Anatomical Variations Research Articles

Optimizing hook implantation angle of the clavicular hook plate: a cadaveric study.

While Clavicle hook plates have demonstrated favorable results regarding bone and shoulder function, their design can potentially lead to complications due to pressure concentration at the plate's tip. This study aims to investigate the impact of different hook implantation angles on the contact surface area between the hook plate and acromion, with the goal of minimizing mismatch and maximizing contact surface area. Twenty soft shoulder cadavers were included in the study, and the contact surface area of the hook plate was measured in different positions based on the hook implantation angle. The results showed variations in compatibility, width, and length of the contact surface area depending on the hook implantation angle and the medial or lateral row placement. The lateral row generally demonstrated superior compatibility (84.0% vs 46.67%, p-value < 0.001), with a broader contact area (3.55 ± 0.08 mm vs 3.09 ± 0.10 mm, p-value = 0.004) and a longer contact area (7.36 ± 0.19 mm vs 5.10 ± 0.23 mm, p-value < 0.001) at specific angles. A detailed analysis of the lateral position revealed that the zero angle of implantation resulted in the greatest contact surface area, measuring 3.91 ± 0.70 mm in width (p value = 0.083) and 8.85 ± 1.24 mm in length (p value < 0.001). Placing the hook laterally and at the zero position according to the hook implantation angle can maximize contact surface area, may reduce stress concentration, and minimize complications in hook plate fixation. Further research and consideration of anatomical variations are warranted to refine the placement technique and enhance patient outcomes. Level V evidence.

Morphological classification, anatomical variations, innervation patterns, musculocutaneous nerve relation of the coracobrachialis muscle: Anatomical study and clinical significance.

The anatomical variations of coracobrachialis muscle (CBM) are of great clinical importance. This study aimed to elucidate the morphological variations, innervation patterns and musculocutaneous nerve (MCN) relation to CBM. Upper limbs of fifty cadavers (30 males and 20 females) were examined for proximal and distal attachments, innervation pattern of CBM and its relation to MCN. Four morphological types of CBM were identified according to number of its heads. The commonest type was the two-headed (63.0%) followed by the single belly (22.0%), three-headed (12.0%) and lastly four-headed (3.0%) type. Moreover, an abnormal insertion of CBM was observed in four left limbs (4.0%); one inserting into the medial humeral epicondyle, the second into the upper third of humeral shaft, the third one in the common tendon of biceps, and the fourth one showing a bifurcated insertion. Also, four different innervation patterns of CBM were identified including MCN (80.0%), lateral cord (14.0%), lateral root of median nerve (4.0%), and median nerve itself (2.0%). The course of MCN was superficial to the single belly CBM (19.0%) and in-between the heads in the other types (71.0%). Measurements of the length and original distance of CBM muscular branches originating from MCN revealed no sex or side significant difference. Awareness of the anatomic variations, innervation patterns, and MCN relation of CBM is imperative in recent diagnostic and surgical procedures to obtain definite diagnosis, effective management and good outcome.

Corrigendum: Anatomical variations of the atlas arches: prevalence assessment, systematic review and proposition for an updated classification system

Corrigendum: Anatomical variations of the atlas arches: prevalence assessment, systematic review and proposition for an updated classification system

Sciatic Nerve and Its Anatomical Variations: In-Depth Understanding Acquired During Dissection Classes

Sciatic Nerve and Its Anatomical Variations: In-Depth Understanding Acquired During Dissection Classes

An unusual configuration of two anomalies in the extensor digitorum profundus complex in a human.

The extensor digitorum profundus complex underwent degeneration of the ulnar segments during primate adaptation and evolution. This process resulted in the preservation of only the extensor pollicis longus and extensor indicis in some apes, including humans. Consequently, anatomical variations within the digitorum profundus complex in modern humans have been well-documented, with detailed reports on their frequency and patterns in previous studies. Here, we report an unusual arrangement involving two anomalies in the extensor digitorum profundus complex, identified in a 66-year-old Japanese male cadaver. In this cadaver, two accessory muscles differentiated from both the extensor pollicis longus and extensor indicis. Notably, the latter muscle featured a tendon bifurcating towards both the thumb and index fingers, referred to as the extensor pollicis et indicis communis. Under the extensor retinaculum, the tendon of the accessory extensor pollicis longus passed through an independent compartment, whereas that of the extensor pollicis et indicis communis traversed a compartment shared by the extensor indicis and the extensor digitorum communis. Both muscles were innervated by the posterior interosseous nerve. Previous studies have reported that the accessory slip of the extensor pollicis longus and extensor pollicis et indicis communis appear at frequencies of 0.6% and 0.4-1.4%, respectively. However, to the best of our knowledge, a configuration in which both appear simultaneously has not been reported. The data from this case could provide essential insights into the variations in the extensor digitorum profundus complex in humans and non-human primates.

