Formalin-embalmed Cadavers Research Articles

The morphological and microscopical characteristics of posterior layer of human thoracolumbar fascia; A potential source of low back pain

Posterior layer of thoracolumbar fascia (PTLF) is the deep fascia of back of the trunk, which connects the trunk, upper limb and lower limb muscles. Very few cadaveric studies of posterior layer of thoracolumbar fascia (PTLF) are found in the literature, which mention the presence of nerve receptors in it but, quantification of the nerve receptors where not found. Providing the morphological and morphometrical data of PTLF may help the exercise physiologists, sports physicians, occupational health assistants and, physiotherapists to modify or invent new protocol of treatment to help the society. In this study, twenty formalin embalmed human cadavers were used and we have documented the orientation of the PTLF and quantified the number of peripheral nerve endings at the different vertebral levels. Mean distance of PTLF from vertebral spines to the musculofascial junction was at thoracic region 3.38cm and 3.34cm; at lumbar region, it was 7.4cm and 7.36cm and at sacral region it was 2.98cm and 2.96cm on right and left side, respectively. The angulation of PTLF varies from 18-110 degrees at different vertebral levels. The microscopic data shows the thickness of PTLF and number of nerve endings in the sacral level is increased compared to that of thoracic vertebral levels. We have contributed the novel morphological and microscopical details to the limited existing data on PTLF. We also have provided the quantitative data of nerve fibers, which are possible nociceptors of PTLF.

Precision of computed tomography and cartilage-reproducing image reconstruction method in generating digital model for potential use in 3D printing of patient-specific radial head prosthesis: a human cadaver study

BackgroundA prosthetic replacement is a standard treatment for an irreparable radial head fracture; however, the surface mismatch of the commercially available designs is concerned for the long-term cartilage wear. The patient-specific implant created from 3D printing technology could be favorable in replicating the normal anatomy and possibly reduce such sequela. Our study aimed to assess the precision of the computed tomography (CT) and cartilage-reproducing image reconstruction method (CIRM) in generating digital models for potentially use in manufacturing the patient-specific prosthesis from 3D printing.MethodsEight intact elbows (3 right and 5 left) from 7 formalin-embalmed cadavers (4 males and 3 females) with mean age of 83 years (range, 79–94 years) were used for this study. Computerized 3D models were generated from CT, and CIRM. The cartilage-reproducing image reconstruction method has compensated the cartilage profile based on the distance between the subchondral surfaces of the radial head and surrounding bones in CT images. The models of actual radial head geometry used as the gold standard was generated from CT arthrography (CTA). All models of each specimen were matched by registering the surface area of radial neck along with the tuberosity. The difference of head diameter, head thickness, and articular disc depth among three models was evaluated and analyzed by Friedman ANOVA and multiple comparison test using Bonferroni method for statistical correction. A p-value of less than 0.01 was considered statistically significant. The difference of overall 3D geometry was measured with the root mean square of adjacent point pairs.ResultsThe analysis displayed the difference of diameter, thickness, and disc depth across the models (p< 0.01). Pairwise comparisons revealed statistically significant difference of all parameters between CTA models and CT models (p< 0.01) whereas no difference was found between CTA models and CIRM models. The mean difference of overall 3D geometry between CTA models and CT models was 0.51±0.24 mm, and between CTA models and CIRM models was 0.24±0.10 mm.ConclusionsCIRM demonstrated encouraging results in reestablish the normal anatomy and could be potentially used in production process of 3D printed patient-specific radial head prosthesis.

Characteristics of the accessory tendon of the extensor hallucis longus muscle: a Taiwanese study.

