Calcaneal tuberosity avulsion fractures - A review

Calcaneal tuberosity avulsion fracture, an extra-articular injury, is a rare fracture caused internally by Achilles tendon driven following intense contraction of gastrocnemius-soleus complex, and externally by low-energy (possibly high-energy). Moreover, the risk of injuries of the skin and Achilles tendon around calcaneal tuberosity is closely related to Lee classification and Carnero-Martín de Soto Classification of calcaneal tuberosity avulsion fracture. Although the diagnosis confirmed by X-ray, digital imaging and computed tomography (CT), magnetic resonance imaging (MRI) should also be used to evaluate soft tissue. In recent years, the understanding of this fracture has witnessed the development of different internal fixation devices and surgical procedures. These advances have been further elaborated scientifically in terms of their ability to provide stable fracture reduction ad resistance to Achilles tendon forces. In order to obtain a comprehensive knowledge of the disease, this article reviewed the new understanding of the anatomy, typing, risk factors, and treatment modalities of calcaneal tuberosity avulsion fracture in recent years.

Facial artery: anatomical variations in the perioral region in cadavers

BACKGROUND

In recent years, there has been an increase in reports of perioral vascular complications resulting from filler injections, such as necrosis of the lip or alar rim, occlusion, and in severe cases, blindness. Conversely, the use of perioral arterial flaps is becoming more prevalent in the treatment of cleft lips, cancer, and trauma. A thorough understanding of perioral arteries is essential to minimize complications and maximize the success of these flaps. However, the course of the facial artery (FA) in the perioral region remains incompletely understood. The aim of this study was to describe the variations of the FA in the perioral region.

METHODS

We dissected 52 embalmed and formaldehyde-fixed Vietnamese cadavers. We then studied the size and distribution of perioral arteries in 102 specimens.

RESULTS

The superior labial artery (SLA) was the most common branch, occurring in 87.25% of cadavers, followed by the inferior labial artery (ILA) at 78.43%. The SLA primarily originated above the mouth corner (cheilion), accounting for 91.01% of cases, and predominantly exhibited a tortuous course within the submucosa (78.65%). The ILA's branching pattern varied, but it was primarily located below the cheilion (91.25%). The ILA also followed a twisted path, generally within the submucosa. The ILA exhibited two patterns: the typical pattern, distributed at the vermilion border of the lower lip (8.82%), and the horizontal labiomental artery pattern, which ran horizontally in the middle of the lower lip area (69.61%). At their origin, the SLA and ILA had average external diameters of 1.29 mm and 1.28 mm, respectively.

CONCLUSION

Numerous anatomical variations in the FA in the perioral region were found. A detailed anatomic description, suggested landmarks, and angiography before the procedure will be useful to help doctors avoid complications.

Technology-Enhanced Preclinical Medical Education (Anatomy, Histology and Occasionally, Biochemistry): A Practical Guide

The recent explosion of technological innovations in mobile technology, virtual reality (VR), digital dissection, online learning platform, 3D printing, and augmented reality (AR) has provided new avenues for improving preclinical education, particularly in anatomy and histology education. Anatomy and histology are fundamental components of medical education that teach students the essential knowledge of human body structure and organization. However, these subjects are widely considered to be some of the most difficult disciplines for healthcare students. Students often face challenges in areas such as the complexity and overwhelming volume of knowledge, difficulties in visualizing body structures, navigating and identifying tissue specimens, limited exposure to learning materials, and lack of clinical relevance. The COVID-19 pandemic has further exacerbated the situation by reducing face-to-face teaching opportunities and affecting the availability of body donations for medical education.To overcome these challenges, educators have integrated various educational technologies, such as virtual reality, digital 3D anatomy apps, 3D printing, and AI chatbots, into preclinical education. These technologies have effectively improved students' learning experiences and knowledge retention. However, the integration of technologies into preclinical education requires appropriate pedagogical approaches and logistics to align with educational theories and achieve the intended learning outcomes.The chapter provides practical guidance and examples for integrating technologies into anatomy, histology, and biochemistry preclinical education. The author emphasizes that every technology has its own benefits and limitations and is best suited to specific learning scenarios. Therefore, it is recommended that educators and students should utilize multiple modalities for teaching and learning to achieve the best outcomes. The chapter also acknowledges that cadaver-based anatomy education is essential and proposes that educational technologies can serve as a crucial complement for promoting active learning, problem solving, knowledge application, and enhancing conventional cadaver-based education.

