Effectiveness of digital and analog learning methods for learning anatomical structures in physiotherapy education.

BACKGROUND: According to the German Physiotherapy Education and Qualification Regulations, teaching of anatomical structures is one of the fundamental subjects of physiotherapy education. Besides exhibits and models, anatomy atlases are usually used as teaching and learning tools. These are available in both analog form such as printed books or in digital form as a mobile application. Furthermore, the use of digital teaching and learning tools is steadily increasing within the education of health professionals. AIM: To assess the efficacy of a digital educational tool in contrast to an analog anatomical atlas in acquiring knowledge about anatomical structures. MATERIAL AND METHOD: The data collection took place in the context of an anatomy tutorial for students of the bachelor's degree program in physiotherapy. In a cross-over design, the students completed two learning assignments, each, with different learning materials provided, either with an anatomy app on a tablet or with an anatomy atlas as a book. The tests to assess the newly acquired knowledge immediately after the task, consisted of questions about the anatomical structures of the knee as well as the shoulder. In addition, the students' satisfaction with the learning materials provided was surveyed using a questionnaire. The survey assessed their satisfaction, their assessment of learning success, and their affinity to digital learning materials. This was done using a 5-point Likert scale and a free-text field. The data was analyzed descriptively, and group differences were calculated using a t-tests. RESULTS: Thirty students participated. The group comparison showed a significantly better outcome for the group that prepared with the analog anatomy atlas for the questions on the knee than the comparison group that used the anatomy app (t(28) = 2.6; p = 0.007). For the questions concerning the shoulder, there was no significant difference between the digital and analog groups (t(28) = 1.14; p = 0.26). The questionnaire revealed that satisfaction with the analog anatomy atlas was significantly higher than with the anatomy app. A total of 93.34% rated their experience with the analog learning tool at least "somewhat satisfied". In contrast, 72.67% of students partially or fully agreed that they "enjoyed learning with digital learning tools". DISCUSSION: Learning anatomical structures with the Human Anatomy Atlas 2023 + app did not show a clear advantage when compared to an anatomy book in these two cohorts of physiotherapy students. The results of the questionnaire also showed greater satisfaction with the analog anatomy atlas than with the anatomy app, whereas most students stated that they frequently use digital learning tools, including some for anatomical structures. Satisfaction with the learning tool seems to play a central role in their effectiveness. In addition, sufficient time must be provided for users to familiarize themselves with the user interface of digital applications to use them effectively. REGISTRATION: Diese klinische Studie wurde nicht in einem Studienregister registriert.

A comparative approach for characterizing the relationship among morphology, range-of-motion and locomotor behaviour in the primate shoulder.

Shoulder shape directly impacts forelimb function by contributing to glenohumeral (GH) range-of-motion (ROM). However, identifying traits that contribute most to ROM and visualizing how they do so remains challenging, ultimately limiting our ability to reconstruct function and behaviour in fossil species. To address these limitations, we developed an in silico proximity-driven model to simulate and visualize three-dimensional (3D) GH rotations in living primate species with diverse locomotor profiles, identify those shapes that are most predictive of ROM using geometric morphometrics, and apply subsequent insights to interpret function and behaviour in the fossil hominin Australopithecus sediba. We found that ROM metrics that incorporated 3D rotations best discriminated locomotor groups, and the magnitude of ROM (mobility) was decoupled from the anatomical location of ROM (e.g. high abduction versus low abduction). Morphological traits that enhanced mobility were decoupled from those that enabled overhead positions, and all non-human apes possessed the latter but not necessarily the former. Model simulation in A. sediba predicted high mobility and a ROM centred at lower abduction levels than in living apes but higher than in modern humans. Together these results identify novel form-to-function relationships in the shoulder and enhance visualization tools to reconstruct past function and behaviour.

Spatial Anatomy of the Radial Nerve in the Extended Deltopectoral Approach.

