Muscular Insertions Research Articles

Camillo Golgi's contributions to the anatomic basis of sensitivity in tendons.

Between 1878 and 1880 Camillo Golgi, professor of Histology and General Pathology at the University of Pavia, studied the termination of the nerves inside the tendons, near their muscular insertion. He defined two fundamental categories of corpuscles. The first type, which he called muscle-tendon terminal organs, was morphologically characterized by spindle structures which at one end seemed to relate to the muscle fibers while at the other end they gradually merged with the tendon bundles. Golgi discovered that these structures received from one to four myelinated nerve fibers, which lost their myelin sheath as they entered the bundle, within which they divided dichotically, ending in a large number of terminal arborizations that had the appearance of reticular intertwines. In the superficial thickness of the tendon, near the muscle, Golgi also noticed a second category of corpuscles, which he described as claviform bodies or formations similar to Pacinian bodies. In 1890 Vittorio Mazzoni precisely defined their morphological characteristics. These corpuscles were later called Golgi muscle-tendon organs and Golgi-Mazzoni corpuscles. On the basis of their position and histological appearance, Golgi also correctly hypothesized their physiological role: to be receptors of muscular tension for the muscle-tendon organs and transducers of sensitivity to touch and pressure for the Golgi-Mazzoni corpuscles.

A new carcharodontosaurid specimen sheds light on the anatomy of South American giant predatory dinosaurs.

Carcharodontosaurids were gigantic terrestrial dinosaurs and top predators of dinosaur faunas in Gondwanan landmasses during the "Mid"-Cretaceous Period. Despite their wide geographical and stratigraphical distribution, essential parts of their anatomy are still poorly known. The present contribution aims to describe a new partial skeleton of the carcharodontosaurid Taurovenator violantei, which was previously known only by an isolated postorbital bone coming from Cenomanian-Turonian beds of northern Patagonia, Argentina. The neck of Taurovenator is composed of notably high anterior cervicals, bearing neural spines with expanded, flange-like dorsal tips which are successively imbricated. This condition has been reported previously in the carcharodontosaurid Acrocanthosaurus, but its occurrence in Taurovenator and other members of the clade suggests it may represent a synapomorphy of this theropod family. This unique neck morphology was probably related to strong modifications in musculature and restriction in the range of movements within the neck, but not with the head. The new specimen also affords valuable anatomical information on the forelimb of Patagonian carcharodontosaurids. As in other giganotosaurines, Taurovenator shows strongly reduced forelimbs, particularly the forearm, showing hand elements with elongated non-ungual phalanges, and well-marked articular surfaces and muscular insertions, suggesting highly movable digits. This new specimen of Taurovenator allows us to expand anatomical and morpho-functional discussions about the carcharodontosaurid clade.

Shape variation in the limb long bones of modern elephants reveals adaptations to body mass and habitat.

During evolution, several vertebrate lineages have shown trends towards an increase in mass. Such a trend is associated with physiological and musculoskeletal changes necessary to carry and move an increasingly heavy body. Due to their prominent role in the support and movement of the body, limb long bones are highly affected by these shifts in body mass. Elephants are the heaviest living terrestrial mammals, displaying unique features allowing them to withstand their massive weight, such as the columnarity of their limbs, and as such are crucial to understand the evolution towards high body mass in land mammals. In this study, we investigate the shape variation of the six limb long bones among the modern elephants, Elephas maximus and Loxodonta africana, to understand the effect of body mass and habitat on the external anatomy of the bones. To do so, we use three-dimensional geometric morphometrics (GMMs) and qualitative comparisons to describe the shape variation, at both the intraspecific and interspecific levels. Our results reveal that the two species share similar negative ontogenetic allometric patterns (i.e. becoming stouter with increased length) in their humerus and femur, but not in the other bones: the proximal epiphyses of the stylopod bones develop considerably during growth, while the distal epiphyses, which are involved in load distribution in the elbow and knee joints, are already massive in juveniles. We attribute this pattern to a weight-bearing adaptation already present in young specimens. Among adults of the same species, bone robustness increases with body mass, so that heavier specimens display stouter bones allowing for a better mechanical load distribution. While this robustness variation is significant for the humerus only, all the other bones appear to follow the same pattern. This is particularly visible in the ulna and tibia, but less so in the femur, which suggests that the forelimb and hindlimb adapted differently to high body mass support. Robustness analyses, while significant for the humerus only, suggest more robust long bones in Asian elephants than in African savanna elephants. More specifically, GMMs and qualitative comparisons indicate that three bones are clearly distinct when comparing the two species: in E. maximus the humerus, the ulna and the tibia display enlarged areas of muscular insertions for muscles involved in joint and limb stabilization, as well as in limb rotation. These results suggest a higher limb compliance in Asian elephants, associated with a higher dexterity, which could be linked to their habitat and foraging habits.

