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1.
J Hand Surg Am ; 49(1): 8-14, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37978963

RESUMO

PURPOSE: The purpose of the study was to determine if the sphericity of the thumb metacarpophalangeal (MCP) joint influences the joint's rotational axis (RA) and elongation patterns of the ulnar collateral ligament (UCL). METHODS: Ulnar collateral ligament origins and attachments of 28 fresh-frozen cadaveric thumbs were marked with a radiopaque marker. Lateral radiographs were obtained in neutral and 20°, 40°, and 60° of flexion. The dorsal and palmar joint gap and the length of four different UCL portions were digitally measured in all flexion states. The RA was determined by the intersection of the midshaft axis of the proximal phalanx in neutral and flexion states. Sphericity of the MCP joint was assessed using morphometric parameters. Joints were grouped as round or flat. Differences in all measured parameters between groups were analyzed. RESULTS: During flexion, the dorsal joint gap increased by 322% in flat joints and 163% in round joints. The palmar joint gap decreased to 45% in flat joints and to 87% in round joints. The RA was at 29% of metacarpal height and 96% of metacarpal length in flat joints and at 40% of height and 86% of length in round joints. Maximum UCL elongation (111%) was noted at 40° flexion in the dorsal proper UCL in flat joints and at 60° flexion in the accessory UCL (117%) in round joints. CONCLUSIONS: In flat MCP joints, the RA is more dorsal and distal in the metacarpal head compared to round joints, resulting in a hinged flexion motion. Elongation of the UCL is highest at end flexion in round joints and highest at midflexion in flat joints. CLINICAL RELEVANCE: The different kinematics of flat and round MCP joints may contribute to the understanding of the pathophysiology of UCL ruptures. The propensity of this injury and the position in which they occur may be affected by the MCP joint morphology.


Assuntos
Ligamento Colateral Ulnar , Ligamentos Colaterais , Humanos , Polegar , Ligamento Colateral Ulnar/diagnóstico por imagem , Ligamento Colateral Ulnar/lesões , Ligamentos Colaterais/lesões , Fenômenos Biomecânicos , Articulação Metacarpofalângica
2.
J Morphol ; 285(1): e21665, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38100740

RESUMO

In embryonic development, the vertebral column arises from the sclerotomal compartment of the somites. The sclerotome is a mesenchymal cell mass which can be subdivided into several subpopulations specified by different regulatory mechanisms and giving rise to different parts of the vertebrae like vertebral body, vertebral arch, ribs, and vertebral joints. This review gives a short overview on the molecular and cellular basis of the formation of sclerotomal subdomains and the morphogenesis of their vertebral derivatives.


Assuntos
Somitos , Coluna Vertebral , Animais , Diferenciação Celular , Morfogênese , Costelas
3.
Surg Radiol Anat ; 45(12): 1587-1592, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37837464

RESUMO

PURPOSE: A comprehensive analysis of the morphology of fractures of the coronoid process (CP) can aid diagnosis and guide treatment. The involvement of the radial notch of the ulna (RN)-e.g., in anterolateral facet fractures and transverse fractures of the CP-may influence the biomechanical conditions of the proximal radioulnar joint. However, the morphometric relation between the CP and the RN and the extent to what the proximal radioulnar joint can be affected in these types of fractures is unknown. METHODS: A total of 113 embalmed, cadaveric ulnae were dissected. All soft tissue was removed. Strictly lateral, high-resolution photographs were taken and digitally analyzed. The height of the CP and its relation to the RN was measured. Sex differences and correlations between measured parameters were calculated. RESULTS: Mean height of the CP was 16 mm (range: 12-23 mm; SD: 2). Mean height of the RN was 16 mm (11-25 mm; 2.2). The 50% mark of the CP corresponded to 18% (0-56%; 11.2) of the height of the RN. No significant differences were found between male and female specimens. CONCLUSION: The RN of the ulna extends only to a small part to the CP. Transverse or anterolateral fractures of less than 50% of the coronoid process may involve only a small portion of the proximal radioulnar joint.


