Localization of the centers of intramuscular nerve dense regions of the rotator cuff muscles: a guide for botulinum toxin A injection for spasticity accompanied by shoulder pain / Localización de los centros de las regiones densas del nervio intramuscular de los músculos del manguito rotador: una guía para la inyección de toxina botulínica A por espasticidad con dolor de hombro

To accurately localize the centers of intramuscular nerve dense regions (CINDRs) of rotator cuff muscles. Twenty adult cadavers were used. The curves on skin connecting the superior angle of scapula with the acromion, and with the inferior angle of scapula were designed as the horizontal (H) and longitudinal (L) reference lines, respectively. One side of the rotator cuff muscles were removed and subjected to Sihler's staining to show intramuscular nerve dense regions, and the contralateral muscles' CINDRs were labeled with barium sulfate and scanned by computed tomography (to determine body surface projection points (P)). The intersection of the longitudinal line from point P to line H, and that of the horizontal line from point P to line L, were recorded as PH and PL, respectively. The projection of CINDRs on the anterior body surface across the saggital plane was defined as P' and the line connecting P to P' was recorded as Line PP'. Percentage positions of CINDRs of PH and PL on lines H and L, and the depths on line PP' were determined under the Syngo system. Two, four, one, and one CINDRs were identified in supraspinatus, infraspinatus, teres minor, and subscapularis muscles, respectively. The positions of PH of these CINDRs on the H-line are as follows: supraspinatus, 25.43 % and 26.59 %; infraspinatus, 53.85 %, 34.63 %, 35.96 % and 58.17 %; teres minor, 74.50 %; and subscapularis, 20.33 %. The PL on the L-line: supraspinatus, 11.09 % and 14.83 %; infraspinatus, 21.59 %, 27.93 %, 48.55 % and 57.52 %; teres minor, 68.28 %; and subscapularis, 52.82 %. The depth on line PP': supraspinatus, 24.83 % and 25.40 %; infraspinatus, 21.55 %, 16.10 %, 10.01 % and 8.14 %; teres minor, 13.27 %; and subscapularis, 22.88 %. The identification of these CINDRs should provide the optimal target position for injecting botulinum toxin A to treat rotator cuff muscles spasticity accompanied by shoulder pain and to improve the efficiency and efficacy of blocking target localization.

Con el objetivo de localizar con precisión los centros de las regiones densas del nervio intramuscular (CRDNI) de los músculos del manguito rotador, se utilizaron veinte cadáveres adultos. Las curvas en la piel que conectan el ángulo superior de la escápula con el acromion y con el ángulo inferior de la escápula se determinaron como líneas de referencia horizontales (H) y longitudinales (L), respectivamente. Se extrajo de un lado los músculos del manguito rotador y se sometió a la tinción de Sihler para mostrar regiones densas de nervios intramusculares, y los CRDNI de los músculos contralaterales se marcaron con sulfato de bario y se escanearon mediante tomografía computarizada (para determinar los puntos de proyección de la superficie corporal (P)). La intersección de la línea longitudinal desde el punto P a la línea H, y de la línea horizontal desde el punto P a la línea L, se registraron como PH y PL, respectivamente. La proyección de CRDNI en la superficie del cuerpo anterior a través del plano sagital se definió como P 'y la línea que conecta P a P' se registró como Línea PP '. Las posiciones porcentuales de los CRDNI de PH y PL en las líneas H y L, y las profundidades en la línea PP 'se determinaron bajo el sistema Syngo. Se identificaron dos, cuatro, uno y un CINDR en los músculos supraespinoso, infraespinoso, redondo menor y subescapular, respectivamente. Las posiciones de PH de estos CRDNI en la línea H son las siguientes: supraespinoso, 25,43 % y 26.59 %; infraspinatus, 53,85 %, 34,63 %, 35,96 % y 58,17 %; redondo menor, 74,50 %; y subescapular, 20,33 %. El PL en la línea L: supraespinoso, 11.09 % y 14.83 %; infraspinatus, 21,59 %, 27,93 %, 48,55 % y 57,52 %; redondo menor, 68.28 %; y subescapular, 52,82 %. La profundidad en la línea PP ': supraespinoso, 24,83 % y 25,40 %; infraspinatus, 21,55 %, 16,10 %, 10,01 % y 8,14 %; redondo menor, 13.27 %; y subescapularis, 22,88 %. La identificación de estos CRDNI debería proporcionar la posición objetivo óptima para inyectar la toxina botulínica A para tratar la espasticidad de los músculos del manguito rotador acompañada de dolor en el hombro y para mejorar la eficiencia y la eficacia del bloqueo de la localización del objetivo.

