A comprehensive review of the "supracondylar process" with translation of Adachi.

The supracondylar process is a nonpathological projection from the distal humerus that in some patients, can result in compression of regional neurovascular structures, for example, median nerve. Since the first description of the supracondylar process in 1818, it has also been a focus of anthropological study because of its possible relevance to human origins and relationships to other species. Although its overall incidence is low, it is more common in races of European descent. It is particularly interesting for anatomists and anthropologists, but knowledge of its anatomical relationships and effect on pathological processes helps in the diagnosis and treatment of supracondylar process syndrome. One of the most detailed descriptions of this variant process stems from the work of Buntaro Adachi. Herein, a translation of his findings is provided and a review of the supracondylar process and its potential pathological presentations presented.

Ulnar nerve subluxation and dislocation: a review of the literature.

The pathogenesis of ulnar nerve subluxation and dislocation is widely debated. Upon elbow flexion, the ulnar nerve slips out of the groove for the ulnar nerve, relocates medial or anterior to the medial epicondyle, and returns to its correct anatomical position upon extension. This chronic condition can cause neuritis or neuropathy; however, it has also been suggested that it protects against neuropathy by reducing tension along the nerve. This article reviews the extant literature with the aim of bringing knowledge of the topic into perspective and standardizing terminology.

The proximal humeral attachment of the lateral head of the triceps brachii: a cadaveric study and potential site for radial nerve compression.

BACKGROUND: Knowledge of potential compression sites of peripheral nerves is important to the clinician and surgeon alike. One anatomical location for potential compression of the radial nerve, which is rarely mentioned in the literature, is at the proximal humeral attachment of the lateral head of the triceps brachii at the level of the proximal spiral groove. As no anatomical studies have been devoted to this band, the present study was conducted. METHODS: Ten adult fresh-frozen cadavers were dissected and the lateral head's attachment onto the posterior humerus evaluated for a band. This anatomy and its relation to the radial nerve during range of motion of the elbow and forearm were evaluated. RESULTS: A band was found on 15 of 20 arms. On five sides, the band was comprised of grossly muscle fibers of the lateral head of the triceps brachii and was not tendinous. The bands were crescent-shaped, straight, and duplicated on nine, five, and one arm, respectively. The length of the bands ranged from 1.1 to 2.2 cm (mean 1.54 cm). The width of the bands ranged from 0.5 to 1.1 cm (mean 0.8 cm). With elbow extension and the forearm in neutral, all bands were lax. With elbow extension and the forearm supinated, the bands became tauter less the muscular bands. In elbow extension and with the forearm in supination, the bands became most taut less the muscular bands. CONCLUSIONS: The presence of a fibrous band extending from the lateral head of the triceps brachii is common and should be among the differential diagnoses of anatomical sites for potential proximal radial nerve compression when other more common locations are ruled out.

The clinical anatomy of crucifixion.

Crucifixion was a widely used form of execution for capital crimes in antiquity. Civilizations and empires perfected the technique, leading to centuries of discussions, controversies, and questions, many of which concerned the death of Jesus Christ. To this day, much remains to be discovered in both religious and scientific realms. However, the aim of this study is to discuss such facts as are known from the medical perspectives of clinical anatomists. Nails/spikes were driven through the hands/wrists and feet of five adult cadavers, and the cadavers were then dissected to observe the anatomical structures that had been injured or placed at risk for injury. While many historical and archeological facts remain to be discovered, we hope that this cadaveric study will enhance our modern understanding of ancient practices from a medical and anatomical perspective. Clin. Anat. 32:12-21, 2019. © 2019 Wiley Periodicals, Inc.

Defining, diagnosing, clarifying, and classifying the Chiari I malformations.

PURPOSE: Chiari malformations (CM) have been traditionally classified into four categories: I, II, III, and IV. In light of more recent understandings, variations of the CM have required a modification of this classification. METHODS: This article discusses the presentation, diagnostics, and treatment of the newer forms of hindbrain herniation associated with the CM type I. RESULTS: The CM 1 is a spectrum that includes some patients who do not fall into the exact category of this entity. CONCLUSIONS: While CM have been categorically recognized as discrete and individual conditions, newer classifications such as CM 0 and CM 1.5 exhibit some degree of continuity with CM 1; however, they require distinct and separate classification as symptoms and treatments can vary among these clinical subtypes.

Classifications of Odontoid Process Fractures: A Systematic Review and Proposal of a New Simplified Classification System Based on Embryology.

Odontoid fractures are the most common cervical spine fractures in the elderly. Although many classification systems have been developed for them, the ambiguity in various definitions can potentially lead to misunderstandings. This paper aims to review the terminologies and current classification systems of odontoid fractures and propose a new, simplified anatomical classification. Given the descriptive variability of odontoid fractures in current classifications, we systematically reviewed the literature using PRISMA guidelines querying the National Library of Medicine PubMed database. The initial literature search yielded 175 publications. A total of seven reports met the inclusion criteria and were ultimately included for a full review. The classification systems previously used to categorize fractures of the odontoid process often need to be more transparent, imprecise, and incongruous. To simplify them, a new embryologically accurate system is proposed. A new embryological and anatomically-based system, combining the former systems' specific attributes, allows a more straightforward and adaptable classification of odontoid fractures.

Ansa cervicalis: a comprehensive review of its anatomy, variations, pathology, and surgical applications.

