Deltoid Muscle Research Articles

Lateral minimally invasive plate osteosynthesis (MIPO) with long PHILOS for proximal metaphyseal-diaphyseal humeral fracture: surgical techniques and a clinical series.

The minimally invasive plate osteosynthesis (MIPO) for proximal metaphyseal-diaphyseal humeral fracture is an effective alternative treatment with satisfactory outcomes. In this study, we described the surgical techniques and clinical results using MIPO via a lateral approach and long PHILOS plate fixation in 23 patients. All fractures were successfully united within a mean union time of 13.5weeks (range 9-18). There was no iatrogenic radial nerve palsy. The deltoid power was grade 5 in all patients, except for 2 patients who had associated brachial plexus injury and gunshot injury at the deltoid muscle. The mean Constant-Murley score was 85.6 (range 16-98) and DASH score was 12.1 (range 1.7-85). Based on these findings, the lateral MIPO with long PHILOS plate fixation could be an alternative for the proximal metaphyseal-diaphyseal fractures of the humeral shaft.

Effects of Pseudo-Weight Resistance Training Using Mixed-Reality Technology on Muscle Activation in Healthy Adults: A Preliminary Study

The present study investigated the feasibility and effectiveness of pseudo-weight resistance training using mixed-reality (MR) technology for shoulder muscle activation in healthy individuals. Thirty-two healthy students aged 20~35 years participated in this preliminary study and were divided into two groups. Participants in the MR group received 30 min of training three times a week for 4 weeks using a customized MR-based pseudo-weight resistance training system. Those in the control group performed the same exercises using a conventional training program. Muscle activation of the deltoids, upper trapezius, infraspinatus, and supraspinatus were measured before and after the intervention. There was a statistically significant difference in middle deltoid, upper trapezius, and supraspinatus muscle activation in the MR group (p < 0.05), while the control group showed a significant difference in the anterior and middle deltoid, upper trapezius, and supraspinatus (p < 0.05). Regarding the between-group comparison, no statistically significant difference was observed for all six muscles (p > 0.05). Without any superiority of physical weight resistance training in the pseudo-weight training program, an MR-based pseudo-weight resistance training system can potentially be used for muscle-strengthening training, especially for early rehabilitation programs. However, further study using a large sample size with a long experimental duration is needed for more evidence of the presented technology and its use in home training.

Reliability and validity of a new deltoid muscle area measurement method after reverse shoulder arthroplasty

Accurate deltoid muscle assessment after reverse shoulder arthroplasty (RSA) is difficult using magnetic resonance imaging due to metal artifacts. We hypothesized that measuring the deltoid muscle area (DA) in the middle part of the deltoid's total length postoperatively would reduce metal artifacts and allow for an accurate assessment. This study aimed to assess the reliability and reproducibility of magnetic resonance imaging and evaluate its impact on postoperative outcomes. The DA in the middle part of the muscle's total length was measured twice by four examiners using pre and postoperative magnetic resonance imaging in 60 patients who underwent RSA (22 men, 38 women; mean age: 77.4 years). The DA at the greater tuberosity was measured preoperatively, and its correlation with the middle part of the deltoid's total length was evaluated. The Constant-Murley Score was measured at 2 years postoperatively, and its correlation with the DA in the middle part of the deltoid's total length pre- and postoperatively was assessed. Intraclass correlation coefficients for intraobserver measurements of preoperative and postoperative DA in the middle part of the deltoid's total length were almost perfect, with mean values of 0.98 and 0.97, respectively. The intraclass correlation coefficients for interobserver reliability regarding the first and second DA measurements in the middle part of the deltoid's total length were 0.95 and 0.95 (preoperatively) and 0.89 and 0.90 (postoperatively). The Constant-Murley Score was assessed at 2 years postoperatively in 51 patients. Muscle strength was weakly and moderately correlated with preoperative DA (r=0.33, P=.02) and postoperative DA (r=0.49, P<.01), respectively. DA measurement in the middle part of the deltoid's total length after RSA was not affected by metal artifacts and had excellent reproducibility. This measurement method positively correlated with postoperative muscle strength, suggesting its usefulness for predicting postoperative muscle strength.

