking the head and twisting the neck, oblique muscles, like the mm. scaleni, if activated unilaterally initiate movement, counterbalance the torsional moments and keep the joints between neck vertebrae in equilibrium. If activated bilaterally, these muscles keep the neck balanced in an energy-saving upright posture. The tendons of the mm. scaleni may have ossified as cervical ribs The long cervical ribs in brachiosaurids and mamenchisaurids seem to have limited flexibility, whereas the shorter cervical ribs in Diplodocidae allowed free movement. The tails of sauropods do not show pronounced adaptation to torsion, and seem to have been carried more or less in a horizontal, extended posture. In this respect, sauropod tails resemble the necks of herbivorous cursorial mammals. These analyses provide an improved understanding of neck use that will be extended to other sauropods in subsequent studies.

Cervical ribs: identification on MRI and clinical relevance.

To determine the prevalence of cervical ribs on cervical spine MRI and clinical relevance, we reviewed 2500 studies for cervical ribs and compression of neurovascular structures and compared to CT, when available. Brachial plexus or subclavian artery contact by cervical rib was identified on MRI and/or CT in 12 cases with diagnosis of thoracic outlet syndrome in one. Cervical ribs were identified on 1.2% (25/2083) of examinations, lower than on CT (2%), but MRI may offer equivalent anatomic explanation for patient symptoms.

Histology shows that elongated neck ribs in sauropod dinosaurs are ossified tendons.

The histology of cervical ribs of Sauropoda reveals a primary bone tissue, which largely consists of longitudinally oriented mineralized collagen fibres, essentially the same tissue as found in ossified tendons. The absence of regular periosteal bone and the dominance of longitudinal fibres contradict the ventral bracing hypothesis (VBH) postulated for sauropod necks. The VBH predicts histologically primary periosteal bone with fibres oriented perpendicular to the rib long axis, indicative of connective tissue between overlapping hyperelongated cervical ribs. The transformation of the cervical ribs into ossified tendons makes the neck more flexible and implies that tension forces acted mainly along the length of the neck. This is contrary to the VBH, which requires compressive forces along the neck. Tension forces would allow important neck muscles to shift back to the trunk region, making the neck much lighter.

Síndrome do desfiladeiro torácico - ressecção de costela cervical por videotoracoscopia / Thoracic outlet syndrome - cervical rib resection through videothoracoscopic surgery

A base do tratamento cirúrgico da Síndrome do Desfiladeiro Torácico (SDT) é a ressecção da primeira costela, podendo associar-se à escalenectomia ou ainda à ressecção de costela cervical. Esta última é feita tradicionalmente por meio de um acesso supraclavicular ou mesmo axilar, o qual é tecnicamente mais trabalhoso. Pode ser realizada também por meio de acesso paraescapular. Embora tecnicamente atrativa e associada à menor invasividade e maior segurança, com ótimo resultado estético, a ressecção da primeira costela torácica, por intermédio de cirurgia videoassistida transaxilar ou pela técnica videotoracoscópica, é pouco relatada na literatura, e nenhuma referência foi encontrada sobre ressecção de costela cervical mediante essa técnica. Neste artigo, apresentamos essa inovação cirúrgica realizada com sucesso para ressecção de costela cervical em duas pacientes.

The basis of Thoracic Outlet Syndrome (TOS) surgical treatment is the first rib resection and may be associated with scalenectomy or cervical rib resection. The latter is traditionally done through a supraclavicular or axillary access, which is the most technically challenging. It can also be achieved through parascapular access. Although technically attractive and associated with less invasiveness and increased security, with excellent aesthetic results, the first thoracic rib resection via video-assisted transaxillary surgery or videothoracoscopic technique is seldom reported in the literature, and no reference was found on cervical rib resection through this technique. In this article, we introduced this innovation successfully performed for surgical cervical rib resection in two patients.

Measurement of subclavicular pressure on the subclavian artery and brachial plexus in the costoclavicular space during provocative positioning for thoracic outlet syndrome.

BACKGROUND: Thoracic outlet syndrome is thought to be caused by compression of the brachial plexus or subclavian artery in the interscalene, costoclavicular, or subcoracoid space. Some provocative tests are widely used for diagnosing thoracic outlet syndrome. However, whether provocative positions actually compress the neurovascular bundle in these spaces remains unclear. The purpose of this study was to investigate the possibility of neurovascular bundle compression in the costoclavicular space by measuring the pressure applied to the brachial plexus and subclavian artery in provocative positions. METHODS: Bilateral shoulders of eight fresh-frozen transthoracic human cadavers with no obvious anatomical abnormalities were used in this study. There were three female and five male cadavers with a mean age of 81.7 years (range 72-90 years). The pressure on the brachial plexus and subclavian artery between the clavicle and first rib were measured using a 0.13-mm thin pressure sensor in each of four provocative positions (depressed position, alternative Eden position, throwing position, Wright position). RESULTS: Nerve contact pressure was increased in seven shoulders in the Wright position (2.87 +/- 3.13 N/cm(2); range 0.81-9.76 N/cm(2)). The frequency of nerve compression in the Wright position was significantly higher when compared to that in the other three limb positions (P = 0.018). Artery contact pressure was increased in three shoulders in the Wright position (mean 0.59 +/- 0.13 N/cm(2); range 0.45-0.7 N/cm(2)). As was the case with nerve compression, the frequency of compression tended to be higher for the Wright position, but no significant difference was seen. CONCLUSIONS: In four of eight specimens with no obvious anatomical abnormalities, the brachial plexus was compressed in the costoclavicular space in the Wright position. The Wright position thus may be a useful position for inducing nerve compression in the costoclavicular space.