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PubMed1977

Anatomical variations in the articular masses of the seventh cervical vertebra simulating fracture.

The articular masses of the seventh cervical vertebra are variable in that about 87% of patients the superior and inferior facets are not parallel. IN ADDITION, THE INFERIOR FACETS ARE OFTEN POSTERIORLY PLACED IN RELATION TO THE SUPERIOR FACETS. These factors contribute to a notched undulating articular mass seen bilaterally on the lateral and oblique projections simulating fracture. The difference in inclination of the superior and inferior facets may cause either the superior or inferior facets to be obscured on the AP VIEW ANGLED CAUDAD--THE POSTERIOR ARCH VIEW. Since these anomalies are bilateral and fractures are almost always unilateral, the differentiation is most easily made on this posterior arch view.

Cervical Vertebrae↗
PubMed2006

[Anatomic variations of the ilio-caval junction encountered in disk prosthesis implantation].

PURPOSE OF THE STUDY: The retroperitoneal mini-invasive anterior approach to the lumbar spine is widely used for disc excision and insertion of a prosthetic disc. A large operating window is needed. Venous wounds constitute one of the most serious complications. We analyzed the angle and position of the iliocaval on the preoperative angio-MRI in search for correlations with the intraoperative findings. Our aim was to determine whether the preoperative angio-MRI gives indications concerning the operative difficulty and the best strategy for prosthesis fitting. MATERIAL AND METHOD: This prospective study included 35 consecutive patients who underwent surgery for implantation of a Maverick disc prosthesis. Average patient age was 46.7 years. The indication for surgery was isolated degenerative discopathy with invalidating chronic low back pain without alteration of the muscle masse or facet joints. A preoperative angio-MRI was performed with T1 spin-echo sequences for the coronal slices and T2 axial slices passing through the upper extremity of the L5-S1 disc. We searched for correlations between the MRI and operative findings. Elements studied were those used in the Capellades classification: height of the iliocaval junction (high, very high, low, very low), position of the common iliac vein (lateral, intermediate, medial), angle formed by the two common iliac veins. RESULTS: The lateral position was the most frequent (31.5%). The average junction angle was 65 degrees). The only position where it was not possible to "pass" under the iliocaval junction was for a very low medial localization with a narrow angle (45 degrees). DISCUSSION: Our series included a homogenous group comparable with other series in the literature. The junction angle for very low medial localizations is of considerable importance because it is impossible to fit the implant in the L5-S1 under the iliocaval junction if the angle is over 60 degrees. CONCLUSION: The position of the iliocaval junction, and particularly its angle, are of considerable importance for insertion of an L5-S1 disc prosthesis. The preoperative angio-MRI provides information on the potential difficulty of the insertion. In addition, with this preoperative information, the patient can be warned that it may not be possible to insert the implant so that a therapeutic alternative may be proposed.

Adult↗
PubMed2001

Delayed nephrectomy in grade V renal injury with two interesting anatomic variations.

The decision to perform early nephrectomy in hemodynamically stable grade V injury rather than to provide supportive nonoperative care is not universally accepted. The management of isolated grade V renal injury, as well as the management of coexisting abdominal trauma that requires operative intervention, is an area of controversy. We present the case of a grade V renal injury that was initially managed expectantly at a level I trauma center. After transfer to our facility, nephrectomy was performed. The case illustrates the merit of prompt definitive surgical treatment.

Adult↗
PubMed2000

Assessment of some important anatomical variations and dangerous areas of the paranasal sinuses by computed tomography in children.

The purpose of this study is to determine important variations and areas of risk for major complications in paranasal computed tomography (CT). We also made specific measurements for individual differences. This study consisted of 64 children (128 sides). Eleven participants had coronal and axial, and the remaining 53 only coronal CT. The distance of the anterior ethmoidal artery (AEA) and the lamina cribrosa to the inferior turbinate and the orbital roof, and the depth of the lamina cribrosa were measured. The percentages of some of the variations were as follows: upper attachment of uncinate process 25%, freely coursing AEA 43%, aerated anterior clinoids 8%, optic canal bulging 6% and extreme medially coursing carotid canal 3%. The frequencies of some of these variations and the existence of Onodi cells were significantly smaller than compared with adults. Specific measurements varied individually. In conclusion, children deserve more attention while evaluating CT, due to their tiny bony structures.