The goal of this study was to define safe zones to prevent radial nerve injury in an extended deltopectoral approach. Relative distances of the upper margin (UMRN) and lower margin (LMRN) of the radial nerve to the proximal and distal borders of the pectoralis major and deltoid insertions were measured in 20 cadaveric arms. Four proximal humeral zones were identified (zone I, proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon; zone II, proximal border of the deltoid tendon to the distal border of the pectoralis major tendon; zone III, distal border of the pectoralis major tendon to the distal border of the deltoid tendon; and zone IV, distal to the distal border of the deltoid tendon). On fluoroscopic measurement, mean distances between the UMRN and the proximal border of the pectoralis major tendon and the proximal border of the deltoid tendon were 71.6±2.1 mm and 26.2±2.5 mm, respectively. The incidence of the radial nerve in the spiral groove within each defined zone was as follows: zone I, 0%; zone II, 50%; zones III and IV, 100%. There was a significant association between anatomic zone and radial nerve entry into the spiral groove, χ2(3, N=88)=64.53, P<.001. The proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon (zone I) is a safe location to avoid injury to the radial nerve. We recommend placing cerclage wires proximal to zone I from lateral to medial to avoid entrapment of the radial nerve. [Orthopedics. 2023;46(1):e31-e37.].

Muscle Injury Around the Shoulder.

Acute shoulder tendon and intra-articular injuries are common and their imaging well described. However, a subset of patients present with more unusual acute shoulder muscle injury. Of these, pectoralis major muscle injuries are encountered the most often and are increasingly prevalent due to a focus on personal fitness, particularly bench-press exercises. Other muscle injuries around the shoulder are rare. This article reviews the anatomy, mechanism of injury, and the imaging findings in relation to injuries of these muscles around the shoulder. We focus on pectoralis major injury but also review proximal triceps, latissimus dorsi, teres major, and deltoid muscle injuries, providing imaging examples.

Osseous suprascapular canal: rare variant that would hinder suprascapular nerve block and posterior surgical approach.

PURPOSE: To report atypical anatomical variation of an osseous suprascapular canal, and to elaborate on its clinical significance as a potential anatomical factor that could obscure a direct posterior surgical approach and suprascapular nerve block. METHODS: Osteological observational study of the scapula with emphasis on the suprascapular space. The pool of investigated sample size was collectively 768 specimens composed of 529 adult dry scapulae (240 paired, 289 un-paired), 54 children dry scapulae, 135 wet scapulae observed during cadaveric dissections, 47 retrospective 3D CT reconstructions, and 3 retrospective full sequence shoulder MRI. The two reported cases came from the 240 (120 skeleton) observed paired scapulae. Furthermore, the osseous suprascapular canal was examined by X-rays and its internal path was exposed by CT sections. A narrative review was conducted to investigate any relevant reports on the subject matter. RESULTS: Two left dry bone scapulae with unilateral osseous suprascapular canal were found. The incidence of this atypical morphology of an osseous canal is probably five cases reported in three studies including this cases study. CONCLUSIONS: The reported cases aid in explaining additional possible anatomical factors that could lead to below threshold anesthetic effect in posterior suprascapular nerve block procedures. Therefore, it is more practical to visualize the suprascapular canal by some imaging method before attempting to blindly access the suprascapular nerve in nerve block or posterior surgical approach due to the rare potential existence of an ossified barrier hindering the procedure. LEVEL OF EVIDENCE: V Basic Science Research.

Preserved soft anatomy confirms shoulder-powered upstroke of early theropod flyers, reveals enhanced early pygostylian upstroke, and explains early sternum loss.

Anatomy of the first flying feathered dinosaurs, modern birds and crocodylians, proposes an ancestral flight system divided between shoulder and chest muscles, before the upstroke muscles migrated beneath the body. This ancestral flight system featured the dorsally positioned deltoids and supracoracoideus controlling the upstroke and the chest-bound pectoralis controlling the downstroke. Preserved soft anatomy is needed to contextualize the origin of the modern flight system, but this has remained elusive. Here we reveal the soft anatomy of the earliest theropod flyers preserved as residual skin chemistry covering the body and delimiting its margins. These data provide preserved soft anatomy that independently validate the ancestral theropod flight system. The heavily constructed shoulder and more weakly constructed chest in the early pygostylian Confuciusornis indicated by a preserved body profile, proposes the first upstroke-enhanced flight stroke. Slender ventral body profiles in the early-diverging birds Archaeopteryx and Anchiornis suggest habitual use of the pectoralis could not maintain the sternum through bone functional adaptations. Increased wing-assisted terrestrial locomotion potentially accelerated sternum loss through higher breathing requirements. Lower expected downstroke requirements in the early thermal soarer Sapeornis could have driven sternum loss through bone functional adaption, possibly encouraged by the higher breathing demands of a Confuciusornis-like upstroke. Both factors are supported by a slender ventral body profile. These data validate the ancestral shoulder/chest flight system and provide insights into novel upstroke-enhanced flight strokes and early sternum loss, filling important gaps in our understanding of the appearance of modern flight.