The main tendon of the extensor hallucis longus (EHL) muscle attaches to the dorsal aspect of the distal phalanx of the great toe. One or multiple accessory tendons of the EHL have been reported in several ethnic/regional groups, except Taiwan. This study aimed to investigate the incidence, length, and insertion of the accessory tendon of the EHL in Taiwanese people. Anatomical dissection was performed on 48 feet of 24 formalin-embalmed cadavers. The occurrence and morphological characteristics of the accessory tendon of the EHL were recorded and analyzed. The accessory tendon of the EHL was found in 97.92% (47/48) of the legs that were dissected. In one male cadaver, an independent muscle belly was identified in each leg, whereas all the other accessory tendons originated from the main tendon of the EHL. In this study, the insertion of the accessory tendon were classified into four patterns. The most common insertion sites were the first metatarsophalangeal (MTP) joint capsule and proximal phalanx of the great toe. The length of the accessory tendons did not correlate with age or with sex when the two tendons with independent muscle belly were excluded. The accessory tendon of the EHL appears to be a regular feature in Taiwanese people. Most accessory tendons of the EHL (85.7%) attached on the first MTP joint capsule may play a role in the prevention of capsular impingement during great toe extension.

The determination of safe zones for arthroscopic portal placement into the posterior knee by mapping the courses of neurovascular structures in relation to bony landmarks.

Minimally invasive surgery in the posterior knee is high risk for iatrogenic injury to popliteal neurovascularneurovasculature structures. This study aimed to use reliable landmarks to define safe zones for arthroscopic portal placement into the posterior knee. Distances were measured between bony landmarks and neurovascular structures within the popliteal fossa using 45 formalin-embalmed cadavers: small saphenous vein (SSV), medial (MCSN) and lateral (LCSN) cutaneous sural nerves, tibial nerve (TN), common fibular nerve (CFN), popliteal vein (PV) and artery (PA). The structures were measured in relation to medial (MEF) and lateral (LEF) femoral epicondyle, medial (MCT) and lateral (LCT) tibial condyle and the midpoint between the landmarks. The mean distance (mm) between MEF and structures was, male and female, respectively: SSV 37.6 + 12.5, 37.9 + 8.2; MCSN 39.2 + 14, 38.8 + 10.1; TN 39.4 + 10.2, 38.0 + 8.1; PV 38.4 + 12.9, 32.8 + 5.6; PA 38.4 + 12.1, 34.6 + 4.9. At midpoint and MCT all structures medialized between 5 and 28%. The mean distance between LEF and structures was, male and female, respectively: CFN 13.4 + 8.2, 8.4 + 9.1; LCSN 24.9 + 7.3, 18.4 + 10.4. At midpoint and LCT the CFN lateralized by 37-42% and the LCSN medialized by 8-9%. Results suggest posteromedial portal placement can be safely established < 20mm from the medial femoral epicondyle, tibial condyle or the midpoint between the two landmarks. Posterolateral portal placement is of higher risk, and entry point is 18mm from the lateral femoral epicondyle, tibial condyle or the midpoint between the two landmarks in males and 12mm in females. These landmarks will allow safe portal placement in 99% of cases.

Variations in Surgical Anatomy of Common Carotid Artery: A Cadaveric Study

Introduction: Carotid arterial system constitutes the principal blood supply of head, neck and brain. In various physiological mechanisms and pathological processes, carotid bifurcation is an important site both anatomically and surgically. Selection of surgical techniques between carotid stenting and carotid endarterectomy requires prior knowledge of level of carotid bifurcation. Aim: To observe the origin, level of bifurcation and geometric measurements of common carotid artery and its variations. Materials and Methods: An observational cross-sectional study was done on 60 formalin embalmed human adult cadavers, of which 47 were male and 13 were female aged between 35-75 years, which were allotted for dissection for first year Bachelor of Medicine and Bachelor of Surgery (MBBS) students in the Department of Anatomy, Government Siddhartha Medical College, Vijayawada, NRI Medical College, Chinakakani and Dr. Pinnamaneni Siddhartha Institute of Medical Sciences and Research Foundation, Chinoutapalli, India, during the academic years December 2013 to March 2018. Observations from both right and left common carotid arteries (total 120 sides) were noted. The data observed was tabulated. Statistics in terms of simple percentages were used. The mean arterial diameter±standard deviation of both right and left common carotid arteries were calculated using the Microsoft office excel sheet. Results: In the present study, total of 120 sides of 60 origin of right common carotid artery was found normal and the origin of left common carotid artery from brachiocephalic trunk was found in 5%. Normal level of bifurcation of common carotid artery was found in 82 (68.33%) sides, high level in 26 (21.66%) sides and low level in 12 (10%) sides. The mean arterial diameter±standard deviation of lumen at the origin of right common carotid artery was 0.887±0.132 cm and left common carotid artery was 0.906±0.128 cm and for both right and left common carotid arteries was 0.896±0.129 cm. Conclusion: Detailed study of surgical anatomy of common carotid artery is important for many surgical, radiological and clinical applications. Knowledge of its variations will help to make alterations in surgical interventions and radiological procedures.