Biomechanical Investigation of Methods of Grasping a Trombone: A Pilot Study

Trombonists, like other musicians, are at risk for developing use-related musculoskeletal symptoms. This study investigated an ergonomic aid for playing the trombone, the Neotech Trombone GripTM, which assists a trombonist’s left hand in supporting the instrument. The objective of the study was to investigate effects of this device on the left upper extremity while playing the trombone in comparison to the standard, unaided method of grasping it. Seven trombone players used the grip for two weeks prior to providing objective and subjective data in a laboratory environment. They played a scale and a piece of their choice under four conditions: sitting or standing with or without the device on their trombone. While playing, muscle activity in the trapezius, anterior deltoid, middle deltoid, extrinsic finger flexor, and extrinsic finger extensor muscle groups on the left side of the body were collected. Perceptions on the device using a survey were also assessed. Results indicated a consistent decrease in muscle activity in the finger flexor group when using the device. Smaller, less consistent effects were seen in activity in the trapezius (decrease), finger extensor group (increase), and anterior deltoid (increase) muscles, while using the device. Effects were more pronounced in players with smaller hands (among the group of participants). Most players subjectively found the device beneficial and all would recommend it to other players.

Ergonomic Analysis of a Novel Shelf Stocking Cart

This study investigated the potential for an ergonomic intervention, specifically a prototype height-adjustable stocking cart to reduce the physical demands experienced when stocking shelves. This study compared muscle activity, kinematics, and subjective preferences when participants used the prototype cart versus a traditional, manual stocking method. Nine males and three females participated in this study. A traditional stocking method was compared to the prototype cart method for two types of dry grocery products as they were moved to three different destination shelf heights. EMG data, kinematic data, and subjective feedback generally favored the cart prototype over the traditional method. Bilaterally, anterior deltoid muscle activity was reduced for the cart condition when transferring products to the lower and higher shelves; trapezius activity was reduced for only the higher shelf; right side erector spinae activity was reduced for the lower shelf. The cart primarily benefited the anterior deltoid and trapezius descendens through reduced shoulder flexion. There were interaction effects of cart and shelf height on shoulder and spine kinematics. Questionnaire data showed that participants favored using the prototype. Study results support the continued development of the prototype cart toward a commercially available ergonomic aid for shelf stockers.

Effects of a Shoulder-support Exoskeleton on Shoulder Strain during Augmented Reality Interactions

This study determined whether a passive shoulder-support exoskeleton would reduce biomechanical load in the shoulders during augmented reality (AR) interactions. Twenty participants were recruited to a repeated-measures laboratory study to perform AR tasks with and without a shoulder-support exoskeleton. The AR tasks consisted of two standardized tasks (omni-directional pointing and cube placing task). Shoulder muscle activity, postures, discomfort, and task performance (i.e., completion time) were measured during the experimental sessions. The result showed that the shoulder muscle activity (trapezius and deltoid muscles) and subjective shoulder discomfort were significantly lower with the exoskeleton compared to the no-exoskeleton condition (p &lt; 0.05). The shoulder posture data showed that the exoskeleton use increased the 50th percentile of the shoulder flexion (p = 0.02). In contrast, the exoskeleton had limited effects on task performance (p &gt; 0.83). These results suggested that a shoulder-support exoskeleton may have potential to reduce shoulder strain during AR interactions.