Paleohistological inferences of thermometabolic regimes in Notosuchia (Pseudosuchia: Crocodylomorpha) revisited

AbstractNotosuchia is a group of mostly terrestrial crocodyliforms. The presence of a prominent crest overhanging the acetabulum, slender straight-shafted long bones with muscular insertions close to the joints, and a stable knee joint suggests that they had an erect posture. This stance has been proposed to be linked to endothermy, because it is present in mammals and birds and contributes to the efficiency of their respiratory systems. However, a bone paleohistological study unexpectedly suggested that Notosuchia were ectothermic organisms. The thermophysiological status of Notosuchia deserves further analysis, because the methodology of the previous study can be improved. First, it was based on a relationship between red blood cell size and bone vascular canal diameter tested using 14 extant tetrapod species. Here we present evidence for this relationship using a more comprehensive sample of extant tetrapods (31 species). Moreover, contrary to previous results, bone cross-sectional area appears to be a significant explanatory variable (in addition to vascular canal diameter). Second, red blood cell size estimations were performed using phylogenetic eigenvector maps, and this method excludes a fraction of the phylogenetic information. This is because it generates a high number of eigenvectors requiring a selection procedure to compile a subset of them to avoid model overfitting. Here we inferred the thermophysiology of Notosuchia using phylogenetic logistic regressions, a method that overcomes this problem by including all of the phylogenetic information and a sample of 46 tetrapods. These analyses suggest thatAraripesuchus wegeneri,Armadillosuchus arrudai,Baurusuchussp.,Iberosuchus macrodon, andStratiotosuchus maxhechtiwere ectothermic organisms.

The anatomic - magnetic resonance imaging study of distal triceps brachii tendon.

The study aimed to describe the distal triceps brachii insertion on the olecranon and to correlate the findings with those seen in normal MR (Magnetic Resonance) anatomy of the triceps brachii insertion. 14 un-paired fresh frozen elbows were included according to the institution guidelines and dissected. Histologic examination was performed to the distal triceps brachii insertion. The dimension of the distal triceps brachii tendon insertion was measured and defined based on its layer. The measurement of distal triceps brachii insertion was performed with image processing program (Image J, National Institute of Health, Bethesda, Maryland). T1-weighted elbow MR images (3.0T) of a 102 patients were acquired and analyzed according to its sagittal plane. All specimens shows that distal triceps brachii tendon is with three distinct insertional areas in the olecranon which are: (1) capsular, (2) deep muscular, (3) superficial tendinous insertion with the areas of 80.7mm2, 56.4mm2, and 175.2mm2, respectively. The superficial tendinous insertion was observed with a thickened portion, the "central cord" with 0.5 occupation ratio. MR analysis showed that 30% (31/102) of the distal biceps brachii insertion was with a cleft between the bipartite insertion of the superficial tendinous and the deep muscular insertion on olecranon which designated as the "lacuna" which was also found in 35% (5/14) of the specimens. The distal triceps brachii has three distinct insertion on the olecranon. The superficial tendinous layer was separated with the deep muscular layer by a cleft in one third of the cases. Knowledge of this anatomy will help surgeon to understand the partial triceps injury and to avoid iatrogenic injury to the distal triceps tendon during surgery.