Management of complete intra-articular distal femur and patellar fractures in an achondroplastic young adult; small is challenging’ revisited: a case-report

BackgroundPeople with achondroplasia exhibit distinct physical characteristics, but their cognitive abilities remain within the normal range. The challenges encountered during surgical procedures and perioperative care for achondroplastic individuals, are underrepresented in the existing literature.Case presentationIn this report, the management of a 26-year-old North-African achondroplastic male is highlighted. The patient suffered a complete intra-articular distal femur fracture (AO/OTA 33-C1) and an ipsilateral patella fracture (AO/OTA 34-C1). The patient’s unusual anatomical variations and the lack of suitable orthopedic implants posed significant surgical challenges, particularly in the context of a resource-limited developing country. Facial and spinal deformities, which are common in patients with achondroplasia, further complicated the anesthetic approach.ConclusionsThe limited information on operative management of fractures in achondroplastic patients necessitated independent decision-making and diverging from the convenient approach where clear guidance is available in the literature.

Utility of Pulmonary Angiography by 128-Slice Computed Tomographic Scanner in Diagnosis of Tetralogy of Fallot Cases

Tetralogy of Fallot (TOF) is a significant cause of cyanotic congenital heart disease (CHD) encountered in childhood with few cases manifesting in adulthood. It has four classical features (ventricular septal defect, overriding of aorta, hypertrophy of right ventricular hypertrophy, and right ventricular outflow tract obstruction), but the clinical presentation and course can be variable. Due to various anatomical variations and complex anatomy, presurgical planning and postoperative follow-up by pulmonary computed tomographic angiography (CTA) have a very important role. With continued technological advances and the availability of 128-slice computed tomographic (CT) scans, they now play an important role in TOF preoperative evaluation and workup, assisting by minimizing routine invasive digital subtraction catheter angiography. The fast scan of a 128-slice CTA with very sensitive detectors is a very useful modality for studying the complex anatomy and variations as well as its utilization for postoperative management. In this article, we report four cases of TOF where we used a 128-slice scan for performing pulmonary angiography (Optima 660, GE 128, 2180 Premier Row, Orlando, FL 32809, U.S.A.) for preoperative diagnosis and management of three cases and work up for revision surgery for an already operated case with a nonfunctional modified Blalock-Taussig shunt with additional lung parenchymal findings simultaneously. This study will explain the advantageous role of the 128-slice CT scanner over the lesser-slice CT scanners with the ability of pulmonary CTA to facilitate accurate diagnosis and postoperative management.

A bifid ureter originating from separate major calyx and renal pelvis with dual calyceal systems: a case report.

Present case report describes a case of bifid ureter arising directly from separate calyces and renal pelvis of the kidney. Incomplete ureter duplication on the left side in a 78-year-old male cadaver was found during an anatomy class. These ureters converged in a Y-shaped pattern just above the level of the anterior superior iliac spine. In the coronal section of the kidney, the anterior ureter arose from a renal pelvis that was divided into two major calyces in the lower two-thirds of the kidney. On the other hand, the posterior ureter was directly connected to a major calyx in the upper third of the kidney, without the formation of a renal pelvis. This anatomical variation has implications for diagnostic approaches, especially in the use of imaging techniques by urologists for the insertion of stents in the treatment of phyelonephritis.

A transmuscular path of the medial branch of the high division of the median nerve: an anatomical variation of clinical and surgical importance

The median nerve (MN) is a mixed nerve formed in the brachial plexus, which innervates a large part of the upper limb. It presents several variations in its trajectory, resulting in many pathologies and iatrogenic surgical compromises. This report highlights a transmuscular route of the medial branch of the upper division of the MN, which to date does not fit into the classifications described in the literature on MN variations. Knowledge of this high division of the MN, as well as its transfixation by the flexor digitorum superficialis muscle, is of fundamental importance in neuropathy syndromes due to entrapment of the MN, as well as in surgical guidance to prevent injuries. Late diagnosis of traumatic peripheral nerve injuries results in greater functional impairment and greater socioeconomic loss, especially in young patients. Therefore, timely identification is essential to minimize long-term consequences and improve the patient's quality of life.

