Shoulder kinematics with two-plane x-ray evaluation in patients with anterior instability or rotator cuff tearing

Scapular dyskinesis and overhead athletes: A systematic review of electromyography studies

OBJECTIVE

Understanding how the main scapular muscles behave in overhead athletes with scapular dyskinesis (SD).

DESIGN

Systematic Review.

SETTING

Electronic searches were performed in Pubmed (MedLine), Embase, CINAHL, and SPORTDiscus databases.

PARTICIPANTS

Overhead athletes with SD.

MAIN OUTCOME MEASURES

Electromyographic activity of the upper (UT), middle (MT), and lower (LT) trapezius, and serratus anterior (SA).

RESULTS

Eight studies were included in this review. The UT activity showed a tended to increase its activity mainly during tasks over 90° compared to 45°. SA activity had similar behavior, mainly during isometric tasks. The MT also increased its activity mainly in tasks with overhead angulations when compared to lower angulations. The LT activation tended to decrease its EMG activity at angulations below 60° in overhead athletes with SD.

CONCLUSIONS

The EMG behaviour of UT and SA for non-athletes appears to differ from what has already been described in the literature. The MT seems to be the most neglected muscle for scapular stabilization in overhead athletes with SD. The decrease in LT activity suggests that this may have implications for the performance of these athletes.

Development of a musculoskeletal shoulder model considering anatomic joint structures and soft-tissue deformation for dynamic simulation

The shoulder joint has a high degree of freedom and an extremely complex and unstable kinematic mechanism. Coordinated contraction of the rotator cuff muscles that stop around the humeral head and the deltoid muscles and the extensibility of soft tissues, such as the joint capsule, labrum, and ligaments, contribute to shoulder-joint stability. Understanding the mechanics of shoulder-joint movement, including soft-tissue characteristics, is important for disease prevention and the development of a device for disease treatment. This study aimed to create a musculoskeletal shoulder model to represent the realistic behavior of joint movement and soft-tissue deformation as a dynamic simulation using a rigid-body model for bones and a soft-body model for soft tissues via a spring-damper-mass system. To reproduce the muscle-contraction properties of organisms, we used a muscle-expansion representation and Hill's mechanical muscle model. Shoulder motion, including the movement of the center of rotation in joints, was reproduced, and the strain in the joint capsule during dynamic shoulder movement was quantified. Furthermore, we investigated narrowing of the acromiohumeral distance in several situations to induce tissue damage due to rotator cuff impingement at the anterior-subacromial border during shoulder abduction. Given that the model can analyze exercises under disease conditions, such as muscle and tendon injuries and impingement syndrome, the proposed model is expected to help elucidate disease mechanisms and develop treatment guidelines.

Neuropathy of the suprascapular and axillary nerves in rotator cuff arthropathy: a prospective electrodiagnostic study

PURPOSE

Prevalence of axillary (AN) and/or suprascapular (SSN) neuropathy in rotator cuff tear arthropathy (RCTA) is unknown. We aimed to prospectively evaluate for preoperative neurodiagnostic abnormalities in order to determine their prevalence, location, and influence on reverse shoulder arthroplasty (RSA) outcomes.

METHODS

Patients who underwent RSA for RCTA were prospectively included. An electromyography and nerve conduction study were performed pre and post-surgery. Clinical situation: VAS, Relative Constant-Murley Score (rCMS) and ROM over a minimum of two years follow-up.

RESULTS

Forty patients met the inclusion criteria; mean follow-up was 28.4 months (SD 4.4). Injuries in RCTA were present in 83.9% (77.4% in AN and 45.2% in SSN). There were no differences on preoperative VAS, ROM, and rCMS between patients with and without preoperative nerve injuries. Four acute postoperative neurological injuries were registered under chronic preoperative injuries. Six months after RSA, 69% of preoperative neuropathies had improved (82.14% chronic injuries and 77.7% disuse injuries). No differences in improvement between disuse and chronic injuries were found, but patients with preoperative neuropathy that had not improved at the postoperative electromyographic study at six months, scored worse on the VAS (1.44 vs 2.66; p .14) and rCMS (91.6 vs 89.04; p .27).

CONCLUSIONS

The frequency of axillary and suprascapular neuropathies in RCTA is much higher than expected. Most of these injuries improve after surgery, with almost complete neurophysiological recovery and little functional impact on RSA. However, those patients with preoperative neuropathies and absence of neurophysiological improvement six months after surgery have lower functional results.

Effectiveness of a joint mobilizations protocol for shoulder subacromial pain syndrome: A pilot study

BACKGROUND

Subacromial pain syndrome (SPS) is the most frequent shoulder pathology. The aims of this prospective randomized study were to evaluate the effects of some specific shoulder joint mobilizations ("spin correction"), and the effectiveness of a rehabilitation program, named Shoulder Global Concept, in SPS patients.

METHODS

45 patients with SPS were randomly assigned to two groups, to benefit from a different first session of mobilizations: the experimental group received all specific mobilizations, while the control group received the same program but without the spin correction mobilizations. The second session was identical for both groups, with all specific mobilizations. Before and after the first two sessions, range of motion (ROM) in flexion, abduction, external and internal rotations, pain and functional status with Constant score and Quick Dash were evaluated. Evaluation was repeated with 24 patients after 11 rehabilitation sessions. Rehabilitation with Shoulder Global Concept included 13 mobilizations aiming at improving the ROM with passive and active-assisted mobilizations, static stretching, and muscle strengthening.

RESULTS

All ROM were improved at the end of the first session for both groups, but significantly more in the experimental group for glenohumeral (GH) abduction and external rotation (p < 0.05). Functional scores, pain and strength were significantly improved after 11 rehabilitation sessions with the Shoulder Global Concept.

CONCLUSION

This manual therapy method was able to improve shoulder mobility in one session. The additional joint mobilizations (spin correction) specifically increased GH abduction and external rotation. Rehabilitation of SPS with Shoulder Global Concept allowed to improve functional capacity and decrease pain.

The latissimus dorsi creates a dynamic track for the inferior angle of the scapula during arm abduction in humans

BACKGROUND

The importance of several scapulothoracic muscles, including trapezius and serratus anterior, in maintaining physiological scapula kinematics has been highlighted in the past. However, the relationship between the scapula and the latissimus dorsi muscle remains unclear. Our clinical surgical observation is that the latissimus dorsi does not directly attach but rather runs superficial to the inferior angle of the scapula. Based on this observation, we hypothesise that the latissimus dorsi creates a dynamic track on which the scapula glides under the muscle belly during elevation of the arm, creating the latissimus-scapula overlap (LSO).

METHODS

All consecutive patients who had a whole-body computed tomography scan (CT) in case of polytrauma evaluation between 2018 and 2021, with complete depiction of the scapula and latissimus dorsi muscle, were analysed. 150 shoulders in 90 patients with arms up were matched according to their age (within five years), gender, and affected side with 150 shoulders in 88 patients with arms down. Patients with pathologies of the upper extremities or thorax that potentially could alter LSO measurements were excluded. LSO was calculated as a ratio of the measured area of the latissimus dorsi projection on the scapula and the total scapula area.

RESULTS

The mean age of the 178 patients (48 females; 13 males) was 60 years. The arms-up group showed a significantly higher LSO than the arms-down group (19.9 ± 6.3% vs. 2.7 ± 2.2%; p < 0.0001). In the arms-up group, approximately one fifth of the scapula was overlapped inferiorly by the muscle belly of the latissimus dorsi, contrary to the almost non-existing LSO in the arms-down group.

CONCLUSION

With arms up, humans show a significantly higher LSO in comparison to arms down indicating that the latissimus dorsi indeed creates a dynamic track on which the scapula is forced to travel during abduction of the arm. This finding of increased LSO during the elevation of the arm warrants further consideration of the role of the latissimus dorsi in scapula kinematics and potentially scapular dyskinesis.

LEVEL OF EVIDENCE

Level two diagnostic study.

Biomechanical and neuromuscular characteristics in patients with traumatic anterior shoulder instability undergoing arthroscopic Bankart repair: a clinical prospective cohort study protocol

INTRODUCTION

Traumatic shoulder dislocation is a common shoulder injury, especially among the young and active population. More than 95% of dislocations are anterior, in which the humeral head is forced beyond the anterior glenoid rim. The injury leads to increased joint laxity and recurrence rates are high. There is evidence that the shoulder biomechanics and neuromuscular control change following dislocation, but the existing literature is scarce, and it remains to be established if and how these parameters are useful in the clinical setting. The aim of this exploratory prospective cohort study is to investigate biomechanical and neuromuscular outcomes in patients with traumatic anterior shoulder instability undergoing arthroscopic Bankart repair, to test the hypothesis that examinations of these characteristics are applicable in the clinical setting to assess shoulder instability.

METHODS AND ANALYSIS

This is a prospective multicentre cohort study with repeated measures of 30 patients undergoing arthroscopic Bankart repair. With carefully selected and completely non-invasive examination methods, we will investigate biomechanical and neuromuscular outcomes in the affected shoulders once presurgically and twice post surgically at 6 and 12 months. Patients' contralateral shoulders are investigated once to establish a preinjury level.

ETHICS AND DISSEMINATION

The study was approved by the Capital Region Ethics Committee (journal-no: H-21027799) and the Capital Region Knowledge Center for Data Reviews (journal-no: P-2021-842) before patient recruitment began. The study results will be published in international peer-reviewed journals, online and in other relevant media, presented at medical conventions and disseminated to clinicians and patients as appropriate.