The effects of anatomical errors on shoulder kinematics computed using multi-body models.

Joint motion calculated using multi-body models and inverse kinematics presents many advantages over direct marker-based calculations. However, the sensitivity of the computed kinematics is known to be partly caused by the model and could also be influenced by the participants' anthropometry and sex. This study aimed to compare kinematics computed from an anatomical shoulder model based on medical images against a scaled-generic model and quantify the effects of anatomical errors and participants' anthropometry on the calculated joint angles. Twelve participants have had planar shoulder movements experimentally captured in a motion lab, and their shoulder anatomy imaged using an MRI scanner. A shoulder multi-body dynamics model was developed for each participant, using both an image-based approach and a scaled-generic approach. Inverse kinematics have been performed using the two different modelling procedures and the three different experimental motions. Results have been compared using Bland-Altman analysis of agreement and further analysed using multi-linear regressions. Kinematics computed via an anatomical and a scaled-generic shoulder models differed in average from 3.2 to 5.4 degrees depending on the task. The MRI-based model presented smaller limits of agreement to direct kinematics than the scaled-generic model. Finally, the regression model predictors, including anatomical errors, sex, and BMI of the participant, explained from 41 to 80% of the kinematic variability between model types with respect to the task. This study highlighted the consequences of modelling precision, quantified the effects of anatomical errors on the shoulder kinematics, and showed that participants' anthropometry and sex could indirectly affect kinematic outcomes.

Morphological integration and evolutionary potential of the primate shoulder: Variation among taxa and implications for genetic covariances with the basicranium, pelvis, and arm.

Within the primate order, the morphology of the shoulder girdle is immensely variable and has been shown to reflect the functional demands of the upper limb. The observed morphological variation among extant primate taxa consequently has been hypothesized to be driven by selection for different functional demands. Evolutionary analyses of the shoulder girdle often assess this anatomical region, and its traits, individually, therefore implicitly assuming independent evolution of the shoulder girdle. However, the primate shoulder girdle has developmental and functional covariances with the basicranium and pelvic girdle that have been shown to potentially influence its evolution. It is unknown whether these relationships are similar or even present across primate taxa, and how they may affect morphological variation among primates. This study evaluates the strength of covariance and evolutionary potential across four anatomical regions: shoulder girdle, basicranium, pelvis, and distal humerus. Measures of morphological integration and evolutionary potential (conditioned covariance and evolutionary flexibility) are assessed across eight anthropoid primate taxa. Results demonstrate a consistent pattern of morphological constraint within paired anatomical regions across primates. Differences in evolutionary flexibility are observed among primate genera, with humans having the highest evolutionary potential overall. This pattern does not follow functional differences, but rather a separation between monkeys and apes. Therefore, evolutionary hypotheses of primate shoulder girdle morphological variation that evaluate functional demands alone may not account for the effect of these relationships. Collectively, our findings suggest differences in genetic covariance among anatomical regions may have contributed to the observable morphological variation among taxa.

Anatomic safe zones for arthroscopic snapping scapula surgery: quantitative anatomy of the superomedial scapula and associated neurovascular structures and the effects of arm positioning on safety.