Assuntos
Articulação do Cotovelo , Fraturas do Rádio , Fraturas da Ulna , Humanos , Masculino , Feminino , Ulna/anatomia & histologia , Articulação do Cotovelo/anatomia & histologia , Extremidade Superior
4.
J Hand Surg Eur Vol ; 48(8): 768-772, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37005740

RESUMO

Studies on graft reconstruction techniques for ruptured thumb metacarpophalangeal (MCP) ulnar collateral ligaments (UCL) do not consider the variety of MCP joint morphology. Optimal reconstruction method for flat MCP joints is therefore unclear. Twenty-four fresh-frozen, human thumbs were tested for flexion, extension and valgus stability of the MCP joint. After resection of the UCL, four reconstruction methods, differing in the metacarpal origin and phalangeal attachment, were performed on each specimen, which were then tested again in the same way. Specimens were grouped as 'round' or 'flat' depending on morphometric parameters and group differences were analysed. In flat joints, only the non-anatomical Glickel reconstruction and a modified Fairhurst reconstruction maintained normal mobility and stability. In round joints, only the Glickel reconstruction maintained normal mobility and stability. The original Fairhurst method and a modification with the origin palmar in the metacarpus were disadvantageous in both flat and round joints.


Assuntos
Ligamento Colateral Ulnar , Ligamentos Colaterais , Humanos , Ligamento Colateral Ulnar/cirurgia , Polegar/cirurgia , Ligamentos Colaterais/cirurgia , Amplitude de Movimento Articular , Articulação Metacarpofalângica/cirurgia
5.
Arch Orthop Trauma Surg ; 143(5): 2485-2491, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35635575

RESUMO

BACKGROUND: Complex proximal humeral fracture ranks among the most common fracture types, especially in elderly patients. In locked plate fixation of proximal humerus fractures, the calcar is deciding for screws providing further medial column support. To date, the biomechanical effect of the length of these calcar screws is not well known. The purpose of this study was to analyze the effect of long calcar screws on fresh frozen prefractured cadaveric specimens. METHODS: In the present biomechanical study, 8 pairs of cadaveric proximal humeri were fractured identically using a custom-made fracture simulator. ORIF was performed using a locking plate (PHILOS; Fa. Synthes). The specimens were tested in a biomechanical setup under increased axial load without any calcar screws installed, with short calcar screws and long calcar screws installed. Strain gages (4-wire-120 Ohm, Fa. Vishay) mounted on the locking plate were used to evaluate the fixation strain and to give an estimate for primary stability.. RESULTS: The measured strain of the locking plate without calcar screws (804,64 µm/m) at maximum load (200 N) was significantly higher than with short (619,07 µm/m; p = 0.02) or long calcar screws (527,31 µm/m; p = 0.007). Additionally, strain with short calcar screws was noticeably higher in comparison to long calcar screws (619,07 µm/m vs. 527,31 µm/m; p = 0.03). CONCLUSION: Use of calcar screws improves the stability of realistically impacted 3-part varus humeral fractures. Long calcar screws that are positioned as close as possible to the joint provide further primary stability compared to short calcar screws. LEVEL OF EVIDENCE: Basic science study.


Assuntos
Fixação Interna de Fraturas , Fraturas do Ombro , Humanos , Idoso , Parafusos Ósseos , Fraturas do Ombro/cirurgia , Úmero/cirurgia , Placas Ósseas , Cadáver , Fenômenos Biomecânicos
6.
Clin Anat ; 36(1): 42-49, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36177789