A Cadaveric Study of Thread Cubital Tunnel Release with Newly Developed Threads

Objective

The percutaneous thread transection technique is a surgical dissecting method using a dissecting thread inserted through a needle under ultrasound guidance without skin incision. As the new dissecting threads were developed domestically, this cadaver study was conducted to compare the effectiveness and safety between the new threads (ultra V sswire and smartwire-01) and a pre-existing commercial dissecting thread (loop & shear) by demonstrating a modified looped thread cubital tunnel release.

Methods

The percutaneous cubital tunnel release procedure was performed on 29 fresh cadaveric upper extremities. The preexisting commercial thread was used in 5 upper extremities. The two newly developed threads were used in 24 upper extremities. Two practitioners performed the procedures separately. After the modified looped thread cubital release, anatomical and histological analyses were performed by a blinded anatomist. The presence of the dissected cubital tunnel and damaged adjacent soft tissue was assessed.

Results

Out of the 29 cadaveric upper extremities, 27 specimens showed complete dissection of the Osborne ligament and the proximal fascia of the flexor carpi ulnaris muscle. One specimen was incompletely dissected in each of the ultra V sswire and smartwire-01 groups. There were no injuries of adjacent structures including the ulnar nerve, ulnar artery, medial antebrachial cutaneous nerve, or flexor tendon with either the commercial thread or the newly developed threads. The anatomical analysis revealed clear and sharp incisional margins of the cubital tunnel in the Smartwire-01 and loop & shear groups. All three kinds of threads maintained proper linear elasticity for easy handling during the procedure. The smartwire-01 provided higher visibility in ultrasound than the other threads.

Conclusion

The newly developed threads were effective and safe for use in the thread cubital tunnel release procedure.

The human masseter muscle revisited: First description of its coronoid part

INTRODUCTION

The masseter muscle is considered to be bilayered, consisting of a superficial and a deep part. However, a few historical texts mention the possible existence of a third layer as well, but they are extremely inconsistent as to its position. Here we performed an anatomical study to clarify the presence and morphological characteristics of a distinct third layer of the masseter muscle.

MATERIALS AND METHODS

We dissected 12 formaldehyde-fixed human cadaver heads, analysed CTs of 16 fresh cadavers, evaluated MR data from one living subject and examined histological sections using methyl methacrylate embedding of one formaldehyde-preserved head.

RESULTS

An anatomically distinct, deep third layer of the masseter muscle was consistently demonstrated, running from the medial surface of the zygomatic process of the temporal bone to the root and posterior margin of the coronoid process. Ours is the first detailed description of this part of the masseter muscle.

CONCLUSIONS

To facilitate discussion of this newly described part of the masseter, we recommend the name M. masseter pars coronoidea (coronoid part of the masseter) as a further reference. The arrangement of its muscle fibers suggest it being involved in stabilising the mandible by elevating and retracting the coronoid process.

Clinical Anatomy of Human Donor C7 Nerve Roots for Surgical Transfer in Patients with Spastic Arm Paralysis

BACKGROUND

Contralateral C7 (CC7) nerve transfer has successfully restored hand function in patients with spastic hemiplegia from chronic central nervous system injuries. However, little is known about the morphology and anatomy of the donor C7 nerve root in patients undergoing this procedure. This study quantified intraoperative measurements of donor C7 nerve roots during CC7 transfer surgery for spastic hemiplegia in patients treated at a high-volume center to describe observed anatomical variations for successful direct anastomosis.

