Short Ligament Research Articles

An unusually long ligamentum arteriosum

During routine laboratory dissections an unusually long ligamentum arteriosum, measuring 40 mm, was observed. Apparently, such a length for an otherwise normal ligamentum has not been reported previously. Forty-three other ligamenta in adults and three in newborn or stillborn infants were also measured having a range of 8 mm to 24 mm (mean 15.47 mm) and 7.5 mm to 11 mm (mean 9.5 mm) respectively. Since short and long ligaments have been reported previously, both in the newborn as well as in the adult, the variability in length of this structure appears normal and without any functional significance.

The anatomy and biomechanics of thelateral aspect of the knee

The lateral and posterolateral aspects of the knee are complex and often confusing anatomic regions. The structures that comprise the lateral aspect of the knee are the lateral knee retinaculum, which is comprised of the iliopatellar band, and iliotibial tract. The complicated posterolateral corner is an integrated complex that includes the lateral collateral ligament, the popliteus tendon, the fabellofibular ligament, the arcuate ligament, the popliteofibular ligament, and the short lateral ligament. It is only recently that a much clearer understanding of the anatomic structures of the lateral and posterolateral aspects of the knee have been delineated. As a result a more accurate determination of the biomechanical contributions of each these structures has occurred. The lateral collateral ligament is the primary restraint to varus rotation at all degrees of knee flexion. The posterolateral structures, of which the popliteofibular ligament has been shown to play a major role, are also a primary restraint to external rotation. These same structures play a secondary role in the control of anterior and posterior translation of the knee. It is the hope that this improved understanding of the anatomy and biomechanics of the lateral and posterolateral aspects of the knee will translate into improved clinical management of the instabilities that are often so debilitating and clinical challenging.

Anterior sacrodural attachments–Trolard's ligaments revisited

SUMMARY. In contrast to the attention paid to the structures surrounding spinal nerve roots in the intervertebral foramina, the anterior dural attachments are largely ignored, although they have been described since the last decades of the 19th century. These anterior attachments were systematically studied in a series of 30 cadaver dissections and were found to be present in almost 94% of cases. Four types of anterior attachments were observed. The most frequent form (84%) being a system of filaments that present as a double cross vault between the dura mater and the posterior longitudinal ligament extending from L3 to S3 levels. Less frequent were sagittal filaments (30%), short strong ligaments (17%) and a median septum from L3 to the end of the dural sac (7%). No attachments were found in two cadavers. Further studies are needed to clarify the possible role of these structures in transmitting movement to the dural sac and periradicular sleeves when mobilising the last three lumbar vertebrae or the sacrum.

Ovarian maldescent

To describe and assess the incidence and impact of ovarian maldescent in infertile women.Observational clinical study.Referral infertility practice.Women undergoing operative intervention as part of infertility evaluation or treatment.Anatomic observation at laparoscopy or laparotomy.Failure of the gonad to descend into the true pelvis occurred in 5 of 2,025 operative observations of patients evaluated and treated for infertility. Inappropriate descent of the ovary is associated with a short infundibulopelvic ligament and attachment of the superior pole of the ovary above the pelvic brim adjacent to the fimbriated end of an elongated, ipsilateral fallopian tube. It may be bilateral or unilateral and sometimes is associated with Mullerian duct abnormalities.The incidence of ovarian maldescent is low, its relationship to infertility is unclear, and it does not necessarily preclude conception when other infertility factors are recognized and treated. Its rarity and altered anatomy has the potential for therapeutic misadventure at laparoscopy, laparotomy, and IVF oocyte retrieval.

Histologie appearance of axial osteochondral fragments from the proximoplantar/proximopalmar aspect of the proximal phalanx in horses

Summary Osteochondral fragments from the axial proximoplantar/proximopalmar region of the proximal phalanx were removed from 38 joints in 30 horses. Ninety-three percent of the horses were Standardbreds, and 28 of the 30 had a low-grade lameness. All but 1 of the horses had hind limb involvement. A total of 43 fragments were removed. Most (71%) of the fragments involved the medial aspect of the joint and had to be dissected from a covering of synovial tissue. Histologically, the circumference of most fragments consisted of a transition zone at the attachment of the joint capsule, a region of nonarticular, non-weight-bearing cartilage, a region where organized, dense connective tissue, presumably remnants of the short sesamoidean ligament were attached, and a region consisting of irregular truncated bony surfaces covered by mature fibrous tissue, which appeared to be the result of healing of a chronic fracture. There were several areas of degenerate hyaline cartilage, but no areas of normal hyaline cartilage or areas containing retained cartilage cores or other evidence of delayed endochondral ossification. Immunohistochemical staining of 4 segments from 1 horse revealed sensory substance P immunoreactive nerves in the fibrous tissue surrounding the bony fragments and within the central cancellous spaces. The histologic appearance suggests that these osteochondral fragments may be a result of fracture, rather than a manifestation of osteochondrosis.

