Muscular Element Research Articles

Comparative anatomy on 3-D MRI of the urogenital sinus and the periurethral area before and during the second stage of labor during childbirth.

To describe the observable MRI changes in the urogenital sinus during the second stage of labor and delivery by comparing the changes in the positions of the anatomical structures of the maternal perineum using MRI-based vector 3-D models. Seven pregnant women underwent 3-D MRI sequences using a Philips 1T Panorama open MRI during the pre-labor period and during the second stage of labor. A 3-D vector reconstruction platform (BABYPROGRESS, France) enabled the transformation of volumes of 2-D images into finite element meshes. The polygonal meshes labeled with the principal components of the urogenital sinus were used as part of a biomechanical study of the pressure exerted on the perineum during fetal descent. The expansion of the urogenital sinus was observed in all patients. Qualitative stretching was observed toward the rear and bottom of the iliococcygeus, pubococcygeus, puborectalis and obturator internus muscles. Significant length differences were measured along the iliococcygeus and pubococcygeus muscles but not along the tendinous arch of the levator ani or the puborectalis muscle. The inversion of the levator ani muscle curvature was accompanied by the transmission of pressure generated during fetal descent to the pubic muscle insertions and the descent of the tendinous arch of the levator ani. Mechanical pressures responsible for the tensioning of the constituent muscles of the urogenital sinus were qualitatively identified during the second stage of labor. MRI-based vector 3-D models allow the quantitative assessment of levator ani muscle stretching during labor, but 2-D MRI is not sufficient for describing perineal expansion. Vector 3-D models from larger scale studies have the potential to aid in the calibration of a realistic simulation based on the consideration of the reaction of each muscular element. These models offer perspectives to enhance our knowledge regarding perineal expansion during childbirth as a risk factor for postpartum perineal defects.

Modified pectoralis major myocutaneous flap in reconstruction of head and neck defects

To report the experience of use of modified pectoralis major myocutaneous (PMMC) flaps in reconstruction of head and neck postoperative defects. A total of 107 patients who underwent head and neck defect reconstruction using modified PMMC flaps after tumor rescetion between Jan 2008 and Dec 2013 were analyzed retrospectively. The success rate of reconstruction with modified PMMC flaps was 94.4% (101/107). Five patients had partial flap necrosis and their wounds healed with dressing change. One patient (0.9%) had total flap necrosis, followed by the second reconstruction using contralateral PMMC flap. The modified falcate PMMC flap can obtain optimum quantity of the skin in the chest and decreasing the closing tension of the donnor site in favor of wound healing. The pedicle without muscle will not only maintain the partial function of the pectoralis major, but also help to avoid pressing the vascular pedicle within the subclavian tunnel. The muscular element the pedicled muscles of the PMMC flap can increase the ability of the flap to resist infection, which can use for covering an exposed carotid artery and improving the neck fibrosis of irradiated patients.

Alterations in Knee Kinematics After Partial Medial Meniscectomy Are Activity Dependent

Background: Alterations in knee kinematics after partial meniscectomy have been linked to the increased risk of osteoarthritis in this population. Understanding differences in kinematics during static versus dynamic activities of increased demand can provide important information regarding the possible underlying mechanisms of these alterations. Hypothesis: Differences in the following 2 kinematics measures will increase with activity demand: (1) the offset toward external tibial rotation for the meniscectomized limb compared with the contralateral limb during stance and (2) the difference in knee flexion angle at initial foot contact between the meniscectomized and contralateral limbs. Study Design: Controlled laboratory study. Methods: This study compared side-to-side differences in knee flexion and rotation angles during static and dynamic activities. Thirteen patients (2 female) were tested in a motion capture laboratory at 6 ± 2 months after unilateral, arthroscopic, partial medial meniscectomy during a static reference pose and during 3 dynamic activities: walking, stair ascent, and stair descent. Results: The meniscectomized limb demonstrated more external tibial rotation compared with the contralateral limb during dynamic activities, and there was a trend that this offset increased with activity demand (repeated-measures analysis of variance [ANOVA] for activity, P = .07; mean limb difference: static pose, –0.1° ± 3.3°, P = .5; walking, 1.2° ± 3.8°, P = .1; stair ascent, 2.0° ± 3.2°, P = .02; stair descent, 3.0° ± 3.5°, P = .005). Similarly, the meniscectomized knee was more flexed at initial contact than the contralateral limb during dynamic activities (repeated-measures ANOVA for activity P = .006; mean limb difference: reference pose, 1.0° ± 2.5°, P = .09; walking, 2.0° ± 3.9°, P = .05; stair ascent, 5.9° ± 5.3°, P = .009; stair descent, 3.5° ± 4.0°, P = .004). Conclusion: These results suggest both a structural element and a potential muscular element for the differences in kinematics after partial medial meniscectomy and highlight the importance of challenging the knee with activities of increased demands to detect differences in kinematics from the contralateral limb. Clinical Relevance: With further investigation, these findings could help guide clinical rehabilitation of patients with torn meniscus tissue, especially in the context of the patients’ increased risk of joint degeneration.

