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Anatomical variants of peripheral nerves of the lower limb are relatively frequent and vulnerable to injury if not considered by the surgeon. Surgical procedures or percutaneous injections are often performed without knowing the anatomical situation. In a patient with normal anatomy, these procedures are mostly performed smoothly without major nerve complications. But in the case of anatomical variants, surgery may be challenging as “new” anatomical prerequisites complicate the procedure. In this context, high-resolution ultrasonography as the first-line imaging modality to depict peripheral nerves, has become a helpful adjunct in the preoperative setting. It is crucial, on the one hand, to gain knowledge of anatomical nerve variants and, on the other hand, to depict the anatomical situation preoperatively, to minimize the risk of surgical trauma to a nerve and make surgeries safer.

It has been assumed that connections between the postparotid terminal branches of the facial nerve are purely motor. However, the nature of their fibers remains unexplored. The aim of this study is to determine whether these connections comprise motor fibers exclusively. In total 17 connections between terminal facial nerve branches were obtained from 13 different facial nerves. Choline acetyltransferase antibody (ChAT) was used to stain the fibers in the connections and determine whether or not all of them were motor. All connections contained ChAT positive and negative fibers. The average number of fibers overall was 287 (84–587) and the average proportion of positive fibers was 63% (37.7%–91.5%). In 29% of the nerves, >75% of the fibers were ChAT+ (strongly positive); in 52.94%, 50%–75% were ChAT+ (intermediately positive); and in 17.65%

The aim of this study is to demonstrate the relationship between the proximal attachment of the coracobrachialis muscle and the short head of the biceps brachii and the distal attachment of the pectoralis minor. Their correlation with the bifurcated coracoid process (CP) will be also assessed. On the basis of these observations, a new classification of structures attached to the coracoid process is proposed. Classical anatomical dissection was performed on one hundred forty-five upper limbs. Three types of relationship between the coracobrachialis muscle and the short head of the biceps brachii were observed in the cadavers. In type I (occurring in 54%), the coracobrachialis and the short head of the biceps brachii created a common junction attached to a single CP. Type II was divided into two subtypes (a and b). Subtype IIa (frequency 10%) was represented by independent proximal attachments of the short head of the biceps brachii and the coracobrachialis muscles to the CP. In subtype IIb (frequency 5%), the coracobrachialis muscle was two-headed (the first head located under the second) and not connected to the short head of the biceps brachii; all heads were attached to a single CP. Type III (frequency 31%) was characterized by a two-headed coracobrachialis muscle, the first head originating from a bifurcated CP laterally to the short head of the biceps brachii and the second medially to this structure. Different variations connected with the mentioned structures could be problematic for surgeons during operations, so detailed knowledge of them could contribute to more efficient procedures.

We have described a novel nerve plexus of the upper neck. By exploring how the individual components of this specific anterolateral nerve plexus communicate with each other, patient care could be improved regarding the preoperative diagnosis, intraoperative navigation, and minimally invasive treatment.Using a surgical microscope, 11 adult cadaveric heads (22 cadaveric hemi-sides) were dissected. The region of the junction between the atlanto-occipital and craniocervical junctions was explored, specifically, the innervation of this region via adjacent nerve connections. Branches from these regional nerve sources were analyzed for interconnections, and, when found, these branches were documented and measured.A delicate nerve plexus was found overlying the anterolateral C1-C2 junction in all specimens. The plexus was contributed by the sympathetic trunk, vagus nerve, hypoglossal nerve, and C1 and C2 ventral rami. We termed this plexus the anterolateral cervical atlanto-occipital (ALCAO) plexus. On all but 2 cadaveric hemi-sides (91%), the C2 ventral ramus provided the most input into the plexus, with 1-2 branches. On 2 cadaveric hemi-sides, the C1 ventral ramus was the primary contributor and, on average, this nerve contributed 1-2 branches to the plexus. For 8 cadaveric hemi-sides (36.4%), the C1 fibers that are known to travel with the hypoglossal nerve and be distributed to the geniohyoid and thyrohyoid muscles arose from C1 nerve fibers that first traversed the ALCAO plexus. The sympathetic trunk contributed 1-4 lateral branches, with most of these arising superiorly from the superior cervical ganglion. The vagus nerve contributed 1-2 lateral branches and the hypoglossal nerve contributed 1-2 anteromedial branches. This plexus was located more or less lateral to the sympathetic trunk and superior cervical ganglion and medial to the transverse process of C1 and C2. The plexus innervated the rectus capitis lateralis, rectus capitis anterior, and lateral atlanto-occipital joint and, on 4 cadaveric hemi-sides, the atlantoaxial joint. Additionally, small branches were seen traveling to the anterior atlantoaxial and anterior atlanto-occipital membranes on 55% and 77.2% of the cadaveric hemi-sides, respectively. On 6 hemi-sides, very small branches from the ALCAO plexus ended in the periosteum over the anterolateral aspect of the anterior arch and transverse process of the C1 vertebra.It is important to recognize that the course of these interneural connections varies and could result in unforeseen complications during surgical procedures. A comprehensive knowledge of these neural connections will be useful when considering surgery and evaluating pathology of the neck and skull base.

Acting in medial rotation of the arm, the subscapularis (SM) is the most powerful and largest muscle of the rotator cuff. It is morphologically variable, especially in the number of tendons, place of insertion, and number of bellies, and it is sometimes fused with another muscle. An accessory subscapularis muscle (ASM) is among the morphological variations of the SM, but it is a really rare variant. The present case describes a very rare ASM that is divided into proximal tendinous attachment, intermediate fleshy muscular belly and distal tendinous attachment. Its origin is located on the lateral border of the scapula, but some fibers are connected with the muscular part of the SM. Its distal attachment is fused with the capsule of shoulder joint, above the tendinous insertion of the SM. Such an arrangement allows for greater stabilization of the joint. Moreover, there is a possibility that it could be used during treatment of ruptured SM tendons.