METHODS

A database of images from 21 patients (2 females, 19 males) undergoing CC7 surgery was searched for photographic data that contained a standard ruler measuring donor C7 nerve root length after surgical sectioning and before transfer. Two independent observers analyzed these images and recorded C7 nerve root diameter, length, and branch lengths.

RESULTS

Mean (SD) values of donor C7 nerve measurements were length, 53.5 (8.0) mm; diameter, 5.1 (0.9) mm; branch length following surgical sectioning, 18.3 (6.3) mm. Right-sided donor C7 nerve roots yielded significantly longer branches compared with left-sided donor C7 nerve roots (P = 0.01). Other patient factors such as age, sex, or laterality of brain injury did not influence intraoperative anatomy.

CONCLUSIONS

We report detailed intraoperative measurements of the donor C7 root during CC7 nerve transfer for spastic hemiplegia. These findings describe existing variation in surgical C7 nerve root anatomy in patients undergoing this procedure and may serve as a general reference for the expected donor C7 length in successful direct anastomosis.

A preliminary observational study on the vascular, nerve, and lymphatic anatomy and histology of the labia minora from cadaveric and surgical samples

INTRODUCTION AND HYPOTHESIS

To better understand details of the fine anatomy of the labia minora, present images of the vascular anatomy and characterize the nerve and lymphatic distribution of the labia minora.

METHODS

Two fixed and five fresh cadaveric specimens were perfused and dissected, and the vascular network was photographed. Labia minora samples, prepared from cadavers, and tissue resulting from labia reduction surgery underwent hematoxylin and eosin staining and S100 and D2-40 immunohistochemical staining.

RESULTS

Arteries emanated from the base to the edge of the labia minora, where there was a larger feeding artery, and the arteries were anastomosed. The veins formed anastomotic branches in the same direction as the edge of the labia minora. Arteries and veins that accessed the labia minora were successfully perfused at the same time with no obvious association. Sensory nerve endings were abundant, mostly larger with myelinated nerve trunks and Schwann cells in the central area with suggested neurovascular associations and smaller with no obvious aggregation at the edge. The medial area had 23.63 ± 11.82 nerves/view, the lateral area 21.30 ± 11.49 nerves/view (P > 0.05). The thickest nerve bundle was 3.16 ± 1.41 mm from the medial epidermis and 3.13 ± 1.47 mm from the lateral epidermis. Lymphatic vessels showed no obvious regional distribution. Labia minora were 21.77 ± 5.69 mm wide with 252.87 ± 63.01 lymphatic vessels at 3.67 ± 1.61/mm2 density. The shortest inner diameter of dilated lymphatic vessels was 161.09 ± 49.99 μm.

CONCLUSION

A larger feeding artery exists in the labia minora, which should be noticed in the pre-surgery design of labiaplasty. No difference was observed in the nerve distribution between the medial and lateral sides. Lymphedema might not be the cause of labial hypertrophy.

Transvaginal minimally invasive approach: An update on safety from an anatomical, anatomopathological and clinical point of view

INTRODUCTION

The aim of this work was to analyze the transvaginal approach in minimally invasive surgery in terms of anatomical, histopathological and functional characteristics, to show the safety of this surgical approach.

METHODS

Anatomical study was first conducted by dissection on fresh cadavers of adult women in order to measure the distance between the vaginal incision and the ureters, rectum and hypogastric nerves. In parallel, an anatomopathological study detailed and compared the macroscopic and histological characteristics of the anterior and posterior surfaces of vaginal samples obtained from cadavers and patients in the context of a hysterectomy for benign pathology. Finally, patients who underwent a transvaginal approach nephrectomy or transplantation were retrospectively enrolled for a clinical examination and an evaluation of their sexuality.

RESULTS

The anatomical study conducted on seventeen cadavers showed that the posterior vaginal fornix was remote from the major structures of the pelvis such as rectum, ureters, hypogastric plexus, which allowed a safe incision. Mechanical tests further demonstrated that the posterior vaginal fornix was more extensible than the anterior and histological features showed no major vascular or nervous structures. Ten patients were included in the retrospective clinical study. Long-term follow up showed no negative impact on the texture of the vagina or satisfaction from sexual intercourse.

