Human shoulder anatomy: new ultrasound, anatomical, and microscopic perspectives.

This study aimed to describe the shoulder anatomy, together with the anatomical relationships in adults and early stages of development. The shoulder muscles were studied from ultrasound, anatomical, and microscopic perspectives in a sample of 34 human shoulders. Thickness measurements were taken of the tendons and fasciae of the subscapularis, long head tendon of the biceps brachii, supraspinatus, infraspinatus, and teres minor. Ultrasound and dissection techniques are strongly correlated. However, the measurements obtained from the dissection technique were superior to those obtained from the ultrasound in all cases, except for the thickness of the long head tendon of the biceps brachii, the teres minor tendon, and the fascia thickness of the infraspinatus. In addition, the study of shoulder anatomy revealed no differences between females and males. Relevant findings from dissection included a clear overlap between the infraspinatus and supraspinatus, which shared tendon fibers, and a similar connection between the transverse ligament of the long head tendon of the biceps brachii and the subscapularis, which created a more interconnected shoulder function. The study of the anatomical measurements shows an underestimation of the shoulder measurements in the ultrasound compared with the dissection technique, but a high correlation between the measurements made by the two techniques. We present reference values for the tendon and fascia thicknesses of the rotator cuff, with no differences observed by gender. The relationships between shoulder structures described in the anatomical study imply as well that, in the event of an injury, adjacent tissues may be affected. This extended information may facilitate future optimal clinical explorations.

What Is New about the Semimembranosus Distal Tendon? Ultrasound, Anatomical, and Histological Study with Clinical and Therapeutic Application.

The semimembranosus muscle inserts into several tendons that are associated with some pathologies. Although ultrasound is useful for studying, diagnosing, and managing these pathologies, the correct interpretation of any images requires a clear knowledge of the related anatomical structures and the inter-related functions. We studied 38 cryopreserved non-paired knees from adult anatomical specimens and 4 non-paired knees from 29 to 38-week-old fetuses. The semimembranosus muscle and its tendons were located, observed, and injected under ultrasound guidance. The macroscopic anatomy was studied using dissection and anatomical cuts and the tendons were analyzed histologically. Measurements of muscle were taken 10 cm from the medial epicondyle and just before the tendon divided. The ultrasound facilitated the identification of the different divisions of the tendon of semimembranosus muscle and the rotation of the muscle and tendon from medial to posterior. An anatomical study confirmed this rotation and revealed an average width, thickness, and diameter of 38.29 mm, 14.36 mm, and 112.64 mm, respectively. Important relationships were observed between the divisions of the main tendons and the medial collateral ligament, the posterior side of the knee and popliteus muscle. This information can help to explain knee pathologies and facilitate rehabilitation after surgery.

Possible Points of Ulnar Nerve Entrapment in the Arm and Forearm: An Ultrasound, Anatomical, and Histological Study.

BACKGROUND: Ulnar nerve entrapment is one of the most common entrapment neuropathies, usually occurring in the cubital tunnel of the elbow and in Guyon's canal of the wrist. However, it can also occur at other anatomical locations. PURPOSE: Our aim was to review other possible locations of ulnar nerve entrapment in an ultrasound and anatomical study. MATERIAL AND METHODS: Eleven upper limbs from eight adult corpses were ultrasonographically examined and subsequently dissected in a dissection laboratory. Four specific anatomical points were analysed, and any anatomical variations were documented. Moreover, six samples of the nerve were taken for histological analysis. RESULTS: Distinct anatomical relationships were observed during ultrasound and dissection between the ulnar nerve and the medial intermuscular septum, the triceps aponeurosis, Osborne's fascia at the elbow, the arcuate ligament of Osborne and the intermuscular aponeurosis between the flexor carpi ulnaris and the flexor digitorum superficialis muscles. A statistical study showed that these locations are potential areas for ulnar nerve compression. In addition, a fourth head of the triceps brachii muscle was found in some specimens. CONCLUSION: Results demonstrate that ultrasound is a good tool to investigate ulnar nerve entrapment neuropathy and to identify other anatomical points where the nerve can remain compressed.

