Revisiting the inferior supports of Chopart joint complex

Aims

The Chopart joint complex is a joint between the midfoot and hindfoot. The static and dynamic support system of the joint is critical for maintaining the medial longitudinal arch of the foot. Any dysfunction leads to progressive collapsing flatfoot deformity (PCFD). Often, the tibialis posterior is the primary cause; however, contrary views have also been expressed. The present investigation intends to explore the comprehensive anatomy of the support system of the Chopart joint complex to gain insight into the cause of PCFD.

Methods

The study was conducted on 40 adult embalmed cadaveric lower limbs. Chopart joint complexes were dissected, and the structures supporting the joint inferiorly were observed and noted.

Results

The articulating bones exhibit features like a cuboid shelf and navicular beak, which appear to offer inferior support to the joint. The expanse of the spring ligament complex is more medial than inferior, while the superomedial part is more extensive than the intermediate and inferoplantar parts. The spring ligament is reinforced by the tendons in the superomedial part (the main tendon of tibialis posterior), the inferomedial part (the plantar slip of tibialis posterior), and the master knot of Henry positioned just inferior to the gap between the inferomedial and inferoplantar bundles.

Conclusion

This study highlights that the medial aspect of the talonavicular articulation has more extensive reinforcement in the form of superomedial part of spring ligament and tibialis posterior tendon. The findings are expected to prompt further research in weightbearing settings on the pathogenesis of flatfoot.

Muscle Architecture of Leg Muscles: Functional and Clinical Significance

Background

Architectural properties of the muscles are the prime predictors of functional attributes and force-generating capacity of the muscles. This data is vital for musculoskeletal modelling and selecting the appropriate muscle-tendon units for tendon transfers.Cadaveric data for architectural properties is the gold standard and primary input for musculoskeletal modelling. There is a paucity of these datasets, especially in the leg muscles.

Methods

Sixty muscles of the anterior and lateral compartments from twelve formalin-fixed lower limbs were studied for gross architecture, including the peculiar fibre arrangements and architectural properties of muscles. Muscle weight, muscle length, fibre length, pennation angle and sarcomere length were measured. Normalised fibre length, fibre length to muscle length ratio (FL/ML ratio), and the physiological cross-sectional area (PCSA) were calculated from the obtained data.

Results

Muscles displayed a combination of architectural strategies and were partly fusiform and partly pennate. The tibialis anterior and peroneus longus were the heaviest muscles in their respective compartments and showed more extensive origin from the nearby deep facial sheets.Long fibre length and less pennation angle were seen in muscles of the extensor compartment. Potential muscle power was highest in the tibialis anterior and peroneus longus and least in the extensor hallucis longus.

Conclusions

Arching of the foot and eversion are peculiar to humans and recent in evolution. Due to the functional demand of maintaining the medial longitudinal arch and eversion, the tibialis anterior and peroneus longus have more muscle weight and larger physiological cross-sectional area and are potentially more powerful.Extensor compartment muscles were architecturally more suited for excursions because of the long fibre length and less pennation angle.This study contributes baseline normative data for musculoskeletal modelling platforms and simulation tools - an emerging area in biomechanics and tendon transfers.

Subcutaneous Dorsomedial Triangle of Forearm: Surgical Anatomy and Clinical Implication

Background The purpose of the study was to provide a practical landmark for localizing the dorsal branch of the ulnar artery and nerve, to approach for microsurgical flaps, for harvesting nerve grafts and also to avoid these nerves during insertion of wrist arthroscopy portals. Material and methods Forty adult cadaveric upper limbs (20 right and 20 left) were dissected for localizing the dorsal branches of the ulnar artery and nerve. The ramification patterns of the nerve were mapped. The wrist arthroscopy portals are located radial and ulnar to the tendon of extensor carpi ulnaris at the level of the wrist joint, and their designated names are '6R & 6U', respectively. The distance of branches of the nerve from the 6U and 6R portals for wrist arthroscopy was recorded. Results The present study has delineated a subcutaneous dorsomedial triangular area in the distal forearm. The construction of this triangle uses palpable landmarks, i.e. pisiform bone, styloid process and subcutaneous border of the ulna. The measure of the sides of the triangle uses proportion rather than absolute measurements and hence is person specific. The dorsal branches of the ulnar nerve and artery are consistently given off in the triangle's upper third and middle third, respectively. Four branching patterns have been mapped, with one dominant pattern in 67.5% of limbs. In three-fourths of cases, one branch of the dorsal branch of the ulnar nerve consistently overlies the 6U portal and hence runs a higher risk of injury. Conclusion The study suggests more practical, accurate, reliable and consistent surface landmarks for the localization of the dorsal branch of the ulnar artery and nerve for reconstructive microsurgery for distal hand defects.