The Feasibility of Ultrasound-Guided Knee Arthrocentesis Training Using Formalin-Embalmed.

Background:The use of ultrasound guidance during knee arthrocentesis has proven to increase operator confidence and accuracy, particularly in novice healthcare providers. Realistic and practical means of teaching this procedure to medical trainees are needed. This study is intended to assess the feasibility and efficacy of using formalin-embalmed human cadavers in the instruction of ultrasound-guided knee arthrocentesis to medical trainees.Methods:Twenty participants received a 30-minute didactic orientation detailing the principles of ultrasound-guided knee arthrocentesis, followed by a training practicum performed on human cadavers. The practicum included a 25-minute training period, followed by a 15-minute assessment period. Participants were objectively assessed on their ability to independently aspirate synovial fluid from the suprapatellar bursa using ultrasound guidance. Digital pretraining and posttraining questionnaires were administered to evaluate each participant’s confidence in their ability to independently locate the site of optimal needle placement and successfully aspirate synovial fluid with the guidance of ultrasound imaging.Results:An analysis via the Wilcoxon rank sum testing revealed that participant self-confidence increased significantly after training across all assessment items (p < 0.0001). Fifteen participants (75%) successfully aspirated 1 mL of synovial fluid on their first attempt, whereas 3 participants (15%) were successful on their second attempt. Two participants (10%) failed to perform a successful aspiration within the 15-minute time limit. The average time required to aspirate 1 mL of synovial fluid was 41 seconds.Conclusions:Ultrasound images of the formalin-embalmed suprapatellar bursa are of sufficient quality to use in the instruction of arthrocentesis to medical trainees. Brief instruction using formalin-embalmed cadaver models significantly increases trainee confidence and prepares first-year medical students to successfully and independently perform ultrasound-guided knee arthrocentesis.

Effect of Embalming Fluid on the Histological Appearance of Organs - A Cadaveric Study

Objective: Histopathological investigations with tissues from embalmed cadavers are generally notconsidered ideal for determining the cause of death at autopsy in forensic medicine. Instead fresh tissuefixed in 10% formalin is usually preferred. The aim of the present study was to compare the histologicalappearances of samples processed from routine formalin-embalmed cadaver with samples fixed in 10%formalin from a fresh cadaver.Methods: The study was carried out on cadavers received as donation to the department of Anatomy frombody donors. Tissue samples of four organs comprising kidney, lung, liver and spleen were obtained from afresh cadaver (used as control) as well as from embalmed cadavers. The quality of the slides was graded 1to 3 based on organ microscopic architecture, cell morphology and state of epithelium, as follows: 1 - highdegree of cell distortion, 2 -moderately good sections and 3 - near normal.Results: Kidney: Slight architectural distortion, with collapsed convoluted tubules were observed inembalmed tissue sections (grade 2). Lung: The architecture of the embalmed tissue showed alveolarspaces that were cystically dilated, but pneumocytes appeared normal (grade 2). Liver and spleen: Thecell morphology and The cell morphology and architecture appeared almost as preserved as in fresh tissue.(grade 3).Conclusion: Of the four organs studied, liver and spleen were well preserved and close to normal, whereascytoarchitecture of lung and kidney specimens showed slight distortion. However this is a preliminary studyand efforts are on to study more number of specimens with varying concentrations of formalin.

Fiber type composition of contiguous palmaris longus and abductor pollicis brevis muscles: Morphological evidence of a functional synergy.