Traumatic diaphragm rupture treated with left anterolateral thoracotomy approach: a case report

Background: Traumatic diaphragmatic rupture (TDR) is a life-threatening condition due to the herniation of abdominal organs into pleural cavities. Rupture can occur in patients with major blunt or penetration trauma of the lower chest. Blunt TDR is usually caused by momentary high energy damage and is associated with severe trauma. This study aims to evaluate our hospital's experience with managing patients with blunt TDR, including its incidence, modes of diagnosis, operative treatments, postoperative outcomes, and factors predictive of patient outcomes. Case Report: A 44 years old man was referred to our hospital complaining of dyspnea. Eleven hours before his admission, he was riding his motorcycle, fell to the road, and hit the tree on his left chest. After the accident, he feels dyspnea, chest pain, and abdominal pain. The patient was brought to the nearest hospital and underwent a chest x-ray and left chest tube insertion, with initial production was blood 1700 ml. On examination, there was an increased respiratory rate, a visible bruise of the posteroinferior left chest near the left flank and a pre-installed chest tube thoracostomy on the left chest. Chest x-ray showed an intrathoracic herniation of abdominal viscera, the "collar sign" appeared, and the abdomen x-ray showed the left upper quadrant abdominal organ displaced into the left thorax cavity. Thus suspected, the underlying condition of TDR in this patient. We decided to perform left anterolateral thoracotomy and continued with laparotomy and splenectomy Conclusion: TDR is a rare case. The trauma may include shearing a stretched diaphragm, avulsion from a muscular insertion point, or increased abdominal pressure exceeding the bursting pressure of the diaphragm. Intra-abdominal organ injuries are more common than intrathoracic injuries. Initial operative approaches were laparotomy and thoracotomy.

Advancement of the muscle insertion toward the limbus as an alternative or adjunct to resection

To describe the surgical outcomes of patients that underwent strabismus surgery involving advancement of the muscular insertion line toward the limbus. The medical records of patients who underwent rectus muscle advancement surgery between January 2009 and June 2019 and had at least 1 year of follow-up were reviewed retrospectively. Patients were classified into one of four types of deviation: (1) convergence insufficiency, without distance deviation; (2) small-angle distance esotropia, with diplopia; (3) residual strabismus after previous surgery; and (4) large-angle exotropia. The first group underwent 2 mm advancement of the medial rectus insertion bilaterally; the second, 2-3 mm advancement of the lateral rectus muscle bilaterally; the third, 2-3 mm advancement of the lateral or medial rectus muscle, with or without simultaneous resection; and the fourth, 3 mm advancement of the medial rectus with simultaneous resection, with or after maximum recession of the lateral rectus, bilaterally or unilaterally. A total of 25 patients were included (mean age, 28.76 ± 22.75 years): 4 with convergence insufficiency, 3 with small-angle distance esotropia and diplopia, 16 with residual strabismus, and 2 with large-angle exotropia. Mean postoperative follow-up was 4.76 ± 2.03 years. Surgery was successful in all patients at 1 year (residual deviation ≤10Δ), and all but 1 at 5 years; 1 patient required reoperation. Advancement of the muscle insertion proved successful as an alternative or adjunctive procedure to other forms of muscle tightening in the subtypes of patients evaluated in this study.

Functional morphology of the hindlimb of fossilized pygmy hippopotamus from Ayia Napa (Cyprus).

We studied the functional morphology of the postcranial skeleton of the endemic hippopotamus Phanourios minor, derived from the Upper Pleistocene site of Ayia Napa. The deposit, which consists of a hard limestone substrate on which the species moved, has yielded a great abundance of hippopotamus material, making the Ayia Napa locality one of the most important paleontological sites in Cyprus. The immigration of the large-sized mainland Hippopotamus to Cyprus led to the emergence of a new insular species with its main characteristic being the extremely reduced body size. In this study, all the hindlimb elements of the Cypriot hippo are described in detail and compared with those of the modern species, with the extant Hippopotamus amphibius being considered similar to the possible ancestor of P. minor. In some cases, the morphological comparison is reinforced using bones of other extinct insular and mainland hippos. Additionally, we provided a functional analysis of the hindlimb joints, suggesting specific locomotor habits for the species. The anatomical examination reveals that the elements in P. minor are robust with marked muscular insertion areas resembling those found in Hippopotamus. However, there are also similarities with Choeropsis liberiensis in certain morphofunctional traits. P. minor adapted to slow but powerful locomotion with remarkable stabilization, particularly in the zeugopodium and the autopodium. The knee was less mobile in the craniocaudal direction compared with that in recent hippos, while the abduction-adduction movements of the thigh were advanced. The pes presented good mobility in the sagittal plane and limitation in transversal movements. Thus, P. minor displayed modifications to its limbs, influenced by the mountainous island environment and the body size reduction, resulting in specialized locomotion, which was different from that of extant hippopotamuses.