Case Report of snare-assisted coaxiality optimized technique during valve deployment in patient with pure aortic regurgitation

In high-risk patients with pure native aortic regurgitation (PNAR), transcatheter aortic valve replacement (TAVR) remains an off-label intervention. Due to anatomical variations in the aortic root and technical challenges unique to PNAR, the transfemoral approach (TF-TAVR) requires continued accumulation of experience and technological refinement. In this context, we successfully and safely performed a snare-assisted TF-TAVR procedure for a patient with PNAR, characterized by significant aortic angulation. We introduced an innovative technique termed “snare-assisted coaxiality optimized technique” (SACOT) during valve deployment. SACOT played a crucial role in optimizing valve positioning, enhancing coaxiality, and achieving the ideal implantation depth for PNAR. Post-procedure assessments demonstrated stability and the absence of paravalvular regurgitation (PVR).

The association between variations in the number of thoracic and lumbar vertebrae and rib morphology in adolescent idiopathic scoliosis.

Preoperative counting of thoracic and lumbar vertebrae is crucial in adolescent idiopathic scoliosis (AIS) due to reported anatomical variations and potential surgical site misidentification. This study investigated characteristics associated with the vertebral number variations AIS, particularly focusing on rib morphology. Based on three-dimensional computed tomography, patients were categorized into the non-variant number group, comprising individuals with 12 thoracic and 5 lumbar vertebrae, and the variant number group, comprising individuals with different numbers of vertebrae. Additionally, the most caudal rib morphology was classified as normal, unilateral, or hypoplastic. A total of 359 patients were included in our study (41 males, 318 females, age: 16.3 ± 3.1years), with 44 patients (12.3%) assigned to the variant number group. Logistic regression analysis identified unilateral ribs (odds ratio [OR]: 10.50) and lumbosacral transitional vertebrae (LSTV) (OR 6.49) as significant risk factors associated with variations. Further analysis revealed hypoplastic ribs as a significant risk factor associated with LSTV (OR: 4.58). 8 CONCLUSION: Our study suggests that abnormal rib morphology may be associated with vertebral number variations. Close attention to rib morphology is, therefore, warranted in cases with atypical vertebral numbers. Accordingly, to ensure surgical safety and accuracy, spine surgeons must communicate these variations to the surgical team, standardize nomenclature for describing them, and intraoperatively verify fusion levels with them.

Anatomic Study of Vascular Supply of the External Ear Using CT Angiography in Congenital Microtia

Background: The morphology of the arteries of the external ear on the affected side of congenital microtia differs from normal. The present study aimed to use computed tomography angiography (CTA) to describe the anatomic variations of arteries in microtia and provide theoretical guidance for the first stage of autologous auricular reconstruction by the 2-stage method. Methods: Ten patients with unilateral microtia from May 2021 to August 2021 were included. Computed tomography angiography and 3-dimensional reconstruction were used to analyze the supply and branches of the main arteries of the auricle. The number of the superficial temporal artery (STA) and posterior auricular artery (PAA) branches to the auricle, vessel diameter, and the presence or absence of the STA and PAA branches were documented. The skin flap and incision were designed combined with the anatomic of auricular arteries. Results: The blood supply of the auricle mainly came from the STA and PAA. The STA’s preauricular branch and PAA’s posterior auricular branch were absent to varying degrees, and the middle branch was more prominent. The average diameter of the STA on the healthy auricle was 3.07±0.96 mm, and the average diameter of the PAA was 1.72±0.50 mm. The average diameter of the STA on the microtia auricle was 2.65±0.42 mm, and the average diameter of the PAA was 1.53±0.67 mm. There was a statistically significant difference in the diameter of STA between the healthy auricle and the microtia auricle (P=0.006). However, there was no significant difference in the diameter of the PAA between the healthy auricle and the microtia auricle (P=0.112). The skin flap and incision were designed and combined with the preoperative CTA images, and no flap necrosis was observed in all patients. Conclusion: The vascular distribution of arteries in microtia patients was clearly and accurately assessed by CTA. In our experience, the data and detailed imaging were useful in designing skin flaps and incisions during the first stage of autologous auricular reconstruction by the 2-stage method.