Errors in Augmented Reality Interactions Affected Muscular Loads in the Neck and Shoulders

The use of augmented reality (AR) head-mounted displays is becoming increasingly prevalent due to their ability to provide interactive experiences with high degrees of freedom. However, AR interactions have been shown to be associated with increased biomechanical loads in the neck and shoulders. This repeated-measures study evaluated the effects of interaction errors on neck and shoulder biomechanical loads during AR tasks. Twenty participants performed two standardized AR tasks (omni-directional pointing and cube placing) with and without AR interaction errors. During the tasks, neck and shoulder angles and muscle activity were collected. The results showed that the presence of errors led to increased neck extension and shoulder flexion angles. Peak muscle activity in the shoulders (anterior and medial deltoids) also increased with errors. These findings highlight the importance of reducing interaction errors in AR interfaces to minimize risks of musculoskeletal discomfort and injuries in the neck and shoulders

Effects of using passive back- and arm-support exoskeletons for cart pushing and pulling

Though studies have shown both BSEs and ASEs are effective in reducing physical demands for various manual material handling tasks, limited evidence is currently available on their effects in pushing and pulling tasks. We evaluated the impacts of using a passive back-support (BSE) and an arm-support exoskeleton (ASE) on trunk kinematics, and the back and arm musculature for pushing and pulling of a moderately loaded (100 kg) cart. Fourteen volunteers performed cart the tasks, each of whom was randomly assigned one of the exoskeletons (BSE or ASE). Wearing the BSE substantially reduced lumbar muscle activity during both pushing (up to ~39%) and pulling (up to ~35%) compared to not wearing EXOs, while wearing an ASE had no significant impacts. For the anterior deltoid muscle, neither BSE nor ASE had beneficial impacts. Findings from the current study help to understand the effects of BSEs and ASEs in pushing and pulling tasks.

Minimally invasive plate osteosynthesis (MIPO) for scapular fractures.

Presentation of aminimally invasive surgical approach for the treatment of scapular fractures and the clinical outcome using this technique. Displaced extra-articular fractures of the scapula body and glenoid neck (AO 14B and 14F) and simple intra-articular fractures of the glenoid. Complex intra-articular fractures and isolated fractures of the coracoid base. Make astraight or slightly curved incision along the lateral margin of the scapula leaving the deltoid fascia intact. Identify the interval between the teres minor muscle and infraspinatus to visualize the lateral column, whilst retracting the deltoid to visualize the glenoid neck. Reduce and align the fracture using direct and indirect reduction tools. Asecond window on the medial border of the scapula can be made to aid reduction and/or to augment stability. Small (2.0-2.7 mm) plates in a90° configuration on the lateral border and, if required, on the medial border are used. Intra-operative imaging confirms adequate reduction and extra-articular screw placement. Direct postoperative free functional nonweight-bearing rehabilitation limited to 90° abduction for the first 6weeks. Sling for comfort. Free range of motion and permissive weight-bearing after 6weeks. We collected data from 35patients treated with minimally invasive plate osteosynthesis (MIPO) between 2011 and 2021. Average age was 53 ± 15.1years (range 21-71years); 17had atypeB and 18atypeF fracture according the AO classification. All patients suffered concomitant injuries of which thoracic (n = 33) and upper extremity (n = 25) injuries were most common. Double plating of the lateral border (n = 30) was most commonly performed as described in the surgical technique section. One patient underwent an additional osteosynthesis 3months after initial surgery due to pain and lack of radiological signs of healing of afracture extension into the spine of the scapula. In the same patient, the plate on the spine of scapula was later removed due to plate irritation. In 2patients postoperative images showed ascrew protruding into the glenohumeral joint requiring revision surgery. After standardisation of intra-operative imaging following these two cases, intra-articular screw placement did not occur anymore. No patient suffered from iatrogenic nerve injury and none developed awound infection.

Muscular reflex gains reflect changes of mind in reaching.