Anatomic evaluation of the triceps tendon insertion at the proximal olecranon regarding placement of fracture fixation devices

PurposeOlecranon fractures, especially with a small proximal fragment, remain a surgical challenge. Soft tissue irritation and affection of the triceps muscle bear a risk of complications. In order to find an area for a soft-tissue sparing placement of implants in the treatment of olecranon fractures, we aimed to define and measure the segments of the proximal olecranon and evaluate them regarding possible plate placement.MethodsWe investigated 82 elbow joints. Ethical approval was obtained from the local ethics committee, After positioning in an arm holder and a posterior approach we described the morphology of the triceps footprint, evaluated and measured the surface area of the triceps and posterior capsule and correlated the results to easily measurable anatomical landmarks.ResultsWe found a bipartite insertional footprint with a superficial tendinous triceps insertion of 218.2 mm2 (± 41.2, range 124.7–343.2), a capsular insertion of 159.3 mm2 (± 30.2, range 99.0–232.1) and a deep, muscular triceps insertion area of 138.1 mm2 (± 30.2, range 79.9–227.5). Olecranon height was 26.7 mm (± 2.3, range 20.5–32.2), and olecranon width was 25.3 mm (± 2.4, range 20.9–30.4). Average correlation between the size of the deep insertion and ulnar (r = 0.314) and radial length (r = 0.298) was obtained.ConclusionsWe demonstrated the bipartite morphology of the distal triceps footprint and that the deep muscular triceps insertion area by its measured size could be a possible site for the placement of fracture fixations devices. The size correlates with ulnar and radial length.

Long bone shape variation in the forelimb of Rhinocerotoidea: relation with size, body mass and body proportions

Abstract In quadrupeds, limb bones are strongly affected by functional constraints linked to weight support, but few studies have addressed the complementary effects of mass, size and body proportions on limb bone shape. During their history, Rhinocerotoidea have displayed a great diversity of body masses and relative size and proportions of limb bones, from small tapir-like forms to giant species. Here, we explore the evolutionary variation of shapes in forelimb bones and its relationship with body mass in Rhinocerotoidea. Our results indicate a general increase in robustness and greater development of muscular insertions in heavier species, counteracting the higher weight loadings induced by an increased body mass. The shape of the humerus changes allometrically and exhibits a strong phylogenetic signal. Shapes of the radius and ulna display a stronger link with body mass repartition than with the absolute mass itself. Congruent shape variation between the humerus and the proximal part of the ulna suggests that the elbow joint is comprised of two strongly covariant structures. In addition, our work confirms the uniqueness of giant Paraceratheriidae among Rhinocerotoidea, whose shape variation is related to both a high body mass and a cursorial forelimb construction.

Subscapularis minor-does it exist?

It has been well established that the subscapularis is divided in two different parts with a tendinous insertion at its superior two-thirds and a muscular attachment on its inferior third. The objective of this cadaveric study was to follow the muscular insertion of the subscapularis medially in order to determine the origin of this inferior muscle insertion and whether a subscapularis minor can be individualized MATERIALS AND METHODS: Twenty-six shoulders from thirteen fresh-frozen cadaveric specimens (5 males and 8 females; mean age, 74.4 years) were dissected in our anatomy lab. The humeral insertion of the subscapularis was then analyzed, and the inferior muscular part of the insertion was identified. The muscle fibers were followed medially until their scapular origin which was recorded as line drawings and photographs. We measured the dimensions of both the humeral insertion and of the scapular origin of the fibers going to the muscular portion. In all cases, the fibres going to the tendinous portion and those going to the muscular portion of the insertion had a different orientation. The fibres going to the muscular portion of the humeral insertion did not originate from the subscapularis fossa but on the glenoid neck and in a depression at the infero-lateral part of the scapular pillar. The mean length of the superior tendinous portion of the humeral insertion was 3.42 cm (± 0.43 cm); the mean length of the inferior muscular portion of the humeral insertion was 1.88 cm (± 0.80 cm). The mean length of the scapular origin in the depression at the infero-lateral part of the scapular pillar of the fibres going to the muscular portion of the humeral insertion was 3.7 cm (± 0.17 cm). The fibres of the subscapularis do not all originate from the subscapularis fossa. An additional origin exists at the inferior part of the glenoid neck and in a depression at the infero-lateral part of the scapular pillar. The fibers which originate at this location all insert on the humerus at the muscular portion of the subscapularis humeral insertion. This portion however does not seem to correspond to the so-called subscapularis minor which has been previously described.

