Anatomical variations of the calcaneofibular ligament in human foetuses.

Ligaments anatomy often show a huge anatomy variations between species and individuals. For example calcaneofibular ligaments (CFL) characterize the great variability of morphological shape or presence of additional bands. The aim of this study was to propose first anatomical classification of CFL concerning on human fetuses. We investigated thirty spontaneously-aborted human fetuses aged 18-38 weeks of gestation at death. Sixty lower limbs (30 left and 30 right) fixed in 10% formalin solution were examined. The morphological variability of CFL was assessed. Four types of CFL morphology were observed. Type I was characterized by a band shape. This was the most common type, occurring in 53% of all cases. Based on our study we are proposing a classification based on four morphological types of CFL. Types 2 and 4 are further divided into subtypes. Present classification may be useful to better understand the anatomical development of ankle joint.

Five-headed superior omohyoid.

The omohyoid is an infrahyoid muscle with two bellies. It is responsible for lowering and positioning of the hyoid bone. It is morphologically variable in the origin, insertion and morphology of its bellies. Quantitative variations of the superior belly of the omohyoid muscle are not common. We present a case of a five-headed superior omohyoid, and a short clinical review related to this muscle. All the bellies had their origin in an intermediate tendon and were attached to the hyoid bone. The volume of its superior part was greater than usual. Knowledge of the anatomy of this muscle is important, especially for surgeons operating in the anterolateral neck region.

Embryological approach to the morphology of the ligamentum mucosum of the human knee joint.

PURPOSE: The ligamentum mucosum is a ligamentous structure within the synovial layer of the knee joint capsule. It usually arises from the infrapatellar fat pad and is inserted into the intercondylar notch of the femur. In recent years, more attention has been paid to this structure because of its clinical significance. Despite the growing attention, the complex morphology of the ligamentum mucosum has led to many misunderstandings among the scientists and clinicians. Therefore, the main objective of this study was to characterize the morphology of the ligamentum mucosum and its attachment points, classify it, and evaluate its prevalence. METHODS: Classical anatomical dissection was performed on 70 lower limbs of human fetuses fixed in 10% formalin solution. Morphology was carefully assessed, and morphometric measurements were performed. The types revealed were classified. RESULTS: The ligamentum mucosum was present in 100% of all 70 specimens examined. Two types were detected. Type I (65.71%) - "cord-like". This type was the most common and is characterized by a single longitudinal ligament. The proximal attachment of the ligamentum mucosum was located in the middle of the infrapatellar fat, and the distal attachment was at the tip of the intercondylar notch. Type II (34.29%) - "vertical septum". This type is less common, but its morphology is much more complex compared to type I. It is wider and thicker than type I. Proximally, it is attached to the infrapatellar fat pad and distally through the entire intercondylar notch down to the anterior surface of the anterior cruciate ligament. It divides the joint cavity into medial and lateral sides. CONCLUSION: The ligamentum mucosum exhibits high morphologic variability, and the view that it is a vestigial remnant of the embryologic development of the knee should be reconsidered. We have proposed an anatomical classification of its types in human fetuses, which is a valuable addition to existing knowledge and will hopefully change the approach of clinicians and scientists.

Case report of a bifurcated fibular (lateral) collateral ligament: which band is the dominant one?

BACKGROUND: The fibular collateral ligament is a permanent and extracapsular ligament of the knee joint. It is located on the lateral aspect of the knee and extends from the lateral epicondyle of the femur to the lateral surface of the head of the fibula. As one of the main knee joint ligaments it is a stabilizer of the posterolateral corner of the knee and resists varus stress. The case report displays the bifurcated variant of the fibular collateral ligament. The aim of this study is to determine which of those bands should be considered dominant. MATERIALS AND METHODS: Classical anatomical dissection was performed on the left knee joint. The fibular collateral ligament was thoroughly cleansed around its origin, distal attachments, and course. Appropriate morphometric measurements were collected. RESULTS: A bifurcated variant of the fibular collateral ligament with inverted proportions of its two bands (main and accessory one) constitutes our findings. It originated on the lateral epicondyle of the femur. Then it divided into two bands (A1 and A2). Band A1 inserted to the head of the fibula. A bony attachment of band A2 was located on the lateral aspect of the lateral condyle of the tibia. CONCLUSIONS: Although the fibular collateral ligament is a permanent structure it presents morphological variations. It is important to constantly extend morphological knowledge for all scientists concerned in anatomy.