CONCLUSIONS

Anatomical, histological and functional data supported that transvaginal approach by posterior vagina fornix incision is a minimally invasive surgery that can be performed safely and effectively by a skilled surgeon in cases with a specific surgical indication for this approach.

Bifascicular nature of the flexor digitorum profundus and flexor pollicis longus tendons: forgotten anatomical characteristics rediscovered with US imaging

OBJECTIVES

To demonstrate the bifid configuration of the flexor digitorum profundus (FDP) and flexor pollicis longus (FPL).

METHODS

In the first part of this study, 20 digits from 4 cadaver hands were dissected and analyzed using anatomical and histological slices. The second part of the study was carried out over a 12-month period starting in August 2018. It was a prospective US imaging study of 300 digits from 30 healthy participants performed by two radiologists in a double-blinded manner. This study focused on two items: tendon shape and whether a central septum separated the two hemitendons. Descriptive statistics were calculated along with the inter-rater reliability.

RESULTS

In 100% (300/300) of fingers and thumbs, the FDP and FPL tendons were made up of two parallel bundles arranged side by side, with a central vertical septum between these two hemitendons, starting at the head of the proximal phalanx (PP) and continuing distally. This central septum was always present starting at the proximal third of PP for the FDP of the index, middle, and ring fingers. The septum was more difficult to identify in the thumb and little finger. Cohen's kappa indicated near perfect agreement when all digits were considered together (≥ 0.9), and substantial agreement for the thumb (0.71) and for the little finger (0.82).

CONCLUSIONS

With US imaging, the bifascicular nature of the FDP and FPL tendons is easy to see, as these tendons have a double-barreled configuration starting at the head of the proximal phalanx.

KEY POINTS

•Analysis of anatomical slices of the hand tendons found a bifascicular appearance of the flexor digitorum profundus and flexor pollicis longus tendons starting at the head of the proximal phalanx. •This distinct feature of two hemitendons arranged side by side was seen in 100% of tendons we examined with US. It is associated with a vertical central septum that causes anisotropy. •Awareness of this "forgotten" anatomical detail has practical implications when interpreting images generated by latest-generation US systems and during surgery on hand flexor tendons.

Single origin of the epithelium of the human middle ear

OBJECTIVE

The epithelium lining the human middle ear and adjacent temporal bone cavity shows a varying morphological appearance throughout these cavities. Its embryologic origin has long been debated and recently got attention in a newly proposed theory of a dual embryologic origin. The epithelial morphology and its differentiating capabilities are of significance in future mucosa-targeted therapeutic agents and could affect surgical approaches of the temporal bone. This study aims to analyze reported murine histological findings that led to the theory of a dual epithelial embryological origin and immunohistochemically investigate whether such an epithelial embryological origin in the human fetal middle ear could be true.

METHODS

By combining a sagittal sectioning technique and immuno-histochemical staining, a comprehensive immuno-histological overview of the fetal human middle ear during a critical stage of tympanic cavitation was provided. A critical analysis of previously reported findings leading to the theory of a dual epithelial embryological origin and a comparison of these findings to the findings in the human fetal middle ear was performed.

RESULTS

The reported findings and critical analysis provide multiple arguments for an entirely endodermal embryonic origin of the epithelium lining the tympanic cavity.

CONCLUSION

Different morphological epithelial appearances throughout the tympanic and temporal bone cavities could be explained by different stages of epithelial differentiation rather than different embryologic origin and endodermal rupture does not seem to be a necessity for these cavities to form.