RESUMO

Safe intubation of newborns remains a challenge. This investigates the upper airway anatomy of (pre-)term infants was investigated to improve airway management and the development of airway devices. Angles and diameters of both oral and nasal intubation pathways of 22 cadavers of premature and term stillborn infants were measured, relative to their gestational age (GA) and tested for statistical significance. The systematic influence of sex on the distribution of values was examined. Cast models of the oral and nasal intubation pathway were (produced using a silicone dental impression material) 3D-scanned. No significant correlation with GA was seen in the angles studied. However, four distances around the hard and soft palate did show statistically significant positive correlations with GA. Regarding differences between the sexes, only the angle between the entrance of the trachea and the esophagus was greater for male cadavers. The angles of the ventilation pathway of (pre-)term infants do not depend systematically on GA. Anatomically, laryngeal masks might therefore also be well-suited ventilators for preterm infants. Alterations in the size but not the shape of laryngeal masks for small preterm infants is recommended. The data obtained may thus be used as a basis for the development of airway devices and airway simulators for medical education and clinical training.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Recém-Nascido Prematuro , Lactente , Recém-Nascido , Masculino , Humanos , Intubação Intratraqueal , Idade Gestacional , Manuseio das Vias Aéreas
7.
J Anat ; 241(3): 831-845, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35751554

RESUMO

In the thorax of higher vertebrates, ribs and intercostal muscles play a decisive role in stability and respiratory movements of the body wall. They are derivatives of the somites, the ribs originating in the sclerotome and the intercostal muscles originating in the myotome. During thorax development, ribs and intercostal muscles extend into the lateral plate mesoderm and eventually contact the sternum during ventral closure. Here, we give a detailed description of the morphogenesis of ribs and thoracic muscles in the chicken embryo (Gallus gallus). Using Alcian blue staining as well as Sox9 and Desmin whole-mount immunohistochemistry, we monitor synchronously the development of rib cartilage and intercostal muscle anlagen. We show that the muscle anlagen precede the rib anlagen during ventrolateral extension, which is in line with the inductive role of the myotome in rib differentiation. Our studies furthermore reveal the temporary formation of a previously unknown eighth rib in the chicken embryonic thorax.


Assuntos
Galinhas , Músculos Intercostais , Animais , Embrião de Galinha , Músculos Intercostais/fisiologia , Músculo Esquelético , Costelas , Somitos
8.
Clin Biomech (Bristol, Avon) ; 92: 105588, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35121348

RESUMO

BACKGROUND: Various fixation methods are available for the operative treatment of metatarsal shaft fractures: Kirschner wire, Titanium elastic nail, plate, or an intramedullary bone stabilization system within a balloon catheter. The aim of this study was to compare the stability of these techniques. METHODS: 72 metatarsals II to V from fresh frozen human cadaver feet were used. A shaft fracture was performed and fixed with a 1.6-mm Kirschner wire, a 1.5-mm Titanium elastic nail, a locking 6-hole-plate, or an intramedullary bone stabilization system. In a cantilever configuration, the head of the metatarsals was loaded statically (2 mm/min until failure; all groups) or cyclically (0 to 20 N for 1000 cycles with 10 mm/s, after 1000 cycles 2 mm/min until failure; plate and bone stabilization system). FINDINGS: The mean failure strength for static loading was 17 N for Kirschner wire, 13 N for Titanium elastic nail, 73 N for plate and 34 N for the bone stabilization system (P < .01). For cyclic loading, the mean cycle of failure was 1000 for plate and 961 for the bone stabilization system (P = .76). The mean failure strength after cyclic loading was 73 N for plate and 48 N for the bone stabilization system (P = .03). INTERPRETATION: Stability differs depending on the fixation method, with a plate showing the greatest stability and Kirschner wire or Titanium elastic nail the least. The stability of the bone stabilization system for fixing metatarsal shaft fractures is intermediate.