Is the plantaris muscle the most undefined human skeletal muscle?

The plantaris muscle is located in the posterior aspect of the superficial compartment of the lower leg, running from the lateral condyle of the femur to the calcaneal tuberosity. Classically, it is characterized by a small and fusiform muscle belly, which then changes into a long slender tendon. From the evolutionary point of view, the muscle is considered vestigial. However, it has recently been suspected of being a highly specialized sensory muscle because of its high density of muscle spindles. It has a noticeable tendency to vary in respect of both origin and insertion. Researchers have published many reports on the potential clinical significance of the muscle belly and tendon, including mid-portion Achilles tendinopathy, 'tennis leg syndrome', and popliteal artery entrapment syndrome. The right knee joint area was subjected to classical anatomical dissection, during which an atypical plantaris muscle was found and examined in detail. Accurate morphometric measurements were made. The muscle belly was assessed as bifurcated. Morphologically, superior and inferior parts were presented. There was a tendinous connection (named band A) with the iliotibial tract and an additional insertion (named band B) to the semimembranosus tendon. Both bands A and B presented very broad fan-shaped attachments. The human plantaris muscle is of considerable interest and has frequent morphological variations in its proximal part. Its specific characteristics can cause clinical problems and lead to confusion in diagnosis. More studies are needed to define its actual features and functions.

"Popliteofascial muscle" or rare variant of the tensor fasciae suralis?

Anatomical variations are routinely encountered during dissections of muscles and in clinical practice, so anatomists and clinicians need to be aware of them. One such muscle is the tensor fascia suralis, a very rare muscle located in the popliteal fossa. It can originate from any of the hamstring muscles and it inserts into the fascia of the leg. This report presents a case of a variant muscle located very deep to the biceps femoris; it originated from the posterior surface of the femur and inserted into the fascia of the leg. It is unclear whether this is a rare variant of the tensor fascia suralis or a completely new muscle.

Possible effect of morphological variations of plantaris muscle tendon on harvesting at reconstruction surgery-case report.

PURPOSE: Seemingly a well-known, weak, and vestigial plantaris muscle should not be a revelation. However, recent studies have shown that this structure is incredibly underestimated and perceived only as an infirm flexor of the talocrural joint, the knee joint or a great source of graft tissue. Usually, the origin of this inconspicuous muscle begins at the lateral supracondylar line of the femur and the knee joint capsule. It continues distally, forming a long and slender tendon. In most cases, it inserts onto the calcaneal tuberosity on the medial side of the Achilles tendon. However, many morphological variations have been discovered during anatomical dissections and surgical procedures. Nevertheless, according to the present literature, no other studies presented such a complex insertion variant, with indisputable clinical value and significant proof of development of this forgotten muscle. METHODS: The dissection of the right thigh, knee, crural and talocrural region was performed using standard techniques according to a strictly specified protocol. RESULTS: Four different insertion points were observed. The first band (A) inserted near to the tarsal canal flexor retinaculum. The second band (B) bifurcates into two branches-B1 and B2. B1 is located on the medial side and B2 is located on the lateral side of the calcaneal tuberosity. The third band (C) is inserted into the superior nonarticular calcaneal surface of the calcaneus anteriorly to the Achilles tendon. CONCLUSION: A differently shaped plantaris tendon could be considered a cause of harvesting procedure failure. In the light of new case reports perhaps what we are now witnessing is remodeling and transformation of the Plantaris muscle. If so, the awareness of the influence on the onset of Achilles midportion tendinopathy or a potential role in tibialis posterior conflict can be crucial for every clinician.

A highly complex variant of the plantaris tendon insertion and its potential clinical relevance.