The palmaris longus (PL) tendon is used in surgical opponensplasty to restore functional hand movements in thenar paralysis. Although successful PL autologous tendon transfer has been attributed to an established synergistic relationship between the PL and abductor pollicis brevis (APB) muscles in vivo, this functional relationship may be dependent on the quality of their spatial relationship and properties of their constituent muscle fibers. The purpose was to compare the proportion of type I and type II muscle fibers in the APB based on its contiguous morphological relationship with the PL tendon for indirect insight into their functional synergy, contractile capacity, and digastric arrangement. Twenty-four contiguous PL and APB specimens were harvested from the upper limbs (12 right and 12 left) of twelve formalin-embalmed cadavers (mean age: 74±10years). The fiber type composition of these muscles was determined by labeling serial cross sections with myosin heavy chain (MyHC) type I and type II monoclonal antibodies. The PL consisted of a relatively heterogeneous fiber type composition irrespective of the presence of a discrete (type I: 41±11%; type II: 55±12%; hybrid: 4±3%) or rudimentary (type I: 49±10%; type II: 45±9%; hybrid: 6±4%) tendinous connection with the APB. The APB fascicles arranged contiguously with the PL through a discrete tendon had significantly greater proportions of type II fibers (41±19%) compared to those with rudimentary PL connections (type II: 15±8%). Therefore, the APB fascicles arranged in a digastric relationship with the PL may have the capacity to produce more powerful contractions than those with rudimentary PL tendons based on the known contractile properties of type II muscle fibers. Knowledge of the spatial relationship between the PL and thenar musculature prior to PL autologous tendon transfer may be a useful indicator of the quality of established synergy in vivo.

Macro/microscopic distribution of the dorsal nerve of penis in human glans penis.

This study aimed to elucidate the macroscopic and microscopic distributions of the dorsal nerve of penis (DNP) that provides the greatest sensitivity over the glans penis. The glandes of 23 penises of formalin-embalmed cadavers were investigated to confirm the macroscopic and microscopic distributions of the DNP within the glans penis by whole-mount Sihler's staining and histological sectioning. Superficial regions of the mid-glans were reconstructed in three dimensions to define the microstructure of terminal branches of the DNP that project towards the skin surface. A mean of 6.7 bundles of the DNP consisting of several nerve fibres converged linearly towards the distal end of the penis, rather than diverging laterally as they travelled. Lateral branches of the DNP extended linearly to the distal end with ramifications, while dorsomedial branches of the DNP gave off nerve fibres to the dorsum of the mid-glans and the corona. The intrastromal ramifications of the DNP were more developed in the distal half of the glans penis than the proximal glans containing the corpus cavernosum. These ramifications gave rise to radial nerve fibres that project towards the skin surface to form a plexiform network of terminal branches in the dermis. Linear projections of the main branches of the DNP throughout the glans and fine networks of terminal branches in the dermis were distinctly visualized in the human penis.

Using formalin embalmed cadavers to teach fracture identification with ultrasound

BackgroundUltrasound is being utilized more frequently to diagnose fractures in bone and track fracture reduction quickly, and without radiation exposure in the ED. Realistic and practical methods of teaching sonographic fracture identification to medical trainees are needed. The objective of this study is to determine the feasibility of using formalin-embalmed human cadavers in teaching medical trainees to use ultrasound to identify synthetic fractures in tibia, radius, and metacarpal bones.MethodsFirst-year medical students attended an orientation presentation and a 15-min scanning workshop, to evaluate fractures in cadaver bones with an instructor. Next participants independently scanned bones to determine if a fracture was present. Questionnaires were given that assessed participant self-confidence and ability to evaluate still ultrasound images for fracture and differentiate between tissue layers before, after, and 5 months following training.ResultsParticipants were collectively able to scan and differentiate between fractured and unfractured bone in 75% of 186 total bone scanning attempts (tibia: 81% correct, metacarpal: 68% correct, radius: 76% correct). When evaluating still ultrasound images for fracture, participants’ scores rose significantly following training from an average score of 77.4 to 91.1% (p = 0.001). Five months post-training, scores fell slightly, to an average of 89.8% (p = 0.325).ConclusionsUltrasound images of formalin-embalmed cadaveric fractures are of sufficient quality to use in teaching fracture identification to medical trainees. With only 15 minutes of scanning experience, medical trainees can learn to independently scan and significantly increase their ability to identify fractures in still ultrasound images.

Three-dimensional reconstruction of the luminal structure of human seminal vesicle.