Purpose Lumbar discogenic diffuse pain is still not understood. Authors describe the sinuvertebral nerve (SVN) as one possible cause. Body-donor studies are rare and controversial. Therefore, the aim was to revisit the origin, course and distribution in a body-donor study. Methods Six lumbar blocks (3 female, 3 male) aged between 59 and 94 years were dissected. After removal of the back muscles, lamina, dura mater and cauda equina, the anterior vertebral venous plexus, spinal artery and SVN were exposed and evaluated. Results 43 nerves out of 48 levels could be evaluated. The origin of the SVN was constituted by two roots: a somatic and a sympathetic branch arising from the rami communicantes. In 4/48 intervertebral canals studied (8.3%), we found two SVN at the same level. In 35/48 cases, one SVN was found. In 9/48 cases, no SVN was found. The SVN had a recurrent course below the inferior vertebral notch; in the vertebral canal it showed different patterns: ascending branch (31/43, 72.1%), common branch diverging into two branches (10/43, 23.3%), double ascending branch (1/43, 2.3%) finalizing two levels above and a descending branch (1/43, 2.3%). In 12/43 cases (27.9%) the SVN had ipsilateral connections with another SVN. The distribution ended in the middle of the vertebral body supplying adjacent structures. Conclusion A thorough understanding of the anatomy of the SVN might lead to significant benefits in therapy of discogenic low back pain. We suggest blocking the SVN at the level of the inferior vertebral notch of two adjacent segments. Level of evidence I Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding

The aim of the present study is to describe in detail the morphology and innervation pattern of the anconeus muscle, bearing in mind clinical implications such as iatrogenic injuries during surgical elbow approaches. A cadaveric study was performed; 56 elbows from 28 formalin-fixed cadavers belonging to the Anatomy Department of Universidad Complutense of Madrid were dissected. The triceps–anconeus nerve was located and dissected. A second innervation to the anconeus muscle from a branch of the posterior interosseous nerve (PIN) was occasionally detected. Taking the lateral epicondyle as a landmark, the entry points of both nerves in the muscle were referenced, the triceps–anconeus nerve was referenced at 0°, 30°, 45°, 70° and 90° of elbow flexion, and the PIN branch at 0°. Anconeus muscle was present in all specimens. The triceps–anconeus nerve was present in all of the dissected elbows. A branch from PIN to the anconeus muscle was present in 38 of the 54 elbows (70.4%). There were statistically significant differences in all measurements regarding the specimens’ gender, being higher for men. There is evidence of a high frequency of a double innervation pattern for the anconeus muscle: the main branch of triceps–anconeus muscle depending on the radial nerve, which is liable to being damaged during posterior elbow approaches, and a secondary branch depending on the PIN. There are very few references to this finding in Anatomical literature and none with such a large sample size.

Anatomy is a fundamental subject for both medical and surgical training. Anatomy departments might collaborate with clinicians organizing continuing medical education (CME) and other professional development courses. The courses should have a large practical component (in content and organization) but also should provide the latest scientifically based theoretical knowledge, respecting the learning of anatomy as well as aiming at performing different techniques. Anatomy departments should support these courses by establishing hands-on practical training courses and components.

There is a general agreement in all fields of sciences that practical pre-graduate education in human anatomy is absolutely necessary. It constitutes an inseparable partner with theoretical learning on the path to knowledge. As such is it critical to (1) establish the set of specific objectives for each practical session (PS), and (2) define more precisely the outcomes (i.e., knowledge, skills and attitudes) that are expected by students. The principle for efficiency of practical sessions (PSs) is that they should take place immediately after didactic sessions of the corresponding topic(s). In this way, students could best reinforce their learning. Considering that the morphology of the human body can be learned by means other than direct observation/dissection of anatomical donors, media, models and imaging have also gained popularity as “anatomy learning tools” in recent years. Imaging is a perfect complement for teaching in the dissecting room, but always in correlation with the reality of bodydonor sections, prosections and dissections of the same region. Anatomical models and computer programs express the reality of the human body, however, anatomical variations and many other qualities (i.e., surgical skills, ethics, pathology, professionalism) can only be appreciated via hands-on use of an anatomical donor to science. Therefore, the anatomical donor remains the Gold Standard for anatomy teaching, especially topographical Anatomy.

In humans, the incidence of congenital defects of the intraembryonic celom and its associated structures has increased over recent decades. Surgical treatment of abdominal and diaphragmatic malformations resulting in congenital hernia requires deep knowledge of ventral body closure and the separation of the primary body cavities during embryogenesis. The correct development of both structures requires the coordinated and fine-tuned synergy of different anlagen, including a set of molecules governing those processes. They have mainly been investigated in a range of vertebrate species (e.g., mouse, birds, and fish), but studies of embryogenesis in humans are rather rare because samples are seldom available. Therefore, we have to deal with a large body of conflicting data concerning the formation of the abdominal wall and the etiology of diaphragmatic defects. This review summarizes the current state of knowledge and focuses on the histological and molecular events leading to the establishment of the abdominal and thoracic cavities in several vertebrate species. In chronological order, we start with the onset of gastrulation, continue with the establishment of the three-dimensional body shape, and end with the partition of body cavities. We also discuss well-known human etiologies.

Introduction Morton's neuroma is an entrapment neuropathy of the third common plantar digital nerve, caused by the deep transverse metatarsal ligament (DTML). Minimally invasive or percutaneous surgery is a very common procedure, but surgical effectivity of this technique remains controversial. The goal of our study was to prove the effectiveness and safety of a new ultrasound‐guided technique for DTML‐release in a cadaver model. Materials, Methods, and Results The DTML was visualized in 10 fresh frozen donated body to science‐feet (eight male and two females, five left and five right) using an US device (GE Logic R7; 13 MHz linear probe, Madrid, Spain). Consecutively, minimally invasive ultrasound‐guided surgery was performed. Exclusion criteria of the donated bodies to science were previous history of forefoot surgery and space occupying mass lesions. The complete release of the ligament was achieved in all specimens without damage of any important anatomical structures as proven by anatomical dissection. Conclusions The results of this study indicate that our novel approach of an ultrasound‐guided release of the DTML is safer and more effective compared to blind techniques. The DTML could reliably be visualized and securely cut through a dorsal, minimally invasive surgical incision of only 2 mm.