The dominance of dorsal scapular artery as the blood supply to muscles of the back in the absence of two primary vessels: a cadaveric case report.

Understanding of rare or unknown anatomical variations of the vasculature of the neck is critical to reduce the risk of complications during surgeries and other invasive procedures in the neck and shoulder regions. Bilateral dissection of the neck and muscles of the back of an 87-year-old Caucasian male donor was performed to demonstrate the origin, course and termination of the arteries that arise in the neck. Several anatomical variations were noted on the right side of the neck of the donor body - (i) only inferior thyroid and ascending cervical arteries originated from the thyrocervical trunk (TCT), from the first part of the subclavian artery (SA), whereas the transverse cervical (TCA) and suprascapular (SSA) arteries were entirely absent, (ii) Dorsal scapular artery (DSA) emerged normally from the third part of the SA. However, after supplying the rhomboids and levator scapulae muscles, DSA provided two additional branches to the trapezius muscle and a branch to the supraspinatus muscle. Interestingly, the branches to the trapezius muscle from the DSA were the only sources of blood supply to the muscle. We report a unique anatomical variation involving the absence of the TCA and SSA from the TCT. The unilateral absence of these major vessels and the branches of DSA supplying the trapezius and supraspinatus muscles have not been reported previously in the literature in a single case report. This case study may provide useful information for head and neck reconstruction and shoulder repair surgeries.

Metopism: An anatomical variant that the physician should take into account

Introduction: During childhood these sutures close, forming the characteristic sutures of the skull, one of these is the frontal suture, which joins the two frontal bones perfectly, simulating a single frontal bone. However, this suture can persist into adulthood, giving an anatomical variant known as metopism. Case Report: A 19-year-old Mexican male presented with high-energy trauma related to a traffic accident while riding a motorcycle without wearing a safety helmet. A simple skull computed tomography (CT) was considered due to moderate risk factors for traumatic brain injury (TBI), based on the Master’s classification, progressive headache, presence of hematoma, facial injuries. When performing the simple skull tomography, persistence of the metopic suture was observed. Conclusion: Metopism has generally been reported as a postmortem finding in population studies aimed at its search. This report has special attention because it was identified as a differential diagnosis of a skull fracture following a traumatic brain injury. The important finding that differentiates metopic suture from a fracture is the presence of serrated and sclerotic edges. A persistent metopic suture can be easily diagnosed by an anteriorposterior radiograph.

Captive Bolt Gun-Related Vascular Injury: A Single Center Experience

This article investigates the clinical and radiological characteristics of captive bolt gun head injuries, a rare form of low-velocity penetrating brain injury. Eleven consecutive patients were included in the study. Vascular injuries and the rate of infection were systematically analyzed. Radiological findings reveal common bolt trajectories in the anterior cranial fossa, with identified risk factors for a poor outcome including trajectory crossing midline, hematocephalus, and paranasal sinus involvement. Only one patient had a good outcome. Despite meticulous microsurgical techniques, this study highlights often unfavorable clinical outcomes in captive bolt gun injuries, with vascular injury identified as a potential contributing risk factor for a poor outcome. Knowledge of variant vascular tree anatomy and corresponding vascular territory is important. To avoid potential vascular injuries, a complete removal of bone fragments was not always performed and it did not increase the rate of infection, challenging the conventional wisdom advocating for the complete removal of bone fragments. These findings contribute novel insights into captive bolt gun-related injuries, paving the way for further research.

Anatomical variations of Koerner's septum: a computed tomography-based, single-centered study.