Decisions for action are accompanied with a continual processing of sensory information, sometimes resulting in a revision of the initial choice, called a change of mind (CoM). While the motor system is tuned during the formation of a reach decision, it is unclear whether its preparatory state differs between CoM and non-CoM decisions. To test this, participants (n=14) viewed a random dot motion (RDM) stimulus of various coherence levels for a random viewing duration. At the onset of a mechanical perturbation, which rapidly stretched the pectoralis muscle, they indicated the perceived motion direction by making a reaching movement to one of two targets. Using electromyography (EMG), we quantified the reflex gains of the pectoralis and posterior deltoid muscle. Results show that reflex gains scaled with both the coherence level and viewing duration of the stimulus. We fit a drift diffusion model (DDM) to the behavioral choices. The decision variable (DV), derived from the DDM, correlated well with the measured reflex gain at the single trial level. However, when matched on DV magnitude, reflex gains were significantly lower in CoM than non-CoM trials. We conclude that the internal state of the motor system, as measured by the spinal reflexes, reflects the continual deliberation on sensory evidence for action selection, including the post-decisional evidence that can lead to a change of mind.

Coupling Effects of Cross-Corticomuscular Association during Object Manipulation Tasks on Different Haptic Sensations

The effects of corticomuscular connectivity during object manipulation tasks with different haptic sensations have not been quantitatively investigated. Connectivity analyses enable the study of cortical effects and muscle responses during movements, revealing communication pathways between the brain and muscles. This study aims to examine the corticomuscular connectivity of three Electroencephalography (EEG) channels and five muscles during object manipulation tasks involving contact surfaces of Sandpaper, Suede, and Silk. The analyses included 12 healthy subjects performing tasks with their right hand. Power-Based Connectivity (PBC) and Mutual Information (MI) measures were utilized to evaluate significant differences in connectivity between contact surfaces, EEG channels, muscles, and frequency bands. The research yielded the following findings: Suede contact surface exhibited higher connectivity; Mu and Gamma frequency bands exerted greater influence; significant connectivity was observed between the three EEG channels (C3, Cz, C4) and the Anterior Deltoid (AD) and Brachioradialis (B) muscles; and connectivity was primarily involved during active movement in the AD muscle compared to the resting state. These findings suggest potential implementation in motor rehabilitation for more complex movements using novel alternative training systems with high effectiveness.

Differences in SARS-CoV-2 specific humoral and cellular immune responses after contralateral and ipsilateral COVID-19 vaccination

Individual doses of dual-dose vaccine-regimens are sequentially administered into the deltoid muscle, but little attention has so far been paid to the immunological effects of choosing the ipsilateral or the contralateral side for the second dose. In an observational study, 303 previously naive individuals were recruited, who received the second dose of the COVID-19 vaccine BNT162b2 on either the ipsilateral (n=147) or the contralateral side (n=156). Spike-specific IgG, IgG-avidity, and neutralizing antibodies were quantified using ELISA and a surrogate assay 2 weeks after dose 2. A subgroup of 143 individuals (64 ipsilateral, 79 contralateral) was analysed for spike-specific CD4 and CD8 T-cells using flow-cytometry. Median spike-specific IgG-levels did not differ after ipsilateral (4590 (IQR 3438) BAU/ml) or contralateral vaccination (4002 (IQR 3524) BAU/ml, p=0.106). IgG-avidity was also similar (p=0.056). However, neutralizing activity was significantly lower after contralateral vaccination (p=0.024). Likewise, median spike-specific CD8 T-cell levels were significantly lower (p=0.004). Consequently, the percentage of individuals with detectable CD8 T-cells was significantly lower after contralateral than after ipsilateral vaccination (43.0% versus 67.2%, p=0.004). Spike specific CD4 T-cell levels were similar in both groups, but showed significantly higher CTLA-4 expression after contralateral vaccination (p=0.011). These effects were vaccine-specific, as polyclonally stimulated T-cell levels did not differ. Both ipsilateral and contralateral vaccination induce a strong immune response, but secondary boosting is more pronounced when choosing vaccine administration-routes that allows for drainage by the same lymph nodes used for priming. Higher neutralizing antibody activity and higher levels of spike-specific CD8 T-cells may have implications for protection from infection and severe disease and support general preference for ipsilateral vaccination. Financial support was provided in part by the State chancellery of the Saarland to M.S.