Assuntos
Fixação Intramedular de Fraturas , Fraturas Ósseas , Ossos do Metatarso , Fenômenos Biomecânicos , Placas Ósseas , Parafusos Ósseos , Cadáver , Fixação Interna de Fraturas/métodos , Fixação Intramedular de Fraturas/métodos , Fraturas Ósseas/cirurgia , Humanos , Ossos do Metatarso/cirurgia
9.
Clin Biomech (Bristol, Avon) ; 89: 105478, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34517193

RESUMO

BACKGROUND: The brachialis muscle lies in close anatomic relation to the anterior capsule of the elbow joint. The contribution of the brachialis muscle to elbow stability has not yet been fully investigated. Therefore, the aim of this biomechanical in-vitro study was to analyze its influence on joint stability. METHODS: Nine fresh frozen cadaveric elbows were evaluated for stability against valgus and varus/posterolateral rotatory forces. Brachialis loading was measured indirectly using strain gauges. Three distinct scenarios were analyzed: A) with intact lateral ulnar and ulnar collateral ligaments B) with a ruptured lateral ulnar collateral ligament C) with ruptured lateral ulnar and ulnar collateral ligaments. FINDINGS: In all scenarios, an increased strain was observed under posterolateral rotatory/varus forces. The maximum measured strain occurred with elbow flexion of 30° and pronation of the forearm. The strain was significantly higher with dual-ligament rupture (mean - 210.5 µm/m; min. 97.8 µm/m; max. -310 µm/m; SD 107.8 µm/m; p = .034) compared to intact ligaments (mean - 106.9 µm/m; min. -32.51 µm/m, max. -287 µm/m; SD 100.2 µm/m) and single-ligament rupture (mean - 109.5 µm/m; min. - 96.7 µm/m; max - 130.4 µm/m; SD 18.2). INTERPRETATION: A strain of the brachialis muscle was observed under varus/posterolateral rotatory forces with a pronated forearm and the strain increased significantly in the event of a dual-ligament rupture. This suggests that the brachialis muscle may influence varus/posterolateral rotatory stability of the elbow. Hence, a concomitant tear of the brachialis muscle might result in pronounced instability following simple elbow dislocation. LEVEL OF EVIDENCE: Basic Science Study, Biomechanics.


Assuntos
Ligamentos Colaterais , Articulação do Cotovelo , Instabilidade Articular , Fenômenos Biomecânicos , Cadáver , Cotovelo , Humanos , Músculo Esquelético
10.
Resuscitation ; 163: 57-63, 2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33862177

RESUMO

AIM: Intraosseous (IO)-access plays an alternative route during resuscitation. Our study in preterm and term stillborns was performed to find alternative IO puncture sites beside the recommended proximal tibia. METHODS: The cadavers used were legal donations. 20 stillborns (mean: 29.2weeks, IQR 27.1-39.6) were investigated. Spectral-CT were analysed to calculate the diameter and circumferences of: i) proximal humerus ii) distal femur iii) proximal tibia iv) diaphyseal tibial. Contrast medium was applied under video documentation to investigate the drainage into the vascular system. RESULTS: In term newborns, diameter of the cortex of the proximal humeral head is 12.1 ±â€¯1.8 mm, distal end of the femur 11.9 ±â€¯3.4 mm and the proximal tibial bone 12.0 ±â€¯2.4 mm with cross-sectional diameter of 113.5 ±â€¯19.7 mm2, 120.6 ±â€¯28.2 mm2 and 111.6 ±â€¯29.5 mm2, respectively. Regarding the preterm groups, there is a strong age-related growth in diameter and cross -sectional size. The diaphyseal area is the smallest in all measured bones with an age-dependent increase and is about half of that of metaphyseal diameters (proximal and distal) and about one third of that of metaphyseal cross sectional areas. The proximal femoral head region has the largest diameter of all measured bones with an egg-shaped formation with an extensive joint capsula. All investigated metaphyseal areas lack a clearly enclosed bone marrow cavity. Infusion of contrast medium into the distal femoral end and the proximal humerus head demonstrate the drainage of contrast medium into the central venous system within seconds. CONCLUSION: Proximal humeral head and distal femoral end might be alternative IO areas which may lead to further IO puncture sites in neonates.

