The variations of osseous structure of the internal acoustic canal: an anatomical study.

OBJECTIVES: The internal acoustic meatus is an osseous canal that connects the inner ear to the posterior cranial fossa. It is located in the petrous portion of the temporal bone. A thin cribriform osseous plate known as the fundus is situated at the lateral end of the canal. This study assesses the structural and numerical variations of the fundus formations. METHODS: Fifty-four temporal bones of unknown gender and age were examined with the surgical microscope. RESULTS: The temporal bones analyzed were 46.2% right-sided and 53.7% left-sided. Only one temporal bone had two parallel transverse crests, while three had a single anterior crest that split into two branches posteriorly. The number of foramina at the transverse crest varied, with 29.6% having none, 48.1% having a single foramen, and 22.2% having several foramina. An anterior crest structure was seen in 53.7% of the temporal bones, with 5% having a slightly constricted entry to the facial canal. In cases with a single nerve foramen, 48.1% had one, while 51.8% had more than one, including examples with three or four foramina. A crest was found between the foramina of the single nerve in 7% of patients. Furthermore, a crest between the saccular nerve foramen and the high fiber foramina was seen in 25.9% of cases, and 5% had two saccular nerve foramina. CONCLUSION: We think that revealing the anatomical, structural and numerical variations in the fundus will be useful in explaining the disease-symptom relationship. LEVEL OF EVIDENCE: Level 4.

A case of left testicular artery with high origin passing through a left renal vein fenestration.

BACKGROUND: Fenestrations of are extremely rare in the venous system, especially renal veins. This paper aims to present a case of left renal vein fenestration where a high origin testicular artery passes through it. Materials and Methods The variation was observed incidentally in a 74-year-old Caucasian male cadaver during routine retroperitoneal dissections for second year medical students. RESULTS: A fenestration in the mid portion of the left renal vein was observed. The length and height of the fenestration was 23 and 3.6 millimeters, respectively. The left testicular artery passed through the fenestration and followed a normal course distal to the fenestration. Posterior to the left renal vein, the testicular artery originated from the lateral aspect of abdominal aorta, just caudal to the left renal artery. On the right side, the testicular artery had a similar high origin, and two renal arteries were present. No venous variations were observed on the right side. CONCLUSIONS: The long course of the left renal vein is a factor of preference for donor kidney selection. Uncommon variations of the left renal veins, such as fenestrations, might result in a change in surgical technique and would put the left donor kidney at risk of prolonged anastomosis time and lower survival rates.

The variations of osseous structure of the ınternal acoustic canal: an anatomical study

Abstract Objectives The internal acoustic meatus is an osseous canal that connects the inner ear to the posterior cranial fossa. It is located in the petrous portion of the temporal bone. A thin cribriform osseous plate known as the fundus is situated at the lateral end of the canal. This study assesses the structural and numerical variations of the fundus formations. Methods Fifty-four temporal bones of unknown gender and age were examined with the surgical microscope. Results The temporal bones analyzed were 46.2% right-sided and 53.7% left-sided. Only one temporal bone had two parallel transverse crests, while three had a single anterior crest that split into two branches posteriorly. The number of foramina at the transverse crest varied, with 29.6% having none, 48.1% having a single foramen, and 22.2% having several foramina. An anterior crest structure was seen in 53.7% of the temporal bones, with 5% having a slightly constricted entry to the facial canal. In cases with a single nerve foramen, 48.1% had one, while 51.8% had more than one, including examples with three or four foramina. A crest was found between the foramina of the single nerve in 7% of patients. Furthermore, a crest between the saccular nerve foramen and the high fiber foramina was seen in 25.9% of cases, and 5% had two saccular nerve foramina. Conclusion We think that revealing the anatomical, structural and numerical variations in the fundus will be useful in explaining the disease-symptom relationship. Level of evidence: Level 4.

Topographic and morphometric anatomy of the proximal part of the dorsal scapular nerve.