Surgical anatomy of the upper eyelid relating to upper blepharoplasty or blepharoptosis surgery

Eyelid anatomy, including thickness measurements, was examined in numerous age groups. The thickest part of the upper eyelid is just below the eyebrow (1.127±238 µm), and the thinnest near the ciliary margin (320±49 µm). The thickness of skin at 7 mm above the eyelashes was 860±305 µm. The results revealed no significant differences among the age groups. Fast fibers (87.8±3.7%) occupied a significantly larger portion of the orbicularis oculi muscle (OOM) than nonfast fibers (12.2±3.7%). The frontalis muscle passed through and was inserted into the bundles of the OOM on the superior border of the eyebrow at the middle and medial portions of the upper eyelid. Laterally, the frontalis muscle inserted about 0.5 cm below the superior border of the eyebrow. Fast fibers occupied a significantly larger portion of the OOM than did non-fast fibers. The oculomotor nerve ends that extend forward to the distal third of the levator muscle are exposed and vulnerable to local anesthetics and may be numbed during blepharoplasty. The orbital septum consists of 2 layers. The outer layer of loose connective tissue descends to interdigitate with the levator aponeurosis and disperses inferiorly. The inner layer follows the outer layer, then reflects and continues posteriorly with the levator sheath. Widths of the tarsal plate at its lower border, mid-height, and upper border were 21.8±1.8, 16.2±1.6, and 8.3±1.0 mm, respectively. The widths of the levator aponeurosis were 32.0±2.2, 29.2±3.5, and 27.2±3.9 mm, respectively. Below the levator, the "conjoint fascial sheath" (CFS) is attached to the conjunctival fornix. The CFS was 12.2±2.0 mm anteroposterior length and 1.1±0.1 mm thick. The shape was equilateral trapezoid with a longer base anteriorly. The superior palpebral muscle was trapezoidal. The lengths of its sides were 15.58±1.82 and 22.30±5.25 mm, and its height was 13.70±2.74 mm. The width of the levator aponeurosis was approximately 4 mm wider than the superior palpebral muscle.

Ultrasound-assessed non-culprit and culprit coronary vessels differ by age and gender

AIM: To investigate age- and gender-related differences in non-culprit versus culprit coronary vessels assessed with virtual histology intravascular ultrasound (VH-IVUS).

METHODS: In 390 patients referred for coronary angiography to a single center (Luzerner Kantonsspital, Switzerland) between May 2007 and January 2011, 691 proximal vessel segments in left anterior descending, circumflex and/or right coronary arteries were imaged by VH-IVUS. Plaque burden and plaque composition (fibrous, fibro-fatty, necrotic core and dense calcium volumes) were analyzed in 3 age tertiles, according to gender and separated for vessels containing non-culprit or culprit lesions. To classify as vessel containing a culprit lesion, the patient had to present with an acute coronary syndrome, and the VH-IVUS had to be performed in a vessel segment containing the culprit lesion according to conventional coronary angiography.

RESULTS: In non-culprit vessels the plaque burden increased significantly with aging (in men from 37% ± 12% in the lowest to 46% ± 10% in the highest age tertile, P < 0.001; in women from 30% ± 9% to 40% ± 11%, P < 0.001); men had higher plaque burden than women at any age (P < 0.001 for each of the 3 age tertiles). In culprit vessels of the lowest age tertile, plaque burden was significantly higher than that in non-culprit vessels (in men 48% ± 6%, P < 0.001 as compared to non-culprit vessels; in women 44% ± 18%, P = 0.004 as compared to non-culprit vessels). Plaque burden of culprit vessels did not significantly change during aging (plaque burden in men of the highest age tertile 51% ± 9%, P = 0.523 as compared to lowest age tertile; in women of the highest age tertile 49% ± 8%, P = 0.449 as compared to lowest age tertile). In men, plaque morphology of culprit vessels became increasingly rupture-prone during aging (increasing percentages of necrotic core and dense calcium), whereas plaque morphology in non-culprit vessels was less rupture-prone and remained constant during aging. In women, necrotic core in non-culprit vessels was very low at young age, but increased during aging resulting in a plaque morphology that was very similar to men. Plaque morphology in culprit vessels of young women and men was similar.

CONCLUSION: This study provides evidence that age- and gender-related differences in plaque burden and plaque composition significantly depend on whether the vessel contained a non-culprit or culprit lesion.