The seminal vesicles are the glands of male reproductive organs that produce the fluid and nutrient constituents of semen. It has been believed for a long time that the lumen of a seminal vesicle was a single-coiled tubular structure with irregular diverticula. There are several previous reports on the symmetry, differences in morphological sizes and classification of the seminal vesicles. However, a three-dimensional-coiled tubular structure is difficult to understand using a classical anatomical methodology, and hence, three-dimensional reconstruction is needed to understand the structure of the lumen. Thirty-one seminal vesicles harvested from 21 formalin-embalmed cadavers were investigated. The seminal vesicle along with the ampulla of the ductus deferens was separated, and the length and width of each seminal vesicle were measured. The vesicles were then embedded in coloured paraffin, and the resulting paraffin block was sectioned transversely and photographed at an interval of 500μm, with the sectioned surfaces then utilized in three-dimensional reconstruction performed by 'Reconstruct' software. The mean length and width of the seminal vesicles were 39.4mm and 13.4mm, respectively, and the right seminal vesicle was a little larger than the one on the left. The size differed from previous reports, while the luminal structure was similar to the classification of Aboul-azm (Archives of Andrology, 3, 1979, 287-292) but differed from that of Pereira (AJR. American Journal of Roentgenology, 69, 1953, 361-379). The seminal vesicles typically comprised about 9 curls and had about 12 diverticula. The seminal vesicles resembled a skein of coral rather than comprising a single strand. These findings will help in improving the understanding of pathophysiologies of the seminal vesicles, such as recurrent inflammation of the gland.

Morphological Study of the Posterior Tibial Nerve in Tarsal Tunnel of the Human Foot

The passage of the posterior tibial nerve in the tarsal tunnel has a great clinical significance, thus detailed anatomical knowledge is mandatory for safe clinical intervention. This study was to identify the morphological appearance of the tibial nerve and its bifurcation. Sixty lower limbs of formalin embalmed cadavers were randomly selected. Data were collected through the application of standard dissection method of the tarsal tunnel of lower limbs (30 rights and 30 left) of formalin embalmed cadavers. The posterior tibial nerve and its branches were exposed from the distal end of the leg toward plantar surface beyond its bifurcation by resecting the skin and flexor retinaculum. The study triggered several findings: The posterior tibial nerve is flattened shaped in 21 specimens 70% and has a rounded shape in 9 specimens 30%in the right foot. In the left foot it is flattened in 17 specimens 56.7% and rounded shape in 13 specimens 43.3%. Posterior tibial nerve bifurcates into medial and lateral planter nerves inside tarsal tunnel in 20 specimens 66.7% in the right foot and in 21 specimens 70% in the left foot. This study concludes that posterior tibial nerve commonly has flattened shape and divided into medial and lateral planter nerves inside tarsal tunnel.

Intramuscular Nerves of the Inferior Rectus Muscle: Distribution and Characteristics

ABSTRACT Purpose Knowledge of the distribution of intramuscular nerves of the extraocular muscles is crucial for understanding their function. The purpose of this study was to elucidate the intramuscular distribution of the oculomotor nerve within the inferior rectus muscle (IRM) using Sihler’s staining. Method Ninety-three IRM from 50 formalin-embalmed cadavers were investigated. The IRM including its branches of the oculomotor nerve was finely dissected from its origin to the point where it inserted into the sclera. The intramuscular nerve course was investigated after performing Sihler’s whole-mount nerve staining technique that stains the nerves while rendering other soft tissues either translucent or transparent. Results The oculomotor nerve enters the IRM around the distal one-fourth of the muscle and then divides into multiple smaller branches. The intramuscular nerve course finishes around the distal three-fifth of the IRM in gross observations. The types of branching patterns of the IRM could be divided into two subcategories based on whether or not topographic segregation was present: (1) no significant compartmental segregation (55.9% of cases) and (2) a several-zone pattern with possible segregation (44.1% of cases). Possible compartmentalization was less clear for the IRM, which contained overlapping mixed branches between different trunks. Conclusion Sihler’s staining is a useful technique for visualizing the gross nerve distribution of the IRM. The new information about the nerve distribution and morphological features provided by this study will improve the understanding of the biomechanics of the IRM, and could be useful for strabismus surgery.