Support system of Lisfranc joint complex: An anatomical investigation with an evolutionary perspective

BACKGROUND

The anatomical arrangement of the Lisfranc joint between the midfoot and forefoot is complex and not just critical for bipedal gait but also for prevention, management, and rehabilitation of injuries in this region.

MATERIAL AND METHODS

In forty adult cadaveric lower limbs, the Lisfranc mortise, the ligaments and supports were observed and noted.

RESULTS

The structural arrangement that accords stability to the joint has osseous, ligamentous, and tendinous components. A bony mortise, which is deep medially, disrupts the linearity of the joint line. An extensive Lisfranc ligament with confluent interosseous and plantar parts was observed. Tibialis posterior, peroneus Longus and Lisfranc ligament exhibit a unique anatomical arrangement that supports the joint inferiorly.

CONCLUSION

The study documents a unique lattice of tendons and ligament offering dynamic support to the joint. Demands of assumption of erect posture and bipedal walking in humans like adduction of the first ray of the foot, maintenance of longitudinal and transverse arches of the foot and ability stiffen midfoot for efficient forefoot take-off are well reflected in the joint structure and supports.

New insights in anterior cruciate ligament morphology: implications for anterior cruciate ligament reconstruction surgeries

The frequency of injury of anterior cruciate ligament (ACL), the importance of anatomy in surgical repair and potential of the injured ACL to predispose to osteoarthritis necessitates the need for understanding its precise anatomy. Available studies have focussed on tunnel positioning and hence attachment site of the ligament. Few studies which have focussed on morphology reflect ambiguities in size, fibre bundle, number and disposition. Since a near anatomical repair of the ACL is the treatment of choice, the present study was planned to describe the morphology of ACL. Twenty-two ACL (11 right and 11 left) isolated from knee joints of collection of adult embalmed lower limbs were utilised for the study. The ACL morphology and morphometry were studied for footprints and fibre bundles. Three distinct bundles of differing lengths constitute a spiral ACL complex. These bundles are positioned as- intermediate with posteromedial and anterolateral flanking in respective positions. The tibial and femoral footprints are paw-shaped and oval respectively. Tibial footprints are approximately 2.5 times larger in area than the femoral footprints. The unique morphology of ACL vis a vis its spiralization, and its mechanical advantage of in terminal extension and conjunct rotation of knee (which are peculiarly human trait) are discussed. It is recommended to utilize the concept of spiralization and differing bundle length in ACL surgeries to achieve the favourable clinical outcome.

Changing medical education scenario: a wakeup call for reforms in Anatomy Act

Background

Anatomy Act provides legal ambit to medical educationists for the acquisition of cadavers. The changing medical education scenario, socio-demographic change, and ethical concerns have necessitated an urgent review of its legal and ethical framework. Suitable amendments addressing the current disparities and deficiencies are long overdue.

Methods

Anatomy Act in India is a state Act, which ensures the provision of human bodies for medical education and research.

The methodology included three components namely:

Comparison of various Anatomy Acts clause by clause,

Feedback from anatomists, and

Formulation of comprehensive model Anatomy Act.

Results

Various Acts studied showed discrepancies in the purpose of the Act, roles and duties of stakeholders, regulation for body donation, the procedure to handle unclaimed bodies, disposal of dissected bodies, etc. No Act defines a donor and neither addresses the issue of transport of anatomical material. Only ten states have a clause for body donation. Acts of only six states have been amended over the last 50 years. Three states denied having an Act. The whole exercise of review of Acts, extensive feedback received from end-users, and taking into account global good practices, culminated in drafting a comprehensive model Anatomy Act founded on ethical principles.

Conclusion

India, with the largest number of medical colleges, is not only at the forefront but also a hub of medical education in the Southeast Asia region. Legal reform can be a torchbearer to promote ethical and transparent practices for obtaining cadavers for other countries of the region with similar socio-demography and shall also motivate anatomic fraternity across the globe for critical analysis of their respective Anatomy Acts.

