The anatomic basis for localized occipital thinning: A normal anatomic variant

The radiographic evidence presented in this case confirms that the asymptomatic, incidentally found occipital radiolucencies previously described by Keats are not a problem in differential diagnosis of inner table erosion. The entity appears to be a developmental variant with typical features and occurring in a characteristic location.     

The anatomic coracoclavicular ligament reconstruction

The surgical management of chronic or acute acromioclavicular joint dislocations can be divided into three broad groups. These are repair of the acromioclavicular and coracoclavicular ligaments, reconstruction of the acromioclavicular or coracoclavicular ligaments, and tendon transfer. Biomechanical analysis of the coracoclavicular and acromioclavicular ligaments has determined that the coracoclavicular ligaments play a major role with/without the acromioclavicular ligaments intact. Based on this biomechanical analysis, we have devised a novel technique to reconstruct anatomically the coracoclavicular ligaments. The anatomic position of the coracoclavicular ligaments is discussed as determined by osteological measurements as well as the technique.     

Percutaneous cholecystostomy: anatomic considerations

In 100 consecutive patients undergoing abdominal computed tomography, the anatomic relationships among the gallbladder fundus, liver, and right hemicolon were evaluated to assess the feasibility of direct transperitoneal versus percutaneous transhepatic cholecystostomy. In only 17% of patients was there no interposition of colon or liver between the skin and the gallbladder fundus. In 13% of patients the right hemicolon lay between the gallbladder fundus and skin. In the remaining 70% of patients, the gallbladder fundus was positioned posterior to the liver margin. Thus, in 83% of patients studied, percutaneous cholecystostomy would necessitate a transhepatic approach.     

Vascular anatomic variation in rabbits

PURPOSE: To explore the vascular anatomic variation along the aortic arch in New Zealand White rabbits with the goal of highlighting potential anatomic configurations that might be encountered in the performance of preclinical endovascular research in rabbits. MATERIALS AND METHODS: Digital subtraction angiography images of the brachiocephalic artery (BCA) and aortic arch in New Zealand White rabbits were obtained after creation of elastase-induced aneurysms at the origin of the right common carotid artery (RCCA) in 214 animals. The patterns of origin of the RCCA and left common carotid artery (LCCA), right subclavian artery (RSCA) and left subclavian artery (LSCA), and right vertebral artery (RVA) and left vertebral artery (LVA) were analyzed. RESULTS: Five predominant variations of vessel origin were identified. In 200 of 214 cases (93%), the LCCA originated from the bifurcation of the BCA and aorta. In eight cases (4%), the LCCA directly originated from the aorta. In two cases (1%), the LCCA originated from the BCA. Aberrant RSCA anatomy in which the RSCA originated from the aortic arch instead of the BCA was found in three cases (1.5%). In a single case (0.5%), aberrant RSCA anatomy with the RVA originating from the BCA was encountered. CONCLUSIONS: Anatomic variation of the BCA in New Zealand White rabbits is similar to that seen in humans. Understanding of the normal and variant anatomy of the rabbit will aid investigators who use the rabbit model for endovascular research.     

Pseudopathologic hip fracture: anatomic explanation

Fracture of the hip may result in external rotation of the femoral diaphysis. When this occurs the proximal diaphysis may appear homogeneously dense, particularly in elderly woman. Computed tomography shows that the misleading appearance is due to variations in cortical thickness anteroposteriorly and mediolaterally. This finding is important as this appearance of the femur must be distinguished from a pathologic fracture.     

Avoiding pitfalls in anatomic ACL reconstruction

As interest in double-bundle anterior cruciate ligament (ACL) reconstruction grows, we continue to refine our technique to perform the most anatomic reconstruction possible. Our experience has brought to our attention the potential mistakes that should be avoided when performing an anatomic double-bundle ACL reconstruction. These mistakes include (1) failure to visualize the femoral insertion completely, (2) use of the clock face to reference femoral tunnel positioning, (3) nonanatomic tunnel placement leading to graft impingement, (4) mismatching tibial and femoral tunnels, and (5) failure to restore the native tension pattern of the ACL. It is also important to recognize that a double-bundle ACL reconstruction is not necessarily equivalent to an anatomic double-bundle reconstruction. This article reviews potential mistakes in DB ACL reconstruction and describes our way of avoiding them.     

The postlobectomy chest: anatomic considerations

The authors present a systematic review of the changes that occur in pulmonary and extrapulmonary anatomy as the result of lobar collapse or resection. Differences in the changes produced by lobectomy and lobar collapse are noted.     

Posterolateral supporting structures of the knee: findings on anatomic dissection, anatomic slices and MR images

In this article we study the ligaments and tendons of the posterolateral corner of the knee by anatomic dissection, MR-anatomic correlation, and MR imaging. The posterolateral aspect of two fresh cadaveric knee specimens was dissected. The MR-anatomic correlation was performed in three other specimens. The MR images of 122 patients were reviewed and assessed for the visualization of different posterolateral structures. Anatomic dissection and MR-anatomic correlation demonstrated the lateral collateral, fabellofibular, and arcuate ligaments, as well as the biceps and popliteus tendons. On MR images of patients the lateral collateral ligament was depicted in all cases. The fabellofibular, arcuate, and popliteofibular ligaments were visualized in 33, 25, and 38% of patients, respectively. Magnetic resonance imaging allows a detailed appreciation of the posterolateral corner of the knee.     