Fiber Type Composition of Contiguous Palmaris Longus and Abductor Pollicis Brevis Muscles: Morphological Evidence of a Functional Synergy

IntroductionThe palmaris longus (PL) tendon can be transferred to the thumb for use in surgical opponensplasty to restore functional hand movements in patients with thenar paralysis. Successful opponensplasty outcomes using the PL tendon have been attributed to an intrinsic synergy of the PL with the abductor pollicis brevis (APB) such that no specific muscular retraining is needed upon tendon transfer. This synergy has been demonstrated electromyographically in which synchronous EMG signals were recorded from the PL and APB during functional thenar movements in healthy young individuals, in vivo. Thus, although an established synergistic relationship between these muscles has been demonstrated, this functional relationship may depend on their spatial relationship and properties of their constituent muscle fibers. The purpose of this study was to compare the proportions of type I and type II muscle fibers in the APB from cadaveric muscle based on its contiguous morphological relationship with the PL tendon for further insight into their functional synergy, contractile capacity and digastric arrangement.MethodsTwenty‐four contiguous PL and APB specimens were harvested from the upper limbs (12 right, 12 left) of twelve formalin‐embalmed cadavers (mean age: 74 ± 10 years). The 24 limbs were classified into two groups based on the following morphological criteria: (1) APB with discrete PL tendon connections, or (2) APB with non‐discrete, or rudimentary, PL tendon connections. Cadaveric specimens were obtained from the body bequeathal program at the University of Western Ontario and approved for research use by the Committee for Cadaver Use in Research (REF#21092016). The fiber type composition of the APB and PL muscles was determined by labeling serial cross‐sections with myosin heavy chain type I and type II monoclonal antibodies.ResultsThe APB fascicles from 11 hands (46%) were classified as discrete based on their continuity with the PL tendon. Conversely, the APB fascicles from 13 hands (54%) were classified as non‐discrete due to rudimentary or minimal connections with the PL tendon. The PL consisted of a relatively heterogeneous fiber type composition irrespective of the presence of a discrete (type I: 41 ± 11%, type II: 55 ± 12%, hybrid: 4 ± 3%), or rudimentary (type I: 49 ± 10%,type II: 45 ± 9%, hybrid: 6 ± 4%), tendinous connection with APB musculature. The APB fascicles arranged in a digastric manner with the PL tendon had significantly greater proportions of type II fibers (41 ± 19%) compared to those with rudimentary PL connections (type II: 15 ± 8%).ConclusionThe APB fascicles arranged in a digastric relationship with the PL may have the capacity to produce more powerful contractions than those with rudimentary PL tendons based on the known contractile properties of type II muscle fibers. Knowledge of the spatial relationship between the PL and thenar musculature prior to PL autologous tendon transfer may be a useful indicator of the quality of established synergy in vivo.Support or Funding InformationSupported by NSERC

Skull Abnormalities in Cadavers in the Gross Anatomy Lab.