Plantar osteochondral fragments in the metatarsophalangeal joints in Standardbred trotters; result of osteochondrosis or trauma?

SummaryHindlimb fetlock joints with plantar osteochondral fragments (POF) were collected from 21 horses (17 Standardbred trotters, 4 Swedish Warmblood riding horses; 8 stallions, 5 geldings, and 8 mares; ages 5 months‐21 years) and from 28 horses with no metatarsophalangeal joint pathology. The morphology of the osteochondral fragments and adjacent tissues was studied by dissection, high‐resolution radiography, and histology. There were 22 joints affected, and 20 out of 25 POF found were located medially. In 3 joints there were fragments both laterally and medially. The fragments were attached to the short sesamoidean ligaments and facing the joint cavity they had a smooth cartilage covered surface which measured between 4 times 2 mm and 12 times 6 mm. A small central trabecular osseous core was seen radiographically in the young horses (<1 year of age), and the proportion of the bony component increased during the first years of life. In 18 out of 25 POF sites, a defect was seen in the adjacent bone of the proximal phalanx. Histology did not show any findings indicative of osteochondrosis.It is suggested that plantar osteochondral fragments are the result of outwardly rotated hindlimb axes and subsequent point loading in the medial fetlock area. Repeated high tension loads in the short sesamoidean ligaments may cause fragments of tissue with osteogenic properties to come off the proximal phalanx into the ligament, later forming osteochondral fragments.

Abnormal aorta and iliac arteries in children with urogenital abnormalities

Retroiliac ureters have been found in association with a variety of urogenital abnormalities but the iliac artery usually retains a retroperitoneal position. We report 7 children with various urogenital abnormalities (cloacal malformation 4, bladder agenesis 1, urogenital sinus 1, neuropathic bladder 1) in whom the lower aorta and iliac arteries were so distorted as to pose a significant operative hazard. In all cases the distal aorta and/or iliac arteries lay within the peritoneal cavity, often anterior to the bladder. In 3 cases the aorta was fixed by a short ligament to the umbilicus, and in 3 patients one of the iliac arteries ran across the pelvis behind the pubic bones before entering the leg. In one patient an anomalous iliac artery was inadvertently divided during reconstruction of a cloaca; when recognized, the vessel was rejoined. Recognition of an association between urogenital or cloacal malformations and a major vascular anomaly is of great importance to reconstructive surgeons who, if not forewarned, could unintentionally compromise the arterial supply to one or both lower limbs.

Regional differences in the morphology and enzyme distribution of the spiny dogfish ( Squalus acanthias) ciliary epithelium

The ciliary epithelium of spiny dogfish eyes has previously been used for studies of epithelial electrolyte transport and the results are found to be comparable to those obtained in mammals. In this study we report the ultrastructure and enzyme histochemistry of the ciliary epithelium of spiny dogfish in comparison with that of mammals. In contrast to the mammals, the lens in spiny dogfish is connected to the anterior and middle part of the ciliary epithelium by a broad zonula-like suspensory ligament and by a short ligament to the ventral papilla, while the posterior region is mainly free of zonula-like fibers. The non-pigmented epithelium (NPE) of the posterior region shows numerous membrane infoldings, interdigitations and many mitochondria in the cytoplasm as well as histochemical staining for Na+ K(+)-ATPase and carbonic anhydrase (CA). These findings are similar to those seen in the anterior pars plicata of mammals which is mainly involved in aqueous secretion. In the anterior and middle part, the NPE cells have only a few membrane infoldings and few mitochondria in the cytoplasm, but abundant surfaces of rough endoplasmic reticulum, numerous ribosomes and Golgi material, indicating protein synthesis. Histochemically the cells stain for Na+, K(+)-ATPase but not for CA. These findings are comparable to the pars plana in mammals. In contrast to mammals, where the pigmented epithelium (PE) shows nearly no staining for Na+, K(+)-ATPase but an intensive one for CA, the PE cells of spiny dogfish are heavily stained for Na+, K(+)-ATPase in all regions of the eye, but show nearly no staining for CA.