BACKGROUND: Neurovascular anatomy has not been previously quantified for the arthroscopic snapping scapula approach with the patient in the most frequent patient position ("chicken-wing" position). The purposes of this study were (1) to determine anatomic relationships of the superomedial scapula and neurovascular structures at risk during arthroscopic surgical treatment of snapping scapula syndrome (SSS), (2) to compare these measurements between the arm in the neutral position and the arm in the chicken-wing position, and (3) to establish safe zones for arthroscopic treatment of SSS. METHODS: Eight fresh-frozen cadaveric hemi-torsos (mean age, 55.8 years; range, 52-66 years) were dissected to ascertain relevant anatomic structure locations including the (1) spinal accessory nerve, (2) dorsal scapular nerve, and (3) suprascapular nerve. A coordinate measuring device was used to collect data on the relationships of anatomic landmarks and at-risk structures during the surgical approach. RESULTS: The dorsal scapular nerve was a mean of 24.4 mm medial to the superomedial scapula in the neutral position and 33.1 mm medial in the chicken-wing position (P < .001); the dorsal scapular nerve was 21.7 mm medial to the medial border of the scapular spine in the neutral position and 35.5 mm medial in the chicken-wing position (P < .001). The mean distance from the superomedial angle to the spinal accessory nerve intersection at the superior scapular border was 16.5 mm in the neutral position and 15.0 mm in the chicken-wing position (P = .031). The average distance from the superomedial angle to the closest point of the spinal accessory nerve was 11.6 mm and 10.4 mm in the neutral position and chicken-wing position, respectively (P = .039). CONCLUSION: Neurologic structures around the scapula vary significantly between the neutral arm position and the chicken-wing position commonly used in the arthroscopic treatment of SSS. The chicken-wing position improves safe distances for the dorsal scapular nerve during medial-portal placement and should be considered as a primary position for arthroscopic management of SSS.

Combined Feedback Feedforward Control of a 3-Link Musculoskeletal System Based on the Iterative Training Method.

The investigation and study of the limbs, especially the human arm, have inspired a wide range of humanoid robots, such as movement and muscle redundancy, as a human motor system. One of the main issues related to musculoskeletal systems is the joint redundancy that causes no unique answer for each angle in return for an arm's end effector's arbitrary trajectory. As a result, there are many architectures like the torques applied to the joints. In this study, an iterative learning controller was applied to control the 3-link musculoskeletal system's motion with 6 muscles. In this controller, the robot's task space was assumed as the feedforward of the controller and muscle space as the controller feedback. In both task and muscle spaces, some noises cause the system to be unstable, so a forgetting factor was used to a convergence task space output in the neighborhood of the desired trajectories. The results show that the controller performance has improved gradually by iterating the learning steps, and the error rate has decreased so that the trajectory passed by the end effector has practically matched the desired trajectory after 1000 iterations.

A Matlab toolbox for scaled-generic modeling of shoulder and elbow.

There still remains a barrier ahead of widespread clinical applications of upper extremity musculoskeletal models. This study is a step toward lifting this barrier for a shoulder musculoskeletal model by enhancing its realism and facilitating its applications. To this end, two main improvements are considered. First, the elbow and the muscle groups spanning the elbow are included in the model. Second, scaling routines are developed that scale model's bone segment inertial properties, skeletal morphologies, and muscles architectures according to a specific subject. The model is also presented as a Matlab toolbox with a graphical user interface to exempt its users from further programming. We evaluated effects of anthropometric parameters, including subject's gender, height, weight, glenoid inclination, and degenerations of rotator cuff muscles on the glenohumeral joint reaction force (JRF) predictions. An arm abduction motion in the scapula plane is simulated while each of the parameters is independently varied. The results indeed illustrate the effect of anthropometric parameters and provide JRF predictions with less than 13% difference compared to in vivo studies. The developed Matlab toolbox could be populated with pre/post operative patients of total shoulder arthroplasty to answer clinical questions regarding treatments of glenohumeral joint osteoarthritis.

The pectoral girdle of StW 573 ('Little Foot') and its implications for shoulder evolution in the Hominina.

The ca. 3.67 Ma adult skeleton known as 'Little Foot' (StW 573), recovered from Sterkfontein Member 2 breccia in the Silberberg Grotto, is remarkable for its morphology and completeness. Preservation of clavicles and scapulae, including essentially complete right-side elements, offers opportunities to assess morphological and functional aspects of a nearly complete Australopithecus pectoral girdle. Here we describe the StW 573 pectoral girdle and offer quantitative comparisons to those of extant hominoids and selected homininans. The StW 573 pectoral girdle combines features intermediate between those of humans and other apes: a long and curved clavicle, suggesting a relatively dorsally positioned scapula; an enlarged and uniquely proportioned supraspinous fossa; a relatively cranially oriented glenoid fossa; and ape-like reinforcement of the axillary margin by a stout ventral bar. StW 573 scapulae are as follows: smaller than those of some homininans (i.e., KSD-VP-1/1 and KNM-ER 47000A), larger than others (i.e., A.L. 288-1, Sts 7, and MH2), and most similar in size to another australopith from Sterkfontein, StW 431. Moreover, StW 573 and StW 431 exhibit similar structural features along their axillary margins and inferior angles. As the StW 573 pectoral girdle (e.g., scapular configuration) has a greater affinity to that of apes-Gorilla in particular-rather than modern humans, we suggest that the StW 573 morphological pattern appears to reflect adaptations to arboreal behaviors, especially those with the hand positioned above the head, more than human-like manipulatory capabilities. When compared with less complete pectoral girdles from middle/late Miocene apes and that of the penecontemporaneous KSD-VP-1/1 (Australopithecus afarensis), and mindful of consensus views on the adaptiveness of arboreal positional behaviors soliciting abducted glenohumeral joints in early Pliocene taxa, we propose that the StW 573 pectoral girdle is a reasonable model for hypothesizing pectoral girdle configuration of the crown hominin last common ancestor.