Background The skull encompasses and houses one of the most important organs in the body—the brain—and like all tissues in the body, it is comprised of living cells that are constantly remodeling as this maintains the strength and homeostasis of the bone. In the present study, abnormal bone growth patterns were observed and the possible causes of said findings were investigated in multiple cadaver skulls dissected during head and neck anatomy courses at Detroit Mercy Dental over the past year. There are many factors, both intrinsic and extrinsic, with differences in stimulation to the skull resulting in skull abnormalities. Materials and Methods. For this study, skull abnormalities were examined from 65 formalin-embalmed cadaver heads, obtained from the Gross Anatomy Laboratory at the University of Detroit Mercy School of Dentistry between the years 2016 and 2019. We have recorded the age, sex, and previous chief medical issues of all lab specimens used in the study. Skulls were later evaluated for possible indications of bone disease such as hypertosis frontalis interna (HFI) or Paget's disease. Results Among the sixty-five specimens provided to the Detroit Mercy Dental cadaver lab, 19 specimens (29%) were found to present with irregular, undulating, thickening of the frontal bone internal surface. The findings located on the skulls closely resembled the gross anatomic appearance of HFI or Paget's disease; however, a conclusive diagnosis of these skull abnormalities cannot be made without a pathologist biopsy and radiological examination. Twelve of the nineteen specimens that displayed possible bone disease, approximating 63% prevalence, were females; their ages ranged from 68 to 95 years old. Thus, seven of the nineteen specimens exhibiting features of skull abnormalities, approximating 36% prevalence, were males with ages ranging from 70 to 103 years old. In addition, five of these nineteen specimens collected (26% prevalence) had been diagnosed with neurological disorders, including Alzheimer's, dementia, depression, and Parkinson's disease. In the current study, the proportion of specimens exhibiting skull abnormalities was higher compared to the overall prevalence observed in previous studies. Conclusion Possible causes of observed anatomical abnormalities in the skull of cadavers of a gross anatomy laboratory were investigated, and it was determined that hypertosis frontalis interna (HFI) may contribute to such abnormalities. This is a condition that affects bone growth in the frontal skull. Our numbers of skull abnormalities were higher than previous studies and might be due to the fact that HFI was predominately present as an incidental finding during imaging of postmenopausal females or observed postmortem in cadavers. In addition, Paget's disease or hormonal imbalances could also result in similar features, and thus cannot be ruled out as a plausible cause. Paget's disease causes the bone to deposit at a faster rate than normal, which will result in thick and brittle bone. Studies that will involve further examination of new cadavers for the presence of HFI is needed, either using biopsy specimens and/or radiological examination to explore possible causes for the abnormal bone growth in the frontal bone.

Formalin embalmed cadavers are effective training tools for hands-on skills training of combat advanced trauma life support course (C-ATLS)

Introduction: Use of cadavers as replacement of mannequins has been practiced since many years now and they are more suitable in resource scarce societies where cadavers are available. Cadavers that are used for the purpose of anatomy teaching at undergraduate level can be used for hands on training of various clinical and procedural skills. We describe the finding of a hands on workshop on procedural skills conducted at our institute. Methodology: During hands on session of combat advanced trauma life support course (C-ATLS), procedural skills Tracheostomy, Colostomy, Diagnostic Peritoneal Lavage, Suprapubic Catheter Insertion, Tube Thoracostomy, Pericardiocentesis, Venesection and Application of External Fixator were taught using traditionally embalmed human cadavers. Structured and non-structured feedbacks from both facilitators of the course and participants were obtained to assess the suitability of cadavers for skills training. Results: Most facilitators and participants responded that use of cadavers in the skills training was suitable as per the learning objectives and needs. Some drawbacks of using these cadavers were also noted. Conclusion: Traditionally fixed human cadavers can be effectively used for hands on training program of procedural skills of C-ATLS.

Intramuscular Nerve Distribution of the Inferior Oblique Muscle

ABSTRACTPurpose: The intramuscular nerve distribution in the extraocular muscles is important for understanding their function. This study aimed to determine the intramuscular nerve distribution of the oculomotor nerve within the inferior oblique muscle (IO) using Sihler’s staining.Method: Seventy-two IOs from 50 formalin-embalmed cadavers were investigated. The IO including its branch of the oculomotor nerve was finely dissected from its origin to its insertion point into the sclera. The total length of the muscle and its width were measured. The intramuscular nerve course was investigated after performing Sihler’s staining, which is a whole-mount nerve-staining technique that stains the nerves while rendering other soft tissues either translucent or transparent.Results: The total length of the muscle and muscle width were 30.0 ± 2.8 mm (mean±standard deviation), 8.8 ± 1.2 mm, respectively. The oculomotor nerve enters the IO around the middle of the muscle and then divides into multiple smaller branches without distinct subdivisions. The intramuscular nerve distribution within the IO has a root-like arborization and supplies the entire width of the muscle. The Sihler’s stained intramuscular nerve course (covering a length of 7.6 ± 1.2 mm) finishes around the distal one-third of the IO in gross observations.Conclusion: Sihler’s staining is a useful technique for visualizing the gross nerve distribution of the IO. This new information about the nerve distribution and morphological features will improve the understanding of the biomechanics of the IO.

Topography of the Central Retinal Artery Relevant to Retrobulbar Reperfusion in Filler Complications.