Terminal Condylar Facets of the Femur: Implications for Knee Arthroplasty

In wake of changing lifestyle and increasing surgical expertise, knee replacement surgeries have become common. Attempts at improving the postoperative range of motion have prompted high-flexion knee arthroplasties. Consequently, there is a need to study the anatomy of knee joint in high flexion. This study focused on a holistic description of terminal condylar articular facet (TCAF; part of the femoral articular area in contact with the tibia in high flexion) of medial and lateral condyles and their quantification. In total, 104 dry femora and 16 dissected cadaveric knee joints (10 adult and 6 fetal) were studied. In most cases, the medial TCAF showed a tongue- or wedge-shaped extension in its lateral half, which has been referred to as extended condylar facet (ECF). The surface area of the ECF was approximately 0.5 cm². In adult cadaveric dissections, the fibrous capsule showed the lax attachment beyond the ECF, thus creating a cave in the medial tibiofemoral compartment. These features were absent in fetal dissection. The presence of an ECF has not been documented in dry bones and has not been quantified. The variability of the size of this extension supports the hypothesis of this being an acquired trait. This study is expected to provide factual data for implant design improvement and a new anthropological data on Indian femora.

Is tricuspid valve really tricuspid?

Advancement in imaging techniques and interventional cardiology procedures have generated renewed interest in anatomy of tricuspid valve complex. The purpose of the present study was to characterize the morphology of tricuspid valve leaflets using objective criteria. Thirty-six embalmed cadaveric hearts were utilized for the present study. Leaflet morphology was studied using newly defined criteria. Commissural zones were identified and leaflets were delineated. Presence of scallops was also recorded. Single leaflet was observed in six cases, double in 26 cases, and triple in four cases. The anterior leaflet is large with multiple scallops and frequently accrues portion of inferior leaflet. The septal leaflet is in the form of a plateau and also frequently accrues parts of inferior leaflet. The inferior leaflet rarely occurs as independent leaflet. A wide un-indented basal zone exists across the valve leaflets. The study found that the tricuspid valve is rarely tricuspid. It also generated the hypotheses that the tricuspid valve does not open completely due to presence of a wide basal zone and the valve does not close completely owing to incongruence and lack of coaptation of leaflets. The findings provide clear understanding of leaflet morphology of tricuspid valve. This will help imaging specialists for interpretation of images and cardiologists for interventional procedures. The findings also enhance our understanding of pathophysiology of conditions like functional tricuspid regurgitation.

Cadaveric Study of Mode of Termination of Gonadal Veins: Implications for Procedures Utilizing Terminal Ends of Gonadal Veins as Entry Portals

CONTEXT

The terminal ends of gonadal veins act as an entry portal in gonadal embolization procedures used for treating varicocele in males and pelvic congestion disease in females. Here, we studied the modes of termination of gonadal veins in adult cadavers.

MATERIALS AND METHODS

Thirty-five adult formalin-fixed cadavers (seventy sides) were studied over a period of 4 years. The modes of termination of gonadal veins were observed under the following study variables: (a) number, (b) locale of termination, and (c) termination angle.

RESULTS

Variations in study parameters were observed in eight sides of seven cadavers (seven unilateral and one bilateral). Double veins at termination were observed in six cadavers; anomalous termination was observed in three cadavers. Angle of termination differed from normal in 3 cadavers. In one of these cadavers, the left ovarian vein drained into the left suprarenal vein.

CONCLUSION

Duplication of terminal ends, anomalous drainage site, and varied angles of termination call for caution to ensure the success of procedures, which use terminal ends of gonadal veins as entry portals.

A Rare Anomaly of Duodenum: A Case Report

 Anatomical variations of duodenum such as atresia, stenosis, and variations in shape have been described by various authors, but the existence of a gross anomaly in shape and position of midgut segment of the duodenum is rare. Few reported cases of duodenal anomalies date back to early twentieth century. In the wake of advancement of imaging techniques and minimal access surgeries, authors report a case of a rare duodenal anomaly. The reported case assumes significance because of thepossibility of misinterpretation of radiological images which has been discussed while citing such references. The present case reports an anomaly of the position of the midgut segment of the duodenum in an adult female cadaver. It was observed that the lower half of second part of duodenum was coiled like a serpent on the upper pole of right kidney. This part coursed initially upwards running parallel and to the right of the upper half of the second part of the duodenum. The third part coursed downwards and to the left, posterior to head and neck of pancreas, in its course sandwiching the commencement of portal vein.