Cross-sectional imaging of popliteal artery entrapment syndrome

A 63-year-old asymptomatic man with unlimited exercise tolerance is investigated for suspected popliteal aneurysms, due to absent pedal pulses and prominent popliteal pulsations. Contrast-enhanced computed tomography (CT) shows occlusion of the left popliteal artery with geniculate collaterals surrounding the popliteal vein (A). The medial head of gastrocnemius separates the popliteal vein and the occluded (entrapped) popliteal artery. CT also shows entrapment of the right popliteal artery, due to extrinsic compression by the abnormally sited tendon of the medial head of gastrocnemius, which separates the artery and vein, mirroring the muscular anatomy on the left (B). A second 55-year-old man, normally walking 10-12 miles per day without restriction, presents with acute right leg claudication at 200 m. Contrast-enhanced CT demonstrates left popliteal artery stenosis with post-stenotic dilatation and right distal popliteal embolic occlusion due to a popliteal aneurysm with thrombus secondary to bilateral popliteal entrapment syndrome (PAES) (C). Axial balanced flow fast field echo magnetic resonance images and corresponding CT axial images demonstrate that the left medial head of gastrocnemius passes between the popliteal artery and popliteal vein. However, the aneurysmal right popliteal artery and the right popliteal vein are both located medial to, and are not separated by, the medial head of gastrocnemius (D). PAES is an uncommon cause of occlusive arterial disease, which is often bilateral. It is caused either by abnormal muscular insertions, typically of the medial head of gastrocnemius or the popliteus muscle, or by anomalous fibrous bands (types II, III, and IV, according to the modified Whelan classification).1Rich N.M. Collins G.J. McDonald P.T. Kozloff L. Clagett G.P. Collins J.T. Popliteal vascular entrapment: its increasing interest.Arch Surg. 1979; 114: 1377-1384Google Scholar Less commonly, an abnormal course of the popliteal vessels around normally inserted muscles is responsible for the entrapment (type I). Arteriovenous (type V) and functional entrapments have also been described. As illustrated, cross-sectional studies are very useful in demonstrating the abnormal anatomy. These two cases also show that muscular abnormalities are not always symmetrical in bilateral PAES (all limbs presenting as type II, except for the right leg of the second patient, which can be classed as type I, due to the medial course of the artery around a normal insertion of the medial head of gastrocnemius). Both patients consented to the publication of the case details and relative images.

Multiple iliopsoas tendons: a cadaveric study and treatment implications for internal snapping hip syndrome

PurposeThis cadaveric study aimed at describing the anatomical variations of the iliopsoas complex.MethodsThe iliopsoas complex was dissected unilaterally in 28 formalin-embalmed cadavers—13 males and 15 females with a mean age of 85.6 years. The number, courses and widths of the iliacus and psoas major tendons were determined. Patients with previous hip surgery were excluded. The following measurements were taken from the mid-inguinal point: the distance to the point of union of the psoas major and iliacus tendon; and the distance to the most distal insertion of iliopsoas.ResultsThe presence of single, double and triple tendon insertions of iliopsoas were found in 12, 12 and 4 of the 28 specimens, respectively. When present, double and triple tendons inserted separately onto the lesser trochanter. The average length of the iliopsoas tendon from the mid-inguinal point to the most distal attachment at the lesser trochanter was 122.3 ± 13.0 mm. The iliacus muscle bulk merged with psoas major at an average distance of 24.9 ± 17.9 mm proximal to the mid-inguinal point. In all cases, the lateral-most fibres of iliacus yielded a non-tendinous, muscular insertion on to the anterior surface of the lesser trochanter and the femoral shaft, rather than joining onto the main iliopsoas tendon(s). The average total width of the psoas major tendon decreased with an increasing number of tendons: 14.6 ± 2.2 mm (single tendon), 8.2 ± 3.0 mm (2 tendons present) and 5.9 ± 1.1 mm (3 tendons present) (P < 0.001).ConclusionsThe results of this study suggest that multiple tendinous insertions of iliopsoas are present as an anatomical variant in more than 50% of the population. The non-tendinous muscular insertion of the iliopsoas on to the anterior surface of the lesser trochanter and femoral shaft found represents a novel anatomical variant not previously described.Level of evidenceLevel V