The clinical anatomy of variations of the pectoralis minor.

Shoulder pathology is a very common medical presentation and can be due to anatomical variations. Therefore, knowledge of variants is important for the clinician treating patients with such complaints so that misdiagnosis is minimized and iatrogenic injury prevented. A review of the literature was performed of the variant anatomy of the pectoralis minor muscle. The aim of this review is to better inform clinicians who might treat patients with shoulder pathology so that if identified, variants of the pectoralis minor muscle are better appreciated.

Exploring the functional morphology of the Gorilla shoulder through musculoskeletal modelling.

Musculoskeletal computer models allow us to quantitatively relate morphological features to biomechanical performance. In non-human apes, certain morphological features have long been linked to greater arm abduction potential and increased arm-raising performance, compared to humans. Here, we present the first musculoskeletal model of a western lowland gorilla shoulder to test some of these long-standing proposals. Estimates of moment arms and moments of the glenohumeral abductors (deltoid, supraspinatus and infraspinatus muscles) over arm abduction were conducted for the gorilla model and a previously published human shoulder model. Contrary to previous assumptions, we found that overall glenohumeral abduction potential is similar between Gorilla and Homo. However, gorillas differ by maintaining high abduction moment capacity with the arm raised above horizontal. This difference is linked to a disparity in soft tissue properties, indicating that scapular morphological features like a cranially oriented scapular spine and glenoid do not enhance the abductor function of the gorilla glenohumeral muscles. A functional enhancement due to differences in skeletal morphology was only demonstrated in the gorilla supraspinatus muscle. Contrary to earlier ideas linking a more obliquely oriented scapular spine to greater supraspinatus leverage, our results suggest that increased lateral projection of the greater tubercle of the humerus accounts for the greater biomechanical performance in Gorilla. This study enhances our understanding of the evolution of gorilla locomotion, as well as providing greater insight into the general interaction between anatomy, function and locomotor biomechanics.

Discerning excellence from mediocrity in swimming: New insights using Bayesian quantile regression.

AbstractPurpose: Previous research has captured point estimates for population means of somatic variables associated with swimming speed across strokes, but have not determined if predictors of swimming speed operate the same at the upper tails of the distribution (τ = 0.9) as they do at the median levels (τ = 0.5) and lower levels (τ = 0.1). Method: Three hundred sixty-three competitive-level swimmers (male [n = 202]; female [n = 161]) participated in the study. To identify key somatic variables associated with 100-m swimming across and between strokes controlling for age, we used a Bayesian allometric quantile regression model, refined using Bayes Factors and Leave-one-out cross validation. Results: High probabilities (>99%) were found for arm-span, seated-height and shoulder-breadth being the strongest somatic predictors across strokes. For individual strokes, Bayesian quantile regression demonstrated that the relative importance of predictors differs across quantiles. For swimmers in the 0.9 quartile, shoulder-breadth is a more important than height for front-crawl, wide shoulders are important for breaststroke swimmers but can be detrimental when combined with narrow hips, seated-height and hip-width are important for backstroke swimming speed, and calf girth for butterfly. Conclusion: These results highlight the importance of considering key somatic variables for talent identification in swimming and ensure young swimmers focus on strokes compatible with their somatic structure. The most important new insight is that predictors differ for the best swimmers compared to average or poorer swimmers. This has implications beyond swimming, pointing to the importance of considering the upper tails of distributions in performance and talent identification contexts.