The ansa cervicalis is a neural loop in the neck formed by connecting the superior root from the cervical spinal nerves (C1-2) and the inferior root descending from C2-C3. It has various anatomical variations and can be an important acknowledgment in specific operations of the neck region. This is a review the anatomy, variations, pathology and clinical applications of the ansa cervicalis.

Drainage of the basal vein of Rosenthal into the confluence of sinuses.

An adult female was found to have a variation of the left basal vein of Rosenthal after presenting with complaints of headache. The vein, in this case, drained directly into the confluence of sinuses instead of the great vein of Galen. Variation of the basal vein is likely due to the embryonic development of the deep cerebral venous system as primitive structures either differentiate further or regress with age. Such changes may result in the uncommon presentation seen in this case. To our knowledge, this is the first case reported of the basal vein draining into the confluence of sinuses.

The Basal Subarachnoid Cisterns: Surgical and Anatomical Considerations.

The basal subarachnoid cisterns are expansions of the subarachnoid space and transmit cranial nerves and intracranial vessels. Providing neurosurgeons with key concepts, anatomical landmarks, and techniques can result in safer procedures and better patient outcomes. In this review, we discuss the major basal subarachnoid cisterns including their embryology, history, anatomical descriptions, and use during surgical approaches.

Internal Morphology of the Odontoid Process: Anatomic and Imaging Study with Application to C2 Fractures.

OBJECTIVE: Fracture of the odontoid process is a critical injury to diagnose and often treat. The aim of this anatomic study was to present a comprehensive understanding of this part of the C2 vertebra. METHODS: We used 20 C2 vertebrae. Samples underwent imaging (computed tomography [CT] with and without three-dimensional reconstruction, micro-CT, 1.5T magnetic resonance imaging) and sagittal and coronal sectioning using a bone saw. Sectioned specimens were imaged under a digital handheld microscope, and transillumination of the bone was used to highlight its internal trabecular pattern. Three samples underwent infusion of the odontoid process with a hardening substance and were then decalcified. RESULTS: Internal trabecular patterns of the odontoid process of all specimens were discernible. In sagittal and coronal sections, trabecular patterns were highlighted with transillumination, but the patterns were much clearer using the digital microscope. Magnetic resonance imaging and CT provided the least detail of the imaging methods, but the trabecular patterns could be identified. Three-dimensional reconstruction of CT data was the preferred imaging method over magnetic resonance imaging and CT without three-dimensional reconstruction. The most distinct trabecular and cortical patterns were seen using micro-CT. Osteoporosis was seen in 2 specimens (10%). Five specimens (25%) were found to have a subdental synchondrosis. For most specimens, the trabeculae were found throughout the odontoid process. CONCLUSIONS: Improved knowledge of the anatomy, structural composition, and variations within the C2 vertebra may allow for better treatment options and patient care.

A Contralateral Transfalcine Approach to the Mesial Frontoparietal Region and Cingulate Gyrus: A Cadaveric Feasibility Study.

BACKGROUND: Neurosurgery for lesions located the mesial frontoparietal region and cingulate gyrus may need significant brain retraction, which may cause neural injury. Therefore, the goal of this anatomic study was to evaluate a contralateral transfalcine approach to these regions. METHODS: Eight adult cadaver heads were used in this study. An 8 × 8 cm craniotomy was performed, and bilateral longitudinal incisions were made into the dura mater adjacent to the superior sagittal sinus. Measurements were then taken to see how much retraction was necessary for an ipsilateral approach to the mesial frontoparietal region down to the cingulate gyrus and compared with measurements using a contralateral transfalcine approach to this same region. RESULTS: Ipsilateral approaches required 1.5 to 3 cm of lateral retraction (40-50°) from the midline, whereas contralateral transfalcine approaches required 0.5 to 1 cm of lateral retraction (10-20°). CONCLUSION: In comparison with the traditional ipsilateral interhemispheric approach to lesions of the mesial frontoparietal region and cingulate gyrus, the contralateral transfalcine approach was found to necessitate less hemispheric retraction and provided a better working angle. Clinical validation of this technique is now necessary.

Iliolumbar Vein: Anatomy and Surgical Importance During Lateral Transpsoas and Oblique Approaches to Lumbar Spine.

OBJECTIVE: Safe surgical approaches to the anterolateral lumbar spine require a good working knowledge of the anatomy and anatomic variations of this region. As the iliolumbar vein is in the vicinity of both oblique and lateral transpsoas approaches to the lower lumbar spine, the following study was performed to better elucidate its anatomy, variations, and position during such surgical procedures. METHODS: Fifteen (30 sides) fresh frozen adult cadavers underwent dissection of the iliolumbar vein (ILV). The origin, course, variants, relations, and morphometrics of each vein were documented. Fluoroscopy of the vessels was performed. Lastly, anterior oblique and lateral transpsoas approaches to the lumbar spine were carried out in order to evaluate for potential ILV injury. RESULTS: An ILV was found on all but 2 sides (93.3%). It arose as a common trunk from the common iliac vein on 14 sides. Left ILVs tended to have a more distal origin than right ILVs. ILVs had a mean length of 3.7 cm and a mean width of 0.9 cm and were significantly larger on right versus left sides (P < 0.05). Left-sided ILVs tended to have more branches than right-sided veins. The majority of vertical branches of the ILV traveled anterior to the ventral rami of the lumbar spinal nerves, most commonly L4. The ILV and, in particular, its vertical branches coursed next to the L4 and L5 vertebrae. CONCLUSIONS: The ILV should be considered during both oblique and lateral transpsoas approaches to the lumbar spine.