11.
Clin Biomech (Bristol, Avon) ; 84: 105329, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33765570

RESUMO

INTRODUCTION: Biomechanical functionality as well as trauma mechanisms of the atlantoaxial complex are still an issue of controversy. The transverse atlantal ligament is the strongest stabilizator. The present study aimed to analyze the bending forces of the transverse atlantal ligament and of the base of the odontoid in elderly specimens. METHODS: In this biomechanical study five cadaveric specimen with a mean age of 72 at death and bone mineral density measuring for 555.3 Hounsfield units on average were used. To analyze the strain of the transverse atlantal ligament and the dense base, strain gauges were used. A custom biomechanical setup was used to test each specimen at C1/2 flexion and the strain of the transverse atlantal ligament and the dens base (µm/m) were measured. FINDINGS: In four out of five, a rupture of the transverse atlantal ligament was observed, the mean force required for the ligament to fall was 175 N (min. 99.8 N; 249.2 N; SD 64.7) by a mean strain of 2102.9 µm/m (min. 1953.5 µm/m; max. 2272.3 µm/m; SD 189.7). In one specimen with the lowest Hounsfield units (155), the dens base fractured before the transverse atlantal ligament ruptured and no strain could be measured at the transversal ligament during movement afterwards. INTERPRETATION: The transverse atlantal ligament fails at an average of 175 N in the elderly, which is less than the value reported previously. In osteoporotic specimen the generated force to rupture the transverse atlantal ligament can fracture the dens itself.


Assuntos
Articulação Atlantoaxial , Articulação Zigapofisária , Idoso , Articulação Atlantoaxial/diagnóstico por imagem , Fenômenos Biomecânicos , Humanos , Ligamentos Articulares , Movimento , Amplitude de Movimento Articular
12.
Dev Dyn ; 250(1): 39-59, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32406962

RESUMO

In vertebrates, the trunk consists of the musculoskeletal structures of the back and the ventrolateral body wall, which together enclose the internal organs of the circulatory, digestive, respiratory and urogenital systems. This review gives an overview on the development of the thoracic and abdominal wall during amniote embryogenesis. Specifically, I briefly summarize relevant historical concepts and the present knowledge on the early embryonic development of ribs, sternum, intercostal muscles and abdominal muscles with respect to anatomical bauplan, origin and specification of precursor cells, initial steps of pattern formation, and cellular and molecular regulation of morphogenesis.


Assuntos
Parede Abdominal/embriologia , Parede Torácica/embriologia , Vertebrados/embriologia , Músculos Abdominais/embriologia , Animais , Humanos , Músculos Intercostais/embriologia , Costelas/embriologia , Esterno/embriologia
13.
Sci Rep ; 10(1): 14106, 2020 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-32839497

RESUMO

The intervertebral disc (IVD) has long been considered unique to mammals. Palaeohistological sampling of 17 mostly extinct clades across the amniote tree revealed preservation of different intervertebral soft tissue types (cartilage, probable notochord) seen in extant reptiles. The distribution of the fossilised tissues allowed us to infer the soft part anatomy of the joint. Surprisingly, we also found evidence for an IVD in fossil reptiles, including non-avian dinosaurs, ichthyosaurs, plesiosaurs, and marine crocodiles. Based on the fossil dataset, we traced the evolution of the amniote intervertebral joint through ancestral character state reconstruction. The IVD evolved at least twice, in mammals and in extinct diapsid reptiles. From this reptilian IVD, extant reptile groups and some non-avian dinosaurs independently evolved a synovial ball-and-socket joint. The unique birds dorsal intervertebral joint evolved from this dinosaur joint. The tuatara and some geckos reverted to the ancestral persisting notochord.