Adolescent↗
PubMed2000

The lower labial branches of the mental nerve: anatomic variations and surgical relevance.

PURPOSE: The purpose of this study was to determine the cause of injuries of the lower labial branches (LLB) of the mental nerve (MN) after biopsy of minor salivary glands (BMSG), labial nodule excision, or symphyseal bone procedures using a labial approach. PATIENTS AND METHODS: Thirty-two MN were dissected in 16 cadavers to trace the labial branches. The following factors were recorded: 1) the number of LLB; 2) the angle between the medial LLB and the fibers of the orbicularis oris muscle; 3) the anastomoses between the lateral branches; and 4) the midline crossover innervation of the LLB. The number of branches on each side, as well as values of the angle between the nerves and superficial fibers of the orbicularis oris muscle, were compared using the Wilcoxon test. RESULTS: The mean number of LLB was 2 (SEM, 1; range, 1 to 4); the average angle between the medial LLB and the fibers of the orbicularis oris muscle was 36 degrees (SEM, 2 degrees ), without any statistical difference between the two sides (P = .78); an anastomosis between the 2 lateral branches of the LLB was observed in only 1 case; and the mean midline crossover innervation of the LLB was 25% (SEM, 14%) of the intercommisural distance. This crossover innervation was present only on the ventral surface of the lip. CONCLUSIONS: These data suggest that injuries to the LLB could be prevented if the incision(s) are made horizontally on the dorsal aspect of the lower lip, and the angle between the incision and the long axis of the lip is approximately 36 degrees . In the case of symphyseal bone procedures using a labial route, a "U"-shaped incision parallel to the LLB is suggested.

Chin↗
PubMed1977

Anatomical variations of the median nerve in the carpal tunnel.

In 246 hands in which the carpal tunnel was explored at operation, 29 variations in the course of the median nerve were found. Accessory branches at the distal portion of the tunnel were found in 18 hands, a high division of the median nerve in seven, and accessory branches proximal to the tunnel in four. Based upon these findings and including published reports of others, the variations were classified into four groups: I-variation in the course of the thenar branch; II-accessory branches at the distal portion of the carpal tunnel; III-high divisions of the median nerve; and IV-accessory branches proximal to the carpal canal. The thenar branch variations in 100 cadaver hands (Poisel) were extraligamentous in 46 percent, subligamentous in 31 percent, and transligamentous in 23 percent. The findings emphasize the importance of approaching the median nerve from the ulnar side when opening the carpal tunnel.

Carpal Tunnel Syndrome↗
PubMed1989

[Anatomic variations of the vascular network of the first dorsal commissure. Uses of the kite flap].

Thirty dissections were performed on fresh, unfixed, adult cadavers after vascular injection of silastic or methylene blue. Analysis of the results led to replacement of the concept of a single dorsal intermetacarpal artery, the constant pedicle of the kite flap, by that of an intermetacarpal vascular system composed of one or two supra- and/or sub-aponeurotic vessels. The existence of distinct direct skin branches of this intermetacarpal vascular system is defined. The various possible modes of vascularisation of the kite flap are listed, defining the situations at risk and leading to precise practical applications in terms of surgical technique.

Adult↗
PubMed1997

Anatomic variation of structural properties of periacetabular bone as a function of age. A quantitative computed tomography study.

The shape of the acetabulum, the volume of the periacetabular bone, and its density for 125 patients with a wide age range have been quantified using quantitative computed tomography. The goals were to study the relationship between geometric and densitometric properties and provide normative data for finite-element analysis. Significant correlations were found between acetabular diameter and (1) depth, (2) cancellous periacetabular bone density, and (3) periacetabular total bone volume. Only changes in densitometric properties significantly correlated with age. Sphericity of the acetabulum did not increase with age. Variability in bone morphology and density was found for both male and female groups. Surgeons using purely geometric measures to quantify the integrity of acetabular bone should be aware of their limitations when selecting hardware for total hip arthroplasty.

Acetabulum↗
PubMedDate not supplied

Large isthmus of the cingulate gyrus: an unusual anatomical variation simulating tumor.