The dorsal scapular nerve (DSN) entrapment neuropathy has recently been recognized as a common cause of circumscapular pain and cases of winged scapula. Course of the nerve is important because the middle scalene muscle is frequently accessed for surgical treatments. Studies in the literature have not focused on the morphometric relationship of the DSN with the scalene muscles and its relationship with the long thoracic nerve (LTN). The neck regions of 13 adult cadavers were dissected bilaterally. The relationship of DSN with scalene muscles and LTN was evaluated. Cervical spinal nerves involved in the formation of the DSN were identified. Three types of DSN were observed based on the cervical spinal nerves from which it originates, five types of DSN from its relationship with the scalene muscles, and two types of DSN from its relationship with the LTN. The distance from where the nerve pierces the scalene muscle to the mastoid process was found to be greater in DSNs originating from C4 and C5 (93.85 ± 4.11 mm, p = 0.033). In DSNs not connected with LTN, the distance from where the nerve pierces the scalene muscle to the superior trunk/C5 (12.74 ± 7.73 mm, p = 0.008) and the length of the nerve within the scalene muscle (14.94 ± 5.5 mm, p = 0.029) were found to be statistically significantly greater. The topographic and morphometric anatomy of the proximal part of the DSN is important, especially for scalene muscles-focused surgical treatments and interscalene nerve blocks. We believe our results may guide clinical approaches and surgery.

Variations in the course of the externalbranch of the superior laryngeal nerveand their importance in surgicalprocedures: an experimental cadaveric study.

<br><b>Introduction:</b> Injury of the external branch of the superior laryngeal nerve can cause a hoarse or weak voice due to the functional loss (dysergia) of the cricothyroid muscle. Defining the anatomical variations of the external branch of the superior laryngeal nerve and estimating their frequency are crucial for surgical interventions.</br> <br><b>Aim:</b> To reveal the topography of the external branch in the Anatolian population, to prevent injury of it during the surgical intervention in the anterior neck region.</br> <br><b>Material and methods:</b> 26 bilateral hemilarynges (4 females, 22 males) were dissected. The morphometric and morphological features of the external branch were examined. The obtained results were compared statistically, left and right.</br> <br><b>Results:</b> Landmarks such as the thyroid gland and laryngeal prominence were determined for the detection of the external branch. The variations of the course of the external branch and the points of piercing the cricothyroid muscle or inferior pharyngeal constrictor muscle were evaluated.</br> <br><b>Discussion:</b> Although safe approaches have been described for nerve protection during neck surgeries, injuries may occur during preliminary surgery as the mentioned nerve is thinner and more superficial than other branches of the vagus nerve. However, it can be detected more easily and safely by knowing the defined anatomical landmarks and morphological variations of the external branch.</br> <br><b>Conclusion:</b> The anatomical variations described can be a safe and important guide in surgeries of the anterior neck region.</br>.

Publication rates of congress abstracts is associated with abstract quality: Evaluation of Turkish National Medical Education Congresses and Symposia between 2010 and 2014 using MERSQI.