Vision loss caused by retrograde occlusion of the central retinal artery is a serious complication of cosmetic filler injections. Salvage methods that involve applying hyaluronidases in the retrobulbar space to degrade filler materials have been proposed recently for rescuing the retinal circulation in an ophthalmic emergency. Sixty-six eyeballs and orbital contents were extracted from formalin-embalmed cadavers and dissected carefully to examine the topographic relationship of the central retinal artery and optic nerve. To observe the three-dimensional course of a central retinal artery that invaginates into the optic nerve, serial sections reconstructed at 100-μm intervals using software were visualized in 11 specimens. The central retinal artery ramified from the ophthalmic artery and entered the optic nerve inferiorly at 8.7 ± 1.7 mm (mean ± SD) from the posterior margin of the eyeball. The intraneural course of a central retinal artery changed acutely between the periorbital environment of the fibrous optic nerve sheath, intermediate subarachnoid spaces, and center of the optic nerve stroma. When applying a retrobulbar approach for central retinal artery reperfusion with hyaluronidases, the reliable access route is suggested to be at a depth of 3.0 to 3.5 cm from the border of the inferolateral orbital rim, based on consideration of the entry point of the central retinal artery into the optic nerve.

Anatomical Implications Regarding Femoral Nerve Palsy During a Direct Anterior Approach to Total Hip Arthroplasty: A Cadaveric Study.

Femoral nerve palsy is a serious neurological complication following total hip arthroplasty (THA) via a direct anterior approach. One hypothesis is that the nerve injury is caused by malpositioning of retractors over the anterior wall of the acetabulum. The purpose of this cadaveric study was to clarify the anatomical features of the femoral nerve around the anterior acetabular rim and the potential risk of nerve injury during a direct anterior approach to THA. We dissected 84 cadaveric hips from 44 formalin-embalmed cadavers. When the cadavers were supine, the iliopsoas muscle and the femoral nerve were exposed and the anterior joint capsule and labrum were resected. The measurement points were determined along the acetabular rim every 30°, and a reference line was drawn from the anterior superior iliac spine to the center of the acetabulum, with the intersection of the rim at 0°. The minimum distance to the femoral nerve margin was measured from 0° to 150° (6 points). Other anatomical structures were measured to determine their association with the distance of the shortest measurement points. The mean minimum distances to the femoral nerve were 33.2 mm at 0°, 24.4 mm at 30°, 18.4 mm at 60°, 16.6 mm at 90°, 17.9 mm at 120°, and 23.2 mm at 150°, showing that the distance at 90° was the shortest (p < 0.001). The thickness of the iliopsoas muscle and the femoral length were positively associated with the distance to the femoral nerve at 90°. In this cadaveric study, the femoral nerve was within 16.6 to 33.2 mm of the acetabular rim at points from 0° to 150° of a line drawn from the anterior superior iliac spine. The nerve was closest to the rim at 90°, indicating that this is an area of high risk during retractor placement. Retractor placement at 90° to the anterior acetabular rim should be avoided to reduce the risk of femoral nerve injury.

Branching Pattern of the Medial Calcaneal Neurovascular Bundle in Porta Pedis of the Human Foot

The medial calcaneal nerve (MCN) is the first branch of the posterior tibial nerve (PTN) in the porta pedis, enervates the skin of the heel and medial side of the foot. Heel pain is a common condition encountered by physicians, and this may have a significant clinical association with the MCN’s branching pattern. This study was to identify branching pattern variations in the medial calcaneal neurovascular bundle. This study was carried out using 60lower limbs of formalin-embalmed cadavers, using the tarsal tunnel dissection method for 30right and 30 left lower limbs. The medial calcaneal neurovascular bundle course was identified by exposing the PTN and its branches from the distal end of the leg toward the plantar surface beyond its bifurcation and resecting the skin and flexor retinaculum. Many MCN branching pattern variations (specifically concerning origins, numbers, and levels of branching) were observed. In the right foot a single branch was present in 21 specimens (70%), while two branches were observed in nine specimens (30%). In the left foot, a single branch was present in 22 specimens (73.3%) and two branches were present in 8 specimens (26.7%). In this study, two branches originate from lateral planter artery is the most common observation. This study concludes that a single MCN originating from the TN is the most common variant. Two medial calcaneal arteries (MCAs) originating from the LPA is also common.