TRIAL REGISTRATION NUMBER

NCT05250388.

Fully automatic algorithm for detecting and tracking anatomical shoulder landmarks on fluoroscopy images with artificial intelligence

OBJECTIVE

Patients with rotator cuff tears present often with glenohumeral joint instability. Assessing anatomic angles and shoulder kinematics from fluoroscopy requires labelling of specific landmarks in each image. This study aimed to develop an artificial intelligence model for automatic landmark detection from fluoroscopic images for motion tracking of the scapula and humeral head.

MATERIALS AND METHODS

Fluoroscopic images were acquired for both shoulders of 25 participants (N = 12 patients with unilateral rotator cuff tear, 6 men, mean (standard deviation) age: 63.7 ± 9.7 years; 13 asymptomatic subjects, 7 men, 58.2 ± 8.9 years) during a 30° arm abduction and adduction movement in the scapular plane with and without handheld weights of 2 and 4 kg. A 3D full-resolution convolutional neural network (nnU-Net) was trained to automatically locate five landmarks (glenohumeral joint centre, humeral shaft, inferior and superior edges of the glenoid and most lateral point of the acromion) and a calibration sphere.

RESULTS

The nnU-Net was trained with ground-truth data from 6021 fluoroscopic images of 40 shoulders and tested with 1925 fluoroscopic images of 10 shoulders. The automatic landmark detection algorithm achieved an accuracy above inter-rater variability and slightly below intra-rater variability. All landmarks and the calibration sphere were located within 1.5 mm, except the humeral landmark within 9.6 mm, but differences in abduction angles were within 1°.

CONCLUSION

The proposed algorithm detects the desired landmarks on fluoroscopic images with sufficient accuracy and can therefore be applied to automatically assess shoulder motion, scapular rotation or glenohumeral translation in the scapular plane.

CLINICAL RELEVANCE STATEMENT

This nnU-net algorithm facilitates efficient and objective identification and tracking of anatomical landmarks on fluoroscopic images necessary for measuring clinically relevant anatomical configuration (e.g. critical shoulder angle) and enables investigation of dynamic glenohumeral joint stability in pathological shoulders.

KEY POINTS

• Anatomical configuration and glenohumeral joint stability are often a concern after rotator cuff tears. • Artificial intelligence applied to fluoroscopic images helps to identify and track anatomical landmarks during dynamic movements. • The developed automatic landmark detection algorithm optimised the labelling procedures and is suitable for clinical application.

Anterior-posterior glenohumeral translation in shoulders with traumatic anterior instability: a systematic review of the literature

Background

Reports of glenohumeral translation in shoulders with traumatic anterior instability have been presented. The aim of this systematic review was to investigate anterior-posterior translation in shoulders with traumatic anterior instability.

Methods

This systematic review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies including patients aged ≥15 years with previous traumatic anterior shoulder dislocation or subluxation were included. The outcome was anterior-posterior glenohumeral translation. A search of PubMed, Embase, and Cochrane library was performed on July 17, 2022. Two reviewers individually screened titles and abstracts, reviewed full text, extracted data, and performed quality assessment.

Results

Twenty studies (582 unstable shoulders in total) of varying quality were included. There was a lack of standardization and unity across studies. Radiography, ultrasound, computed tomography, magnetic resonance imaging, motion tracking, instrumentation, and manual testing were used to assess the glenohumeral translation. The glenohumeral translation in unstable shoulders ranged from 0.0 ± 0.8 mm to 11.6 ± 3.7 mm, as measured during various motion tasks, arm positions, and application of external force. The glenohumeral translation was larger or more anteriorly directed in unstable shoulders than in stable when contralateral healthy shoulders or a healthy control group were included in the studies. Several studies found that the humeral head was more anteriorly located on the glenoid in the unstable shoulders.

Conclusion

This systematic review provides an overview of the current literature on glenohumeral translation in traumatic anterior shoulder instability. It was not able to identify a threshold for abnormal translation in unstable shoulders, due to the heterogeneity of data. The review supports that not only the range of translation but also the direction hereof as well as the location of the humeral head on the glenoid seem to be part of the pathophysiology. Technical development and increased attention to research methodology in recent years may provide more knowledge and clarity on this topic in the future.

Observational assessment for determining shoulder fault movements before and after corrective education in participants with chronic shoulder pain: Concurrent validity study

BACKGROUND

Movement faults (MF), described as the alteration of joint position and motion, are an important factor associated with developing shoulder pathologies. However, determining or predicting the exact MF in participants with shoulder pain is limited by the absence of clinical tools and poor validity.

PURPOSE

The aim of the study was to determine the validity of using observational assessment to MFs or controlling MFs in subjects with chronic shoulder pain during shoulder elevation and external rotation.

STUDY DESIGN

Concurrent validity study METHODS: Twenty-seven people with chronic shoulder pain were examined. The index test represented three observational assessments of MF during shoulder external rotation, elevation in the frontal plane, and elevation in the sagittal plane. Three-dimensional motion analysis represented the reference test. The movements of both shoulder joints were evaluated simultaneously, and the index and reference tests were performed concurrently.

RESULTS

The sensitivity and specificity of observational detection were good to excellent (Se: 77.5%, Sp: 81.5%) for MF and excellent (Se: 85.7%, Sp: 100%) for controlling MF. The positive and negative predictive value was (PPV: 93.9, NPV: 57.1) for MF and (PPV: 100%, NPV: 82.8%) for controlling MF. The result of the positive and negative likelihood ratio was (PLR: 5.4, NLR: 0.26) for MF and (PLR: 0, NLR: 0.18) for controlling MF.

CONCLUSIONS

The results revealed that the validity of the observational detection approach for identifying MFs was good to excellent. Moreover, the accuracy of this approach in detecting the control of MFs after patient education was excellent. There was good to excellent accuracy in most MFs once classified by their motion trajectories, except for scapula anterior tilt during glenohumeral joint external rotation or elevation.

Development of a more biofidelic musculoskeletal model with humeral head translation and glenohumeral ligaments

Computational musculoskeletal modeling is useful for understanding upper extremity biomechanics, especially when in vivo tests are unfeasible. A musculoskeletal model of the upper limb with increased biofidelity was developed by including humeral head translation (HHT) and ligaments. The model was validated and ligament contribution and effect of shoulder (thoracohumeral) elevation on HHT was evaluated. Humerus translated superiorly with increased elevation, with translations closely matching (avg. difference 2.83 mm) previous in vitro studies. HHT and ligament inclusion in the model will improve biomechanical predictions of upper extremity movements and study of conditions, like subacromial impingement, rotator cuff tear, or shoulder instability.

Fully automatic tracking of native glenohumeral kinematics from stereo-radiography

The current work introduces a system for fully automatic tracking of native glenohumeral kinematics in stereo-radiography sequences. The proposed method first applies convolutional neural networks to obtain segmentation and semantic key point predictions in biplanar radiograph frames. Preliminary bone pose estimates are computed by solving a non-convex optimization problem with semidefinite relaxations to register digitized bone landmarks to semantic key points. Initial poses are then refined by registering computed tomography-based digitally reconstructed radiographs to captured scenes, which are masked by segmentation maps to isolate the shoulder joint. A particular neural net architecture which exploits subject-specific geometry is also introduced to improve segmentation predictions and increase robustness of subsequent pose estimates. The method is evaluated by comparing predicted glenohumeral kinematics to manually tracked values from 17 trials capturing 4 dynamic activities. Median orientation differences between predicted and ground truth poses were 1.7∘ and 8.6∘ for the scapula and humerus, respectively. Joint-level kinematics differences were less than 2∘ in 65%, 13%, and 63% of frames for XYZ orientation DoFs based on Euler angle decompositions. Automation of kinematic tracking can increase scalability of tracking workflows in research, clinical, or surgical applications.

Load-induced increase in muscle activity during 30° abduction in patients with rotator cuff tears and control subjects

BACKGROUND

Rotator cuff muscles stabilise the glenohumeral joint and contribute to the initial abduction phase with other shoulder muscles. This study aimed to determine if the load-induced increase in shoulder muscle activity during a 30° abduction test is influenced by asymptomatic or symptomatic rotator cuff pathologies.

MATERIALS AND METHODS

Twenty-five patients with unilateral rotator cuff tears (age, 64.3 ± 10.2 years), 25 older control subjects (55.4 ± 8.2 years) and 25 younger control subjects (26.1 ± 2.3 years) participated in this study. Participants performed a bilateral 30° arm abduction and adduction movement in the scapular plane with handheld weights (0-4 kg). Activity of the deltoid, infraspinatus, biceps brachii, pectoralis major, latissimus dorsi and upper trapezius muscles was analysed at maximum abduction angle after normalisation to maximum voluntary contraction. Shoulders were classified into rotator cuff tendinopathy, asymptomatic and symptomatic rotator cuff tears, and healthy based on magnetic resonance images. A linear mixed model (loads, shoulder types) with random effects (shoulder identification) was applied to the log-transformed muscle activities.

RESULTS

Muscle activity increased with increasing load in all muscles and shoulder types (P < 0.001), and 1-kg increments in additional weights were significant (P < 0.001). Significant effects of rotator cuff pathologies were found for all muscles analysed (P < 0.05). In all muscles, activity was at least 20% higher in symptomatic rotator cuff tears than in healthy shoulders (P < 0.001). Symptomatic rotator cuff tears showed 20-32% higher posterior deltoid (P < 0.05) and 19-25% higher pectoralis major (P < 0.01) activity when compared with asymptomatic tears.