There are many parameters that could be used to evaluate the quality of scientific meetings such as publication rates of meeting abstracts as full-text articles after the meeting or scoring with validated quality scales/tools that evaluate individual papers, project proposals, or submitted abstracts. This study aimed to determine the full-text publication rates for abstracts presented at Turkish National Medical Education Congresses and Symposia and to assess the quality of given abstracts. Abstracts presented at national medical education congresses and symposia between 2010 and 2014 in Türkiye were evaluated. Initially, the abstracts were evaluated if they were published as full-text articles in international and national peer-reviewed journals following the meeting. Secondly, the quality of presented abstracts was assessed with the Medical Education Research Study Quality Instrument (MERSQI) scale. Overall publication rate for the abstracts was 11.3%. The publication rate of oral and poster presentations were 26.6% and 8.1%, respectively. Oral presentations had a statistically higher publication rate than poster presentations (p = .000). The mean MERSQI score for abstracts was 7.73 ± 2.59. The oral presentations had higher MERSQI mean scores than poster presentations (8.28 ± 2.46 vs. 7.61 ± 2.6; p = .032). Similarly, published abstracts had a significantly higher score compared to unpublished abstracts (10.07 ± 2.74 vs. 7.43 ± 2.41; p = .000). Interestingly, there was no statistical difference between the mean MERSQI scores of the published oral and poster presentations (9.33 ± 2.45 vs. 10.61 ± 2.72; p = .101). This study showed that the main factor for a meeting abstract to be published as a full-text article is the scientific quality of the study. The quality of presentations at annual medical education meetings in Türkiye were low compared with international meetings which did not improve over five years. An institutional policy that would set quality standards for medical education research and increase the awareness of researchers on the topic might help improve the design, execution, and reporting of such studies in Türkiye. The MERSQI could be a valuable tool to monitor the quality of submitted abstracts and to increase the awareness of novice researchers on high quality research.

First extensor compartment morphology and clinical significance: a cadaver series study.

The first extensor compartment of the wrist is a distinctly variable anatomical area. Anatomical variations in this region contribute to the pathophysiology and treatment failure of de Quervain's disease, which is a kind of tenosynovitis that develops in the first extensor compartment of the wrist. We aim to describe the first extensor compartment morphology, to evaluate the septum frequency, location of the septum, and the number of tendons of abductor pollicis longus (APL) and extensor pollicis brevis muscles (EPB). First extensor compartment of 87 wrists of 45 cadavers were dissected. The presence or absence of septum and number of tendon slips of APL and EPB revealed. The proximal and distal widths of the compartments were measured. Septums were detected in 60.9% (n=53) of the wrists. Incomplete (distal) and complete (proximal) septa were present in 35.6% (n=31) and 25.3% (n=22) of the cases. Only 26.4% of the wrists had a single slip of APL tendon. The Remaining had multiple slips. The median inner width of the proximal and distal compartments in all wrists were calculated as in the order of 9.11±1.14 mm and 8.55±1.12 mm. We believe that understanding the anatomy of the first extensor compartment in the Turkish population would be helpful to surgeons, radiologists, and physiotherapists to diagnose and manage de Quervain's disease.

Variations of the external branch of the superior laryngeal nerve during its course and its importance in surgical approaches: an experimental cadaveric study.

INTRODUCTION: Injury of the external branch of the superior laryngeal nerve can cause a hoarse or weak voice due to the functional loss (dysergia) of the cricothyroid muscle. Defining the anatomical variations of the external branch of the superior laryngeal nerve and estimating the frequency of it, it makes crucial for surgical interventions. AIM: To reveal the topography of the external branch in the Anatolian population, to prevent injury of it during the surgical intervention in the anterior neck region. MATERIALS AND METHODS: Twenty-six bilateral hemilarynges (4 females, 22 males) were dissected. The morphometric and morphological features of the external branch were examined. The obtained results were compared statistically left and right. RESULTS: Landmarks such as the thyroid gland and laryngeal prominence were determined for the detection of the external branch. The variations of the course of the external branch and the points of piercing the cricothyroid muscle or inferior constrictor pharyngeal muscle were evaluated. DISCUSSION: Although safe approaches have been described for nerve protection during neck surgeries, it can expose injuries during preliminary surgery approaches as the nerve is thinner and more superficial than other branches of the vagus nerve. However, it can be detected more easily and safely during the surgical approach by knowing the defined anatomical landmarks and morphological variations of the external branch. CONCLUSION: The anatomical variations described can be a safe and important guide in surgical approaches to be applied in the anterior neck region.

Evaluation of Information on Body Donation Promotion at Official Websites of Turkish Anatomy Departments.