Vertebral Morphology in Partially Sympatric Dolphins: A 3D Approach

In cetaceans, increased body flexibility is associated with increased maneuverability, this affects the animal’s swimming speed and foraging behavior. A more stable body form is associated with fast swimming and wide turns. One factor that affects the flexibility of a cetacean’s body is the structure and interference of its vertebrae. Differences in vertebral morphology confer different muscular insertion sites and a potential mechanical advantage for swimming muscles. We studied vertebral morphology in four closely related and partially sympatric dolphin species from the Southern Hemisphere: Commerson’s dolphin (Cephalorhynchus commersonii), Peale’s dolphin (Lagenorhynchus australis), the dusky dolphin (Lagenorhynchus obscurus) and the hourglass dolphin (Lagenorhynchus cruciger). The former two species are usually considered coastal, associated with complex habitats where foraging strategies require greater maneuverability; they also show plasticity in their prey preferences. The latter two species are considered fast-swimming cooperative feeders, with long distance movements reflecting prey availability in pelagic habitats. We employed three-dimensional (3D) geometric morphometric techniques and multivariate analyses to evaluate differences in vertebral morphology. Our analyses tested whether particular morphologies that limit or enhance flexibility were associated with preferred habitats and feeding strategies. We established links between morphology and behavioral patterns based on the biomechanical significance of specific vertebral morphological features. Principal Component Analyses (PCA) showed great differentiation between species in all the studied regions along the vertebral column. This was especially evident in the middle area, except in the case of dusky and hourglass dolphins which showed no discernible morphological difference in their mid-column vertebrae. PCA results were supported by significant Mahalanobis Distances between groups. Species associated with complex habitats and behaviors possessed morphological features associated with greater flexibility of the column (i.e. spool-shaped vertebrae with short erect processes), whereas cooperative-feeder species possessed features associated with greater stability (i.e. disk-shaped vertebrae with long strongly bent processes). Even though these species are closely related and partially sympatric, vertebral morphology is distinctive and varies with the differential foraging strategies and habitat of each species. These findings reveal high morphological plasticity among these dolphin species, highlighting the importance of behavioral complexity and of habitat use in the evolutionary development of morphological adaptations.

A first glimpse at the influence of body mass in the morphological integration of the limb long bones: an investigation in modern rhinoceroses.

The appendicular skeleton of tetrapods is a particularly integrated structure due to the shared developmental origin or similar functional constraints exerted on its elements. Among these constraints, body mass is considered strongly to influence its integration but its effect on shape covariation has rarely been addressed in mammals, especially in heavy taxa. Here, we propose to explore the covariation patterns of the long bones in heavy animals and their link to body mass. We investigate the five modern rhinoceros species, which display an important range of bodyweight. We used a 3D geometric morphometric approach to describe the shape covariation of the six bones composing the stylopodium and zeugopodium both among and within species. Our results indicate that the appendicular skeleton of modern rhinos is a strongly integrated structure. At the interspecific level, the shape covariation is roughly similar between all pairs of bones and mainly concerns the muscular insertions related to powerful flexion and extension movements. The forelimb integration appears higher and more related to body mass than that of the hind limb, suggesting a specialization for weight support. The integration of the stylopodium elements does not seem to relate to body mass in our sample, which suggests a greater effect of shared developmental factors. Conversely, the covariation of the zeugopodium bones seems more associated with body mass, particularly for the radius-ulna pair. The fibula appears poorly integrated with other bones, especially within non-Rhinoceros species, which may represent a case of parcellation due to a functional dissociation between the hind limb bones. The exploration of the integration patterns at the intraspecific level also highlights a more prominent effect of age over individual body mass on shape covariation within C.simum. This study lends support to previous hypotheses indicating a link between high body mass and high integration level.