CONCLUSIONS

Rotator cuff pathologies are associated with greater relative activity of shoulder muscles, even with low levels of additional load. Therefore, the inclusion of loaded shoulder tests in the diagnosis and rehabilitation of rotator cuff pathologies can provide important insight into the functional status of shoulders and can be used to guide treatment decisions.

LEVEL OF EVIDENCE

Level 2.

TRIAL REGISTRATION

Ethical approval was obtained from the regional ethics committee (Ethics Committee Northwest Switzerland EKNZ 2021-00182), and the study was registered at clinicaltrials.gov on 29 March 2021 (trial registration number NCT04819724, https://clinicaltrials.gov/ct2/show/NCT04819724 ).

Shoulder Impingement Syndrome

Shoulder impingement is the most common diagnosis for shoulder pain. Shoulder impingement syndrome has been scrutinized as a misleading "umbrella" term, due to its vague and nonspecific context. It is better subcategorized into subacromial, internal, and subcoracoid impingement. The evaluation and treatment algorithm for each is grossly similar. A thorough history, focused physical examination, and standard radiographs are the first steps. Advanced imaging with MRI or ultrasound may be useful. The mainstay of treatment includes physical therapy, anti-inflammatory medications, and injections. Surgical treatment is reserved for refractory cases, and includes decompression, debridement, and/or repair of injured structures.

Load-Induced Glenohumeral Translation After Rotator Cuff Tears: Protocol for an In Vivo Study

BACKGROUND

Rotator cuff tears are a common shoulder injury, but they sometimes remain undiagnosed, as symptoms can be limited. Altered shoulder biomechanics can lead to secondary damage and degeneration. In biomechanical analyses, the shoulder (ie, the glenohumeral joint) is normally idealized as a ball-and-socket joint, even though a translation is often observed clinically. To date, no conclusive changes in glenohumeral translation have been reported in patients with rotator cuff tears, and it is unknown how an additional handheld weight that is comparable to those used during daily activities will affect glenohumeral translations in patients with rotator cuff tears.

OBJECTIVE

This study aims to assess the load-induced glenohumeral translation (liTr) in patients with rotator cuff tears and its association with the load-induced changes in muscle activation (liMA).

METHODS

Patients and asymptomatic controls will be recruited. Participants will fill out health questionnaires and perform 30° arm abduction and adduction trials, during which they will hold different handheld weights of a maximum of 4 kg while motion capture and electromyographic data are collected. In addition, fluoroscopic images of the shoulders will be taken for the same movements. Isometric shoulder muscle strength for abduction and rotation will be assessed with a dynamometer. Finally, shoulder magnetic resonance images will be acquired to assess muscle status and injury presence. The dose-response relationship between additional weight, liTr, and liMA will be evaluated.

RESULTS

Recruitment and data collection began in May 2021, and they will last until the recruitment target is achieved. Data collection is expected to be completed by the end of 2022. As of November 2022, data processing and analysis are in progress, and the first results are expected to be submitted for publication in 2023.

CONCLUSIONS

This study will aid our understanding of biological variations in liTr, the influence of disease pathology on liTr, the potential compensation of rotator cuff tears by muscle activation and size, and the association between liTr and patient outcomes. The outcomes will be relevant for diagnosis, treatment, and rehabilitation planning in patients with rotator cuff tears.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04819724; https://clinicaltrials.gov/ct2/show/NCT04819724.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/43769.

Patients with recurrent anterior shoulder instability exhibit altered glenohumeral and scapulothoracic joint kinematics during upper limb movement: A prospective comparative study

BACKGROUND

Altered shoulder kinematics in patients with recurrent anterior shoulder instability remains poorly understood. This prospective study aimed to quantify in vivo glenohumeral and scapulothoracic joint kinematics and joint-contact positions in patients with shoulder instability and healthy controls.

METHODS

Twenty patients with recurrent anterior shoulder instability (mean 28 years) and five patients without shoulder pathology (mean 39 years) were scanned using open CT in six static upper limb positions including 90° of abduction, combined abduction and external rotation, 90° of flexion, lift-off position (i.e. reaching behind the back) and the neutral shoulder with external rotation. Image datasets were digitally reconstructed to quantify shoulder joint kinematics and glenohumeral translation.

FINDINGS

At 90° of abduction, instability patients demonstrated significantly less glenohumeral abduction and a reciprocal increase in upward scapulothoracic rotation compared to controls (mean difference: 13.3°, p = 0.038). With the shoulder in combined abduction and external rotation, instability patients showed a significant increase in glenohumeral rotation and a reciprocal decrease in scapulothoracic rotation compared to controls (mean difference: 5.0°, p = 0.042). There were no significant differences in humeral head translation in the sagittal plane (anterior-posterior axis) for all motions tested (p > 0.05).

INTERPRETATION

Scapulothoracic and glenohumeral kinematics are significantly different between patients with recurrent anterior shoulder instability and those with a healthy shoulder. Instability patients compensate for reduced glenohumeral function during abduction by increasing scapular rotation. With the shoulder in combined abduction and external rotation position, greater glenohumeral joint angles without significantly increased humeral head translation suggest altered neuromuscular control in the unstable shoulder.

Fluoroscopic measurements of the glenohumeral joint position and space in true anteroposterior and axillary views – a reliability study

Two-dimensional (2D) fluoroscopy has been used in shoulder pathologies to estimate the humeral head position (HHP) in the true anteroposterior (AP) view. However, there is a lack of evidence regarding the reliability estimating it in the axillary view and in measuring the shoulder joint space width (JSW). True AP view images (n=36) of subjects with adhesive capsulitis were taken in supine in multiple arm abduction positions. The axillary view images (n=48) were taken in supine and prone in 75° of abduction. The HHP was assessed in the glenoid reference frame. The position and radius of the humeral head along with the superior, inferior, anterior, posterior, and middle JSWs were measured in each image. All the images were coded and randomly presented twice to a physiotherapist at a gap of 48-72 h for intra-rater reliability and to 2 therapists and an orthopaedic surgeon for inter-rater reliability. Reliability was expressed using intraclass correlation coefficients (ICC) and standard error of measurement (SEM). In both the views, inter-rater, and intra-rater reliability was excellent for the radius of the humeral head (inter-rater – 0.95-0.97 and intra-rater -0.98)], moderate (ICC: 0.70 and 0.76), and excellent (ICC: 0.89 and 0.93) for HHP. The reliability for JSWs was moderate to good (ICC: 0.66-0.82) for inter-rater and good to excellent (ICC: 0.75-0.95) for intra-rater analysis. The SEM for HHP and JSWs were <0.4 mm for intra-rater analysis, and <0.7 mm for inter-rater reliability in both views. The study demonstrated that the glenohumeral arthrokinematic parameters can be measured with good to excellent levels of reliability when using 2 D fluoroscopy.

The study is part of a clinical trial (Clinical Trial Registry India: CTRI/2018/12/016657).

Associations between range of motion, strength, tear size, patient-reported outcomes, and glenohumeral kinematics in individuals with symptomatic isolated supraspinatus tears

BACKGROUND

Clinical failure associated with nonoperative treatment of rotator cuff tears may be due to inadequate characterization of the individual's functional impairments. Clinically, restricted passive range of motion (ROM) (restrictions imply capsular tightness), limitations in muscle strength, and larger rotator cuff tears are hypothesized to be related to altered glenohumeral kinematics. Understanding these relationships, as well as the relationship between glenohumeral kinematics and patient-reported outcomes (PROs) prior to exercise therapy, may help characterize functional impairments in individuals with rotator cuff tears. The objectives of the study were to describe the baseline presentation of individuals with an isolated supraspinatus tear, including passive ROM, rotator cuff muscle strength, tear size, PROs, and glenohumeral kinematics, and to determine associations among these variables.

METHODS

One hundred one individuals with symptomatic isolated supraspinatus tears were recruited for the study and underwent assessments of passive glenohumeral ROM, isometric muscle strength, and ultrasonography to assess anterior-posterior tear size. Glenohumeral kinematics during scapular-plane abduction were measured using biplane radiography. Furthermore, PROs including the American Shoulder and Elbow Surgeons (ASES) score and the Western Ontario Rotator Cuff Index (WORC) score were collected.

RESULTS

Individuals presented with decreased ROM, external rotation weakness compared with the uninvolved side, and pain and disability as measured by the ASES and WORC scores. These findings were not associated with glenohumeral kinematics, with the exception of a weak positive association between glenohumeral contact path lengths and WORC scores (ρ = 0.25, P = .03). Tear size was 11.7 ± 5.7 mm, and maximum anterior translation, superior translation, and contact path length were 3.0% ± 3.8% of glenoid width, 3.5% ± 3.8% of glenoid height, and 38.2% ± 20.7% of glenoid size, respectively.

CONCLUSION

Individuals with a symptomatic isolated supraspinatus tear presented with decreased ROM, external rotation weakness, and pain and disability as measured by the ASES and WORC scores. However, no abnormal kinematics associated with these limitations were observed. Thus, given that the tear is isolated to the supraspinatus tendon and no capsular restrictions are present, normal function of the glenohumeral joint may be possible during scapular-plane abduction.