MRI on rotator cuff and shoulder joint pathologies

The shoulder joint is an elegant anatomic structure formed by the humerus, clavicle and the scapula; its range of motion exceeds all other joints, yet under most circumstances, it is stable. The shoulder complex comprises of three joints namely the sternoclavicular, acromioclavicular, and glenohumeral joints. The factors which aid on to this progress including age, occupation, trauma, acromion type, slope and position, acromioclavicular joint degeneration, proximal migration of the humeral head, bony spurs compressing on the tendons. The most commonly affected rotator cuff tendon being the supraspinatus. The tears are further classified as complete/full thickness and partial tears depending on the involvement of the whole or part of the tendon. Being one of the most important stabiliser of the shoulder joint, rotator cuff pathologies can cause major joint dysfunction, like stiffness, restricted/painful joint movements even to the extent of restricting daily activities our study aims to describe MRI characteristics of shoulder and rotator cuff pathologies. And to describe the distribution of rotator cuff pathologies in terms of age, gender, symptomatology and secondary changes/sequelae study, the rotator cuff abnormalities were common in the sixth and seventh decades of life. The incidence of predisposing factors for rotator cuff tears was also found to increase with age as seen in our study, type II and III acromions, acromioclavicular joint arthropathies, osteophytosis/spurs are common in the sixth and seventh decades of life. We noticed in our patients that pain followed by stiffness resulting in reduced range of movement across the shoulder joint is very common. MRI imaging was useful in effectively ruling out the other causes of shoulder pain, overall features conclude that magnetic resonance imaging is very useful in depicting rotator cuff disease diagnosis along with the predisposing factors like the acromion type and orientation, reduction in coracohumeral distance, reduced acromioclavicular distance and other associated features like effusion, bursitis and bone changes. Further research with a larger sample size for a longer study period is suggested to draw broader conclusions and to strengthen the findings of the present study.

Arterial variations of the subclavian-axillary arterial tree: its association with the supply of the rotator cuff muscles / Variaciones arteriales del árbol arterial subclavio-axilar: su asociación con la irrigación del manguito de los rotadores

The subclavian-axillary arterial tree is responsible for the arterial supply to the rotator cuff muscles as well as other shoulder muscles. This study comprised the bilateral dissection of the shoulder and upper arm region in thirty-one adult and nineteen fetal cadaveric specimens. The variable origins and branching patterns of the axillary, subscapular, circumflex scapular, thoracodorsal, posterior circumflex humeral and suprascapular arteries identified in this study corroborated the findings of previous studies. In addition, unique variations that are unreported in the literature were also observed. The precise anatomy of the arterial distribution to the rotator cuff muscles is important to the surgeon and radiologist. It will aid proper interpretation of radiographic images and avoid injury to this area during surgical procedures.

El árbol arterial subclavio-axilar, es responsable del suministro arterial de los músculos correspondientes al manguito de los músculos rotadores, así como de otros músculos del hombro. Este estudio comprende la disección bilateral del hombro y la región superior del brazo en 31 cadáveres adultos y 19 fetos. Las variables y patrones del origen, ramificación de las arterias axilar, subescapular, circunfleja escapular, toracodorsal, circunfleja humeral posterior y supraescapular, identificados en este estudio, corroboran los hallazgos de estudios anteriores. Además, se observaron variaciones únicas no comunicadas previamente en la literatura. La anatomía precisa de la distribución arterial de los músculos del manguito de los músculos rotadores es importante para el cirujano y el radiólogo. Esta información constituirá una ayuda para la adecuada interpretación de imágenes radiológicas y para evitar lesiones en esta área durante los procedimientos quirúrgicos.

Arterial supply to the rotator cuff muscles / Suministro arterial de los músculos del manguito rotador

The arterial supply to the rotator cuff muscles is generally provided by the subscapular, circumflex scapular, posterior circumflex humeral and suprascapular arteries. This study involved the bilateral dissection of the scapulohumeral region of 31 adult and 19 fetal cadaveric specimens. The subscapularis muscle was supplied by the subscapular, suprascapular and circumflex scapular arteries. The supraspinatus and infraspinatus muscles were supplied by the suprascapular artery. The infraspinatus and teres minor muscles were found to be supplied by the circumflex scapular artery. In addition to the branches of these parent arteries, the rotator cuff muscles were found to be supplied by the dorsal scapular, lateral thoracic, thoracodorsal and posterior circumflex humeral arteries. The variations in the arterial supply to the rotator cuff muscles recorded in this study are unique and were not described in the literature reviewed. Due to the increased frequency of operative procedures in the scapulohumeral region, the knowledge of variations in the arterial supply to the rotator cuff muscles may be of practical importance to surgeons and radiologists.