The body is home to a number of unique and intriguing anatomical structures, plenty of which concern the muscles and their tendons. Of these, the plantaris muscle is reported to present a particularly high range of morphological variations. The muscle, passing distally throughout the length of the lower leg, consists of a small muscle belly and a long, thin tendon. It originates, traditionally, on the popliteal surface of the femur and the knee joint capsule, and then inserts to the calcaneal tuberosity. It has been suggested that mid-portion Achilles tendinopathy may be caused by certain plantaris tendon morphologies. This case report describes a new anomalous plantaris tendon insertion, closely related to the Achilles tendon. It comprise four distinct insertions and one direct merge with the calcaneal tendon. The current classification should be extended to accommodate such 'rare cases' to facilitate more successful Achilles tendinopathy treatment.

Intramuscular innervation of plantaris muscle evaluated using a modified Sihler's staining protocol - Proposal for a new classification.

PURPOSE: The plantaris muscle is a morphologically variable structure with regard to both its origin and insertion, and the course of the tendon. We here determined the pattern of branching and distribution of intramuscular nerves of the plantaris muscle to determine its usability for autologous transplantation. No information exists on the innervation of the plantaris muscle using Sihler's staining technique, and hence its intramuscular nerves. The main purpose of the work is to determine the pattern of branching and distribution of the intramuscular nerves of the plantaris muscle. Is the plantaris muscle a good transplant candidate? MATERIALS AND METHODS: Eighty lower limbs from cadavers (40 left, 40 right, 40 male, 40 female, age range 41-94 years) were fixed in 10% formalin solution and examined macroscopically as well as morphometrically with regard to the innervation pattern of the respective plantaris muscle. Afterwards Sihler's staining was used in all 80 plantaris muscles to identify the exact distribution of the muscular branch originating from the main nerve trunk in the muscle belly. RESULTS: Two patterns of branching and nerve distribution could be intensified in the plantaris muscle: Type I, with a single pattern entire up to the muscle and then divided into superior and inferior intramuscular branches.; type II with a double innervation pattern (superior and inferior). The superior and inferior pattern were not connected to each other. CONCLUSION: The plantaris muscle reveals variability with two different innervation patterns. Type II is ideally suited for autologous transplantation. New classifications of innervation are desirable for individual muscles rather than a generalized approach.

Proposal for a new classification of plantaris muscle origin and its potential effect on the knee joint.

PURPOSE: The plantaris muscle (PM) is typically characterized by a short, slim and spindle-shaped muscle belly and long, thin tendon. It is situated posterior to the popliteal muscle, and anterior to the lateral head of the gastrocnemius muscle (GM). Little information exists regarding the high variability of origin of the PM. The main aim of the study was hence to characterize the morphology of the PM and its place of origin, classify it and evaluate its prevalence. METHODS: Classical anatomical dissection was performed on 142 lower limbs (77 left, and 65 right) fixed in 10% formalin solution. The morphology of the origin of the PM and its prevalence was evaluated. RESULTS: The PM was present in 128 lower limbs (90.1%). Six types of origin were observed, the most common being Type I (48.4%). This type was divided into two subtypes (A-B): subtype A attaching to the lateral head of the GM, lateral femoral condyle and to the capsule of the knee joint, and subtype B, attaching to the lateral head of the GM, the lateral femoral condyle, knee joint capsule and the popliteal surface of the femur. The second most common type was Type II (25%), attaching to the capsule of the knee joint and, indirectly, to the lateral head of the GM through the lateral femoral condyle. The third most common type was Type III (10.15%), attaching to the lateral femoral condyle and the knee joint capsule. Type IV (6.25%), the rarest type, attached to the lateral femoral condyle, knee joint capsule and to the iliotibial band. Type V (8.6%) originated only from the lateral condyle of the femur. Type VI (1.6%) contains only "rare cases". CONCLUSION: The PM presents high morphological variability, and its status as a residual muscle should be reconsidered. Our presented classification of its types of origin is a valuable addition for both clinicians and anatomists. Level of Evidence - II Basic Science Research.

Genotoxicity of air pollution in a non-ferrous metal foundry in three bacterial tests and a micronucleus test--a comparative study.

Acetone extracts of dusts and fumes collected at workplaces in a non-ferrous metal foundry exhibited genotoxic activity in all of the tests used. Of the compared tests, the Ames method is the most useful for preliminary screening detection of the genotoxic agents that are present in acetone extracts of dusts and fumes emitted at workplaces in a non-ferrous metal foundry.