Background The surgical procedure itself of lengthening the gastrocnemius muscle aponeurosis is performed to treat multiple musculoskeletal, neurological and metabolical pathologies related to a gastro-soleus unit contracture such as plantar fasciitis, Achilles tendinopathy, metatarsalgia, cerebral palsy, or diabetic foot ulcerations. Therefore, the aim of our research was to prove the effectiveness and safety of a new ultrasound-guided surgery-technique for the lengthening of the anterior gastrocnemius muscle aponeurosis, the “GIAR”- technique: the gastrocnemius-intramuscular aponeurosis release. Methods and results An ultrasound-guided surgical GIAR on ten fresh-frozen specimens (10 donors, 8 male, 2 females, 5 left and 5 right) was performed. Exclusion criteria of the donated bodies to science were BMI above 35 (impaired ultrasound echogenicity), signs of traumas in the ankle and crural region, a history of ankle or foot ischemic vascular disorder, surgery or space-occupying mass lesions. The surgical procedures were performed by two podiatric surgeons with more than 6 years of experience in ultrasound-guided procedures. The anterior gastrocnemius muscle aponeurosis was entirely transected in 10 over 10 specimens, with a mean portal length of 2 mm (± 1 mm). The mean gain at the ankle joint ROM after the GIAR was 7.9° (± 1.1°). No damages of important anatomical structures could be found. Conclusion Results of this study indicate that our novel ultrasound-guided surgery for the lengthening of the anterior gastrocnemius muscle aponeurosis (GIAR) might be an effective and safe procedure.

Morton’s neuroma (MN) is a common condition in clinical practice. The compressive etiology is the most accepted, in which compression occurs in the tunnel formed by the adjacent metatarsals, the deep transverse metatarsal ligament (DTML) and the plantar skin. Ultrasound (US) is a reliable method of study. The presence of insufficient space under the DTML may be related to the appearance of MN. Objectives: To verify the relationship between MN and the space under the DTML between the metatarsal heads of the third (M3) and the fourth (M4) metatarsals using US. Methods: This is a cross-sectional epidemiological study. The research study using the ultrasound (US) technique was carried out on 200 feet belonging to 100 patients aged 18 to 65 of both sexes, with a control group formed by 62 patients and a study group formed by 38 patients diagnosed with MN. Results: The presence of MN and the factors associated with it were studied in 100 patients using ultrasound (US). The assessment and comparison with US of the space inferior to the DTML between M3 and M4 in control groups and patients with MN show that patients with MN have a smaller size in the variable “h” (height or distance DTML-plantar skin), in the variable “b” (base or intermetatarsal distance M3 and M4) and in the variable “s” (surface of the parallelogram “h” × “b”). The predictors of MN are a decrease in dimension “b” and an increase in weight. Sitting in an office chair and the use of a bicycle, due to equinus, have an influence on the space below the DTML, reducing it and promoting the appearance of MN. Conclusions: The two US measurements (“h” and “b”) in the space below the DTML are smaller in patients with MN than in the asymptomatic group. A shorter distance between M3 and M4, and an increase in BMI are predictors of MN.

The anterior compartment of the arm consists of three muscles: the biceps brachii, brachialis and coracobrachialis. The aim of the present study was to characterize possible variations in the morphology of the proximal attachments of the long head of the biceps brachii and to propose an accurate classification of the area which can be useful for planning surgical procedures and planning rehabilitation in the region.Eighty (40 left and 40 right, 40 female, 40 male) upper limbs fixed in 10% formalin solution were examined.The main tendon of the long head of the biceps brachii demonstrated three types of attachment. The most common type, Type I (53.75%), was characterized by a single attachment only for the supraglenoid tubercle. Type III (33.75%) was characterized by a single attachment to the glenoid labrum. Type II (12.5%) was characterized by a double attachment to the glenoid labrum and the supraglenoid tubercle. Additionally, two types of the accessory tendon of the long head of the biceps brachii were identified (Type A-B). Type A (14 cases) was attached to the capsule of the humeral joint, and Type B (six cases) was attached to the greater tubercle of the humerus.The long head of the biceps brachii is characterized by high morphological variability. The new classification proposes three types of proximal attachment (I-III), with two types of accessory long head of the biceps brachii (A-B) tendon. A thorough understanding of the morphological variability of the long head of the biceps brachii is necessary when planning arthroscopic procedures or even planning rehabilitation procedures.

PurposeAmong the few studies that have examined the development of the anterior abdominal wall, several are based on incomplete “series”, substituted in many cases by non-human specimens.Material and MethodsIn total, 19 human embryos corresponding to Carnegie stages 15–23, 36 fetuses with estimated gestational ages ranging from 9 weeks to term, and eight neonates were included in this study. All specimens belong to the collection of the Department of Anatomy and Embryology at the Complutense University of Madrid.ResultsThe muscles of the anterior abdominal wall appear in the dorsal region at stages 15 and 16 (33–37 days). At stages 17 and 18 (41–44 days), this muscular mass grows ventrally and splits into two sheets: the external abdominal oblique muscle and the common mass of the internal abdominal oblique, and the transversus abdominis muscles, all of which end ventrally in the primitive condensation of the rectus abdominis. In embryos at stages 19 and 20 (48 days), the anterior abdominal wall continues to show an umbilical hernia in the amniotic cavity. However, a narrow neck is apparent for the first time and there is a wider anterior abdominal wall below the hernia made up of dense mesenchyme tissue without layers and showing the primordia of the umbilical canal. In embryos at stages 21, 22, and 23 (51–57 days), the abdominal muscles and aponeuroses cross the midline (linea alba) covering the rectus abdominis and pyramidalis muscles while the umbilical hernia has shrunk. In fetuses during the 9th and 10th weeks, the umbilical hernia becomes encircled by the rectus abdominis muscle, its aponeurosis, and the three layers of lateral abdominal muscles, which are more developed and covered by Camper's and Scarpa's fasciae. The inguinal canal has a course and relationships like those described in adults, with Hesselbach's ligament.