Raising public awareness of body donation is crucial for countries like Turkey that have struggling donation programs. The official websites of anatomy departments may contribute to achieving this goal. Nevertheless, previous studies reported institutional or individual reluctance of departments or anatomists, respectively, due to an expectation of adverse publicity. This study aimed to investigate whether the official websites of Turkish anatomy departments provided information on body donation and analyzed the content of these websites. Websites of anatomy departments at 100 medical faculties were evaluated. Only 12 departments (12%) provided information on body donation with varying content. A thematic analysis of the information provided revealed five main themes. These were (1) legal aspects, (2) significance, (3) acceptance/rejection criteria, (4) availability, and (5) redirection. All departments (n = 12, 100%) outlined the legal aspects of body donation, seven departments (58%) highlighted the significance of body donation, seven departments (58%) provided contact information for potential donors, five departments (41%) covered acceptance/rejection criteria, and three departments (25%) provided a link to the official website of the Turkish Society of Anatomy and Clinical Anatomy. Thus, Turkish anatomy departments were reluctant to provide information on body donation, and the content of provided information varied greatly among departments. This lack of information, coordination, and participation in existing awareness activities for body donation in anatomy department websites may be contributing to the low numbers of body donations and donor registrations seen nationally.

Risk of intervertebral disc joint puncture during lumbar puncture.

OBJECTIVE: Penetration of intervertebral disc joint during lumbar puncture might be unnoticed during procedure. However, accelerated degeneration of the disc joint is a long-term consequence of inadvertent penetration. In this paper, we aimed to demonstrate and evaluate the risk of disc puncture during standard lumbar puncture. PATIENTS AND METHODS: 50 human cadavers were used in this study. Disc puncture risk was assessed by using worst case scenario model. Lumbar puncture was performed in a standard fashion using midline route at L3-4, L4-5 and L5-S1 levels. The needle was advanced until it hit resistance from the bone. Lateral X-ray was used to visualize the needle position. Needle ended up in two possible locations - posterior vertebral body wall and intervertebral disc space. RESULTS: The probability of puncturing the joint was 20 % for L3-4, 38 % for L4-5, 16 % for L5-S1. Total probability of disc penetration was 25 %. Statistical analysis revealed significantly increased risk for performing LP at L4-5 level in comparison with L5-S1 (p = 0.023). CONCLUSION: Lumbar puncture carries significant risk of intervertebral disc penetration. This complication is not realized during the procedure and lead to accelerated joint degeneration.

Profile and Motivations of Registered Whole-Body Donors in Turkey: Istanbul University Experience.

Little is known regarding the profiles of whole body donors in Muslim majority countries where donation is scarce. Therefore, this study aims to profile registered donors in Turkey by means of a survey. The explored data could be used to improve ongoing campaign efforts and ethical practices such as commemoration services. Registered donors of the donation programs at the two faculties of medicine of Istanbul University were compared with the national population and a cluster analysis was performed to reveal any concealed sub-groups. Data from 188 respondents were analyzed. The majority of registered donors were married (42%), male (65.4%), aged over 50 years (76%), held a tertiary education degree (49.7%), and were irreligious (58.5%). Cluster analysis revealed two groups with significantly different educational levels, marital statuses, and religious choices. Regarding whether their bodies could be used for education or research, the majority (64.5%) of the respondents left the decision to the anatomy department. Similarly, 73.8% approved indefinite use of their organs, body parts and/or skeletons. The respondents were also willing to share their medical history (94.2%) and personal information (81.6%) if needed. Motivational themes for body donation including usefulness, impermanence, religion, awareness, and kinship were devised after a thematic analysis. Among the respondents, 56.5% were registered organ donors and 63.3% were frequent blood donors. The results of this study provide data that may help revising informed consent forms, developing and implementing thanksgiving ceremonies, and selecting additional targets for supporting body donation campaign activities such as organ and blood donation units.

Current status of cadaver sources in Turkey and a wake-up call for Turkish anatomists.