BiotoecusEigenmann and Kennedy (Teleostei: Cichlidae): description of a new species from the Orinoco basin and revised generic diagnosis

Biotoecus dicentrarchus n.sp. is described from the upper and middle Rio Orinoco drainage in Colombia and Venezuela. The species is distinguished from all other cichlids by having only two anal fin spines and from its sole congener, the Amazonian Biotoecus opercularis (Steindachner), also by dorsal fin shape and count, colour pattern, more reduced dentary lateralis canal and lack of anguloarticular lateralis canal. A revised diagnosis of Biotoecus includes: (1) lack of interhypohyal ligament, (2) reduced lateral line system involving three instead of more lacrimal foramina, loss of infraorbital ossicles, fragmentary dentary canal, loss of distal extrascapular, flank lateral lines with pored instead of tubed scales except occasionally the first scale in the upper lateral line, loss of accessory caudal fin lateral lines, (3) long instead of short or diffuse anteromedial palatovomerine ligament, (4) extraordinarily long caudal peduncle (23·3–26·3% of SL) containing 9 vertebrae, and (5) dorsal fin count VII–I...

Mediastinal pseudomass: pneumonia and atelectasis behind the left pulmonary ligament.

In children, left lower lobe pneumonia posterior to the pulmonary ligament may mimic a paramediastinal mass. Over a period of 6 years we have seen 12 children with this unusual appearance, which we attribute to a peculiar type of atelectasis or infiltration of the left lower lobe or a segment of it. The radiographic appearance is thought to be the result of incomplete anchoring of the left lung by a short pulmonary ligament. The radiographic findings are demonstrated, and the benign clinical course is emphasized.

On the mode III failure of a long submerged defect

This paper analyses the elastic-perfectly plastic failure of a long uniform submerged defect offset from the centre of a uniform block under Mode III loading by a uniform remote longitudinal shear. The analysis confirms that the shorter of the two uncracked ligaments is the first to go fully plastic or to fracture. Solutions are found for the ligament yield load, the crack tip opening displacement (CTOD) and stress intensity factor at each tip, and the mean elastic stress on the shorter ligament. The results are calculated numerically and presented graphically: analytical results are available in the limit of very small remaining ligaments. The results of the Mode III analysis provide insight into the elastic-plastic behaviour of similarly cracked plates in Mode I loading under tension, and more generally illustrate some of the interactions between ‘local’ and ‘global’ plasticity during defect assessment.

The Fine Structure of the Stalk of the Pentacrinoid Larva of a Feather Star, Comanthus japonica (Echinodermata: Crinoidea)

AbstractThe stalk of the pentacrinoid larva of a feather star (Comanthus japonica) is described for the first time by transmission electron microscopy. One end of the stalk bears the calyx and the other end is cemented to the substrate by attachment cement consisting of a meshwork of 5 nm filaments. The stalk is supported by a scries of skeletal ossicles pierced by a central canal: short intercolumnal ligaments connect adjacent skeletal ossicles and central through‐going ligaments run the length of the central canal. At the end of the stalk nearest the calyx, the chambered organ and the closely associated axial organ are histologically similar to those of adult crinoids. Presumed neurosecretory neurons are associated with the intercolumnal ligaments, and the following kinds of nerves run down the central canal: (1) a large stalk nerve in each of the five interradii; (2) smaller coelomic nerves in each of the five radii in association with the epithelium of tubular aboral extensions of the chambered organ; (3) a very small nerve associated with the aboral extension of the axial organ in the stalk axis. This axial organ extension is surrounded by a haemal channel. Because of the small size of the stalk, none of the nerves or the haemal channel were described in previous light microscopic studies. The discussion gives special attention to the controversial motility of the pentacrinoid stalk.

Form and function of radioulnar articular disc

1. The human radioulnar articular disc is a shelf extended medially from articular cartilage on carpal facet of radius. 2. Its medial border is embedded in the wedge of vascular connective tissue which contains fine arcuate ligamentous bands joining the disc to the ulna and articular capsule. 3. The ventral and dorsal borders are loosely attached to short ligaments which go from radius to the inner surface of articular capsule. 4. These arrangements permit radius and disc to rotate on ulna freely during pronation and supination.