Rectus and oblique muscles of eyeball: a morphometric study of Indian population

During the strengthening and weakening procedures of intraocular muscles, distance of insertion from the sclerocorneal junction is an important determinant in the identification of muscles. During repositioning of the aponeurosis of the muscles, it is desired that the width should not change in order to avoid diversion of forces. Available anatomic studies on insertions of extraocular muscles are few, date back to early twentieth century and have been conducted on mostly white population. The present study is an attempt to document the insertions of recti and oblique muscles in Indian population. Forty eyeballs were removed from orbit. Insertion of recti and obliqui were cleaned and eyeballs were perfused with normal saline to regain the volume (hence shape and size) before recording observations. Insertion of recti and obliqui muscles were observed under various study parameters. The distance of insertion of recti from the limbus were found to be 7.3 mm, 8.06 mm, 8.71 mm, and 8.74 mm for medial, inferior, lateral, and superior rectus, respectively. The superior oblique was aponeurotic and found to be more variable in mode of insertion as compared to inferior oblique which had a fleshy and relatively constant insertion. The observations on insertion of recti and obliqui as obtained in present study differ from earlier studies to the tune of 1-1.5 mm. This may be attributed to adoption of method of reperfusion of eyeball before recording observations thus maintaining size close to in vivo. The observations are expected to be closer to actual.

Right Double Inferior Vena Cava (IVC) with Preaortic Iliac Confluence - Case Report and Review of Literature

Anomalies of the inferior vena cava (IVC) are uncommon and most of them remain asymptomatic. Though rare, anomalies of IVC can lead to severe hemorrhagic complications especially during aortoiliac surgery. Prior knowledge of these variations facilitates proper interpretation of radiological images and safe performance of interventional procedures and surgeries. During routine anatomical dissection of abdomen in a female cadaver we observed the presence of right sided duplication of IVC. Both IVCs were present on the right side of abdominal aorta, one ventral and the other more dorsal in position and named ventral right IVC and dorsal right IVC. The ventrally and medially placed IVC, which appeared to be the main IVC was formed by the union of two common iliac veins in front of the right common iliac artery (Preaortic iliac confluence-"Marsupial Cava"). The right external iliac vein continued as the more dorsally and laterally placed dorsal right IVC. The right internal iliac vein after receiving a transverse anastomotic vein from the external iliac continued as the right common iliac vein. This transverse anastomosis was present behind the right common iliac artery. The narrower dorsal right IVC joined the wider ventral right IVC just below the level of renal veins to form a single IVC. The abdominal aorta presented a convexity to the left.

Study of position, shape, and size of mental foramen utilizing various parameters in dry adult human mandibles from north India

Background. As the mental foramen (MF) is an important landmark to facilitate surgical, local anesthetic, and other invasive procedures, the present study was aimed to elucidate its morphological features and morphometric parameters with reference to surrounding landmarks. Material and Method. 105 dry adult human mandibles of unknown sex were observed for position, shape, and number of mental foramina. Their size was measured using a digital vernier caliper and statistically analyzed by mean and standard deviations (SD). Results. In most cases (74.3%), the MF was oval in shape and situated on the longitudinal axis of the 2nd premolar tooth (61% on right side and 59.1% on left side). The mean distance for the right and left sides was measured from various landmarks. Conclusion. Prior knowledge of mental foramen variations helps surgeons in planning surgery in that region to avoid nerve damage and also enable effective mental nerve block anesthesia.

Expression and secretion of the beta subunit of human chorionic gonadotropin by bladder carcinoma in vivo and in vitro

Expression and secretion of the beta subunit of human chorionic gonadotropin (hCG) by bladder carcinoma cell lines were investigated in vitro and in vivo. As an in vitro study, immunoreactive hCG beta (IR-hCG beta) secreted into the culture media of two bladder transitional cell lines (KoTCC-1 and HT-1197) was analyzed using three kinds of enzyme immunoassays which were specific for intact hCG, free hCG beta, and beta core fragment (beta-CF). Both of the cell lines were determined to secrete IR-hCG beta into the media, which consisted principally of free hCG beta, but detectable levels of intact hCG and beta-CF were not present in the media. Northern blot analysis revealed that the hCG beta gene was expressed in both KoTCC-1 and HT-1197 cells where the sizes of mRNA from these cells were smaller than those from placental and NJG choriocarcinoma cells. As an in vivo study, distribution of IR-hCG beta was analyzed in the tumor tissues, sera, and urine of the mice and the rats transplanted with KoTCC-1 cells. By the immunohistochemical study, the IR-hCG beta was clearly observed in transitional cell carcinoma cells of the transplanted tumor. High levels of IR-hCG beta were detected in both the serum and urine from the animals, but there were quantitative and qualitative differences between serum and urinary IR-hCG beta. Quantitatively, the concentrations of IR-hCG beta in the urine were consistently much higher than those in the serum. Qualitatively, free hCG beta was exclusively detected in the serum whereas high levels of beta-CF in addition to free hCG beta were found in the urine. Intact hCG could not be detected in the serum and urine. These distributions of IR-hCG beta in the animals transplanted with KoTCC-1 cells were completely analogous to those in a patient with hCG beta-producing bladder carcinoma. The present study shows that the same metabolic pathway of IR-hCG beta is operating in mice and rats as in humans, indicating that IR-hCG beta found in patients with bladder carcinoma originates from the tumor and it may be recognized as a tumor marker when beta-CF is measured in the patient's urine.