El suministro arterial a los músculos del manguito rotador generalmente es proporcionado por las arterias subescapular, circunfleja escapular, circunfleja humeral posterior y supraescapular. Se realizó la disección bilateral de la región escapulo humeral de 31 especímenes cadavéricos adultos y 19 fetos. El músculo subescapular estaba irrigado por las arterias subescapular, supraescapular y circunfleja escapular. Por otra parte, la arteria supraescapular irrigaba a los músculos supra e infraespinoso. Observamos que los músculos infraespinoso y redondo menor fueron irrigados por la arteria circunfleja escapular. Además de las arterias de origen y sus ramas, observamos que los músculos del manguito rotador son irrigados por la arteria escapular dorsal y las arterias torácica lateral, toracodorsal y circunfleja humeral posterior. Las variaciones en la irrigación de los músculos del manguito rotador registrados en este estudio son únicos y no existe una descripción referente a ellos en la literatura revisada. Debido a la mayor frecuencia de los procedimientos quirúrgicos en la región escápulohumeral, el conocimiento de las variaciones de la irrigación de los músculos del manguito rotador puede ser de importancia práctica para cirujanos y radiólogos.

MUSCLE VOLUME AND STRENGTH CHARATERISTICS OF THE ROTATOR CUFF AND DELTOID MUSCLES IN ASYMPTOMATIC BASEBALL PITCHERS / 体力科学

The purpose of this study was to investigate muscle volume (MV) and strength characteristics of the rotator cuff (supraspinatus, infraspinatus, teres minor, and subscapularis) and deltoid muscles in each shoulder of asymptomatic baseball pitchers. Twelve collegiate baseball pitchers (PG) and ten male students (CG) who never played an overhand sports volunteered to participate in this study. Magnetic resonance imaging (Straits II, Hitachi Medico, 1.5 T) was used to measure the MV of rotator cuff and deltoid muscles in both shoulders of each subject. Since the individual muscles were difficult to identify on MRI scans, the infraspinatus and teres minor were analyzed as one infraspinatus muscle. Shoulder abduction (ABD), external rotation (ER), and internal rotation (IR) strengths were measured each side using a hand-held dynamometer (Power Track II, Jtech Medical Industry) . The MV of deltoid muscle was significantly larger value on the dominant side (DOM) than on the non-dominant side (NDOM) in both the PG and CG groups (p<0.05) . However, no significant differences in the MV of the rotator cuff muscles and the measured shoulder strength (ABD, ER, and IR) were observed between both sides in either group. Similarly, no significant differences in the DOM/NDOM ratio of the muscle volume and the measured shoulder strength were observed between the two groups. These results suggest that the rotator cuff muscle volume and strength does not differ in both sides of the PG, and DOM/NDOM ratios of the rotator cuff muscle volume and strength of the PG does not differ in those of the CG.

Electromyographic analysis of shoulder muscles during shoulder external rotation with reference to load magnitude / 体力科学

Electromyographic muscle activities of the shoulder muscles during shoulder external rotation with reference to load magnitude were studied in 8 healthy male subjects without history of shoulder injuries. In addition, we discussed the relationship between rotator cuff muscles and superficial muscles. The subjects performed shoulder external rotation from 60°internal rotation to 45° external rotation at 20° of shoulder abduction and 20° of flexion. A Cybex dynamometer used to prescribe angle and velocity of the shoulder movement. At the same time, intramuscular wire electrodes were inserted into the supraspinous, infraspinous and teres minor muscles, and then surface electrodes were placed over the posterior deltoid and middle trapezius muscles. The load magnitude ranged 2-18 Nm and the angle velocity was set at 15 deg/sec. The rotator cuff muscles became significantly to be activated from 2 Nm (the supraspinous and infraspinous m.) and from 4-5 Nm (the teres minor m.) compared with the muscle activity during non-load. The superficial muscles became significantly to be activated from 4-7 Nm (the posterior deltoid m.) and from 3-6 Nm (the middle trapezius m.) compared with the muscle activity during non-load. Within the load range (18 Nm 46.8% MVC), %iEMG of the rotator cuff muscles was always larger than that of the superficial muscles. Therefore, we concluded that the contribution of the rotator cuff muscles was larger than that of the superficial muscles up to 3-4 Nm, and activities of the superficial muscles increased gradually from 3-4 Nm during shoulder external rotation.