Correction to: Distal insertional anatomy of the triceps brachii muscle: MRI assessment in cadaveric specimens employing histologic correlation and Play-doh® models of the anatomic findings.

Figures 9, 10, 11, 12 and 15 corrected.

Distal insertional anatomy of the triceps brachii muscle: MRI assessment in cadaveric specimens employing histologic correlation and Play-doh® models of the anatomic findings.

OBJECTIVES: Assess the insertional anatomy of the distal aspect of the triceps brachii muscle using magnetic resonance imaging (MRI) in cadavers with histologic correlation and Play-doh® models of the anatomic findings. MATERIALS: Elbows were obtained from twelve cadaveric arm specimens by transverse sectioning through the proximal portion of the humerus and the midportion of the radius and ulna. MRI was performed in all elbows. Two of the elbow specimens were then dissected while ten were studied histologically. Subsequently, Play-doh® models of the anatomic findings of the distal attachment sites of the triceps brachii muscle were prepared. RESULTS: MRI showed a dual partitioned appearance of the distal attachment sites into the olecranon in all specimens. In the deeper tissue planes, the medial head muscle insertion was clearly identified while superficially, the terminal portion of the long and lateral heads appeared as a conjoined tendon. Histologic analysis, however, showed continuous tissue rather than separate structures attaching to the olecranon. CONCLUSION: Although MRI appeared to reveal separate and distinct attachments of the triceps brachii muscle into the olecranon, histologic analysis delineated complex but continuous tissue related to the attachments of the three heads of this muscle. The Play-doh® models were helpful for the comprehension of this complex anatomy and might serve as a valuable educational tool when applied to the analysis of other musculoskeletal regions.

Does Hallux Valgus Exhibit a Deformity Inherent to the First Metatarsal Bone?

Hallux valgus is a common condition, and it still poses some challenges. The identification of factors associated with the development of the deformity is of paramount importance in obtaining a full correction of the disorder. Hallux pronation is one of the frequently found components, especially in larger deformities, but the cause and exact location of this condition are not fully understood. The aim of the present study was to investigate whether there is a rotational deformity inherent to the first metatarsal bone. A case-control study was conducted on patients with and without hallux valgus who were subjected to computed tomography with multiplanar reconstruction. Statistical analysis was performed by means of a mixed model adjusted for foot and gender to compare metatarsal rotation between cases and controls. Correlations between numerical quantitative measurements were investigated by means of Pearson's correlation coefficient obtained in a linear mixed model. A total of 82 feet (tests) were analyzed in the hallux valgus group and 64 feet (tests) in the control group (N = 146). The hallux valgus group was significantly different from the control group (p< .001). Mean metatarsal bone rotation was 15.36° (range 1.65° to 32.52°) in the hallux valgus group and 3.45° (range -7.40° to 15.56°) in the control group. The difference between the means was 11.9° (confidence interval 9.2° to 14.6°). In conclusion, patients with hallux valgus exhibited increased exclusive bone rotation of the first metatarsal toward pronation compared with the population without this condition.

Persistent sciatic artery found incidentally on hip MRI: report of 4 cases.

The persistent sciatic artery is a rare anatomical variant, representing the persistence of the sciatic artery in adult life that is responsible for the major blood supply to the lower limb in early embryologic development. Such persistence may be bilateral and can remain asymptomatic for many years. However, aneurysmal degeneration has been described as a complication of the persistent sciatic artery, which may cause critical limb ischemia resulting from thrombosis or embolization of aneurysm thrombus. Digital subtraction angiography, Doppler ultrasound, computed tomography angiography and magnetic resonance angiography are the most frequently used diagnostic tools to detect, classify and determine the presence of complications of a PSA. Early detection of this vascular abnormality on imaging studies can avoid life-threatening complications. We describe 4 patients with PSA that were diagnosed as an incidental finding in magnetic resonance imaging of the hip and demonstrate its characteristic imaging appearance.

Comparison between Simple Radiographic and Computed Tomographic Three-Dimensional Reconstruction for Evaluation of the Distal Metatarsal Articular Angle.

The hallux valgus is a pathologic condition in the forefoot that often causes pain and functional limitations. Assessing all deformity components, such as the distal metatarsal articular angle (DMAA) is essential to hallux valgus treatment. Nevertheless, interobserver agreement of DMAA is poor on plain radiographs. The present study compared computed tomographic (CT) 3-dimensional (3D) reconstruction with plain radiographic measurements for measuring the DMAA. We included 43 consecutive patients (77 feet), diagnosed with hallux valgus at the orthopedic outpatient clinic at Hospital de Clínicas de Porto Alegre (Porto Alegre, Brazil) from April 2014 to June 2015 in our prospective study. The DMAAs were measured by 2 observers using CT 3D reconstruction. The results were compared between observers and with the plain radiographic measurements using the concordance correlation coefficient and the Bland-Altman plot to determine the agreement between the 2 methods. The interobserver agreement of the CT 3D measurements was high (concordance correlation coefficient 0.90; p < .001). Significant agreement was found between the plain radiographic and CT measurements (concordance correlation coefficient 0.667; p < .001). The Bland-Altman plot showed that the difference between the plain radiographic and CT measurements increased when greater DMAA values were associated with the presence of metatarsal rotation. The interobserver agreement of DMAA measurements was greater on CT 3D reconstruction than on plain radiography. The poor interobserver agreement of the radiographic DMAA might have resulted from metatarsal rotation.

Estudo anatômico da substância branca do cérebro: da técnica de Klingler à dissecção virtual por ressonância magnética (tratografia) / Brain white matter anatomical study: from the Klingler technique to virtual dissection with magnetic resonance (tractography)

A técnica de dissecção de fibras é um método clássico, utilizado por renomados anatomistas do passado, para a demonstração dos tratos e fascículos integrantes da substância branca do cérebro. Esta técnica, utilizada desde o século XVII, envolve a dissecção em camadas da substância branca cerebral para demonstrar passo a passo a organização anatômica interna do parênquima. A complexidade da preparação do cérebro e da dissecção das fibras fez com que esse método fosse negligenciado por décadas. Com a possibilidade contemporânea e inédita de se visualizar os feixes de substância branca do encéfalo in vivo pela ressonância magnética, os fundamentosanatômicos antigos obtidos com a clássica técnica de dissecção de fibras tornam-se, paradoxalmente, ainda mais relevantes e atuais. Este trabalho descreve as principais etapas da técnica de dissecção de fibras, aprimorada por Joseph Klingler e revitalizada na última década por M. G. Yasargil e Ügur Türe, como uma forma de entendimento da anatomia intrínseca tridimensional do encéfalo para o uso clínico. Este estudo também busca explorar as potencialidades dessa verdadeira “dissecção virtual” através da ressonância magnética(tratografia) em reproduzir e complementar o conhecimentoanatômico das fibras obtido pelo método clássico.