Ultrasound assessment of degenerative muscle sarcopenia: the University of Barcelona ultrasound scoring system for sarcopenia.

AIM: This study aimed to (1) determine the intraobserver and interobserver reliability of ultrasonographic measurement of muscle thickness (MT) and cross-sectional area (CSA) of the rectus femoris and biceps brachii, correlating these values with manual measurements on dissected cadavers and (2) develop the first semiquantitative musculoskeletal ultrasound (MSUS) scoring system of muscle morphology in sarcopenia and assess its intraobserver and interobserver reliability. In addition, the MSUS morphology score was compared with the corresponding histological images to verify concurrent validity. METHODS: Ten cryopreserved limbs of 10 cadavers aged 68-91 years were evaluated. The MSUS scoring system was based on the severity of muscle degeneration on a 3-point qualitative scale: grade 1 (normal), grade 2 (moderate changes) and grade 3 (severe changes). Reliability was assessed with intraclass correlation coefficient (ICC) for the MT and CSA and with Cohen's kappa coefficients (κ) for the MSUS scoring system. Concurrent validity was analysed with ICC. RESULTS: The results showed excellent intraobserver and interobserver reliability for both the MSUS evaluation of MT and CSA (ICC ≥0.93). The MSUS scoring system showed excellent intraobserver reliability (κ=1.0) and very good interobserver reliability (κ=0.85). There was also a high intra- and inter-observer reliability for the histological scorings (ĸ ≥0.85 and mean ĸ=0.70, respectively), as well as high reliability between the histology and MSUS scoring systems (ICC=0.92). All results were statistically significant (p≤0.001). CONCLUSION: MSUS measures of MT and CSA and the novel MSUS scoring system for degenerative muscle changes in sarcopenia was found to be reliable and strongly associated with histological findings.

Ultrasound and Anatomical Study of Accessing the Nerves in the Knee by Fascial Planes.

The fascia is an undifferentiated mesenchymal tissue related to the peripheral nerves. Both can be identified by ultrasound, which is useful when performing peripheral nerve blocks. However, there is no unanimity about the approaching point of each nerve, nor is there a consensus on how to name the appropriate infiltration zone, although the paraneural zone is frequently mentioned. The aims of this study were to determine if ultrasound is accurate for identifying the fascial planes and the paraneural space of the nerves in the knee, infiltrating them, and achieving a correct anatomical diffusion, as well as for establishing access routes to avoid intraneural infiltration. The study was performed in 16 cryopreserved lower extremities of the dissection room of the Faculty of Medicine and Health Sciences, University of Barcelona. Nerves of the knee were injected with colorant guided by ultrasound after they were visualized. Correct location of the nerves by ultrasound was achieved in 98.75% of the cases, correct visualization of the needle by ultrasound in 82.5%, the hypoechogenic image around the nerve after infiltration in 82.5%, and a correct paraneural infiltration in 76.25% of cases. With these results, we can conclude that high-definition ultrasound enables location of the peripheral nerves and adjacent structures as well as the fasciae that surround them, and therefore allows performance of infiltrations in the paraneural spaces.

Is interfascial block with ultrasound-guided puncture useful in treatment of myofascial pain of the trapezius muscle?