A Unigue Jaw Mechanism in the Echidna, Tachyglossus aculeatus (Monotremata)

The specialized tongue of the echidna functions in both capturing and grinding food. These processes can occur simultaneously because the echidna opens and closes its mouth by rotating the mandibles about their own long axes. This action translates the curvature of the attached rami into a downward movement commencing from a point just posterior to the corner of the mouth. Orthal hinge movements of the mandible are prevented by short ligaments which attach the horizontal ramus to the maxilla, and the position of the jaws is unchanged.

A Kinematic Jaw Model for the Rapid Wide Opening and the Closing of the Mouth in Some Labrinae (Pisces, Perciformes)

This paper is the third one of a series of articles (cf. VAN HASSELT, 1978, 1979a) on the morphology and the kinematics of the jaw apparatus of the labrid fishes Labrus berggylta Ascanius, Crenilabrus melops (L.), and Ctenolabrus rupestris (L.). These fishes show very rapid jaw movements during the catching of highly mobile prey (e.g., shrimps, small crabs). By the application of a deductive methodology, a kinematic qualitative jaw model was designed and developed to obtain a mechanism with very rapid, wide opening and rapid closing of the mouth brought about by a very small and relatively slow input movement, as well as closing of the protruded mouth. Premaxillary protrusion will be described in a separate paper. Once construction was begun with some assumptions or axioms, the development of the model progressed on the basis of simple kinematics and incorporation of topographical and biological demands and specifications. The main shape of the model became a symmetrical hollow pyramid-like configuration of essential structures arranged in the walls of the pyramid. These structures comprise a transverse axis of jaw rotation for each jaw at the jaw suspension, an articulating symphyseal line for transverse abduction and adduction, and a point for coupling between the upper and lower jaws. This is the basic model. Small adduction caused by the adducting suspensorium proves to be the most effective input movement for the rapid large jaw-rotations. In the labrids, the suspensorium-jaw apparatus shows adduction (VAN HASSELT, 1978). The location of these structures for the best working of the model appear to diverge somewhat from the positions in the basic model. In particular, the relatively stationary neurocranium and the ab-/adducting suspensorium demand different positions for the transverse axes. The model shows the upper-jaw axis and suspension in an area of minimal ab-/adductive movements, i.e., the area where the distal tips of the maxilla, the palatine, the nasal, and the lacrimal meet and are interconnected by a tangle of short ligaments. A safety mechanism is postulated to avoid any accidental rapid jaw action. In the model, the jaw axes appear to move slightly paramedially. A system with slightly approaching or separating jaw-axes causing rapid large jaw-rotations can be integrated into the basic-model system. A mechanical coupling between these two rapid systems reduces the need for muscles and nervous controls: the labrids have a ligament between the quadrate and the maxilla, and a movably connected suspensorium and palatine (in Ctenolabrus there is a narrow fusion) bearing the lower and upper jaw axes, respectively. The demands for the closing of a protruded mouth, with a maximal cavity inside a non-rotating protruded upper jaw, are incorporated into the basic-model system.

The Fabellofibular and Short Lateral Ligaments of the Knee Joint

The variations in size of the short lateral ligament, the occasional absence of the short lateral ligament, and the reasons for the presence of the fabellofibular ligament are indicated in this study. The short lateral ligament and the fabellofibular ligament are apparently homologous structures cor

AN IDEAL OPERATION FOR TOTAL PROLAPSE OF UTERUS

There persists, especially after several or instrumental labors, an elongation of the round ligaments and of the six consecutive-tissue ligaments associated with the uterus, and more especially the ligamenta cardinalia. There is deepening and sinking of the peritoneal pelvic recesses anterior and, especially, posterior to the uterus. Since the normal anteverted or anteflexed position of the uterine fundus is maintained only if the cervix is high up and far back, such descent of the cervix and fornices permits the fundus to drop back into retroversion, unless there be present unusually short and muscular round ligaments. Slight ptosis of the uterus may occur with the fundus in anteflexion or anteversion, but marked ptosis of the uterus implies an associated retrodeviation. A retroversion or slight retroflexion permits abdominal pressure, among other accessory factors, to cause a ptosis of severe degree. Ptosis does not occur if there are no lengthened ligaments; if the