Painful lesions on the plantar aspect of the first interphalangeal joint (IPJ) of the hallux can be attributed to structures called ossicles, nodules, or sesamoids. The aims of the present study were first to verify that ultrasonography (US) is a high-sensitivity tool for diagnosing an interphalangeal ossicle (IO), and second to prove that US-guided-shaving surgery (“milling”) is a safe and feasible technique for remodeling the IO. The study is divided into three parts. In the first part, the prevalence of IOs was estimated in 12 cadaver feet using US, anatomical dissection, and fluoroscopy. In the second, a detailed US and morphological description of the IO was obtained. In the third, six cadaver feet were subjected to surgical milling. IO prevalence was 41.6% in gross anatomy, 41.6% in US examination and just 16.6% in fluoroscopy. The ossicles had a mean length of 4 mm (± 2 mm) and a width of 7 mm (± 2 mm). The ossicles could be completely shaved in all specimens without injuring important anatomical structures. Our results indicate that US is a more precise tool for diagnosing an IO than X-ray. Moreover, our US-guided mini-invasive surgical technique appears feasible and safe.

The petrooccipital fissure (POF) has relevance to skull base approaches, various tumors and craniosynostoses, and some cases of age-related hearing loss. However, the prevalence of fusion and classification of such is rarely found in the extant medical literature.One-hundred and 10 dry human skulls (220 sides) were used for this study. The skulls were evaluated for fusion of the POF. Both the endocranial and exocranial aspects of the POF were analyzed. A classification scheme was developed to better describe the location of POF fusion.A fused POF was identified on 36 sides (16.4%) and commonly found bilaterally (11%). Of these, 30 sides (83.3%) were completely fused (type I) and 6 sides (2.7%) were partially fused (types II and III). For the partially fused fissures, the fused part was on all but 2 sides with the most anterior portion of the petrous part of the temporal bone and adjacent clivus (type II). For the 2 sides (both right sides), the fusion was more posteriorly located between the petrous part of the temporal bone and lateral clivus (type III). Fusion of the POF was more often found in specimens with a partially or fully ossified petroclival ligament. Completely fused POF was positively correlated to sides with an intrajugular bony septum.A POF fusion was relatively common and associated with an ossified petroclival ligament and intrajugular bony septation. Such a prevalence is important for clinicians and skull base surgeons interpreting imaging of the skull base.

Background Peripheral nerve decompression surgery can effectively address headache pain caused by compression of peripheral nerves of the head and neck. Despite decompression of known trigger sites, there are a subset of patients with trigger sites centered over the postauricular area coursing along the sulcus. The authors hypothesize that these patients experience primary or residual pain caused by compression of the great auricular nerve. Methods Anatomical dissections were carried out on 16 formalin-fixed cadaveric heads (eight female and eight male cadavers) ranging in age from 78 to 89 years. The course of the great auricular nerve was identified in the superficial cervical fascia, at the borders to the sternocleidomastoid muscle and the platysma, and within the parotid gland. Possible points of compression along fascia, muscle, and parotid gland were identified. Ultrasound technology was used to confirm these anatomical findings in a living volunteer. Results The authors' findings demonstrate that the possible points of compression for the great auricular nerve are at Erb's point (point 1), at the anterior border of the sternocleidomastoid muscle in the dense connective tissue before entry into the parotid gland (point 2), and within its intraparotid course (point 3). The mean topographic measurements were as follows: Erb's point to the mastoid process at 7.32 cm on the right and 7.35 cm on the left, Erb's point to the angle of the mandible at 6.04 cm on the right and 5.89 cm on the left, and the posterior aspect of the sternocleidomastoid muscle to the mastoid process at 3.88 cm on the right and 4.43 cm on the left. All three possible points of compression could be identified using ultrasound. Conclusions This study identified three possible points of compression of the great auricular nerve that could be decompressed with peripheral nerve decompression surgery: Erb's point (point 1), at the anterior border of the sternocleidomastoid muscle (point 2), and within its intraparotid course (point 3). These findings were confirmed on ultrasound in a living volunteer.

Dorello's canal is an arched structure of bone-fibrous character located in the petroclival venous confluence atop the petrosal bone in the petroclival region. It is bordered by the petrosphenoidal ligament, the petrous part of the temporal bone and the lateral border of the upper part of clivus. Its content in the vast majority of variants comprises the abducens nerve, the inferior petrosal sinus, the venous drainage and the dorsal meningeal artery or its medial branch. With the development of microsurgical techniques, this area has gained huge clinical importance, mainly concerning the order in which the above-mentioned elements (especially the position of the abducens nerve) are arranged in relation to each other. These structures appear in different variant forms and necessitate an individual clinical approach. The main purpose of this review is to present condensed information about possible intercorrelations among them and to indicate, on the basis of the available literature and research, possible surgical approaches and the need to consider the variability when treatments in this region are planned.

