The morphological variability of the piriformis muscle.

BACKGROUND: The aim of the study is to create several classifications of the piriformis muscle (PM): proximal and distal attachments, potential fusions, and the relationship with the sciatic nerve. It is the first comprehensive anatomical examination of this subject. MATERIALS AND METHODS: One hundred and twenty-four lower limbs from 62 cadavers, fixed in 10% formalin, were examined. RESULTS: The piriformis muscle was present in 120 limbs (96.8% of cases). Four types of proximal attachment were described (I-IV). The most common type was Type I, in which the proximal attachment was at the anterior surface of the sacrum, between S2 and S4 (52 lower limbs; 43.3%). The rarest type was Type IV, in which the proximal attachment was at the gluteal surface of the ilium near the margin of the greater sciatic notch and from the gluteus medius (12 cases; 10%). Three types of distal attachment were distinguished. The most common was Type 1, a single tendon. This type comprised two subtypes: A and B (105 lower limbs; 87.5%). The other two types accounted for 12.5% of the total. Fusions were noted between the piriformis muscle and adjacent muscles in 31.7%. Four patterns were observed in which the sciatic nerve ran against the piriformis muscle. The most common variation in the relationship was the common fibular nerve exiting superior to the piriformis muscle and the tibial nerve passing inferior to it (10 cases; 8.3%). CONCLUSIONS: The piriformis muscle is highly morphologically variable in both its proximal and distal attachments and its relationship with the sciatic nerve. There are four types of proximal attachment and three types of distal attachment. The piriformis muscle shows numerous fusions with its adjacent muscles: gluteus medius or minimus or superior gemellus. A new (fourth) type of relationship was demonstrated between the piriformis muscle and sciatic nerve. The piriformis muscle was absent in four cases.

Congenital, Acquired, and Trauma-Related Risk Factors for Thoracic Outlet Syndrome-Review of the Literature.

Thoracic outlet syndrome is a group of disorders that affect the upper extremity and neck, resulting in compression of the neurovascular bundle that exits the thoracic outlet. Depending on the type of compressed structure, the arterial, venous, and neurogenic forms of TOS are distinguished. In some populations, e.g., in certain groups of athletes, some sources report incidence rates as high as about 80 cases per 1000 people, while in the general population, it is equal to 2-4 per 1000. Although the pathogenesis of this condition appears relatively simple, there are a very large number of overlapping risk factors that drive such a high incidence in certain risk groups. Undoubtedly, a thorough knowledge of them and their etiology is essential to estimate the risk of TOS or make a quick and accurate diagnosis.

A very rare case report: accessory head of the sartorius muscle.

BACKGROUND: The sartorius muscle belongs to the anterior compartment of the thigh. Morphological variations of this muscle are very rare, few cases being described in the literature. MATERIALS AND METHODS: A 88 year-old female cadaver was dissected routinely for research and teaching purposes RESULTS: However, an interesting variation was found during anatomical dissection. The proximal part of the sartorius muscle had the normal course, but the distal part bifurcated into two muscle bellies. The additional head passed medially to the standard head; thereafter there was a muscular connection between them. This connection then passed into the tendinous distal attachment. It created a pes anserinus superificalis, which was located superficially to the distal attachments of the semitendinosus and gracilis muscles. This superficial layer was very wide and attached to the medial part of the tibial tuberosity and to the crural fascia. Importantly, two cutaneous branches of the saphenous nerve passed between the two heads. The two heads were innervated by separate muscular branches of the femoral nerve. CONCLUSIONS: Such morphological variability could be clinically important.

Clinical analysis of cavernous sinus anatomy, pathologies, diagnostics, surgical management and complications - Comprehensive review.

For decades, the cavernous sinus (CS) has been the subject of debates and scientific studies aimed at elucidating its anatomical variability, and at choosing the best method for accessing it so that optimal diagnoses and related surgical treatments can be decided. The present review considers a series of issues related to the CS. The anatomy of the CS and its features is explored first, and the most important structures, spaces and morphological variations are considered. This is followed by CS pathology and selected diagnostic methods that have proved useful in therapy, and then the management of these pathologies is discussed. Examples of therapeutic steps that have proved helpful in specific cases are taken from the literature. Finally, the various surgical accesses and complications that can be encountered during invasive interventions in the CS area are discussed. The aim of this study is to summarize up-to-date anatomical and clinical knowledge about the CS, citing the most informative scientific papers and aggregating their results. Morphological variations of the CS are common but have not been well described in the literature.