OBJECTIVES: Ultrasound-guided puncture is indispensable for the injection of local anesthetic in the interfascial space, the space between 2 muscle fasciae. Interfascial infiltration or block may be useful in treating myofascial pain in the trapezius muscle. METHODS: (1) In 5 cadavers, we studied the diffusion of a physiological saline and latex solution in the interfascial space of the upper muscles of the back, and performed a histological study of the fasciae. (2) We performed an interfascial block in 25 patients with myofascial pain in the trapezius muscle. Depending on the trigger point location, the block was performed between the trapezius and the levator scapulae or between the trapezius and the rhomboideus major. RESULTS: In all cadavers, anatomical dissection showed the latex in the interfascial space. The histological study confirmed the presence of nerve structures in the fasciae and in the interfascial space itself. Pain was assessed in all patients on a visual analog scale (VAS) before and after the injection (at rest and in motion). Preinjection: mean VAS 6.4 (at rest) and 7.6 (in motion). Postinjection: mean VAS 1 (at rest) and 1.6 (in motion). DISCUSSION: The anatomical, histological, and ultrasound findings in the cadaver study confirmed the diffusion of the solution in the interfascial space. Study in patients confirms that the interfascial block in the back musculature can be as effective as in the abdominal musculature. The presence of nerve structures in this space, confirmed by the histological study, seems to explain the pain relief reported by the patients with this interfascial technique.

How to avoid injuries of the superior gluteal nerve.

BACKGROUND: Injuries to the superior gluteal nerve are a common complication in hip replacement surgery. They can be avoided with a good anatomical knowledge of the course of the superior gluteal nerve. METHODS: We dissected 29 half pelvises of adult cadavers. The distance and the angle from the entry points of branches of the superior gluteal nerve into the deep surface of the gluteus medium and minimus muscles to the midpoint of the superior border of the greater trochanter were measured. RESULTS: The dissections revealed that the nerve divided into 2 branches (86.20%) or 3 branches (13.8%). The more caudal branch was responsible for innervation of the tensor fascia latae. CONCLUSIONS: A 2-3-cm safe area above the greater trochanter is appropriate to prevent nerve damage.

Anatomía Humana: estudio de las reacciones de los estudiantes de primero de medicina ante la sala de disección / Human Anatomy: reactions of first year medical students to the dissection room

Introducción: El objetivo de este estudio es reflejar las reacciones físicas y emocionales de los estudiantes de primer curso de Medicina de la Universidad de Barcelona (Campus de Bellvitge) ante la sala de disección. Material y métodos: Los estudiantes responden a tres cuestionarios que valoran la intensidad del miedo, las reacciones físicas y psicológicas frente la sala de disección y los métodos de afrontamiento, en dos momentos del curso: al inicio y al final del curso académico. Resultados: Las reacciones más frecuentes fueron la sensación de disgusto, la pérdida del apetito, las imágenes visuales recurrentes de los cadáveres, el insomnio y las pesadillas. Respecto a los métodos de afrontamiento más usados por los estudiantes para contrarrestar las reacciones adversas correspondieron en juntarse y hacer broma con los amigos, estudiar anatomía y pedir consejo a compañeros y profesores. Conclusiones: La sala de disección representa, para los estudiantes del primer curso de medicina, el primer encuentro relacionado con la muerte y ésta, a la vez, implica el desarrollo de mecanismos de adaptación en su futuro profesional. Los profesores de anatomía no solo tienen una mera función docente como transmisores de contenidos, sino que también deberían dar apoyo a la adaptación progresiva de los alumnos a la sala de disección (AU)

Introduction: The aim of this study is to record the physical and emotional reactions of the first-year medical students at the University of Barcelona (Campus de Bellvitge) to the dissection room. Material and methods: Three questionnaires focusing on degree of fear and psychological and physical reactions were prepared and administered to students before the first dissection session, after the first dissection, and at the end of the course. Results: The most frequent reactions were sensation of disgust, loss of appetite, recurring visual images of cadavers, insomnia and nightmares. To cope with these reactions the students used some methods such as being and joking with friends, expanding their study of anatomy and seeking advice to their friends and teachers. Conclusions: For first-year medical students the dissection room produces the first in a long series of adverse reactions towards different stimuli and towards unpleasant stimuli and death. Would be doctors are obligated to develop mechanisms of adaptation in order to cope with the demands of the profession. As for teachers of anatomy, their role involves not only imparting information, but also providing support for students throughout the course (AU)