Comparative nucleotide and amino acid sequence analysis of the sequence-specific RNA-binding rotavirus nonstructural protein NSP3

NSP3, an acidic nonstructural protein, encoded by gene 7 has been implicated as the key player in the assembly of the 11 viral plus-strand RNAs into the early replication intermediates during rotavirus morphogenesis. To date, the sequence of NSP3 from only three animal rotaviruses (SA11, SA114F, and bovine UK) has been determined and that from a human strain has not been reported. To determine the genetic diversity among gene 7 alleles from group A rotaviruses, the nucleotide sequence of the NSP3 gene from 13 strains belonging to nine different G serotypes, from both humans and animals, has been determined. Based on the amino acid sequence identity as well as phylogenetic analysis, NSP3 from group A rotaviruses falls into three evolutionarily related groups, i.e., the SA11 group, the Wa group, and the S2 group. The SA11/SA114F gene appears to have a distant ancestral origin from that of the others and codes for a polypeptide of 315 amino acids (aa) in length. NSP3 from all other group A rotaviruses is only 313 aa in length because of a 2-amino-acid deletion near the carboxy-terminus. While the SA114F gene has the longest 3' untranslated region (UTR) of 132 nucleotides, that from other strains suffered deletions of varying lengths at two positions downstream of the translational termination codon. In spite of the divergence of the nucleotide (nt) sequence in the protein coding region, a stretch of about 80 nt in the 3' UTR is highly conserved in the NSP3 gene from all the strains. This conserved sequence in the 3' UTR might play an important role in the regulation of expression of the NSP3 gene.

Involvement of H1 and other chromatin proteins in the formation of DNA-protein cross-links induced by visible light in the presence of methylene blue

The formation of DNA-protein cross-links (DPCs), induced by irradiation with visible light, was studied in methylene blue-treated (MB-treated) chromatin and H1-depleted chromatin. The effects of the MB concentration and radiation dose were studied using sodium dodecylsulphate-chloroform-isoamyl alcohol assay and sodium dodecylsulphate-polyacrylamide gel electrophoresis. Under identical experimental conditions, DPC formation was less in H1-depleted chromatin (70%) than in chromatin (92%). The non-histone proteins and core proteins of chromatin contributed towards DPC formation. Of the core proteins, H2A was more cross-linked than H4, whereas the bands for H2B and H3 melted into one in chromatin and H1-depleted chromatin. In both cases, the gel pattern showed the appearance of two new protein bands with approximate molecular weights of 27 kDa and 29 kDa as a result of histone-histone cross-linking. Viscometric studies showed that the dissociation of the compact structure of chromatin in 2 M NaCl was more extensive in irradiated, MB-treated, H1-depleted chromatin than in irradiated, MB-treated chromatin, indicating a reduction in the amount of DPC formation in H1-depleted chromatin.

Visible light induced DNA-protein crosslinking in DNA-histone complex and sarcoma-180 chromatin in the presence of methylene blue

Formation of DNA-protein cross-links by the action of visible light in the presence of methylene blue was studied in calf thymus DNA-calf thymus histone complex and sarcoma-180 chromatin. The extent of cross-link formation decreases with a decrease in the histone to DNA ratio in the DNA-histone complex. In chromatin, it is at a maximum (93%) at a dye to DNA nucleotide ratio (D/P ratio) of 0.04 and is appreciable even at a very low dye concentration (75% at a D/P ratio of 0.0033). Sepharose 4B-CL column chromatography indicates that methylene blue acts as a mediator in the cross-linking process, but not as a linker in the DNA-protein cross-link. Dodecylsulphate-polyacrylamide gel electrophoresis patterns reveal that both histone and non-histone proteins are involved in cross-linking, but to a varied extent. Competition experiments with ethidium bromide demonstrated the necessity of intercalative binding of methylene blue in the formation of DNA--protein cross-links. Viscometric studies in 2 M NaCl indicate that the compact structure of chromatin is stabilized by cross-linking.