Low anterior resections (LAR) are frequently associated with complications such as urinary and fecal incontinence as well as sexual disorders. Typical risk factors are rectal cancer with low tumor location, preoperative radiotherapy, and surgery-related damage of pelvic autonomic nerves. As preserving the pelvic autonomic nerves without any technical assistance is challenging, the objective of this preclinical study was to investigate the technical feasibility of a new method for intraoperative pelvic neuromonitoring. Twelve female pigs undergoing low anterior resections were involved in a prospective preclinical study. Intraoperative pelvic neuromonitoring included direct pelvic nerve stimulation and tissue impedance measurement on the urinary bladder and the rectum for the identification of efferent pelvic nerves in the surgical area. Immunohistochemistry was used to verify the results. Smooth muscle contraction of the urinary bladder and/or the rectum in response to direct stimulation of the innervating nerves was detectable with impedance measurement. The macroscopic contraction of both the urinary bladder and the rectum correlated with a change in tissue impedance compared to the status before contraction. Thus, it was possible to identify pelvic nerves in the surgical area, which allows the nerves to be preserved. The results indicate a reliable identification of pelvic autonomic nerves, which allows nerve damage to be prevented in the future.

Detailed anatomic investigation of peripheral nerve topography underlies the correct application of intraoperative neuromonitoring (IONM) and ultrasonography, both well-established methods to prevent nerve palsy during surgical operations and to elucidate pathomechanisms in disease. In this study, we analyzed the anatomy of selected peripheral nerves in the head and neck regions to improve the outcome of endocrine and migraine surgeries. Anatomic dissections of 204 hemilarynges were performed to study the topography of the inferior laryngeal nerve (ILN). Measurements were taken from the lower rim of the cricoid and from the Zuckerkandl tubercle to the beginning of the furcation of the ILN. For the analysis of peripheral nerves contributing to migraine pathogenesis, 22 hemifaces were investigated by dissection and ultrasonography. The supratrochlear and supraorbital nerves and their relationship to the corrugator supercilii muscle are described. For identification of the ILN, the cricoid offers a suitable intraoperative landmark. A single branch existed in 5% of specimens on the left side and in 3% on the right side. Bifurcation was present in 72.5% and 62% and trifurcation in 18% and 29% of cases, respectively. IONM signals from the vagus nerve were positive if derived proximal to and negative if derived distal to the branching off of a nonrecurrent ILN (nrILN). By ultrasonographic identification of a brachiocephalic trunk, an nrILN could be excluded. For migraine surgery, possible compression points of the supratrochlear and supraorbital nerves were identified, and a workflow algorithm for ultrasound visualization of these nerves is provided. Anat Rec, 302:1325-1332, 2019. © 2019 Wiley Periodicals, Inc.

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.

Background Anatomic variations in the hepatic venous system are the least understood aspect of hepatic anatomy. The variations are diverse, and data are lacking with respect to the population of Spain and methods of detection. The objective was to examine morphological patterns of variations in hepatic venous vascularization using cadaveric dissections vs. radiological imaging, and to analyze the findings with respect to Spain and to published studies. Methods Thirty-one livers were anatomically dissected and analyzed for their hepatic venous anatomy and then compared to the venous anatomy of livers examined in 216 CT scans from 119 men and 97 women, ranging between 27 and 89 years of age. Statistical analysis was done using the Chi squared and Fisher homogeneity tests. Results The hepatic portal vein showed morphological variations in cadavers vs. CT of 67.3% vs. 67.6% (p-I), 29% vs. 12.2% (p-II), 0% vs. 14.6% (p-III), 0% vs. 14.6% (p-IV), 3.2% vs. 0.5% (p-V) and 6.5% vs. 1.9% (p-VI), respectively in cadavers vs. CT. Hepatic vein pattern variation were found in 64.5% vs. 50.7% (h-I), 32.2% vs. 31.5% (h-II), 0% vs. 2.3% (h-III), 0% vs. 4.7% (h-IV), respectively in dissections vs. CT). In Accessory Hepatic Veins the frequency in pattern variation was 64.5% vs. 18.8% (a-2.1), 29.0% vs. 8.0% (a-2.2), 58.1% vs. 11.3% (a-2.3), 9.7% vs. 0.9% (a-2.4), 67.7% vs. 16.9% (a-2.5), 9.7% vs. 4.2% (a-2.6) and 0% vs. 0.5% (a-2.7), respectively, in cadavers vs. CT. CT showed in 27.2% no accessory hepatic veins. Sex was not a factor influencing patterns of variation. Conclusion Anatomical variants of the hepatic portal vein, the hepatic vein and accessory hepatic veins are very diverse and show greater variability in the specimens compared to those detected with radiological images, finding a wider spectrum of variations as it allows the clinician to have a more precise definition of the vasculature. A higher precision in the definition of anatomical variations is warranted for surgical planning in liver resection and transplantation.

Although percutaneous hallux valgus surgery is increasing in popularity, concerns about safety regarding neurovascular and tendinous structures remain. The first aim of this body-donor study was to evaluate the safety of three common percutaneous portals. Secondly, to evaluate percutaneous surgery effectiveness in completing adductor tendon release and first ray osteotomies.Twenty body-donor feet were included and underwent three percutaneous procedures, which are commonly performed in combination: distal metatarsal osteotomy, proximal phalanx osteotomy and adductor tendon release. After surgery, the distance between surgical portals and relevant neurovascular structures was measured. Damage to this neurovascular structures, tendons or articular cartilage was noted. Completion of adductor tendon release and osteotomies was verified.The medial dorsal digital nerve of the hallux was damaged in two specimens. Mild peritendon damage was observed in two feet. The rest of neurovascular and tendinous structures were intact. No cartilage damage was observed. The distance between the adductor tenotomy portal and the lateral dorsal digital nerve of the hallux and the first dorsal metatarsal artery was 3.3mm (SD 1.4) and 2.4mm (SD 1.8), respectively. Complete adductor tenotomy was achieved in 14 feet.The structure with the highest risk of damage during percutaneous hallux valgus surgery is the medial dorsal digital nerve. The lateral dorsal digital nerve and the first dorsal metatarsal artery might be at risk due to the small distance to the adductor tendon release portal. A deep anatomical knowledge and a meticulous surgical technique are required to avoid lesions to neurovascular and tendinous structures.V, Cadaveric study.