The isthmus of the cingulate gyrus connects the cingulate gyrus to the parahippocampal gyrus. This isthmus demonstrates variable morphological appearances ranging from normal to prominent, and very prominent types. One unusual variety is an apparently large isthmus with a potential to be misinterpreted as a tumor, which is the main topic of this paper.

Adolescent↗
PubMed1995

The persistent primitive hypoglossal artery: a rare anatomic variation with frequent clinical implications.

The case of a persistent primitive hypoglossal artery (PHA) in a 72-year-old man dead from myocardial infarction is presented. The autopsy showed the presence of a semicircular marginal infarct on the surface of the left cerebral hemisphere. The PHA anastomized the basilar artery origin with the left internal carotid artery, running through the left hypoglossal canal together with the hypoglossal nerve. The vertebral and posterior communicating arteries were hypoplastic. The PHA represented the morphological base on which the cerebral vascular insufficiency acted, following the generalized circulatory insufficiency due to the myocardial infarct, causing the cerebral infarct. Based on the embryology of the cranial arteries and on the morphological findings we suggest that the persistence of the hypoglossal artery: 1) precedes the vertebral and posterior communicating arteries hypoplasia causing it by competition for the territory of distribution; 2) gives rise to an almost complete dependence of the cerebral circulation from the carotid system with predictable ischemic consequences in the case of a critical reduction of the carotid blood flow; 3) may be associated with an anomalous structure of the vessel wall and exposes the basilar trunk to an unusual haemodynamic stress, predisposing to the onset of aneurysms.

Aged↗
PubMed1994

Biceps brachii muscle attached to the extensor carpi radialis brevis muscle: an unreported anatomical variation in humans.

We report a new muscular variation in humans. It consisted of a biceps brachii muscle attached to the extensor carpi radialis brevis muscle by means of an accessory fasciculus. It was a trapezoid tendinous connection band that arose from the terminal tendon of the biceps brachii muscle and ended in the internal margin of the extensor carpi radialis brevis muscle. This intermuscular connection band was the external slip of the insertion tendon of the biceps brachii muscle, which was also attached by means of two other fascicles to the radial tuberosity (intermediate slip) and the flexor digitorum superficialis muscle (internal slip). This variation was observed in only one of the sixty upper limbs examined.

Adult↗
PubMedDate not supplied

Anatomic variation of the coracoacromial ligament: a macroscopic and microscopic cadaveric study.

The operative management of the subacromial impingement syndrome includes reconstruction in cases with ruptured tendons and enlargement of the subacromial space by arthroscopic or open resection of the coracoacromial ligament and acromioplasty. In nearly 20% of all cases, however, surgical treatment fails. This study was conducted with 124 cadaver shoulders of older specimens with a balanced male/female ratio. The coracoacromial ligament did not present homogenous morphologic characteristics. We found 25.8% of all ligaments undivided, 59.7% bipartite, and 14.5% consisted of three parts. The third part, located most medially, took a hidden path to the coracoid process and was not visible during dissection until after the clavicle was resected. This medially situated third part of the coracoacromial ligament has not been described in the medical literature before the time of our investigation. It could well be responsible for persisting subacromial pain after surgery, if it is not identified and resected during surgery.

Acromion↗
PubMed1998

Dyslexia, neurolinguistic ability, and anatomical variation of the planum temporale.

This article addresses the relationship between patterns of planum temporale symmetry/asymmetry and dyslexia and neurolinguistic abilities. Considerable research indicates that dyslexic individuals typically do not display the predominant pattern of leftward planum temporale asymmetry. Variable findings on the structural basis of symmetry are due partially to measurement issues, which are examined in some detail in this critical review. The physiological basis of symmetry may be reduced neuronal elimination in the right planum, although other alternatives are offered. Theories are offered to explain how symmetrical plana are related to dyslexia, and it is evident that symmetrical plana are not sufficient to produce dyslexia. However, some evidence suggests that nonleftward plana asymmetry is associated with deficits in verbal comprehension, phonological decoding, and expressive language. It is concluded that nonleftward asymmetry is associated with linguistic deficits, but that explanatory theories need to be further developed. Among the many issues that need to be addressed, future research needs to determine whether the relationship between patterns of planum temporale symmetry/asymmetry and linguistic ability is specific to dyslexia or if asymmetry covaries lawfully with linguistic abilities in nondyslexic populations.

Anthropometry↗