Reliability of the Fluoroscopic Assessment of Load-Induced Glenohumeral Translation during a 30° Shoulder Abduction Test

Rotator cuff tears are often linked to superior translational instability, but a thorough understanding of glenohumeral motion is lacking. This study aimed to assess the reliability of fluoroscopically measured glenohumeral translation during a shoulder abduction test. Ten patients with rotator cuff tears participated in this study. Fluoroscopic images were acquired during 30° abduction and adduction in the scapular plane with and without handheld weights of 2 kg and 4 kg. Images were labelled by two raters, and inferior–superior glenohumeral translation was calculated. During abduction, glenohumeral translation (mean (standard deviation)) ranged from 3.3 (2.2) mm for 0 kg to 4.1 (1.8) mm for 4 kg, and from 2.3 (1.5) mm for 0 kg to 3.8 (2.2) mm for 4 kg for the asymptomatic and symptomatic sides, respectively. For the translation range, moderate to good interrater (intra-class correlation coefficient ICC [95% confidence interval (CI)]; abduction: 0.803 [0.691; 0.877]; adduction: 0.705 [0.551; 0.813]) and intrarater reliabilities (ICC [95% CI]; abduction: 0.817 [0.712; 0.887]; adduction: 0.688 [0.529; 0.801]) were found. Differences in the translation range between the repeated measurements were not statistically significant (mean difference, interrater: abduction, −0.1 mm, p = 0.686; adduction, −0.1 mm, p = 0.466; intrarater: abduction 0.0 mm, p = 0.888; adduction, 0.2 mm, p = 0.275). This method is suitable for measuring inferior–superior glenohumeral translation in the scapular plane.

Comparison of glenohumeral joint kinematics between manual wheelchair tasks and implications on the subacromial space: A biplane fluoroscopy study

Scapula and humerus motion associated with common manual wheelchair tasks is hypothesized to reduce the subacromial space. However, previous work relied on either marker-based motion capture for kinematic measures, which is prone to skin-motion artifact; or ultrasound imaging for arthrokinematic measures, which are 2D and acquired in statically-held positions. The aim of this study was to use a fluoroscopy-based approach to accurately quantify glenohumeral kinematics during manual wheelchair use, and compare tasks for a subset of parameters theorized to be associated with mechanical impingement. Biplane images of the dominant shoulder were acquired during scapular plane elevation, propulsion, sideways lean, and weight-relief raise in ten manual wheelchair users with spinal cord injury. A computed tomography scan of the shoulder was obtained, and model-based tracking was used to quantify six-degree-of-freedom glenohumeral kinematics. Axial rotation and superior/inferior and anterior/posterior humeral head positions were characterized for full activity cycles and compared between tasks. The change in the subacromial space was also determined for the period of each task defined by maximal change in the aforementioned parameters. Propulsion, sideways lean, and weight-relief raise, but not scapular plane elevation, were marked by mean internal rotation (8.1°, 10.8°, 14.7°, -49.2° respectively). On average, the humeral head was most superiorly positioned during the weight-relief raise (1.6 ± 0.9 mm), but not significantly different from the sideways lean (0.8 ± 1.1 mm) (p = 0.191), and much of the task was characterized by inferior translation. Scaption was the only task without a defined period of superior translation on average. Pairwise comparisons revealed no significant differences between tasks for anterior/posterior position (task means range: 0.1-1.7 mm), but each task exhibited defined periods of anterior translation. There was not a consistent trend across tasks between internal rotation, superior translation, and anterior translation with reductions in the subacromial space. Further research is warranted to determine the likelihood of mechanical impingement during these tasks based on the measured task kinematics and reductions in the subacromial space.

Changing our Diagnostic Paradigm Part II: Movement System Diagnostic Classification

Diagnostic classification is a foundational underpinning of providing care of the highest quality and value. Diagnosis is pattern recognition that can result in categories of conditions that ideally direct treatment. While pathoanatomic diagnoses are common and traditional in orthopaedic practice, they often are limited with regard to directing best practice physical therapy intervention. Replacement of pathoanatomic labels with non-specific regional pain labels has been proposed, and occurs frequently in clinical practice. For example non-specific low back pain or shoulder pain of unknown origin. These labels avoid some disadvantages of tissue specific pathoanatomic labels, but are not specific enough to direct treatment. A previously introduced movement system diagnostic framework is proposed and updated with application to shoulder conditions. This framework has potential for broad development and application across musculoskeletal physical therapist practice. Movement system diagnostic classification can advance and streamline practice if considered while recognizing the inherent movement variability across individuals.

Scapular motion in the presence of rotator cuff tears: a systematic review

BACKGROUND

Rotator cuff tears (RCTs) remain a significant source of pain and disability in the shoulder. Although much work has been done in the study of the effects of rotator cuff tears on glenohumeral joint motion, much less has been done in understanding the effect of rotator cuff tearing on scapular motion or activation. It remains unknown whether scapular dyskinesis is causative or adaptive. The purpose of this study was to systematically review the literature to determine the relationship between rotator cuff tear presence and size on scapular motion, and if rotator cuff repair restored normal motion.

METHODS

A systematic review using PRISMA guidelines was accomplished to include all studies with biomechanical or clinical outcomes of scapular motion in the presence of RCTs. Studies were excluded if they involved shoulder arthroplasty, rotator cuff tendinopathy, or shoulder impingement without an RCT. From 530 initial references, 42 manuscripts were selected for full review and cross referenced. All studies were evaluated for inclusion and exclusion criteria.

RESULTS

Sixteen studies including 335 rotator cuff tears were included in the final review. There were several findings of interest in the literature. First, although all studies demonstrated scapular dyskinesis, they did not report a consistent pattern of motion in the presence of an RCT. In general, scapular posterior tilt was decreased, and scapular upward rotation was increased, especially in large tears, but the literature was unclear as to whether this was a result of the RCT or an adaptive attempt to maintain elevation. Larger RCTs resulted in more pronounced scapular dysfunction, but there was significant variability within studies. Further, dyskinesis was confounded by pain with more abnormal movement in symptomatic vs. asymptomatic RCTs, the latter of which were not different from normal healthy controls. Four studies addressed the effect of RCT on scapular mechanics and found that repair consistently improved it compared to the normal side, but the time to normalization varied between 5 months and 2 years.

CONCLUSION

Scapular motion is abnormal in the presence of an RCT, but the literature is inconsistent regarding a universally affected variable or consistent degree of scapular dysfunction in this setting. Furthermore, it remains unknown which changes are adaptive vs. pathologic. Understanding the relationship between rotator cuff tearing and scapular dyskinesis will require better biomechanical models that consider scapular dyskinesis in their design.

Interposition grafting for irreparable rotator cuff tears: Systematic review and specialist practice report

The treatment of symptomatic irreparable rotator cuff tears poses significant challenges to both patients and shoulder surgeons. Although reverse shoulder arthroplasty provides reliably good outcomes in the elderly, it is not a good option in younger patients. Various surgical techniques have been proposed for the treatment of irreparable rotator cuff tears; however, no gold standard currently exists. Interposition grafting is used when the rotator cuff cannot be fully repaired onto its footprint, and the remaining defect is bridged with either an allograft, autograft, xenograft or a synthetic graft. This review aims to present the literature on the use of various interposition grafts and techniques to treat large or massive irreparable rotator cuff tears and provide a specialist practice report.

Unilateral and bilateral training competitive archers differ in some potentially unhealthy neck-shoulder region movement behaviour characteristics

BACKGROUND

Excessive unilateral joint loads may lead to overuse disorders. Bilateral training in archery is only performed as a supportive coordination training and as a variation of typical exercise. However, a series of studies demonstrated a crossover transfer of training-induced motor skills to the contralateral side, especially in case of mainly unilateral skills. We compared the cervical spine and shoulder kinematics of unilateral and bilateral training archers.

METHODS

In this cross-sectional study, 25 (5 females, 48 ± 14 years) bilaterally training and 50 age-, sex- and level-matched (1:2; 47.3 ± 13.9 years) unilaterally training competitive archers were included. Cervical range of motion (RoM, all planes) and glenohumeral rotation were assessed with an ultrasound-based 3D motion analysis system. Upward rotation of the scapula during abduction and elevation of the arm were measured by means of a digital inclinometer and active shoulder mobility by means of an electronic caliper. All outcomes were compared between groups (unilaterally vs. bilaterally) and sides (pull-hand- vs. bow-hand-side).

RESULTS

Unilateral and bilateral archers showed no between group and no side-to-side-differences in either of the movement direction of the cervical spine. The unilateral archers had higher pull-arm-side total glenohumeral rotation than the bilateral archers (mean, 95% CI), (148°, 144-152° vs. 140°, 135°-145°). In particular, internal rotation (61°, 58-65° vs. 56°, 51-61°) and more upward rotation of the scapula at 45 degrees (12°, 11-14° vs. 8°, 6-10°), 90 degrees (34°, 31-36° vs. 28°, 24-32°), 135 degrees (56°, 53-59° vs. 49°, 46-53°), and maximal (68°, 65-70° vs. 62°, 59-65°) arm abduction differed. The bow- and pull-arm of the unilateral, but not of the bilateral archers, differed in the active mobility of the shoulder (22 cm, 20-24 cm vs. 18 cm, 16-20 cm).

