This study aimed to bring the trapezius muscle knowledge of the locations where the accessory nerve branches enter the muscle belly to reach the motor endplates and find myofascial trigger points (MTrPs). Although anatomoclinical correlations represent a major feature of MTrP, no previous reports describing the distribution of the accessory nerve branches and their anatomical relationship with MTrP are found in the literature. Both trapezius muscles from twelve adult cadavers were carefully dissected by the authors (anatomy professors and medical graduate students) to observe the exact point where the branches of the spinal accessory nerve entered the muscle belly. Dissection was performed through stratigraphic layers to preserve the motor innervation of the trapezius muscle, which is located deep in the muscle. Seven points are described, four of which are motor points: in all cases, these locations corresponded to clinically described MTrPs. The four points were common in these twelve cadavers. This type of clinical correlation between spinal accessory nerve branching and MTrP is useful to achieve a better understanding of the anatomical correlation of MTrP and the physiopathology of these disorders and may provide a scientific basis for their treatment, rendering useful additional information to therapists to achieve better diagnoses and improve therapeutic approaches.

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Myofascial pain syndrome is characterized by pain and limited range of motion in joints and caused by muscular contracture related to dysfunctional motor end plates and myofascial trigger points (MTrPs). We aimed to observe the anatomical correlation between the clinically described MTrPs and the entry point of the branches of the inferior gluteal nerve into the gluteus maximus muscle. We dissected twenty gluteus maximus muscles from 10 human adult cadavers (5 males and 5 females). We measured the muscles and compiled the distribution of the nerve branches into each of the quadrants of the muscle. Statistical analysis was performed by using Student's t-test and Kruskal-Wallis tests. Although no difference was observed either for muscle measurements or for distribution of nerve branching among the subjects, the topography of MTrPs matched the anatomical location of the entry points into the muscle. Thus, anatomical substract of the MTrPs may be useful for a better understanding of the physiopathology of these disorders and provide basis for their surgical and clinical treatment.

Brazil. Intellectual and scientific content of the study, critical revision. ABSTRACT PURPOSE:To describe an effective experimental model to study the Achilles tendon healing. METHODS:Forty male Rattus norvegicus albinus, Wistar lineage adult male weighing 250 to 300g were used for this experiment and thirty were surgically submitted to bilateral partial transverse section of the Achilles tendon. The right tendon was treated with radio waves (RF) whereas the left tendon served as control. On the third postoperative day, the rats were divided into four experimental groups consisting of ten rats each which were treated with monopolar RF adjusted to 650 kHz and 2w, for two minutes twice a week and a group of normal animals without any intervention, until they were sacrificed on the 7 th , 14 th and 28 th days, respectively. Tendons were weighed and collagen quantification was evaluated by hydroxyprolin content. RESULTS:Significant reduction in collagen content on day 7, 14 and 28 was related to control experiment to normal tendon (7 days, p<0.01; 14 e 28 days, p<0.05). CONCLUSION:The experimental model has been effective and available to be used to study Achilles tendon healing.

SUMMARY:Unlike the venous system, variations in arterial anatomy are less frequent and most of them affect visceral arteries. In limbs, variations of the brachial artery are the most reported and at least six different patterns have been described so far. The commonest is the superficial brachial artery which lies superficially to the median nerve. Much less prevalent are the high origin of the radial artery (brachioradial artery) or the existence of a doubled brachial artery (accessory brachial artery). We present a previously undescribed pattern of brachial artery variation. During dissection of the right upper limb of a 60 year-old male embalmed cadaver, we found the bifurcation of the brachial artery in the proximal portion of the middle third of the arm. Its medial branch reaches the medial aspect of the arm, posterior to the median nerve. Afterwards, this medial branch redirects laterally and crosses again the median nerve, this time lying anterior to the nerve until it reaches the lateral aspect of the arm. At the elbow level, the medial branch originates the radial artery. The lateral branch of the brachial artery remains lateral to the median nerve and continues as ulnar artery and originates the interosseus artery.

Myofascial pain syndrome is characterized by pain and a limited range of joint motion caused by muscle contracture related to motor-end-plate dysfunction and the presence of myofascial trigger points (MTrPs). It is the most frequent cause of musculoskeletal pain, with a worldwide prevalence varying between 13.7% and 47%. Of the patients with myofascial pain syndrome, approximately 17% have pain in the medial hindfoot area. The abductor hallucis muscle is located in the medial, posterior region of the foot and is related to painful plantar syndromes. The objective of this study was to describe the distribution of the medial plantar nerve and their anatomical relationship with MTrPs found in the literature. Thirty abductor hallucis muscles were dissected from 15 human cadavers (8 males and 7 females). The muscles were measured, and the distribution data of the medial plantar nerve branches in each quadrant were recorded. For statistical analysis, we used generalized estimation equations with a Poisson distribution and a log logarithm function followed by Bonferroni multiple comparisons of the means. The data are expressed as the mean ± standard deviation. The level of significance was adjusted to 5% (p<0.05). A high concentration of nerve branches was observed in the first quadrant (Q1) of the abductor hallucis muscle, which is the same area in which the MTrPs are described. The topography of the entry points of the branches of the medial plantar nerve to the abductor hallucis muscle correlates with the topography of the muscular trigger points. The anatomical structure of the MTrPs may be useful for a better understanding of the pathophysiology of myofascial disorders and provide a basis for surgical and clinical treatments.

OBJECTIVES: To verify the pyramidalis muscle’s frequency (bilaterality, unilaterality, or absence) and morphometry (length of the medial border and width of its origin/base) in a sample of the Brazilian population and the anthropometric influence. METHODS: Dissection of 30 cadavers, up to 24h post-mortem. RESULTS: The pyramidalis muscle was present bilaterally and unilaterally in 83.33% and 3.33% of the cadavers, respectively, and absent in 13.33%. The muscles on the right and left sides were symmetrical in length but not in width; the pyramidalis muscles of men were longer, while those of the women were wider. We also found that there was greater variation in the dimensions (length and width) of the men’s muscles. Finally, in this sample of the Brazilian population, the pyramidalis muscle’s unilaterality was more prevalent than in other populations, and its complete absence was less prevalent. CONCLUSIONS: There were no cases of muscle duplication in one or both sides, as described in some studies. Despite all of its morphometric variation, the pyramidalis muscle maintained its triangular shape with longitudinal fibers in every case. Furthermore, no statistically significant correlation was noted between the muscles’ dimensions and person’s age, height, weight, or gender.

Lymphedema remains a challenging morbidity in breast cancer treatment. ARM and SLNB aim to avoid unnecessary damage to the lymphatic drainage of the upper limb. However, our anatomical study suggests that ARM may have potential oncological risks because preserved lymph nodes may harbor malignant cells due their proximity, overlapping drainage pathways, and connecting lymph vessels among lymph nodes.