Koerner's septum (KS) is a bony plate located at the junction of the petrous and squamous parts of the temporal bone. The reported prevalence of KS varied between studies. KS variations are associated with various pathologies and pose difficulties during surgeries. The study aims to determine the KS frequency in Omani patients and analyze its association with sex and side. The present study investigated the KS topography in 344 computed tomography (CT) scans of normal temporal bones of adult Omani patients at Sultan Qaboos University Hospital. The presence of KS and its parts (complete or incomplete), as well as its thickness at three anatomical landmarks were recorded. Additionally, sex and laterality differences in KS parameters were analyzed using a Chi-square test. The overall frequency of KS among Omani subjects was 39.5%. The complete KS was observed only in 14% of cases. The thickness of KS was 0.78 ± 0.21 mm, 0.93 ± 0.28 mm and 0.78 ± 0.21 mm at the head of the malleus (HM), the superior semicircular canal (SSC) and the tympanic sinus (TS), respectively (p<0.01). KS was present most constantly at the level of HM (64.7%), followed by SSC (57.4%), and less constantly at the level of TS (49.3%). KS frequency was similar in both males than females (41.9% vs 37.3%), with statistically insignificant difference (p = 0.38). No side differences were observed concerning KS frequency (p = 0.955). The KS frequency in Omani subjects within the range of previously reported studies. It is incomplete in most of the cases and constantly present at the level of HM. Its thickness is more at the level of SSC.

An anatomical variant of the posterior branch of the great auricular nerve: A case report and a short review of the literature

The great auricular nerve (GAN) is a sensory cutaneous nerve, which provides sensory innervation to the skin overlaying auricle, parotid gland, and mastoid region. The emergency of GAN is located at Erb’s point over the posterior burden of the belly of the sternocleidomastoid muscle (SCM). During its course, it normally bifurcates in a pair of, respectively, posterior and anterior, branches. The latter one then further divides into superficial and deep branches. Some different anatomical patterns of GAN branches were reported in the literature to underline the high variability of the GAN course. The aim of this case report is to underline a particular anatomical variant of a posterior branch of GAN we recently observed. It was characterized by an anomalous bifurcation involving two different groups of fibers, within the same field of innervation, which had an independent course toward the auricular lobe. To promptly face such a somewhat unexpected anomaly, besides the basic recommendation to surgeons of mastering a good knowledge of the high variability of the anatomy of GAN, a careful dissection around the SCM is believed to help the surgeon to recognize other anatomical variants of GAN course with the aim to preserve it.

Clinical Significance of Coronary Arterial Dominance: A Review of the Literature.

Coronary dominance describes the anatomic variation of coronary arterial supply, notably as it relates to perfusion of the inferior cardiac territories. Differences in the development and outcome in select disease states between coronary dominance patterns are increasingly recognized. In particular, observational studies have identified higher prevalence of poor outcomes in left coronary dominance in the setting of ischemic, conduction, and valvular disease. In this qualitative literature review, we summarize anatomic, physiologic, and clinical implications of differences in coronary dominance to highlight current understanding and gaps in the literature that should warrant further studies.

Features of diagnostics and treatments of the patient with type 2 diabetes mellitus and chronic ischtmia with threating lower limb loss

The article presents the result of our own observation of the patient with a poor control of type 2 diabetes mellitus (DM) for a long period, complicated by obliterating atherosclerosis of the arteries of the lower extremities, Menckeberg’s sclerosis and chronic ischemia threatening loss of the lower extremity (CLLI). A feature of the clinical manifestation are complications associated with potentially regional (angiosomal) ischemia of the foot, as well as variant anatomy, represented by hypoplasia of the vascular lower leg in the patient. The clinical consequences of vascular calcification due to long-term decompensation of carbohydrate metabolism and the development of diabetic distal polyneuropathy (DDP) led to falsely high values of the cuff test in the patient. Disadvantages of non-invasive methods for diagnosing limb ischemia and advantages of the complex application of tests for diseases of the arteries of the lower extremities are discussed. Using WIFI classification according to the degree of ulceration, the degree of ischemia, and the degree of infection on the foot (Wound, Ischemia and Foot Infection), the tactics of managing the patient are presented. The important role of ultrasonic duplex scanning (USDS) in the visualization of the arteries of the legs and feet in patients with DM is substantiated. The importance of a multidisciplinary approach in the management of a comorbid patient with type 2 diabetes and CLTI is emphasized.

Novel Anatomical Variation of Left Coronary Artery Origin at the Sinotubular Junction Level With Coeval Hypoplastic Left Circumflex, Superdominant Right Coronary Artery, and Obstructive Coronary Artery Disease: A Case Report

Novel Anatomical Variation of Left Coronary Artery Origin at the Sinotubular Junction Level With Coeval Hypoplastic Left Circumflex, Superdominant Right Coronary Artery, and Obstructive Coronary Artery Disease: A Case Report