CONCLUSIONS

Unilaterally training archers display no unphysiologic movement behaviour of the cervical spine, but show distinct shoulder asymmetris in the bow- and pull-arm-side when compared to bilateral archers in glenohumeral rotation, scapula rotation during arm abduction, and active mobility of the shoulder. These asymmetries in may exceed physiological performance-enhancing degrees. Bilateral training may seems appropriate in archery to prevent asymmetries.

Scapulothoracic Dyskinesis: A Concept Review

PURPOSE OF REVIEW

Scapulothoracic dyskinesis (SD) occurs when there is a noticeable disruption in typical position and motion of the scapula, which can result in debilitating pain. The purpose of this review is to describe the current knowledge regarding the diagnosis and management of scapulothoracic dyskinesis by providing an evidence-based overview of clinical exams and treatment modalities available for orthopedic surgeons and provide insight into which treatment modalities require further investigation.

RECENT FINDINGS

SD is highly prevalent in athletes, particularly those participating in overhead activities (e.g., baseball, tennis, and swimming) and can coexist with several shoulder pathologies. A holistic approach in the diagnosis of SD has been supported in the literature; however, it is important to recognize that diagnosis is currently limited to the absence of a quantitative SD clinical assessment. The main goal of the treatment of SD is to regain proper scapular positioning and dynamics. The standard of care for the management of SD is conservative interventions aimed at optimizing scapular kinematics. Surgical intervention is only considered in the presence of concomitant pathology requiring surgery. Due to the complexity of coordinated movement of the shoulder girdle, recent literature has begun to move away from the use of traditional orthopedic tests, in favor of a more system-based approach for the diagnosis of SD. We present a concise review of clinical exams and treatment modalities available for orthopedic surgeons in the management of SD.

Measuring 3D In-vivo Shoulder Kinematics using Biplanar Videoradiography

The shoulder is one of the human body's most complex joint systems, with motion occurring through the coordinated actions of four individual joints, multiple ligaments, and approximately 20 muscles. Unfortunately, shoulder pathologies (e.g., rotator cuff tears, joint dislocations, arthritis) are common, resulting in substantial pain, disability, and decreased quality of life. The specific etiology for many of these pathologic conditions is not fully understood, but it is generally accepted that shoulder pathology is often associated with altered joint motion. Unfortunately, measuring shoulder motion with the necessary level of accuracy to investigate motion-based hypotheses is not trivial. However, radiographic-based motion measurement techniques have provided the advancement necessary to investigate motion-based hypotheses and provide a mechanistic understanding of shoulder function. Thus, the purpose of this article is to describe the approaches for measuring shoulder motion using a custom biplanar videoradiography system. The specific objectives of this article are to describe the protocols to acquire biplanar videoradiographic images of the shoulder complex, acquire CT scans, develop 3D bone models, locate anatomical landmarks, track the position and orientation of the humerus, scapula, and torso from the biplanar radiographic images, and calculate the kinematic outcome measures. In addition, the article will describe special considerations unique to the shoulder when measuring joint kinematics using this approach.

Bursal Acromial Reconstruction (BAR) Using an Acellular Dermal Allograft as a Surgical Solution for the Treatment of Massive Irreparable Rotator Cuff Tears

Massive, irreparable rotator cuff tears in patients without severe signs of osteoarthritis remains a major challenge for orthopaedic surgeons. These can be a source of significant pain and functional loss occurring most commonly in a relatively frail, elderly patient population. A plethora of surgical techniques covering minimally invasive, arthroscopic techniques and open, salvage procedures have been described for this challenging patient cohort. Continuous evolvement of arthroscopic techniques has led to all-arthroscopic superior capsular reconstruction techniques using allografts, thereby reducing donor side morbidity along with decreased soft tissue dissection. However, conventional superior capsular reconstruction is noted to be a technically complex, time-consuming, and high-cost surgery, which may put this technique beyond the confidence of many shoulder surgeons. The subacromial balloon spacer has emerged as a potential solution in these patients, providing interposition between the humeral head and acromion. However, the subacromial balloon biodegrades rapidly and its effect is only temporary. Thus this technique article presents using an acellular human dermal allograft to reconstruct the bursal layer, which is normally interposed between the humeral head and the acromion. The proposed technique provides a permanent interposition graft preventing humeral acromial contact, which does not undergo rapid biodegradation. The surgical technique is technically feasible, both minimizing surgical time and therefore operative risk to the patient.

Systematic Review With Meta-Analysis: Are Muscle Transfers a Satisfactory Treatment Option to Restore Shoulder Abduction in Delayed Adult Brachial Plexus Injuries?

Brachial plexus injuries usually result in significant upper limb disabilities and shoulder joint instability. Primary nerve reconstruction procedures are more effective if performed within six months from the injury. Secondary procedures, including muscle transfers, are usually indicated for delayed presentation (>6 months) or when the outcomes of primary procedures are unsatisfactory.

A comprehensive systematic search of the MEDLINE, EMBASE, AMED, PubMed, and Cochrane databases was conducted in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data, including demographic information, time to surgery, the extent of brachial plexus injury, surgical techniques, follow-up duration, and functional outcomes were collected and tabulated. Meta-analysis was conducted using Review Manager (RevMan) 5.4 software ([Computer program]. Version 5.3. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014). Seven studies were eligible to be included in this review, with a total of 218 patients. The average patient age was 28.39 ± 3 years, with a mean time to surgery of 29.87 ± 18 months. Forty-six (46) patients (21.10%) were treated as delayed presentation and 172 patients (78.89%) had muscle transfer performed as a secondary procedure. The mean time at follow-up was 18.86 ± 13.5 months. Upper trapezius muscle transfer was the most common transferred muscle (100%) either in isolation (n=159, 72.93%) or in combination with lower trapezius transfer (n=59, 27.06%). The mean preoperative and postoperative shoulder abduction were 12.22 ± 10.09 degrees and 58.36 ± 32.33 degrees, respectively (p < 0.05). Meta-analysis shows a statistically significant difference (CI at 95%, p<0.05) favoring postoperative shoulder abduction.

Muscle transfers especially upper trapezius transfer could be a satisfactory secondary procedure to restore shoulder abduction and enhance shoulder joint stability.

Clinical Factors Related to Improved Scapular Control After a Scapular Conscious Control Program in Symptomatic Overhead Athletes: Secondary Analysis of a Randomized Controlled Trial

Background:

Predictive variables associated with the effects of a scapular conscious control program should be identified and used to guide rehabilitation programs.

Purpose:

To determine whether potential factors are associated with the success of scapular muscle balance with an early control program in patients with subacromial pain and scapular dyskinesis.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

A total of 38 amateur overhead athletes with subacromial pain and medial border prominence were recruited. They performed progressive conscious control of scapular orientation during 45° and 90° of arm elevation. Stepwise logistic regression and receiver operating characteristic curve were used to determine the optimal cutoff point of related factors for success or failure of the program. Potential factors including pain level during activity, pain duration, anterior/posterior shoulder flexibility, forward shoulder posture, posterior displacement of root of spine and inferior angle, scapular kinematics, and muscle activation before conscious control program were recorded as independent variables. Successful control defined as decreases of the upper trapezius/serratus anterior ratio in 2 consecutive trials of the 90° program or failure in the program was used as a dependent variable.

Results:

Having a posterior displacement of the inferior angle of the scapula of ≤16.4 mm and scapular posterior tipping during arm elevation of ≤3.3° (collected before the control program) were associated with the success of the program (R² = 0.286; P < .05). Additionally, participants with each or both variables present at baseline had probabilities of success of 78% and 95%, respectively.

Conclusion:

The value of scapular posterior displacement and posterior tilt should be considered before early scapular control program. Other factors related to the success of the program should be found due to the limited variance explained in the regression model.

Proximal humeral fracture morphology in patients with advanced cuff tear arthropathy: an observational study in a surgically treated cohort

BACKGROUND

In the presence of cuff tear arthropathy (CTA), joint kinematics is alternated and fracture configuration might be different. The purpose of this study was to identify fracture patterns in patients with advanced CTA to facilitate recognition and treatment.

METHODS

Radiographs and computed tomography scans of all patients undergoing surgical treatment for a proximal humeral fracture (PHF) in our institution during a 5-year period were retrospectively analyzed. Fracture pattern according to the AO-OTA and Resch classification and the presence of CTA were evaluated. Glenoid configuration according to Walch, fatty atrophy of the supraspinatus muscle and the centrum-collum-diaphyseal (CCD) angle were analyzed.

RESULTS

A total of 574 out of 713 patients were included. Twenty-three patients (4%) with a mean age of 82 ± 8 years showed advanced CTA with acetabularization of the acromion (≥ stage 3 according to Hamada/Fukuda). There were exclusively valgus fractures with a mean CCD angle of 158° ± 18°. Patients with CTA ≥ grade 3 had a nearly twofold greater risk (risk ratio: 1.8; confidence interval (CI): 95% 1.6-1.9; p < 0.0001) of sustaining a valgus fracture compared to patients without or with CTA < grade 3. The risk for a tuberosity fracture was nearly twofold greater in patients without or with mild CTA (risk ratio: 1.68; confidence interval (CI): 95% 1.17-2.40; p = 0.0046) compared to those with advanced CTA.

CONCLUSION

In advanced CTA, a predominantly valgus fracture pattern can be observed. In addition, fractures of the greater tuberosity were significantly less frequent and were rarely displaced. Up to date, no classification system for PHF has been developed in the setting of CTA although it might indicate a different treatment, and therefore, recognition is crucial. However, when present, this changes the fracture pattern and ability to treat the fracture as the rotator cuff can no longer be utilized as a means of reducing the fragments.