Persisting difficulties in body procurement in Turkey led to the acquisition of donated, unclaimed, autopsied, and imported bodies regulated under current legislature. Yet, no study had investigated the extent of the on-going cadaver problem. This study was aimed to outline cadaver sources in anatomy departments and their effectiveness by means of an online survey. Additionally, official websites of each department were investigated regarding any information on body donation. Unclaimed cadavers (84.8%) were the major source for anatomy departments, followed by donated (50%) and imported cadavers (39.1%). Foundation-based medical faculties were more likely to import cadavers (P = 0.008). There was a moderate increase (rs = 0.567; P = 0.018) in donation registrations to our department after 2000. The departments in cities with significantly higher City-Based Gross Domestic Product measures (US$9,900 vs. US$16,772, P = 0.041), frequencies for mid- or high-school graduates (30.4% vs. 31.3%, P = 0.041), and frequencies for under- or post-graduates (13.1% vs. 15.8%, P = 0.24) had managed to use donated cadavers. Anatomy departments' major reasons for using unclaimed cadavers were education (45.9%), unclaimed cadavers being the only source (24.3%), and receiving inadequate donations (21.6%). Nine out of seventy-four departments (12.2%) provided information regarding body donation on their websites. Body procurement remains as a serious problem in Turkey and it is apparent that current legislature does not provide a sufficient cadaver inflow. Similarly, anatomy departments' effectiveness in public awareness of body donation and support in the National Body Donation Campaign seems questionable. Anat Sci Educ 11: 155-165. © 2017 American Association of Anatomists.

A Minimally Invasive Technique Using a Modified Stoppa Approach for Periacetabular Osteotomy: A Preliminary Cadaveric Study.

BACKGROUND: Developmental hip dysplasia is diagnosed when the femoral head is not sufficiently covered by the acetabulum. Anterior and lateral cover deficiency is seen, as a result a dysplastic hip joint. Various incision modifications have been developed because of the muscle dissection and wide wound scar in Smith-Peterson incision, which was originally used in Bernese osteotomy. This study evaluates applicability of the modified Stoppa approach in the performance of Bernese periacetabular osteotomy (PAO). MATERIALS AND METHODS: Ten hemipelvises of five donor cadavers were used. The transverse Stoppa incision was made 2 cm over the symphysis pubis for quadrilateral surface exposure and pubic and ischial bone osteotomies. The second skin incision, a few centimeters lateral to the original incision, was made along the tensor fascia lata. Iliac bone osteotomy was performed starting just above the rectus femoris insertion. The displacement of the osteotomy was measured clinically and radiographically. RESULTS: The mean anterior coverage calculated with center-edge angle was improved from 22.8° ±2.8 (range 20° min-28° max) preoperatively to 44.1° ± 3.7 (range 36° min-48° max). The displacement of the osteotomy at the iliopectineal line calculated on the iliac inlet view radiographs was 22.1 ± 3.4 mm (range 15 mm min-26 mm max). The clinical amount of the anterior displacement on the cadavers was 17.8 ± 3.35 mm (range 11 mm-21 mm) and lateral displacement was 20.3 ± 3.23 mm (range 15 mm-24 mm). The amount of the posterior intact bone enlargement at the quadrilateral surface was 5.3 ± 0.48 mm. CONCLUSION: This less traumatic two-incision exposure is an adequate technique for Bernese PAO, allowing the bone to be cut under direct visual observation and reducing the need to use fluoroscopy.

Frequency of sternal variations in living individuals.