Morphology of flexor digitorum brevis muscle in northern Tamil Nadu region-an anatomical study with phylogenetic perspective

Abstract Background and aims : "Arches of foot" formed by the combination of skeletal and a muscular element is a unique feature of evolution as an adaptation to habitual erect posture in humans. Flexor digitorum brevis (FDB) is the most superficial intrinsic muscle of the sole that present with variations frequently. The objective of this study was to find out the pattern of presentation of FDB in northern Tamil Nadu region. Material and methods: Thirty soles of 12 male and three female embalmed cadavers were dissected and FDB was observed for variations. A comparative analysis was done with previous studies. Results: Twenty five soles showed absence of FDB tendon to little toe. Three soles confirmed to the classical book description. The soles of a 62 years old male cadaver presented with a variation of FDB. It showed a separate deep slip to the 5th toe arising from intermuscular septum and from long flexor tendon with the slip found to get inserted at the base of middle phalanx bilaterally. The incidence of 83.3% absence of FDB tendon to 5th toe in the present study was significantly higher when compared to many previous reports. Conclusion: Variations of FDB are clinically significant because FDB musculocutaneos flap is used in the reconstruction of the heel pad and FDB tendons are used in tendon transfer surgeries for claw or hammer toe deformities. The absence of FDB tendon to the 5th toe shows clustering around Asian region, which signifies possibility of occurrence of evolutionary changes in specific topographic region

Morphology of flexor digitorum brevis muscle in northern Tamil Nadu region- an anatomical study with phylogenetic perspective

Background and aims: “Arches of foot” formed by the combination of skeletal and a muscular element is a unique feature of evolution as an adaptation to habitual erect posture in humans. Flexor digitorum brevis (FDB) is the most superficial intrinsic muscle of the sole that present with variations frequently. The objective of this study was to find out the pattern of presentation of FDB in northern Tamil Nadu region. Material and methods: Thirty soles of 12 male and three female embalmed cadavers were dissected and FDB was observed for variations. A comparative analysis was done with previous studies. Results: Twenty five soles showed absence of FDB tendon to little toe. Three soles confirmed to the classical book description. The soles of a 62 years old male cadaver presented with a variation of FDB. It showed a separate deep slip to the 5th toe arising from intermuscular septum and from long flexor tendon with the slip found to get inserted at the base of middle phalanx bilaterally. The incidence of 83.3% absence of FDB tendon to 5th toe in the present study was significantly higher when compared to many previous reports. Conclusion: Variations of FDB are clinically significant because FDB musculocutaneos flap is used in the reconstruction of the heel pad and FDB tendons are used in tendon transfer surgeries for claw or hammer toe deformities. The absence of FDB tendon to the 5th toe shows clustering around Asian region, which signifies possibility of occurrence of evolutionary changes in specific topographic region.

Surgical treatment of a severe microstomia developed following leucocytoclastic vasculitis

Narrowing of the oral opening, also known as microstomia, is a rarely seen condition. It can develop iatrogenically after wide excision of perioral tumors with subsequent reconstruction or can be a component of severe scleroderma. In the pediatric population, exposure to caustic agents and subsequent scarring is another cause. This situation can cause problems in feeding, articulation, and oral hygiene. Most of the cases reported have been moderately affected; these require non-surgical treatment or a small procedure, such as a comissuroplasty, to provide an adequate oral opening. A case of severe microstomia developed as a result of a rare condition known as leucocytoclastic vasculitis is presented. A boy aged 2 1/2 years was admitted complaining of severely restricted mouth opening. This resulted from a complicated vasculitic illness, the etiology of which was unknown. The condition subsequently caused necrosis and gangrene with autoamputation of the toes of the right foot, the distal two phalanges of the right index finger, and the distal phalanx of the left ring finger. In addition to the limb problems, he also developed a similar situation around the left side of his mouth. For 21 days, he was treated with antibiotics and antifungal medication. He also had serial skin biopsies, which showed only a leucocytoclastic vasculitis. The initial examination revealed significant scarring around the mouth with a severe microstomia. His mouth opening area was restricted to 1 cm. The surgical correction consisted of opening the mouth using full-thickness incisions on both oral commissures to slightly overcorrect the situation. A moderately extensive dissection was carried out to identify the orbicularis muscles and to allow reconstruction of the muscular element of the commissures. Once the functional area of the commissures had been reconstructed, mucosal flaps were developed and advanced to form the red margin. After 7 years of follow-up, his mouth opening remains satisfactory, and he had been able to have extensive orthodontic treatment.