Graft Tensioning in Superior Capsular Reconstruction Improves Glenohumeral Joint Kinematics in Massive Irreparable Rotator Cuff Tears: A Biomechanical Study of the Influence of Superior Capsular Reconstruction on Dynamic Shoulder Abduction

Background:

Superior capsular reconstruction (SCR) for massive, irreparable rotator cuff tears has become more widely used recently; however, ideal tensioning of the graft and the influence on joint kinematics remain unknown.

Purpose/Hypothesis:

The purpose of this study was to assess the effects of graft tensioning on glenohumeral joint kinematics after SCR using a dermal allograft. The hypothesis was that a graft fixed under tension would result in increased glenohumeral abduction motion and decreased cumulative deltoid forces compared with a nontensioned graft.

Study Design:

Controlled laboratory study.

Methods:

A total of 10 fresh-frozen cadaveric shoulders were tested using a dynamic shoulder simulator. Each shoulder underwent the following 4 conditions: (1) native, (2) simulated irreparable supraspinatus (SSP) tear, (3) SCR using a nontensioned acellular dermal allograft, and (4) SCR using a graft tensioned with 30 to 35 N. Mean values for maximum glenohumeral abduction and cumulative deltoid forces were recorded. The critical shoulder angle (CSA) was also assessed.

Results:

Native shoulders required a mean (±SE) deltoid force of 193.2 ± 45.1 N to achieve maximum glenohumeral abduction (79.8° ± 5.8°). Compared with native shoulders, abduction decreased after SSP tears by 32% (54.3° ± 13.7°; P = .04), whereas cumulative deltoid forces increased by 23% (252.1 ± 68.3 N; P = .04). The nontensioned SCR showed no significant difference in shoulder abduction (54.1° ± 16.1°) and required deltoid forces (277.8 ± 39.8 N) when compared with the SSP tear state. In contrast, a tensioned graft led to significantly improved shoulder abduction compared with the SSP tear state (P = .04) although abduction and deltoid forces could not be restored to the native state (P = .01). A positive correlation between CSA and maximum abduction was found for the tensioned-graft SCR state (r = 0.685; P = .02).

Conclusion:

SCR using a graft fixed under tension demonstrated a significant increase in maximum shoulder abduction compared with a nontensioned graft; however, abduction remained significantly less than the intact state. The nontensioned SCR showed no significant improvement in glenohumeral kinematics compared with the SSP tear state.

Clinical Relevance:

Because significant improvement in shoulder function after SCR may be expected only when the graft is adequately tensioned, accurate graft measurement and adequate tension of at least 30 N should be considered during the surgical procedure. SCR with a tensioned graft may help maintain sufficient acromiohumeral distance, improve clinical outcomes, and reduce postoperative complications.

Radial to Axillary Nerve Transfer Outcomes in Shoulder Abduction: A Systematic Review

Background

Brachial plexus and axillary nerve injuries often result in paralysis of the deltoid muscle. This can be functionally debilitating for patients and have a negative impact on their activities of daily living. In these settings, transferring the branch of the radial nerve innervating the triceps to the axillary nerve is a viable treatment option. Additional nerve transfers may be warranted. This study sought to determine the efficacy of nerve transfer procedures in the setting of brachial plexus and axillary nerve injuries and factors affecting clinical outcomes.

Methods

The U.S. National Library of Medicine's website "PubMed" was queried for "radial to axillary nerve transfer" and "brachial plexus nerve transfer." An initial review by two authors was performed to identify relevant articles followed by a third author validation utilizing inclusion and exclusion criteria. Individual patient outcomes were recorded and pooled for final analysis.

Results

Of the 80 patients, 66 (82.5%) had clinical improvement after surgical nerve transfer procedures. Significant difference in clinical improvement following nerve transfer procedures was correlated with patient age, mechanism of injury, brachial plexus vs isolated axillary nerve injuries, multiple nerve transfers vs single nerve transfers, and surgery within the first 7 months of injury. The branch of the radial nerve supplying the triceps long head showed improved clinical results compared with the branch of the radial nerve supplying the triceps medial head and anconeus.

Conclusion

Nerve transfers have been shown to be effective in restoring shoulder abduction in both isolated axillary nerve injuries and brachial plexus injuries.

Measurement of scapular prominence in symptomatic dyskinesis using a novel scapulometer: reliability and the relationship to shoulder dysfunction

BACKGROUND

No previous studies have investigated whether the extent of scapular dyskinesis is associated with shoulder dysfunction. This study aimed (1) to establish the reliability of a scapulometer in patients with shoulder pain and (2) to investigate the related factors associated with shoulder dysfunction.

METHODS

One hundred participants with symptomatic scapular dyskinesis were recruited. Twenty-one participants were involved in the reliability study to test the intrarater and inter-rater reliabilities of the scapulometer in patients with shoulder pain. After demographic data and self-reported Flexilevel Scale of Shoulder Function (FLEX-SF) scores were recorded, all participants were measured with a scapulometer to determine the posterior displacement of the root of the spine (ROS) and the inferior angle (IFA) of the scapula from the thorax. Next, the participants performed 5 trials of bilateral scapular plane elevation for scapular kinematics and electromyographic (EMG) data collection. Stepwise multiple linear regressions were used to determine the relationships between self-reported FLEX-SF scores and potential factors. In addition to scapular displacement, pain level, scapular kinematics, and EMG data were included as independent variables.

RESULTS

The intrarater and inter-rater reliabilities of the scapulometer were excellent (intraclass correlation coefficient [ICC] = 0.93-0.97) and moderate to good (ICC = 0.74-0.81), respectively. The Bland-Altman plots showed no systematic bias between raters in the ROS and IFA measurements. Final stepwise multiple regression models showed that more ROS distance, higher serratus anterior activity, and lower pain level during arm elevation were associated with higher shoulder function (total R² = 0.253).

CONCLUSION

The reliability of the scapulometer in patients with shoulder pain is moderate to excellent. Scapular dyskinesis may be a compensatory strategy to avoid shoulder pain and improve shoulder function.

Pectoralis Major and Anterior Latissimus Dorsi Transfer for Subscapularis Tears

PURPOSE OF REVIEW

Irreparable subscapularis tears represent a challenging entity, especially when they occur in younger patients with high functional demands. Tendon transfers are one of the options considered for surgical management for this pathology. The purpose of this article is to review the surgical technique and outcome of the two most common tendon transfers considered for irreparable subscapularis tears: pectoralis major and latissimus dorsi.

RECENT FINDINGS

Transfer of the pectoralis major has been considered for decades the transfer of choice for irreparable subscapularis tears. Recently, a series with long-term follow-up (over 18 years) supported the reduction in pain and improvement in functional scores and patient satisfaction after pectoralis major transfer. However, the range of motion and the force in internal rotation were not maintained over time. Transfer of the latissimus dorsi to the lesser tuberosity has been recently described as an alternative with a sound biomechanical rationale and encouraging short-term results. Transfer of the pectoralis major and the transfer of latissimus dorsi to the lesser tuberosity are the two transfers most commonly considered for patients with irreparable subscapularis tears. Transfer of the pectoralis major has a much longer track record. Both procedures seem to improve outcomes. Comparative studies are needed to determine the relative indications of these two procedures.

The latissimus dorsi tendon functions as an external rotator after arthroscopic-assisted transfer for massive irreparable posterosuperior rotator cuff tears

PURPOSE

Latissimus dorsi tendon transfer is a surgical option for the treatment of massive irreparable posterosuperior rotator cuff tear. Whether a favourable clinical outcome is due to the latissimus dorsi muscle contraction rather than the passive tenodesis effect remains to be confirmed. The purpose of the current case-control study was to evaluate the shoulder kinematics and latissimus dorsi activation after latissimus dorsi tendon transfer.

METHODS

Eighteen patients suffering from irreparable rotator cuff tear that underwent latissimus dorsi tendon transfer and 18 healthy individuals were examined using a 3D kinematic tracking system and electromyography. Active maximal flexion-extension and abduction-adduction of the humerus were measured for the operated and the contralateral shoulder of the patients and the shoulder of healthy individuals to evaluate the range of motion (ROM) and scapulohumeral rhythm. Electromyographic comparison of isometric contraction between the latissimus dorsi of the operated and contralateral shoulder was carried out.

RESULTS

After arthroscopic-assisted latissimus dorsi tendon transfer, patients showed comparable flexion and abduction ROM to their asymptomatic contralateral shoulders and to the shoulders of healthy individuals. Significantly higher scapular ROM values were found between the latissimus dorsi tendon transfer side and the shoulders of healthy individuals. While performing external rotation with 0° shoulder abduction, a greater percentage of the electromyographic peak value (p = 0.047) and a higher latissimus dorsi internal/external rotation ratio (p = 0.004) were noted for the transferred muscle in comparison to the contralateral shoulder.

CONCLUSION

Although the arthroscopic-assisted latissimus dorsi tendon transfer failed to normalize scapulothoracic joint movements of patients, a functional latissimus flap and a shoulder ROM similar to the contralateral side or the shoulder of healthy individuals can be expected after this procedure in patients with massive irreparable posterosuperior rotator cuff tear.

LEVEL OF EVIDENCE

III.