Assuntos
Cartilagem/fisiologia , Dinossauros/anatomia & histologia , Fósseis/anatomia & histologia , Disco Intervertebral/anatomia & histologia , Répteis/anatomia & histologia , Jacarés e Crocodilos/anatomia & histologia , Animais , Aves/anatomia & histologia , Vértebras Cervicais/anatomia & histologia , Disco Intervertebral/fisiologia , Lagartos/anatomia & histologia , Vértebras Lombares/anatomia & histologia , Paleontologia/métodos
14.
Histochem Cell Biol ; 154(3): 255-263, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32377843

RESUMO

The vertebrate-specific co-chaperone Mdg1/ERdj4, which is localized in the endoplasmic reticulum, controls the folding and degradation of proteins. We characterized its protein pattern during chick embryonic development. During early development, Mdg1/ERdj4 protein is present in mesenchymal and epithelial cells. In mesenchymal cells, it has a salt and pepper pattern. In contrast, during epithelial tissue differentiation, Mdg1/ERdj4 marks the basal and/or apical compartment of epithelial linings. The distinct protein pattern in epithelial tissue might point to its role in organizing and maintaining the epithelial structure. This could be achieved, e.g. by controlling folding and secretion of membrane-bound receptors or by inhibiting the IRE1α-Xbp1s-SNAI1/2-induced mesenchymalization. High Mdg1/ERdj4 protein levels are maintained in tissue with sustained secretory activity as in ependymal cells or enterocytes, substantiating its important role for secretion. We conclude that the transient elevation of Mdg1/ERdj4 protein levels controls the differentiation of epithelial linings while constitutive high levels are closely linked to secretory activity.


Assuntos
Proteínas de Choque Térmico HSP40/biossíntese , Chaperonas Moleculares/biossíntese , Animais , Embrião de Galinha , Galinhas , Desenvolvimento Embrionário , Proteínas de Choque Térmico HSP40/análise , Imuno-Histoquímica , Chaperonas Moleculares/análise
15.
Surg Radiol Anat ; 42(8): 961-968, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32125486

RESUMO

PURPOSE: Anterior surgical approaches to the thoracic spine are common procedures for the treatment of many diseases of the thoracic spine. Purpose of this anatomic study is to investigate the course of the segmental vessels of the thoracic spine for the anterior and lateral transthoracic approach from the right side. METHODS: 26 formalin-fixed human cadavers (20 femaless/6 male) with an average age of 84.9 ± 8.3 (range 67-97) were included. The segmental arteries and veins of the right thoracic cavity coursing between the third and twelfth thoracic vertebral body have been investigated. To define the localization of the vessels in accordance with the associated vertebral bodies, the distance between the endplates and vessels was measured in the ventral, middle and dorsal parts. RESULTS: The results of the study reveal that not only one, but also two segmental arteries and veins may course over the right hemi-vertebral body, especially in the upper and middle thoracic spine. Furthermore, in the middle and lower thoracic spine (T7-T12) the vessels course over the middle and lower third of the craniocaudal extent of the vertebral body. On the contrary, in the upper thoracic spine (T3-T6), the vessels may course over the entire extent of the vertebral body. CONCLUSION: Due to these common anatomic variations and variability of the course of the segmental vessels, spinal surgeons should remain careful in the identification of the segmental vessels in order to minimize risk of vascular injury in case of right-sided anterior and lateral approach to the thoracic spine.


Assuntos
Veia Ázigos/anatomia & histologia , Coluna Vertebral/irrigação sanguínea , Vértebras Torácicas/irrigação sanguínea , Artéria Vertebral/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Veia Ázigos/lesões , Cadáver , Feminino , Humanos , Complicações Intraoperatórias/etiologia , Complicações Intraoperatórias/prevenção & controle , Masculino , Procedimentos Ortopédicos/efeitos adversos , Procedimentos Ortopédicos/métodos , Coluna Vertebral/cirurgia , Vértebras Torácicas/cirurgia , Artéria Vertebral/lesões
16.
Clin Anat ; 33(5): 661-666, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31576589