Purpose To present a safety-optimized ultrasound-guided minimal invasive carpal tunnel release (CTR) procedure. Materials and Methods 104 patients (67 female, 37 male; mean age 60.6 ± 14.3 years, 95% CI 57.9 to 63.4 years) with clinical and electrophysiological verified typical carpal tunnel syndrome were referred for a high-resolution ultrasound of the median nerve and were then consecutively assigned for an ultrasound-guided CTR after exclusion of possible secondary causes of carpal tunnel syndrome such as tumors, tendovaginitis, ganglia and possible contraindications (e.g., crossing collateral vessels, nerve variations). Applying a newly adapted and optimized algorithm, basing on the work proposed by Petrover et al. CTR was performed using a button tip cannula which has several safety advantages: On the one hand, the button tip cannula acts as a blunt and atraumatic guiding splint for the subsequent insertion of the hook-knife, and on the other hands, it serves as a “hydro-inflation”-tool, i.e., a fluid-based expansion of the working-space is warranted during the whole procedure whenever needed. Results In all patients, successful releases were confirmed by the depiction of a completely transected transverse carpal ligament during and in the postoperative ultrasound-controls two weeks after intervention. All patients reported markedly reduction of symptoms promptly after this safety-optimized ultrasound-guided minimal invasive CTR and at the follow-up examination. No complications were evident. Conclusion The here proposed optimized algorithm assures a reliable and safe ultrasound-guided CTR and thus should be taken into account for this minimal invasive interventional procedure.

Background The frequency of appearance of anatomical variability in the terminal division of the popliteal artery (PA) is different according to the type of sample used, and ranges from 2% to 21%. The PA locates 1,01 cm behind to the lateral meniscus, which makes it vulnerable during surgical procedures. Iatrogenic injury of the PA or its terminal branches increases if anatomical variables are present. Our aim was to describe and review the branching pattern of the PA in a body-donors to science sample to determine the influence of the sample used (body-donors vs imaging test). Methods A sample consisting of 260 popliteal regions, corresponding to 130 corpses (66 women, 64 men), have been dissected. Multivariate analysis was carried out. Results The terminal division of the PA was classified as follows: Pattern 1: the PA divided into the anterior tibial (ATA) and the posterior tibial arteries (PTA) at the level or distal to the lower border of the popliteal muscle (PM) (94.7%). Pattern 2: the PA bifurcated into the ATA and PTA, proximal to the lower border of the PM (3.3%). Pattern 3: the PA divided at the same level into the ATA, PTA and PEA. (2%). No significant differences between gender and side of the limb could be find. Conclusions We propose a classification that encloses three identifiable groups only. This will allow clinicians to bear in mind these variables easily, at the same time avoiding injuries during surgical procedures such as lateral meniscus repair.

Purpose Neuropathy of the Baxter nerve (BN) seems to be the first cause of the heel pain syndrome (HPS) of neurological origin. Methods 41 alcohol–glycerol embalmed feet were dissected. We documented the pattern of the branches of the tibial nerve (TN) and describe all relevant osteofibrous structures. Measurements for the TN branches were related to the Dellon–McKinnon malleolar-calcaneal line also called DM line (DML) for the proximal TT and the Heimkes Triangle for the distal TT. Additionally, we performed an ultrasound-guided injection procedure of the BN and provide an algorithm for clinical usage. Results The division of the TN was 16.4 mm proximal to the DML. The BN branches off 20 mm above the DML center or 30 mm distally to it. In most of the cases, the medial calcaneal branch (MCB) originated from the TN proximal to the bifurcation. Possible entrapment spots for the medial and lateral plantar nerve (MPN, LPN), the BN and the MCB are found within a circle of 5 mm radius with a probability of 80%, 83%, and 84%, respectively. In ten out of ten feet, the US-guided injection was precisely allocated around the BN. Conclusions Our detailed mapping of the TN branches and their osteofibrous tubes at the TT might be of importance for foot and ankle surgeons during minimally invasive procedures in HPS such as ultrasound-guided ankle and foot decompression surgery (UGAFDS).

Pedicle screw loosening is a common and significant complication after posterior spinal instrumentation, particularly in osteoporosis. Radiolucent carbon fiber-reinforced polyetheretherketone (CF/PEEK) pedicle screws have been developed recently to overcome drawbacks of conventional metallic screws, such as metal-induced imaging artifacts and interference with postoperative radiotherapy. Beyond radiolucency, CF/PEEK may also be advantageous over standard titanium in terms of pedicle screw loosening due to its unique material properties. However, screw anchorage and loosening of CF/PEEK pedicle screws have not been evaluated yet. The aim of this biomechanical study therefore was to evaluate whether the use of this alternative nonmetallic pedicle screw material affects screw loosening. The hypotheses tested were that (1) nonmetallic CF/PEEK pedicle screws resist an equal or higher number of load cycles until loosening than standard titanium screws and that (2) PMMA cement augmentation further increases the number of load cycles until loosening of CF/PEEK screws. In the first part of the study, left and right pedicles of ten cadaveric lumbar vertebrae (BMD 70.8 mg/cm3 ± 14.5) were randomly instrumented with either CF/PEEK or standard titanium pedicle screws. In the second part, left and right pedicles of ten vertebrae (BMD 56.3 mg/cm3 ± 15.8) were randomly instrumented with either PMMA-augmented or nonaugmented CF/PEEK pedicle screws. Each pedicle screw was subjected to cyclic cranio-caudal loading (initial load ranging from − 50 N to + 50 N) with stepwise increasing compressive loads (5 N every 100 cycles) until loosening or a maximum of 10,000 cycles. Angular screw motion (“screw toggling”) within the vertebra was measured with a 3D motion analysis system every 100 cycles and by stress fluoroscopy every 500 cycles. The nonmetallic CF/PEEK pedicle screws resisted a similar number of load cycles until loosening as the contralateral standard titanium screws (3701 ± 1228 vs. 3751 ± 1614 load cycles, p = 0.89). PMMA cement augmentation of CF/PEEK pedicle screws furthermore significantly increased the mean number of load cycles until loosening by 1.63-fold (5100 ± 1933 in augmented vs. 3130 ± 2132 in nonaugmented CF/PEEK screws, p = 0.015). In addition, angular screw motion assessed by stress fluoroscopy was significantly smaller in augmented than in nonaugmented CF/PEEK screws before as well as after failure. Using nonmetallic CF/PEEK instead of standard titanium as pedicle screw material did not affect screw loosening in the chosen test setup, whereas cement augmentation enhanced screw anchorage of CF/PEEK screws. While comparable to titanium screws in terms of screw loosening, radiolucent CF/PEEK pedicle screws offer the significant advantage of not interfering with postoperative imaging and radiotherapy. These slides can be retrieved under Electronic Supplementary Material.