Arthroscopic anatomic stabilization of acromioclavicular joint dislocation

A review of the literature shows that there are over 100 different surgical procedures to reconstruct the acromioclavicular joint. Despite these numerous options for reconstruction, the arthroscopic stabilization of this joint has rarely been reported. We describe a new arthroscopic technique to stabilize the acromioclavicular joint using 5-mm corkscrew anchors, No. 5 Fiberwire, and a small titanium platelet. With this technique one obtains the following advantages: anatomic reconstruction, stable stabilization, excellent cosmesis, less morbidity, no need to remove an implant, and avoidance of complications from breakage or migration of metal implants.     

Accessory meningeal artery: an anatomic misnomer

The accessory meningeal artery is misnamed in view of the territory the artery supplies. The name implies that the vessel is an important addition to the middle meningeal artery in supplying the meninges. This is incorrect, because no more than approximately 10% of the blood flow of the accessory meningeal artery reaches the intracranial territory; 90% of the blood is carried to the extracranial structures. After reviewing the anatomy of the accessory meningeal artery we support the notion that the proper name of the vessel should be arteria pterygomeningica, or pterygomeningeal artery.     

Stellate images: anatomic and radiologic correlations

The stellate images are the most well-known and most typical finding in the diagnosis of breast cancer. Its positive predictive value is very high. However, in some cases, the stellate images can correspond to benign lesions. Stellate images require high quality mammograms, precise analysis, and as always in senology, confirmation by clinical examination, ultrasound if necessary, and in the case of palpable lesions, cytology. In this work, we will study malignant and benign stellate images mammographic-pathologic correlation as well as the importance of stellate images in the detection of non-palpable lesions. The typical stellate finding is correlated with the phenomena of fibrosis and elastosis and it is impossible to distinguish benign spicules from malignant spicules on mammography. We will present guidelines in the face of stellate image. Stellate images are for the most part suggestive of malignant lesions, and their discovery should lead to suspicion of cancer until the contrary is proven.     

Normal anatomic measurements in cervical computed tomograms

Radiodiagnostically relevant normal values and variations for measurements of the cervical region, the arithmetical average and the standard deviation were determined from adequate computer tomograms on 60 healthy women and men, aged 20 to 83 years. The sagittal diameter of the prevertebral soft tissue and the lumina of the upper respiratory tract were evaluated at exactly defined levels between the hyoid bone and the incisura jugularis stuni. The thickness of the aryepiglottic folds, the maximal sagittal and transverse diameters of the thyroid gland and the calibre of the great cervical vessels were defined. To assess information about laryngeal function in computerized tomography, measurements of distances between the cervical spine and anatomical fixed points of the larynx and hypopharynx were made as well as of the degree of vocal cord movement during normal respiration and phonation.     

Postoperative evaluation of tibial footprint and tunnels characteristics after anatomic double-bundle anterior cruciate ligament reconstruction with anatomic aimers

Following anatomic double-bundle anterior cruciate ligament (ACL) reconstruction with hamstring tendon autografts, 38 consecutive patients were evaluated with high-speed three-dimensional computed tomography. Scans were performed within 3 days following surgery. The length and width of the reconstructed ACL footprint were measured on axial images. Then, 3D images were converted into 2D with radiologic density for measurement purposes. Tunnel orientation was measured on AP and lateral views. In the sagittal plane, the center of the anteromedial (AMB) and posterolateral bundle (PLB) tibial attachment positions was calculated as the ratio between the geometric insertion sites with respect to the sagittal diameter of the tibia. In addition, the length from the anterior tibial plateau to the retro-eminence ridge was measured; the relationship of this line with the centers of the AM and PL tunnels was then measured. The AP length of the reconstructed footprint was 17.1 mm ± 1.9 mm and the width 7.3 mm ± 1.2 m. The distance from retro-eminence ridge to center of AM tunnel was 18.8 mm ± 2.8 mm, and the distance from RER to center of PL tunnel was 8.7 mm ± 2.6 mm. The distance between tunnels center was 10.1 mm ± 1.7 mm. There were no significant differences between the intra- and inter-observer measurements. The bone bridge thickness was 2.1 mm ± 0.8 mm. In the sagittal plane, the centers of the tunnel apertures were located at 35.7% ± 6.7% and 53.7% ± 6.8% of the tibia diameter for the AMB and PLB, respectively. The surface areas of the tunnel apertures were 46.3 mm² ± 4.4 mm² and 36.3 mm² ± 4.0 mm² for the AM and PL tunnels, respectively. The total surface area occupied by both tunnels was 82.6 mm² ± 7.0 mm². In the coronal plane, tunnel orientation showed the AM tunnel was more vertical than the PL tunnel with a 10° divergence (14.8° vs. 24.1°). In the sagittal plane, both tunnels were almost parallel (29.9° and 25.4° for the AM and PL tunnels, respectively). When using anatomic aimers, the morphometric parameters of the reconstructed tibial footprint in terms of length and distances to the surrounding bony landmarks were similar to the native ACL tibial footprint. However, the native footprint width was not restored, and the surface area of the two tunnel apertures was in the lower range of the published values for the native footprint area.