Evaluation of functional outcome of subtrochantric fracture of femur managed by proximal femoral nail: A prospective study

Background: Subtrochantric region is cortical in nature and vascularity is slow so healing is not as fast as highly vascular area of bone. This area of femur is subjected to stress due to its muscular insertions. So there is greater chance of fixation failure, non-union, and failure of procedure. Keeping all these in view present study has been designed to study the anatomical and functional outcome of subtrochantric fracture treated with proximal femoral nail, to access the stability of fixation and mobility of the patients and compare the result with standard treatment. Method: Patients with sub trochanteric facture admitted in the department of orthopaedics and trauma are enrolled for this study based on inclusion and inclusion criteria. Standard operative procedure was followed management of subtrochantric fracture by proximal femoral nail. Demographic, intra-operative, post-operative variavles are recorded. Result: The duration of surgery was 95.636 + 16799 minutes in present study. The mean volume of blood lost during surgery was 114.387 + 17.90 ml and regarding complication of in intra operative period 12% patient required open reduction. Regarding post operative complication no patient were presented with implant failure, malunion and delayed union was present in 10% patients. Joint stiffness and shortening of limb was present in 8% patients. Discussion and Conclusion: We can conclude that subtrochantric fracture is common in elderly and trivial fall is common cause. Intra-operative variables during proximal femoral nailing were good with less blood loss and minimum deformities. Post-operative variables like non union and joint stiffness was less. Most of the patients have good functional out come.

Paleobiology of Argyrolagus (Marsupialia, Argyrolagidae): an astonishing case of bipedalism among South American mammals

Argyrolagus constitutes, both for its craniodental and postcranial anatomy, one of the most notably specialized South American Neogene metatherians. Differentiating it from any other South American mammal, bipedal jumping has been proposed for Argyrolagus, even though this hypothesis was not supported by morphofunctional studies. Here, we describe the postcranium of A. scaglai (from the Pliocene of Argentina), perform a functional analysis, and interpret it against a varied background of locomotor adaptations of extant mammals. The configuration of joints, the degree of development and location of muscular insertions were mainly analyzed, and functional indices were evaluated. This study indicates that Argyrolagus had stabilized glenohumeral and humeroulnar joints, a great development of the arm retractors, flexors-extensors of the digits, pronator, and supinator muscles, low restrictive humeroradial joint, powerful extensor muscles of the hip, knee, and ankle, good development of the iliac muscle, and restrictive hind limb joints. Joint configurations are interpreted to be optimal to resist the impacts during jumping, avoiding dislocation, compatible with digging activity. A compromise between the capacities to dig and manipulate objects is inferred. It is concluded that Argyrolagus had bipedal jumping locomotion as well as good capacity to dig, constituting an astonishing case of convergence with the small bipedal rodents and small Australian macropodids. We suggest that bipedal jumping in Miocene and Pliocene argyrolagids should not be necessarily related to a particular arid environment. Finally, we evaluate the importance of postcranial features to understand the phylogenetic relationships of Argyrolagidae in a comprehensive phylogeny of Metatheria.