Reseña de la obra de Miguel Rodríguez-Pantoja, Epigrafía latina en verso, Madrid, Akal, 2020, 762 pp. ISBN: 978-84-460-4826-8

Compressed craniofacial nerves might be involved in the pathogenesis of migraine headache, supported by the efficiency of botulinum toxin injections as a new treatment option in migraine headache patients. With regard to surgical, clinically applied anatomy, macroscopic dissections of alcohol glycerine and formalin-embalmed specimens have been made and possible “nerve trigger sites” of craniofacial nerves, in particular of the supraorbital, the supratrochlear, the greater and lesser occipital, and the auriculotemporal and the zygomaticotemporal nerves, were investigated. The courses of the nerves were defined and the interaction with possible anatomical structures leading to a possible entrapment and/or compression is described. New possible compression points concerning these craniofacial nerves have been discovered, and previously described trigger sites have been verified.

PurposeInguinodynia or chronic post-herniorrhaphy pain, defined as pain lasting longer than 3 months after open inguinal hernia repair, has become the most important complication after inguinal surgery and therefore compromises the patient´s quality of life. A major reason for inguinodynia might be the lack of neuroanatomical knowledge and suboptimal “management” of the nerves during surgery.MethodsWe present a detailed neuroanatomic mapping of the inguinal region by dissection including the most important surgical landmarks with all nerves confirmed by immunohistochemistry, ultrasound guided visualization of the iliohypogastric, ilio-inguinal, and genital branch of the genitofemoral nerve, and a practical (preoperative) algorithm for clinical management.ResultsSurgically and ultrasonographically relevant structures (“landmarks”) in open hernia repair are the anterior–superior iliac spine, pubic tubercle, Camper´s fascia (superficial layer of the superficial abdominal fascia), External oblique aponeurosis, Internal oblique muscle, Transversus abdominis muscle, superficial inguinal ring, external spermatic fascia, cremasteric fascia with cremaster muscle fibers, internal spermatic fascia, cremasteric vein (=external spermatic vein = “blue line”), ductus deferens, pampiniform plexus, inguinal ligament and the inferior epigastric vessels.ConclusionA detailed understanding of inguinal anatomy is an indispensable basic requirement for all surgeons to perform inguinal ultrasonography as well as open inguinal hernia repair, avoiding complications, especially postoperative inguinodynia.

The development in interventional respiratory medicine entails the need of bronchial anatomical knowledge, whose variations assume their greatest importance nowadays. The aim of this study was to describe the frequency of these variations and to analyze the bronchial lengths, barely registered before in literature. This observational descriptive study (from June 2018 until April 2019) was conducted in a sample of 17 pairs of lungs, which were dissected and measured at the Cadaver Donation Centre (Universidad Complutense, Madrid), and a second sample of 50 bronchoscopies, performed at the San Carlos Clinic Hospital, which were analyzed during the procedure. Our results show that there are no significant differences in the incidence of variations by sex in any of both samples, and neither in the average length of any bronchus by sex nor lobar pattern. Left main bronchus presents the longest length and left upper lobe bronchus the shortest. The highest percentage of variations is contained in the right lower lobe (25.4%), and the most frequent variation in the subsuperior bronchus (B*) (19.4%). The middle lobe and the left lower lobe present the lowest percentage of variations (11.9%). Only 37.3% of the pairs of lungs/patients did not have any anatomical variation in the general sample. Despite of the small size of the sample, results show a high percentage of variations and a minority of completely normal pairs of lungs, which invites us to reflect about the probable high prevalence of variations in the general population. Further studies with greater samples are needed to confirm our hypothesis.

The aim was to assess the influence of femoral derotational osteotomy on patella tilt (PT), axial patella engagement (AEI) and tibial tuberosity trochlear groove distance (TTTG). Derotational femoral osteotomy was performed on ten lower limbs of body donors embalmed with alcohol–glycerine. Femoral torsion, tibial torsion, knee torsion, PT, AEI and TTTG were evaluated on axial CT slices for an absolute femoral torsion of 15°, 20°, 25°, 30°, 35° and 40°. A linear mixed model analysis was used to estimate the effect of femoral torsion on PT, AEI, TTTG and knee torsion adjusted for correlation due to repeated observations. Estimates with 95% confidence intervals were used to represent the mean change in the dependent variables for one unit of change (degree, mm or AEI) in the predictor variable. A significant correlation was observed between femoral torsion and AEI (p

Background The aim of this study is to provide a safe ultrasound-guided minimally invasive surgical approach for a proximal tarsal tunnel release concerning nerve entrapments. Methods and results The study was carried out on ten fresh-frozen feet. All of them were examined by high resolution ultrasound at the medial ankle region. The surgical approach was marked throughout the course of the flexor retinaculum (laciniate ligament). Once the previous steps were done, the flexor retinaculum release technique was carried out with a 2-mm entry only. As a result, an effective and safe release of the flexor retinaculum was obtained in all fresh-frozen feet. Conclusion The results of our anatomic study indicate that our novel ultrasound-guided minimally invasive surgical approach for the release of the flexor retinaculum might be an effective, safe and quick decompression technique treating selected patients with a proximal tarsal tunnel syndrome.