RESUMO

Ruptures of the distal biceps brachii tendon are generally treated operatively due to their loss of supination and flexion force. A mechanical impingement at the insertion of the tendon at the radial tuberosity is discussed to play a role in the etiology of this injury. The aim of this study was to present a detailed, three-dimensional anatomical analysis of the radioulnar space at the radial tuberosity. A total of 166 imprints of the radioulnar space in neutral rotation and pronation from 84 cadaveric specimens of both arms using silicone impression material were produced for this study. Imprints were cut in slices of 3 mm and digitally measured after picture acquisition using a high-resolution digital camera. Distances were grouped into a proximal, central, and distal groups and used for correlation to morphometric data at the elbow (radial head diameter, ulna and radius length) as well as volume calculation. The mean radioulnar distance was 8.8 ± 4.0 mm in neutral rotation and 7.8 ± 3.9 mm in pronation. In pronation, the central zone was the smallest whereas in neutral rotation the proximal zone was the smallest. The volume of the radioulnar space did not reduce significantly during pronation. Little space is provided for the insertion of the distal biceps brachii tendon especially during pronation. This could play a role in the etiology of distal biceps brachii tendon ruptures and should be considered in the fixation after rupture of the tendon. Clin. Anat., 33:661-666, 2020. © 2019 Wiley Periodicals, Inc.


Assuntos
Pronação , Rádio (Anatomia)/anatomia & histologia , Supinação , Ulna/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Cadáver , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Rádio (Anatomia)/diagnóstico por imagem , Ulna/diagnóstico por imagem
17.
Orthop J Sports Med ; 7(8): 2325967119864590, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31489328

RESUMO

BACKGROUND: Irreparable rotator cuff tears lead to superior translation of the humeral head. Numerous surgical management options are available to treat the condition. PURPOSE: To compare superior capsule stability among different types of patch grafting in irreparable rotator cuff tears. METHODS: Six cadaveric shoulders were tested in a custom-designed shoulder testing system. Superior translation of the humerus and subacromial contact pressure were quantified in an intact condition (condition 1), after cutting the supraspinatus tendon (condition 2), and after additionally cutting the superior capsuloligamentous complex (condition 3). The results were compared among 3 types of patch grafting, in which capsule reconstruction was achieved by glenoidal 3-point (condition 4) or 2-point (condition 5) fixation or by affixing a graft below the acromion (condition 6). RESULTS: No significant difference in subacromial pressure was measured by reconstruction with 2 or 3 anchors compared with conditions 1 and 2 (P > .05). However, with 3-point fixation, lower levels of pressure were measured than with 2-point fixation. Moreover, superior translation values were lower with 3-point fixation; the same applied for values of the preserved capsule as compared with the torn capsule. In condition 6, a significant increase in pressure in the neutral position was documented (P < .05). CONCLUSION: The superior capsuloligamentous complex plays an important role in stabilizing the glenohumeral joint. The results suggest that with additional medial anchoring at the coracoid base, the depressing and centering effect of the superior complex can probably be regained in a more physiological way compared with a reconstructed capsule with 2 glenoid attachments or with an interpositional graft below the acromion.

18.
J Anat ; 235(4): 716-724, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31225912

RESUMO

Somites are epithelial segments of the paraxial mesoderm. Shortly after their formation, the epithelial somites undergo extensive cellular rearrangements and form specific somite compartments, including the sclerotome and the myotome, which give rise to the axial skeleton and to striated musculature, respectively. The dynamics of somite development varies along the body axis, but most research has focused on somite development at thoracolumbar levels. The development of tail somites has not yet been thoroughly characterized, even though vertebrate tail development has been intensely studied recently with respect to the termination of segmentation and the limitation of body length in evolution. Here, we provide a detailed description of the somites in the avian tail from the beginning of tail formation at HH-stage 20 to the onset of degeneration of tail segments at HH-stage 27. We characterize the formation of somite compartment formation in the tail region with respect to morphology and the expression patterns of the sclerotomal marker gene paired-box gene 1 (Pax1) and the myotomal marker genes MyoD and myogenic factor 5 (Myf5). Our study gives insight into the development of the very last segments formed in the avian embryo, and provides a basis for further research on the development of tail somite derivatives such as tail vertebrae, pygostyle and tail musculature.