Three-dimensional in vivo comparative analysis of the kinematics of normal shoulders and shoulders with massive rotator cuff tears with successful conservative treatment

BACKGROUND

This study used in vivo three-dimensional to two-dimensional image registration techniques to compare the glenohumeral kinematics of shoulders with massive rotator cuff tears that were successfully treated conservatively and those of normal shoulders.

METHODS

Ten patients (age, 67.4 ± 3.63 years) with massive rotator cuff tears on one side and without contralateral tears were enrolled. We performed computed tomography and fluoroscopy on both shoulder joints and created three-dimensional bone models of the humerus and scapula using image registration techniques. We measured the humeral superoinferior translation, angle of humeral external rotation, scapular upward rotation, scapular anteroposterior tilt, and scapular external rotation of the torn shoulders with good range of motion after effective conservative treatment and compared these measurements to those of the contralateral normal shoulders.

FINDINGS

There was a significant difference in the initial position of the humeral head relative to the glenoid in the tear group; it was 2.0 mm higher than that in the normal group (p < .05). This difference disappeared in the range from 40° to full elevation. The scapular motion of the tear group was significantly more upwardly rotated than that of the normal group: by 9.9° at rest (p < .05) and by 11.6° at terminal elevation (p < .05). No significant differences were detected for humeral head external rotation, scapular anteroposterior tilt, and scapular external rotation between the two groups.

INTERPRETATION

Kinematics of shoulders with massive cuff tears could not be recovered completely even though the patients had no significant symptoms after successful conservative treatment.

Scapular Dyskinesis: From Basic Science to Ultimate Treatment

Background: This study intends to summarize the causes, clinical examination, and treatments of scapular dyskinesis (SD) and to briefly investigate whether alteration can be managed by a precision rehabilitation protocol planned on the basis of features derived from clinical tests. Methods: We performed a comprehensive search of PubMed, Cochrane, CINAHL and EMBASE databases using various combinations of the keywords “Rotator cuff”, “Scapula”, “Scapular Dyskinesis”, “Shoulder”, “Biomechanics” and “Arthroscopy”. Results: SD incidence is growing in patients with shoulder pathologies, even if it is not a specific injury or directly related to a particular injury. SD can be caused by multiple factors or can be the trigger of shoulder-degenerative pathologies. In both cases, SD results in a protracted scapula with the arm at rest or in motion. Conclusions: A clinical evaluation of altered shoulder kinematics is still complicated. Limitations in observing scapular motion are mainly related to the anatomical position and function of the scapula itself and the absence of a tool for quantitative SD clinical assessment. High-quality clinical trials are needed to establish whether there is a possible correlation between SD patterns and the specific findings of shoulder pathologies with altered scapular kinematics.

Subacromial space outlet in female patients with multidirectional instability based on hypermobile Ehlers-Danlos syndrome and hypermobility spectrum disorder measured by ultrasound

OBJECTIVE

The objective of the study was to compare the acromiohumeral distance (AHD) between patients diagnosed with hypermobility type of the Ehlers-Danlos syndrome (hEDS) or hypermobility spectrum disorder (HSD) and healthy controls by evaluating the relative amount the tendon occupies in the subacromial area. Furthermore, the aim was to evaluate if there was a change in AHD with arm elevation within and between groups.

METHODS

Twenty-nine female patients with hEDS/HSD (aged 34 ± 12.9 years) and 20 healthy controls (aged 33 ± 10.8 years) participated in the study. The supraspinatus tendon (SST) thickness and AHD were measured using ultrasound. The interplay between the SST and the AHD was expressed as the occupation ratio (OcAHD), calculated as the SST thickness as a percentage of AHD. The measures were performed in the resting position and in subsequently 45° and 60° of active arm elevation in the scapular plane.

RESULTS

The main finding is that patients with hEDS/HSD have a larger subacromial space outlet compared with the controls when measured by ultrasound. Furthermore, in both groups, we found an increased OcAHD during active arm elevation compared with the resting position, which indicates that similar mechanisms occur for patients with hEDS/HSD and healthy controls.

CONCLUSION

Patients with hEDS/HSD have a larger available subacromial space outlet compared with healthy individuals. OcAHD increased during active arm elevation compared with the resting position in both groups. This knowledge is important when designing rehabilitation exercise programs for shoulder instability patients with abnormal glenohumeral biomechanics.

Biomechanical Effect of Superior Capsule Reconstruction Using a 3-mm and 6-mm Thick Acellular Dermal Allograft in a Dynamic Shoulder Model

PURPOSE

To biomechanically compare the effect of superior capsule reconstruction (SCR) using a 3- and 6-mm thick acellular dermal allograft for the treatment of irreparable rotator cuff tears.

METHODS

Eight fresh-frozen cadaveric shoulders were tested using a dynamic shoulder model. Maximum abduction angle (MAA), glenohumeral superior translation (ghST), subacromial peak contact pressure (sPCP), and cumulative deltoid force (cDF) were compared among 4 conditions: (1) intact shoulder, (2) simulated irreparable rotator cuff tear (RCT), (3) SCR using a 3-mm-thick acellular dermal allograft, (4) SCR using a 6-mm-thick acellular dermal allograft.

RESULTS

Compared with the intact state, simulated irreparable RCTs significantly decreased MAA (P < .001), while significantly increasing ghST (P = .001), sPCP (P < .001), and cDF (P < .001). SCR with a 3-mm-thick graft significantly increased MAA (P = .01) and decreased ghST (P = .01) compared with the RCT state, however, showed similar sPCP and cDF. Compared with the torn state, SCR with a 6-mm-thick graft significantly increased MAA (P < .001) and significantly decreased ghST (P < .001), sPCP (P < .001), and cDF (P = .001). Using a 6-mm-thick graft demonstrated similar MAA, ghST, sPCP, and cDF compared with the intact state. When comparing the 3-mm to the 6-mm thick graft, significant differences were found in ghST (P = .03), sPCP (P < .001), and cDF (P = .02).

CONCLUSIONS

SCR with a 6-mm-thick acellular dermal allograft better restored normal glenohumeral joint position and forces compared with a 3-mm-thick graft for the treatment of irreparable RCTs.

CLINICAL RELEVANCE

Graft thickness may affect the clinical success following SCR with commercially available dermal allografts. Using a thicker (>3 mm) graft was able to biomechanically better restore native glenohumeral joint properties.

Effects of trapezius kinesio taping on scapular kinematics and associated muscular activation in subjects with scapular dyskinesis

STUDY DESIGN

Crossover repeated-measure design.

INTRODUCTION

Scapular dyskinesis rehabilitation programs that focus on inhibiting upper trapezius (UT) and activating the lower trapezius (LT) may assist in restoring scapular movements. We hypothesized that taping may be able to normalize scapular movements and associated muscular recruitment.

PURPOSE OF THE STUDY

The purpose of this study was to investigate the immediate effects of kinesio taping over trapezius on scapular kinematics and muscular activation in different dyskinesis patterns. We expected that taping can improve scapular kinematics and muscular activation in subjects with dyskinesis.

METHODS

Fifty-four participants with inferior angle prominence (pattern I), medial border prominence (pattern II), and mixed pattern (pattern I + II) were recruited. Kinesio taping was applied over 3 parts of trapezius muscles, including UT, middle trapezius (MT), and LT. The scapular kinematics and electromyographic data of trapezius and serratus anterior were collected during scapular plane elevation without taping and after each taping application.

RESULTS

UT taping decreased UT activity (5%-7%; P = .001-.003) in 72% of participants with pattern II and pattern I + II dyskinesis, with increased posterior tipping (2.2°-2.5°; P = .003) in pattern II dyskinesis. MT taping increased UT activity (3%; P = .003) in 48% of participants with pattern II dyskinesis.

DISCUSSION

The taping over the trapezius muscle may help to restore coordinated scapular muscle balance and increased upward rotation of the scapula, especially in pattern II dyskinesis. Although no electromyography or kinematic difference was found with LT taping in each dyskinesis pattern, methods of applying LT taping need to be further investigated.

CONCLUSION

Reduced UT muscle activity and scapular posterior tipping are appropriate when applying taping over UT muscle in patterns II and I + II dyskinesis. Caution should be taken when applying taping over MT and LT muscles in terms of increased UT activity, especially in pattern II dyskinesis.

Morphological evaluation of the scapula by three-dimensional computed tomography to elucidate shoulder joint function

INTRODUCTION

There are many variations of scapula morphology. Evaluation of scapula morphology is necessary to elucidate shoulder joint movement. We aimed to analyze the bone morphology of various parts constituting the scapula to identify certain conserved features among them.

MATERIALS AND METHODS

Thirty-one healthy individuals were the subjects. We created a scapular three-dimensional (3D) model using computed tomography (CT). X and Y axes were set on a glenoid surface. We measured the approximate plane of the upper and lower scapular bodies and scapular spine and the central axis of the coracoid and acromion. The anatomical position of the scapular spine, upper and lower bodies, coracoid, and acromion was measured. The positional relationship between the upper and lower bodies and scapular spine and the coracoid and acromion was evaluated. The average angle of the upper and lower scapular bodies and the scapular spine with respect to the XZ plane was calculated. The average angle of the coracoid and acromion with the X-axis on the XY plane and Z-axis on the YZ plane was calculated.

RESULTS

On the XY plane, approximate planes of the upper and lower part of the body and the scapular spine were significantly correlated to each inclination. On the XY plane, inclinations of the central axes of the coracoid and acromion were significantly correlated.