PURPOSE: To evaluate the variations of the sternum and provide the prevalence of sternal foramen and its anatomical relationships. METHODS: In this retrospective study, 544 subjects ranging in age from 18 to 95 years were evaluated. Sternal variations, prevalence of sternal foramen and its anatomical relationships to mediastinal structures were examined with the axial, sagittal and coronal reformat images of the patients who underwent thoracic computerized tomography. RESULTS: In 500 subjects, following sternal variations were found: sternal sclerotic band in 120 (24%), sternal cleft in 3 (0.6%), sternal foramen in 26 (5.2%), focal cortical notch and defect in 44 (8.8%) patients. The manubriosternal fusion was partial in 65 (13%) patients and complete in 112 (22.4%) patients. The sternoxiphoid fusion was partial in 201 (40.2%) and complete in 153 (30.6%) patients. There was no xiphoid process in 9 patients (1.8%; 29-51 years; mean age 38 years). Xiphoidal ending types were as follows: single-ended 361 (72.2%), double-ended 125 (25%), and triple-ended xiphoid 5 (1%) patients. The sternal foramen was adjacent to the lung in 13 (2.6%), to the pericardium of heart in 3 (0.6%), and to mediastinal fat in 10 (2%) patients. CONCLUSION: The sternum is a very critical anatomic structure of the anterior chest wall with several variations that can be confused with pathologic conditions. Radiologists' familiarity with these variations is important for better radiologic evaluation in making differential diagnosis.

Publication Rates and Inconsistencies of the Abstracts Presented at the National Anatomy Congresses in 2007 and 2008.

BACKGROUND: Despite significant efforts made for, most abstracts presented during a meeting do not proceed and publish as a manuscript in scientific journals. AIMS: To investigate publication rates of national anatomy congresses. STUDY DESIGN: Descriptive study. METHODS: All abstracts presented at two annual meetings in 2007 and 2008 were extracted. PubMed and Google Scholar database search used for publication history. Presentation and study types, publication rates and mean publishing times were evaluated. Inconsistency rates between meeting abstract and final published article were also considered. RESULTS: Among 342 abstracts, 195 (57%) were followed by a full-text article. Publication rates for oral and poster presentations were 75% and 52.2%, respectively. The mean publication time was 23.7±23 months. Overall, 89.2% of the articles were published within 5 years. There were no inconsistencies in 50 (25.6%) articles, while 145 (74.4%) had inconsistencies compared to the abstracts presented at the congress. Getting adequate information for 45 (23.1%) articles was not possible. There was no standard reporting format for the abstracts. CONCLUSION: Our study shows that, overall publication rates for abstracts presented at national anatomy meetings were higher than those presented at national meetings for clinical specialties.

The amount of information provided in articles published in clinical anatomy and surgical and radiologic anatomy regarding human cadaveric materials and trends in acknowledging donors/cadavers.

AIM: Appreciating the contribution of donor-cadavers to medical education is a well observed practice among anatomists. However, the appreciation of their contribution in research and scientific articles remains dubious. We aimed to evaluate how much data anatomists provide about specimens they have used and how frequently anatomists acknowledge their cadavers in published articles. MATERIALS AND METHODS: We evaluated all articles performed on human cadaveric specimens that were published in Clinical Anatomy and Surgical and Radiologic Anatomy between January 2011 and December 2015. We evaluated how much data on the demographics, preservation method(s), source, and ethical/legal permissions regarding cadavers were provided. We also evaluated the number of articles that acknowledged donor-cadavers. RESULTS: The majority of articles provided demographic data (age and sex) and preservation method used in the article. The source of the specimens was not mentioned in 45.6 % of the articles. Only 26.2 % of the articles provided a degree of consent and only 32.4 % of the articles reported some form of ethical approval for the study. The cadavers and their families were acknowledged in 17.7 % of the articles. We observed that no standard method for reporting data has been established. CONCLUSIONS: Anatomists should collaborate to create awareness among the scientific community for providing adequate information regarding donor-cadavers, including source and consent. Acknowledging donor-cadavers and/or their families should also be promoted. Scientific articles should be used to create a transparent relationship of trust between anatomists and their society.

A new anatomic trait for identifying the mendosal suture in young children: the mendosal-lambdoidal angle.