Changes in histological structure and microvasculature of the rat tongue after transection of the hypoglossal nerve.

This investigation was made on sequential changes in the tongue caused by unilateral transection of the hypoglossal nerve in the rat. These changes were examined on the basis of gross inspection of the lingual dorsal surface, histological aspects of the intrinsic muscle and interstitial tissues, morphological changes in the capillary loops of the filiform papillae utilizing plastic microcorrosion casts, and blood flux and number of erythrocytes in the lingual dorsum as determined by laser Doppler flowmetry. The period of examination following denervation of the hypoglossal nerve was divided into 3-5 days, 1, 2-3, 4-5, 6-7 and 66 weeks. The initial sign of histological change was an edematous change that later developed to atrophic change of the muscular element. This pathological change caused a change in volume on the lesion side of the tongue and finally formed a depression on the dorsal surface and a scallop-like lateral margin. Four to five weeks after denervation, the lesion half swelled, and its lingual apex elongated forward with a coving of the lingual median groove. The filiform papillae showed decreased keratinization, and interpapillary intervals were somewhat widened. Capillary loops in the papillae began to change, showing slight twistings at the tips of loops. Additionally, bulging, coiling and tortuosity were observed on both crura. The loops showed more complicated transformation, and little recovery was observed even 66 weeks after denervation. Blood flux in the dorsal mucosa decreased very slowly after a slight increase. This process seemed to be in proportion to the transformational complexity of the capillary loops in the filiform papillae. In conclusion, unilateral transection of the hypoglossal nerve, which is composed almost entirely of efferent neurons, caused edema and atrophic change in the intrinsic lingual muscle fibers with interstitial fibrosis in the lesion half of the tongue. Capillary loops in the filiform papillae were transformed markedly and successively by transection of the hypoglossal vasomotor neuron together with a slight decrease in blood flow in the dorsal mucosa. None of these changes recovered even at 66 weeks after transection.

Sinusoidal vessels in the periodontal ligament of hamster incisors: their distribution, structure and possible function.

Vascular architecture in the periodontal ligament of hamster incisors was investigated by use of vascular casts under a scanning electron microscope (SEM). In addition to ordinary nutrient blood vessels, anastomosing vessels of large caliber developed, surrounding the incisor. From their characteristic configuration, these vessels were regarded as "sinusoids". The plexus of sinusoidal vessels was connected with capillaries in the papillary layer of the enamel organ at the labial periodontal ligament, and with veins penetrating into the alveolar bone on the lingual side. Transmission electron microscopic (TEM) observation showed that the sinusoidal wall was composed of only a thin layer of endothelial cells, lacking a smooth muscular element, and surrounded by densely arranged collagen fibers. Although the frequent association of Ruffini-type nerve endings with sinusoidal vessels was noted, neither direct contact nor specialized structures between these was recognizable. A possible function of the periodontal sinusoids is discussed on the basis of their distribution and ultrastructural evidence.

On the Laminar Formation of the Masseter Muscle in the Lion (Panthera leo)

An investigation was made of the laminar structure of the masseter muscle in 3 lions (Panthera leo s. Felis leo), and the findings obtained were evaluated in comparison with those in some other carnivora. Although the general aspect of the masseter of the lion resembled that of the cat, there was no close similarity or analogy between them. The construction of the masseter in the lion was as follows. The superficial layer consisted of primary and secondary sublayers, the intermediate layer was composed of anterior and posterior portions, and the deep layer also had anterior and posterior portions. Among these three layers (the masseter proper muscle), the superficial layer was extremely well developed as a characteristic feature of this species. The maxillomandibularis muscle was developed in a muscular element of its origin and had its tendinous insertion on the anteroinferior margin of the masseteric fossa. The zygomaticomandibularis muscle was also fairly well developed in the form of two muscular bundles which originated from the temporal crest, a shelf forming a lateral protrusion on the basis of the zygomatic process, and its posterior surface. Both muscles were also well developed as the masseter improper. Such a huge and complicated laminar pattern of the masseter muscle in the lion should be sufficient to exert a strong force as a predatory animal.