CASE REPORT: HUMAN DIGASTRIC SARTORIUS MUSCLE WITH AN EVO‐DEVO APPROACH

INTRODUCTIONHox genes are essential in the fixation of the anteroposterior axes in symmetrical individuals. During mammal evolution of the musculoskeletal system's paired appendages there has been expresión HOX genes; for example, Tbx4 genes determine the identity of hind limbs when paired paraxial mesoderm originates hypaxial and epaxial muscles. From an ontogenetic perspective, muscle embryology has myogenic hierarchical control genes such as Myf5, MyoD, myogenin and MRF4, when linked with diversity controlling genes like Kdm5, Med13, Tcfap4 Atrophin1, Rere, Elongin‐B, ZBTB20, AF10/AF17, Kdm2, Sin3A justify muscular morphological diversity, loss or duplication. Once this is understood trough an evolutionary perspective, one may understand sartorius muscle diversity in mammals. In the case of ruminants, this muscle has a morphology with two superior heads. Interestingly enough, the same sartorius morphology has been documented in humans like an anatomical variant. The present case aims to describe this anatomical variant with an EVO‐DEVO approach.REPORT CASEDuring the course of a second year anatomy class, at La Universidad de La Sabana, the class professor, when exploring the corpse of a 40 year old male, noticed a digastric belly sartorius muscle on the left lower limb, while also noticing an uncommonly thick sartorium on the right lower limb. [Figure 1]. When it came to the digastric sartorius muscle, both bellies ran parallel to each another, however they were covered by different fascia. The medial head originated from the superior border of the anterior superior iliac crest. The lateral head had its classical origin. Both heads had the classical muscular insertion.DiscussionIn natural populations, there are reports of morphological left – right differences, however, reports of individuals with asymmetric morphologies are rare, suggesting the possibility that asymmetric individuals might arise as a result of imperfect development. This may be reflected by the genome's instability due to interactions with environmental factors or “noise”. The stability of the genome is an intrinsic capacity of an organism to resist external disturbances that may occur during natural development and growth. In this case report, the obvious sartorius muscles asymmetry is evidence that invites us to consider the Evo‐Devo perspective. Such idea suggests the possibility that any disturbance during early ontogeny of the lower limb might have occurred as consequence of the genome's lack of buffer capacity. This reminds us, that myogenic control and diversity genes define an individual's symmetry when they are buffered.ConclusionA molecular Evo‐Devo approach should be started in ontogenical manner in order to explain the asymmetry cases that might be found.Support or Funding InformationPROSEIMThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

An Analysis of Extraocular Muscle Forces in the Piked Dogfish (Squalus acanthias).

Vertebrates utilize six extraocular muscles that attach to a tough, protective sclera to rotate the eye. The goal of the study was to describe the maximum tetanic forces, as well as the torques produced by the six extraocular muscles of the piked dogfish Squalus acanthias to understand the forces exerted on the eye. The lateral rectus extraocular muscle of Squalus acanthias was determined to be parallel fibered with the muscle fibers bundled into discrete fascicles. The extraocular muscles attach to the sclera by muscular insertions. The total tensile forces generated by the extraocular muscles ranged from 1.18 N to 2.21 N. The torques of the extraocular muscles ranged from 0.39 N to 2.34 N. The torques were greatest in the principal direction of movement for each specific muscle. The lateral rectus produced the greatest total tensile force, as well as the greatest torque force component, while the medial rectus produced the second greatest. This is likely due to the constant rotational movement of the eye anteriorly and posteriorly to stabilize the visual image, as well as increase the effective visual field during swimming. Rotational forces in dimensions other than the primary direction of movement may contribute to motion in directions other than the principal direction during multi-muscle contraction that occurs in the vertebrate eye. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 302:837-844, 2019. © 2018 Wiley Periodicals, Inc.

Comparative hindlimb bone morphology in noctilionid fisher bats (Chiroptera: Noctilionidae), with emphasis onNoctilio leporinuspostnatal development

AbstractThe hindlimbs allow bats to attach to the mother from birth, and roost during independent life. Despite the great morphological diversity in Chiroptera, the hindlimbs morphology and its postnatal development have been poorly studied. Postnatal development of hindlimbs inNoctilio leporinusis described, further comparing the morphology of adults with that ofNoctilio albiventrisand previously reported species (Desmodus rotundus,Artibeus lituratus,Molossus molossus). The ossification ending sequence at autopodium elements ofN. leporinusdoes not follow the distal to proximal directional sequence described forD. rotundus, exhibiting a heterochronic delayed ossification ending for the digits ofN. leporinusregarding other hindlimb elements, associated with the bigger relative autopodium size of this fisher bat regarding other bat species. Noctilionid bats share the same adult hindlimb bone morphology, except for differences at hindlimb proportions and calcar ossification degree. There are differences in the number and position of bony processes, slots and sesamoids of adult noctilionid fisher bats regarding previously reported species; most differences are concentrated at the autopodium and are related to an increased surface for muscular insertion and the structural support of claws. These facts seem to be closely associated with functional demands of the feeding strategy of noctilionid fisher bats.