How to Differentiate Pronator Syndrome from Carpal Tunnel Syndrome: A Comprehensive Clinical Comparison.

The diagnostic process that allows pronator syndrome to be differentiated reliably from carpal tunnel syndrome remains a challenge for clinicians, as evidenced by the most common cause of pronator syndrome misdiagnosis: carpal tunnel syndrome. Pronator syndrome can be caused by compression of the median nerve as it passes through the anatomical structures of the forearm, while carpal tunnel syndrome refers to one particular topographic area within which compression occurs, the carpal tunnel. The present narrative review is a complex clinical comparison of the two syndromes with their anatomical backgrounds involving topographical relationships, morphology, clinical picture, differential diagnosis, and therapeutic options. It discusses the most frequently used diagnostic techniques and their correct interpretations. Its main goal is to provide an up-to-date picture of the current understanding of the disease processes and their etiologies, to establish an appropriate diagnosis, and introduce relevant treatment benefiting the patient.

Additional head of the rectus femoris muscle: a case report.

PURPOSE: The aim of the present case is to describe an interesting variation of the additional head of the rectus femoris. METHODS: A male body donor, 81 years old at death, was subjected to routine anatomical dissection for research and teaching purposes at the Department of Anatomical Dissection and Donation, Medical University of Lodz, Poland. RESULTS: We have found an example of an accessory head of the quadriceps femoris, a double-headed rectus femoris in which the proximal attachment is connected to the rectus femoris muscle originating from the anterior inferior iliac spine. The muscle belly of this additional structure is separate but fused distally with the vastus lateralis muscle. It then passes into the patellar ligament inserted into the tibial tuberosity. CONCLUSIONS: Knowledge of the possible occurrence of an additional head is nevertheless important for clinicians, especially for orthopedists performing reconstructive surgeries. It could also be significant for physiotherapists arranging rehabilitation plans after such surgeries because it could potentially help to achieve faster recovery.

Classification of the superior mesenteric artery.

The aim of this study was to characterize the branching pattern and morphology of the superior mesenteric artery (SMA), and also to create a new SMA classification, which seems necessary for clinicians performing surgery in this anatomical area. The anatomical variations in the branching patterns of the SMA were examined in 30 cadavers fixed in 10% formalin. Morphometric measurements were then obtained twice by two researchers. In the proposed classification system, Type I, characterized by all normal branches-inferior pancreatoduodenal artery, ileocolic artery, right colic artery, middle colic artery and intestinal arteries-occurred in 53.33% of the specimens. Type II, characterized by absence of the inferior pancreatoduodenal artery, was present in 26.67%. Type III, characterized by absence of the right colic artery, was present in 3.33%. Type IV, characterized by a common trunk for the inferior pancreatoduodenal artery and middle colic arteries, was observed in 3.33%. Type V, characterized by an aberrant hepatic artery and absence of the inferior pancreatoduodenal artery, was observed in 13.33%. The origin of the SMA was at the Th12/L1 level in 10% of cases, at L1 in 43.33%, at L1/L2 in 36.67%, and at L2 in 10%. The SMA is characterized by high morphological variability, the variants being associated with distinct clinical aspects. The introduction of a new, structured, anatomical classification seems necessary for all clinicians.

Clinical importance of variability in the branching pattern of the internal iliac artery - An updated and comprehensive review with a new classification proposal.

The main aim of this study is to present, describe and compare the most significant anatomical classifications of the internal iliac artery (IIA) and its branches, their pros and cons, to relate them to clinical practice and note their clinical importance, and to offer a new classification based on number of main vessels origins. Many classifications covering the detailed morphology of the IIA have been developed, focusing on the destination of vessels making it possible to determine the name and type of branching precisely. However, because the allocation criteria are overdetailed and of doubtful accuracy, these classifications have become impractical for clinical practice and advanced statistical calculations. The argument of this research paper is that highly variable vascularized regions should be classified from either an anatomical point of view to determine detailed morphology aspects or a clinical perspective. Presented classification proposes unification of many branching types presented among various classifications, which look identical when determining the origin pattern from the main vessel and differ only in the destination point of the vessel, what brings clarity and increases the statistical usefulness of the collected data. This should translate into better cooperation between scientists and clinicians and thus benefit patients. The paper proposes a new, clinically useful classification based on the model of vessel origins from the main stem. The IIA is the main vascular supply to the pelvic region, so precise knowledge of origin and its branching pattern is essential for all clinicians, especially for general and orthopaedic surgeons, gynecologists, obstetricians and urologists.