The Ratio of the Transverse to Longitudinal Diameter of the Glenoid Projection Is of Good Predictive Value for Defining the Reliability of Critical Shoulder Angle in Nonstandard Anteroposterior Radiographs.

PURPOSE: To investigate (1) whether measurement of the critical shoulder angle (CSA) is still reliable in some nonstandard anteroposterior radiographs; and (2) whether the ratio of the transverse to longitudinal diameter of the glenoid projection (RTL) could be used to determine the reliability of the CSA in nonstandard anteroposterior radiographs. METHODS: The authors analyzed radiology records from 2017 to 2019 for patients with computed tomography (CT) scans of the shoulder. According to the Suter-Henninger classification system, each CT scan underwent 3-dimensional (3D) reconstructions to obtain 8 digitally reconstructed radiographs (DRRs), including 1 type A1 film and 7 type D1 films with different rotation angles. CSA and RTL were measured on all films, and 2 blinded reviewers evaluated DRRs. The relationship between RTL and CSA was determined by Pearson correlation test. The threshold value was determined by receiver operating characteristic (ROC) analyses using RTL as predictors and defined reliable CSA as criterion in the logistic regression. Intra- and inter-rater reliability were assessed by the intraclass correlation coefficient (ICC). Discriminative capacity was calculated with ROC analyses and area under the curve (AUC). An optimal measurement cutoff with resultant sensitivity and specificity was calculated. RESULTS: A total of 86 patients were included, mean age 40.70 ± 18.25 years, 19 of whom had rotator cuff tears (RCTs) and 67 without RCTs. Spearman's correlation test revealed that the deviation of CSA was positively correlated with RTL, correlation coefficient 0.544 (P < .001) in all patients and 0.686 (P < .001) only in patients with RCTs. ROC analysis of all patients showed that the AUC of the RTL was 0.90, and the optimal cutoff point was 0.25 (sensitivity 88%, specificity 87%). ROC analysis only of patients with RCTs showed that the AUC of the RTL was 0.95, and the optimal cutoff point was 0.22 (sensitivity 95%, specificity 92%). CONCLUSION: The ratio of the transverse to longitudinal diameter of the glenoid projection (RTL) is of good predictive value in defining the reliability of the CSA in malposition films. Based on the results, the CSA can be considered reliable if its RTL is <0.25. LEVEL OF EVIDENCE: III, retrospective cohort study investigating a diagnostic test.

Biceps Tendon Changes and Pitching Mechanics in Youth Softball Pitchers.

With the lack of pitch count regulation, youth softball pitchers are experiencing unremitting high stresses on the anterior shoulder. The purpose of this study was to examine the association of acute changes in the long head of the biceps tendon with pitching kinematics and kinetics in youth softball pitchers following an acute bout of pitching. Twenty-three softball pitchers (12.17±1.50 yrs.; 160.32±9.41 cm; 60.40±15.97 kg) participated. To investigate the association between biceps tendon changes and kinematic and kinetic changes from pre- to post-simulated game, each biceps tendon measure was split into those whose biceps tendon thickness, width, and/or area increased pre- to post-simulated game, and those whose did not. There were significant differences in biceps tendon longitudinal thickness (Z=- 2.739, p=0.006) and pitch speed; as well as a difference between groups in biceps tendon transverse thickness and the amount of change in trunk rotation at the start of the pitching motion (p=0.017) and the amount of change in trunk flexion at ball release (p=0.030). This study illustrates the association of trunk and lower extremity kinematics and shoulder kinetics with morphologic changes in the biceps tendon with an acute bout of windmill softball pitching.

The Shoulder Trans-pectoralis Arthroscopic Portal Is a Safe Approach to the Arthroscopic Latarjet Procedure: A Cadaveric Analysis.