CONCLUSIONS

The findings revealed for the first time the correlation between the inclinations of the scapular body and scapular spine and the inclination angle between the coracoid and acromion.

Evaluation and Management of Scapular Dyskinesis in Overhead Athletes

PURPOSE OF REVIEW

This review will outline scapular function in throwing, discuss scapular dyskinesis as an impairment of function that can be associated with throwing injuries and altered performance, and present an algorithm that encompasses guidelines for evaluation and can serve as a basis for treatment.

RECENT FINDINGS

Optimal scapular function is integral to optimal shoulder function. Multiple roles of the scapula in arm function and throwing have been identified while scapular dysfunction continues to be associated with various shoulder pathologies. Although scapular motion alterations may be common in overhead athletes, various reports have shown that identification and management of the alterations can result in improved rehabilitation and performance outcomes. Baseball throwing occurs as the result of integrated, multisegmented, sequential joint motion, and muscle activation within the kinetic chain. The scapula is a key component link within the chain through its function to maximize the scapulohumeral rhythm and efficient throwing mechanics. Evaluation and management beginning with the scapula can produce improved outcomes related to shoulder pathology in overhead athletes.

The Coupled Kinematics of Scapulothoracic Upward Rotation

BACKGROUND

Scapulothoracic upward rotation (UR) is an important shoulder complex motion allowing for a larger functional work space and improved glenohumeral muscle function. However, the kinematic mechanisms producing scapulothoracic UR remain unclear, limiting the understanding of normal and abnormal shoulder movements.

OBJECTIVE

The objective of this study was to identify the coupling relationships through which sternoclavicular and acromioclavicular joint motions contribute to scapulothoracic UR.

DESIGN

This was a cross-sectional observational study.

METHODS

Sixty participants were enrolled in this study; 30 had current shoulder pain, and 30 had no history of shoulder symptoms. Shoulder complex kinematics were quantified using single-plane fluoroscopy and 2D/3D shape matching and were described as finite helical displacements for 30-degree phases of humerothoracic elevation (30 degrees-60 degrees, 60 degrees-90 degrees, and 90 degrees-120 degrees). A coupling function was derived to estimate scapulothoracic UR from its component motions of acromioclavicular UR, sternoclavicular posterior rotation, and sternoclavicular elevation as a function of acromioclavicular internal rotation. The proportional contributions of each of the component motions were also calculated and compared between phases of humerothoracic elevation and groups.

RESULTS

Scapulothoracic UR displacement could be effectively predicted using the derived coupling function. During the 30- to 60-degree humerothoracic elevation phase, acromioclavicular UR accounted for 84.2% of scapulothoracic UR, whereas sternoclavicular posterior rotation and elevation each accounted for < 10%. During later phases, acromioclavicular UR and sternoclavicular posterior rotation each accounted for 32% to 42%, whereas sternoclavicular elevation accounted for < 11%.

LIMITATIONS

Error due to the tracking of sternoclavicular posterior rotation may have resulted in an underprediction of its proportional contribution and an overprediction of the proportional contribution of acromioclavicular UR.

CONCLUSIONS

Acromioclavicular UR and sternoclavicular posterior rotation are the predominant component motions of scapulothoracic UR. More research is needed to investigate how these coupling relationships are affected by muscle function and influenced by scapular dyskinesis.

Validity and reliability of serratus anterior hand held dynamometry

BACKGROUND

Strength testing of the serratus anterior muscle with hand held dynamometry (HDD) in supine subjects has low reproducibility, and is influenced by compensatory activity of other muscles like the pectoralis major and upper trapezius. Previously, two manual maximum voluntary isometric contraction tests of the serratus anterior muscle were reported that recruited optimal surface electromyography (sEMG) activity in a sitting position. We adapted three manual muscle tests to make them suitable for HHD and investigated their validity and reliability.

METHODS

Twenty-one healthy adults were examined by two assessors in one supine and two seated positions. Each test was repeated twice. Construct validity was determined by evaluating force production (assessed with HHD) in relation to sEMG of the serratus anterior, upper trapezius and pectoralis major muscles, comparing the three test positions. Intra- and interrater reliability were determined by calculating intra-class correlation coefficients (ICC) smallest detectable change (SDC) and standard error of measurement (SEM).

RESULTS

Serratus anterior muscle sEMG activity was most isolated in a seated position with the humerus in 90° anteflexion in the scapular plane. This resulted in the lowest measured force levels in this position with a mean force of 296 N (SEM 15.8 N). Intrarater reliability yielded an ICC of 0.658 (95% CI 0.325; 0.846) and an interrater reliability of 0.277 (95% CI -0.089;0.605). SDC was 127 Newton, SEM 45.8 Newton.

CONCLUSION

The results indicate that validity for strength testing of the serratus anterior muscle is optimal with subjects in a seated position and the shoulder flexed at 90° in the scapular plane. Intrarater reliability is moderate and interrater reliability of this procedure is poor. However the high SDC values make it difficult to use the measurement in repeated measurements.

Asymptomatic Rotator Cuff Tears

Asymptomatic rotator cuff tears (RCTs) are prevalent in the general population; they are positively associated with age and are common in the contralateral shoulder of individuals who are being treated for shoulder pain or a symptomatic RCT. Asymptomatic RCTs are likely to become symptomatic over time, corresponding with decreased patient-reported function, strength, and range of motion. Previous studies have largely reported inconsistent findings regarding patient-reported outcomes, strength, range of motion, and kinematics in individuals with asymptomatic RCTs. Future research would benefit from characterizing any functional alteration that is associated with asymptomatic rotator cuff pathology, including determining whether such alterations are detrimental or compensatory and understanding the mechanism by which an asymptomatic RCT becomes symptomatic.

A three-dimensional scapular motion analysis in patients with arthroscopic anterior capsulolabral repair of the shoulder: The effect of scapular stabilization taping

BACKGROUND

The aim of this study was to investigate the scapular kinematics during dynamic humeral movements in patients with arthroscopic anterior capsulolabral repair of the shoulder along with the potential biomechanical corrective effects of scapular stabilization taping.

METHODS

Twenty patients with unilateral traumatic anterior shoulder instability and arthroscopic anterior capsulolabral repair participated in the study. Dynamic shoulder kinematics were assessed during the scapular plane shoulder elevation for both the operated and non operated shoulders and also under two conditions: no-taping and taping. Statistical analysis to compare sides and conditions was performed with analysis of variance models.

RESULTS

The scapula was more internally rotated position in operated shoulders than in non operated shoulders. Furthermore, the scapula was less internally rotated and more downwardly rotated at 120° of elevation in the taping condition.

CONCLUSIONS

Operated shoulders demonstrated kinematics alterations when compared to non operated shoulders underwent arthroscopic anterior capsulolabral repair. Additionally, changes in the scapular orientation with the taping was very small but followed a pattern, which would be suggested to be an orientation that potentially produce more scapular stability and to increase stress on the inferior glenohumeral ligament.

Comparison of scapular upward rotation during arm elevation in the scapular plane in healthy volunteers and patients with rotator cuff tears pre- and post-surgery

BACKGROUND

Function loss caused by rotator cuff tears alters the scapular orientation, however, few prior studies have reported on scapular movements after rotator cuff repair. The purpose was to determine the scapular orientations before and after rotator cuff repair.

METHODS

We recruited 14 healthy controls, 10 small and six massive rotator cuff tear in patients. The scapular upward rotation during arm elevation was analyzed using fluoroscopic imaging.

FINDINGS

Before surgery, both rotator cuff groups demonstrated greater scapular upward rotation compared to healthy controls. Two months postoperation, the analyses showed significant differences between the patients with small rotator cuff tears and healthy controls at arm elevations of 90°, and between patients with both rotator cuff tear groups and healthy controls at arm elevations of 120°. At five months post-operation, significant differences still existed between the healthy controls and both rotator cuff groups. In regard to the temporal effects in the patients with small rotator cuff tears, the scapular upward rotation decreased significantly over time (2-5 months postoperation) at arm elevations of 120°. We did not identify a main effect owing to time in the patients with massive rotator cuff tears.

INTERPRETATION

In patients with small rotator cuff tears, scapular upward rotation was reduced over the period of 2-5 months postoperation, however, the patients with massive rotator cuff tears showed greater scapular upward rotation throughout the experimental period. The results suggested that the execution of the rehabilitation program should consider that the tear size could affect scapular motion.

Snapping scapula syndrome: arthroscopic surgical treatment

Objectives

To evaluate the results of patients undergoing arthroscopic surgical treatment for snapping scapula syndrome.

Methods

This is a retrospective study of 11 patients undergoing scapulothoracic arthroscopy for the treatment of snapping scapula syndrome. The study included patients with clinical diagnosis of snapping scapula syndrome who did not show pain improvement after at least six months of physical therapy. Patients were assessed using the DASH, UCLA, visual analogue pain assessment (VAS), and Short-Form 36 (SF36) scores.

Results

The mean age at surgery was 38.4 years (21–48). The mean duration of symptoms before surgery was 2.8 years (range 6 months to 6 years). The mean follow-up duration was 12 months (range: 6.4–28). The mean postoperative scores were: DASH, 7.8 points; VAS, 1.5 points, being ten cases (90%) of mild pain and one case (10%) of moderate pain; UCLA, 32; and SF-36, 79.47.

Conclusions

The arthroscopic approach for the treatment of snapping scapula syndrome presents excellent functional results.