PURPOSE: Radiologic diagnosis of skull fractures in young children is difficult due to numerous accessory sutures. This is especially true around the occipital bone because it has more than one ossification center. Normal anatomic variants, such as the mendosal suture, may be misinterpreted as a skull fracture. We investigated the anatomic traits of the mendosal suture in young children. METHODS: We retrospectively evaluated 52 children, aged between 1 month and 4 years, who had undergone head computed tomography with three-dimensional reconstructions. We evaluated the presence or absence of the mendosal suture. If present, then we measured the length of the suture and the angle between the lambdoidal and mendosal suture lines. RESULTS: The presence of the mendosal suture was bilateral in 12 children and unilateral in 5 children. The mendosal suture had a mean length of 13.9 ± 3.4 mm on the right side and 11.2 ± 4 mm on the left side. The angle between the mendosal and lambdoidal sutures had a mean value of 54.2° ± 11° for the right side and 53.6° ± 13.9° for the left side. The 95 % confidence interval for the mean value of the angle had a lower and upper bounds of 48° and 60° on the right side and 46° and 61° on the left side, respectively. CONCLUSIONS: The angle between mendosal and lambdoidal suture lines may help radiologists to identify the mendosal suture.

A mixed-type intermesenteric trunk as a major contributor to the ascending, transverse, and descending colons: a case report.

PURPOSE: We present a case in which a mixed-type intermesenteric trunk was the major arterial supply for the ascending, transverse, and descending colons. METHODS: We dissected a cadaver of a man aged 74 years that was used for a routine abdominal dissection course of 2nd year medical students. RESULTS: We observed that a mixed-type intermesenteric trunk supplied the majority of the colon, originating from the inferior mesenteric artery. The vessel was non-tortuous and had a counter clockwise course. It gave branches that supply the marginal artery at the splenic and hepatic flexures and at the transverse colon and finally it anastomosed with the ileocolic artery at the ileocecal junction. Through the intermesenteric trunk, the inferior mesenteric artery supplied the descending, transverse, and ascending colons with contributions from the sigmoidal and ileocolic arteries. CONCLUSIONS: The intermesenteric trunk is an important central connection between the superior and inferior mesenteric arteries. It probably is an embryologic remnant that constituted a longitudinal anastomosis between both mesenteric arteries.

Anatomical relations between anterior coracoscapular ligament and suprascapular neurovascular structures and a proposal for classification.

OBJECTIVE: Although suprascapular nerve entrapment is rare, the most common site of compression is the suprascapular notch. The anterior coracoscapular ligament (ACSL), which lies inferior to the superior transverse scapular ligament (STSL), may also be a cause of entrapment. We aimed to investigate the presence of ACSL and its relations to the suprascapular nerve and vessels. METHODS: We dissected 50 shoulders of 26 cadavers. We excluded 2 shoulders due to previous shoulder surgery. We observed the course of the suprascapular nerve, artery, and vein(s), and examined whether they passed between STSL and ACSL or under ACSL. We classified the anatomical relations between neurovascular structures, STSL, and ACSL. In Type I, the suprascapular nerve passed between STSL and ACSL; in Type Iia, the suprascapular nerve and a single suprascapular vein passed between STSL and ACSL; in Type Iib, a suprascapular vein passed under ACSL and the suprascapular nerve passed between STSL and ACSL; in Type III, the suprascapular artery, vein, and nerve passed between STSL and ACSL. RESULTS: ACSL was present in 16 shoulders (32%). The suprascapular nerve passed between STSL and ACSL in all cases. We observed Type I, Type Iia, Type Iib, and Type III anatomical relations in 14%, 12%, 2%, and 4% of cases, respectively. CONCLUSION: Vascular structures that pass under STSL may cause suprascapular nerve entrapment. Presence of ACSL with vessel(s) passing under it and/or between it and STSL may increase the risk of nerve entrapment.