Assuntos
Aves/embriologia , Somitos/embriologia , Cauda/embriologia , Animais , Embrião de Galinha , Desenvolvimento Embrionário
19.
J Shoulder Elbow Surg ; 28(3): 555-560, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30391185

RESUMO

BACKGROUND: Acute injuries to the anterior medial collateral ligament (AMCL) can occur due to valgus trauma or during other dislocating events to the elbow. AMCL lesions are often associated with bony lesions, such as radial head fractures or fractures of the coronoid process. We analyzed the insertion of the AMCL on the sublime tubercle in relation to surrounding osseous structures. We aimed to increase the understanding of the involvement of the AMCL in bony lesions to the sublime tubercle. METHODS: We investigated 86 elbows from 43 embalmed human specimens. We measured the most ventral extensions of the AMCL at the sublime tubercle in relation to a clearly defined and reproducible landmark. We used as our landmark a horizontal line (baseline) originating on the lesser sigmoid notch in a right angle to the ulnar ridge. RESULTS: The mean distance of the coronoid process tip to the baseline was 4.0 mm (standard deviation [SD], 1.3 mm; range, 1.4-6.7 mm). The mean distance of the ventral extension of the AMCL to the horizontal line was 3.7 mm (SD, 2.6 mm; range: 9.4-2.2 mm). The mean horizontal distance between the ventral aspect of the AMCL and the coronoid tip was 13.7 mm (SD, 2.5 mm; range, 7.7-20.5 mm). CONCLUSIONS: We present a detailed description of the insertional anatomy of the AMCL at the sublime tubercle. These values could be helpful for classifications of coronoid fractures and to estimate the involvement of the AMCL in fractures of the sublime tubercle.


Assuntos
Ligamentos Colaterais/anatomia & histologia , Articulação do Cotovelo/anatomia & histologia , Ulna/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Pontos de Referência Anatômicos , Cadáver , Epífises/anatomia & histologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
20.
Ann Anat ; 221: 179-185, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30393181

RESUMO

The practice of human and veterinary medicine is based on the science of anatomy and dissection courses are still irreplaceable in the teaching of anatomy. Embalming is required to preserve body donors, for which process formaldehyde (FA) is the most frequently used and well characterized biocidal substance. Since January 2016, a new occupational exposure limit (OEL) for FA of 0.37mg/m3 issued by the European Committee on Hazardous Substances is obligatory since FA has been classified as a human 1B carcinogen. The anatomical institutes in the German-speaking region are called upon to consolidate efforts to reduce use of FA in anatomical curricula and body donations. As a result, the Anatomische Gesellschaft (AG) has formed a "Working Group for Reduction of Formaldehyde Exposure in Dissection Courses" tasked with discussion and recommendation of measures to reduce FA. Based on the assessment of the Working Group, the AG has issued an official opinion to the effect that, at this point in time, embalming of body donors without FA completely is not feasible. Therefore, a combination of approaches are to be used to reduce FA exposure, including technical and structural (architectural) adaptations, modification of protocols for fixation and preservation as well as organizational measures. One structural measure considered unavoidable is the integration of air supply and exhaust of individual dissecting tables into the ventilation system of the anatomy building. To embalm human body donors, intra-arterial perfusion fixation with up to 4% FA and a total fluid volume of 150mL/kg body weight will suffice. For animals where body weights and biology of bodies vary widely (i.e. special needs of fixation for ruminants, large animals as horses) perfusion fixation with up to 4% FA and a quantity of fixative solution of 10-15% of the body weight may be required. Preservation of body donors in storage (immersion) can be done with 40% ethanol or in a full bath preservation containing up to 2% FA. Corpse humidification in the dissecting room is possible with 2% phenoxyethanol, in each case without FA. In veterinary anatomy, microbiological burden is often higher and therefore might lead to a need of FA in long-time storage. Compliance with the current OEL in all institutes would appear to be feasible in combination with various organizational measures.


Assuntos
Anatomia/educação , Formaldeído/efeitos adversos , Exposição Ocupacional/prevenção & controle , Hipersensibilidade Respiratória/prevenção & controle , Humanos , Guias de Prática Clínica como Assunto
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