Clinical Significance of Sacral and Pudendal Nerve Anatomy

The neuroanatomy and neurophysiology of the external urethral closure mechanisms still are under debate because the motor fibers that emanate from the sacral plexus and pudendal nerve to supply this segment have not been traced, nor has their functional interrelationship been established. Therefore, we dissected 3 male human cadavers (aged 31 to 69 years) by tracing the entire sacral plexus, particularly the pudendal nerve, from the cauda equina throughout the branching of the nerves to their final destination. The dissection demonstrated that the extrinsic urethral sphincter, formed by the rhabdosphincter around the membranous urethra as well as the levator ani muscle and pelvic floor (especially the transversus perinei muscle), is innervated by somatic nerve fibers that emanate primarily from sacral roots S2 and S3.In 5 patients with neurogenic lower urinary tract dysfunction electrostimulation of the sacral root and pudendal nerve markedly increased intraurethral closure pressures. Stimulation of the pudendal nerve or its transversus perinei branch alone resulted in an increase in intraurethral closure pressure to 60 to 70cm. water—an increase similar to that produced by stimulation of the sacral root without neurotomy. By means of neurotomy and/or neural blockade with lidocaine we were able to differentiate between the contributions of each muscular element to the external sphincteric mechanism. Almost 70 per cent of the closure pressure of the external urethral sphincter is induced by stimulation of the S3 ventral root, while the other 30 per cent derives from S2 and S4 neuronal impulses.

Reconstruction of the lower lip using a neurovascular island flap

TALIACOTIUS (1597) illustrated the reconstruction of a lip with an upper arm flap; Dieffenbach (rg McGregor, 1972; Bretteville-Jensen, 1973; Karapandzic, 1974). Distant flaps, however, have no muscular element and thus provide no sphincteric control, while in my experience local flap reconstructions often give an aperture too small to insert dentures or permit normal eating. The neurovascular island flap to be described will reconstruct defects up to the whole of the lower lip, while even larger defects may be repaired by a flap from each side.

Caliceal urodynamics.

In this study the author emphasizes the existence of a muscular element that had not been described until now. This muscular element is situated around Malpighi's pyramid and its fibres are followed by the caliceal muscle and the elements that form Henle's peripapillar ring. The systolic and diastolic function of this peripyramidal muscle can be observed in the urographies, during the evacuation of the collector tubules of Bellini, and its synchronization with the next caliceal and pyelic musculature.

Angiographic features of hamartoma of the kidney. A case report.

Hamartoma of the kidney is a rare benign tumor in the absence of tuberous sclerosis. It may be bilateral (1, 5). Often it is a combination of more than one connective tissue element, with either the fatty, fibrous, muscular, or vascular element predominating. Conventional methods of investigation are effective when the fatty tissue is dominant in the neoplasm (1). To date, 7 cases have been reported after aortography (2–4, 6, 7). In the case which follows, renal angiography illustrated some distinctive arteriographic changes that were also noted by Viamonte (8). A 29-year-old female was admitted with a 3-week history of left flank pain and a palpable left kidney mass. The findings of the laboratory examinations were normal. An intravenous pyelogram showed a mass in the superior pole of the left kidney, displacing the collecting system (Fig. 1). A nephrotomogram demonstrated the lesion to be ill-defined superiorly; inferiorly, however, it was sharply delineated from adjacent normal kidney structure. The ma...

The use of the cathode ray for recording heart sounds and vibrations: II. Studies on the muscular element of the first heart sound

Studies were made on the muscular elements in the first heart sound, using hearts of dogs, by eliminating normal movement and tensing the auriculoventricular valves. This was accomplished by occluding the venae cavae, by tensing a ligature around the auriculoventricular sulcus to produce an “isometrically” contracting heart, or by inflating small balloons in the ventricular cavities to pressures of 50 mm. Hg or more. It was found that muscular sounds could be recorded and heard as long as the vigor of myocardial contraction was maintained. The possible mechanism underlying the phenomenon is discussed.