An ongoing clinical trial regarding intra- and post-surgical morbidity in maxillary apicoectomies showed significant higher morbidity for upper canines and palatal roots of upper 1st premolars. Analysis of available presurgical cone beam computed tomography (CBCT)-scans revealed the existence of an unknown bone-canal branching off from the bone-canal or groove of the anterior superior alveolar artery (asaa). Aim of the study was the determination of the contents of this newly found bone canal in human cadaver heads, its prevalence as possible standard anatomical structure and its automatized detection with a contemporary high-resolution TRIUM-CBCT-device in vivo. 35 human cadaver heads were dissected, the prevalence of the bone-canal determined and its contents analyzed by histology. 835 consecutive routine high-resolution TRIUM-CBCT-scans from routine patients were analyzed by an automatized detection- and tracing-algorithm for in vivo-determination of prevalence of this bone canal. Automatized detection and additional manual tracing were statistically evaluated by SSPS 20.0 software. The bone-canal was found in 96% of the anatomical specimens, its content identified as artery not described until now and named after the first finder “Arteria Kurrekii”. Automatized tracing of TRIUM-CBCT-scans with additional manual tracing revealed an in vivo prevalence of this newly found artery of 95% (p ≤ 0.05). The newly found anterior superior palatal alveolar artery (aspaa—“Arteria Kurrekii”) might have the same clinical impact for surgical procedures in the maxilla as the posterior superior alveolar artery (psaa). Its first detection was enabled by high-resolution TRIUM-CBCT devices and prevalence as standard anatomical structure proven in vivo by automatized CBCT-scan analysis.

We present an anatomical mapping of the most important muscles influencing the nose, incorporating constant anatomical structures, and their spatial correlations. At our disposal were the midfaces of 18 bodies of both sexes, obtained by informed consent from body donors aged between 60 and 80 years. Macroscopically, we dissected the nasal regions of eight corpses, six midfaces were prepared according to plastination histology, four by creating plastinated slices. On their way from their periosteal origin to the edge of the skin, the muscles of the nose cross the subcutaneous adipose tissue, dividing it into superficial and deep layers. The individual muscle fibers insert into the skin directly at the reticular corium. Sometimes, they reach the border of the epidermis which represents a special arrangement of corial muscle attachments. The course of the anatomical fibers of individual nasal muscles presented macroscopically and microscopically in this study offers surgeons a detailed overview of the anatomically important muscular landmarks of the midface.

Summary Background Recent findings on the pathogenesis of frontal migraine headache support, besides a central vasogenic cause, an alternative peripheral mechanism involving compressed craniofacial nerves. This is further supported by the efficiency of botulinum toxin injections as a new treatment option in frontal migraine headache patients. Methods The supraorbital regions of 22 alcohol-glycerine-embalmed facial halves of both sexes were dissected. Both the supratrochlear and supraorbital nerves (STN and SON, respectively) were identified, and their relationship with the corrugator supercilii muscle (CSM) was investigated by dissection and ultrasound. The course of both nerves was defined, and the interaction between the supraorbital artery (SOA) and SON was determined. Results We discovered a new possible compression point of the STN passing through the orbital septum and verified previously described compression points of both STN and SON. Osteofibrous channels used by the STN and SON were found constantly. We described the varying topography of the STN and CSM, the SON and CSM, and the SON and SOA. Further, we provide an algorithm for the ultrasound visualization of the supraorbital neurovascular bundle. Conclusion Our data support the hypothesis of a peripheral mechanism for frontal migraine headache because of following potential irritation points: first, the CSM is constantly perforated by the SON and frequently by the STN; second, the topographic proximity between SOA and SON and the osteofibrous channels is used by the SON and STN; and third, the STN passes through the orbital septum.

Aims The aim was to develop a new laparoscopic technique for placement of a pudendal lead. Methods Development of a direct, feasible and reliable minimal-invasive laparoscopic approach to the pudendal nerve (PN). Thirty-one embalmed human specimens were dissected for the relevant anatomic structures of the pelvis. Step-by-step documentation and analysis of the laparoscopic approach in order to locate the PN directly in its course around the medial part of the sacrospinous ligament and test this approach for feasibility. Landmarks for intraoperative navigation towards the PN as well as the possible position of an lead were selected and demonstrated. Results The visible medial umbilical fold, the intrapelvine part of the internal pudendal artery, the coccygeus muscle and the sacrospinous ligament are the main landmarks. The PN traverses the medial part of the sacrospinous ligament dorsally, medially to the internal pudendal artery. The medial part of the sacrospinous ligament has to be exposed in order to display the nerve. An lead can be placed ventrally on the nerve or around it, depending on the lead type or shape. Conclusions A precise and reliable identification of the PN by means of laparoscopy is feasible with an easy four-step approach: (1) identification of the medial umbilical fold; (2) identification of the internal iliac artery; (3) identification of the internal pudendal artery and incision of the coccygeus muscle ('white line', arcuated line); and (4) exposition of the medial part of the sacrospinous ligament to display the PN.

We present an anatomical mapping of the most important muscles influencing the nose, incorporating constant anatomical structures, and their spatial correlations. At our disposal were the midfaces of 18 bodies of both sexes, obtained by informed consent from body donors aged between 60 and 80 years. Macroscopically, we dissected the nasal regions of eight corpses, six midfaces were prepared according to plastination histology, four by creating plastinated slices. On their way from their periosteal origin to the edge of the skin, the muscles of the nose cross the subcutaneous adipose tissue, dividing it into superficial and deep layers. The individual muscle fibers insert into the skin directly at the reticular corium. Sometimes, they reach the border of the epidermis which represents a special arrangement of corial muscle attachments. The course of the anatomical fibers of individual nasal muscles presented macroscopically and microscopically in this study offers surgeons a detailed overview of the anatomically important muscular landmarks of the midface.