PURPOSE: To assess the proximity of neurovascular structures in a layered approach during medial portal placement and determine standardized measurements for establishing a portal medial to the coracoid used in arthroscopic Latarjet-type procedures. METHODS: Twelve shoulders (6 right and 6 left) in 6 fresh frozen cadaveric torsos were mounted in the modified beach-chair position. A standard posterior portal and 3 anterior portals-central, lateral, and medial-were used. A long spinal needle was placed along the path of the medial portal to the lateral tip of the coracoid, superficial to the conjoined tendon and pectoralis minor. A second long spinal needle was directed toward the medial base of the coracoid, penetrating the pectoralis minor. Superficial and deep plane dissections were performed, and distances to surrounding neurovascular structures were recorded. RESULTS: In the superficial plane, the cephalic vein and lateral pectoral nerve were located a mean distance (± standard deviation) of 4.6 ± 1.9 mm and 9.4 ± 2.6 mm from the spinal needle, respectively. In the deep plane, the axillary nerve was 24.9 ± 7.4 mm from the needle; the lateral cord of the brachial plexus, 25.5 ± 8.1 mm; the axillary artery, 34.1 ± 6.0 mm; and the musculocutaneous nerve, 42.2 ± 9.2 mm. The portal was consistently established 45.0 to 50.0 mm distal and 30.0 to 35.0 mm medial to the coracoid, which was a minimum distance of 10 mm to the lateral pectoral nerve. CONCLUSIONS: In a cadaveric model, the creation of a medial trans-pectoralis major portal used in the arthroscopic Bankart-Bristow-Latarjet procedure can avoid compromise of vital neurovascular structures, alleviating concerns of creating a portal medial to the coracoid. Portal placement 45.0 to 50.0 mm distal and 30.0 to 35.0 mm medial to the palpable tip of the coracoid process may be a safe approach to perform the arthroscopic Bankart-Bristow-Latarjet procedure. CLINICAL RELEVANCE: Creation of a portal medial to the level of the coracoid may pose a risk to neurovascular structures. This cadaveric study establishes a working zone for medial trans-pectoralis portal placement, which avoids vital neurovascular structures, and provides standardized measurements for establishing this portal for use in the arthroscopic Bankart-Bristow-Latarjet procedure.

Histología del bíceps en pacientes con tendinopatía crónica tratados con tenodesis subpectoral / Histology of the biceps in patients with chronic tendinitis treated with subpectoral tenodesis

Introducción: El objetivo de este estudio fue evaluar los cambios morfológicos en la zona intrarticular y extrarticular de la porción larga del bíceps de pacientes sometidos a una tenodesis subpectoral.materiales y métodos: Se incluyeron 9 pacientes con diag-nóstico de tendinopatía del bíceps, a quienes se les realizó una tenodesis subpectoral de la porción larga del bíceps. La porción eliminada del tendón del bíceps se colocó en formalina al 10% y se dividió en 2 segmentos. Quedaron definidas la zona proximal, desde la inserción supraglenoidea hasta el borde proximal del pectoral mayor y la zona distal correspondiente a la inserción del pectoral mayor. Los segmentos se tiñeron con hematoxilina y eosina, y se evaluaron histológicamente utilizando el puntaje de Bo-nar.Resultados: Macroscópicamente todos los tendones estaban engrosados en la región proximal. En la evaluación histológica, entre las variables más relevantes evaluadas por el puntaje de Bonar, el puntaje de morfología celular en la zona proximal fue significativamente más alto que en la zona distal (p <0,0001).Conclusiones: Nuestros hallazgos mostraron niveles más altos de patología dentro del bíceps proximal, lo que respalda la eliminación de dicho segmento cuando se realiza un procedimiento para la tendinopatía crónica del bíceps, lo cual se puede lograr con una tenodesis subpectoral. Nivel de Evidencia: IV

Introduction: The objective of the present study was to evaluate the morphological changes in the intra- and extra-articular area of the long head of the biceps in patients who had undergone subpectoral tenodesis. methods: We included 9 patients with a diagnosis of biceps tendinitis, who underwent subpectoral tenodesis of the long head of the biceps. The removed portion of the biceps tendon was placed in 10% formalin and divided into 2 segments. The proximal area extended from the supraglenoid insertion to the proximal edge of the pectoralis major and the distal area corresponded to the insertion of the pectoralis major. The segments were histologically evaluated using the Bonar score. Results: Macroscopically, all the tendons were found to be thickened in the proximal region. In the histological evaluation, among the most relevant variables evaluated by the Bonar score, the cell morphology score in the proximal area was significantly higher than in the distal area (p <0.0001). Conclusion: Our findings showed higher levels of pathology within the proximal biceps, supporting the elimination of this segment for chronic biceps tendinopathy, which can be accomplished through subpectoral tenodesis. Level of Evidence: IV