Exploring the Design of Upper Limb Strength Training Through High-Intensity Interval Training Combined With Exergaming: Usability Study.

High-intensity interval training (HIIT) has become a popular exercise strategy in modern society, with the Tabata training method being the most popular. In the past, these training methods were mostly done without equipment, but incorporating exergaming into the training may provide a new option for muscle training. The aim of this study was to explore the differences in upper limb muscle activation using an HIIT program combined with exergaming. A total of 15 healthy male participants were recruited for the study, and the differences in muscle activation were compared between push-ups and exergaming (Nintendo Switch Ring Fit Adventure with the Ring-Con accessory) during HIIT. Prior to the tests, participants underwent pretests, including maximal voluntary contractions of various muscle groups, maximal push-up tests, and maximal movement tests using the exergaming device. The push-up and exergaming tests were conducted on separate days to avoid interference, with a warm-up period of 5 minutes on a treadmill before testing. Muscle activation in the lateral and anterior portions of the deltoid muscle, the sternal and clavicular heads of the pectoralis major muscle, and the latissimus dorsi muscle were measured during the maximal voluntary contractions and single-round tests for each exercise mode. A repeated measures ANOVA was used to assess the variations in muscle activation observed across the 2 distinct modes of exercise, specifically push-ups and exergaming. In exergaming, the number of repetitions for push-ups was significantly fewer than for single-site exercises across both exhaustive (mean 23.13, SD 6.36 vs mean 55.67, SD 17.83; P=.001; effect size [ES]: 2.43) and single-round (mean 21.93, SD 7.67 vs mean 92.40, SD 20.47; P=.001; ES: 4.56) training. Heart rate differences were not significant (all P>.05), yet exergaming led to better muscle activation in specific muscle groups, particularly the right anterior deltoid (mean 48.00%, SD 7.66% vs mean 32.84%, SD 10.27%; P=.001; ES: 1.67) and right pectoralis major (sternal head: mean 38.99%, SD 9.98% vs mean 26.90%, SD 12.97%; P=.001; ES: 1.04; clavicular head: mean 43.54%, SD 9.59% vs mean 30.09%, SD 11.59%; P=.002; ES: 1.26) during exhaustive training. In single-round training, similar patterns were observed with the anterior deltoid (mean 51.37%, SD 11.76% vs mean 35.47%, SD 12.72%; P=.002; ES: 1.30) and pectoralis major (sternal head: mean 53.27%, SD 10.79% vs mean 31.56%, SD 16.92%; P=.001; ES: 1.53; clavicular head: mean 53.75%, SD 13.01% vs mean 37.95%, SD 14.67%; P=.006; ES: 1.14). These results suggest that exergaming may be more effective for targeted muscle activation. In conclusion, HIIT can increase muscle activation in the upper extremities and can be incorporated into exergaming strategies to provide a fun and engaging way to exercise.

Anatomical Considerations for the Injection of Botulinum Neurotoxin in Shoulder and Arm Contouring.

The utilization of botulinum neurotoxin in the field of body contouring is on the rise. Body contouring procedures typically focus on specific muscle groups such as the superior trapezius, deltoid, and lateral head of the triceps brachii. The authors propose identifying optimal injection sites for botulinum neurotoxin to achieve desired aesthetic contouring of the shoulders and arms. The authors conducted a modified Sihler's staining method on specimens of the superior trapezius, deltoid, and lateral head of the triceps brachii muscles, totaling 16, 14, and 16 specimens, respectively. The neural distribution exhibited the most extensive branching patterns within the horizontal section (between 1/5 and 2/5) and the vertical section (between 2/4 and 4/4) of the superior trapezius muscle. In the deltoid muscle, the areas between the anterior and posterior deltoid bellies, specifically within the range of the horizontal 1/3 to 2/3 lines, showed significant intramuscular arborization. Furthermore, the middle deltoid muscle displayed arborization patterns between 2/3 and the axillary line. Regarding the triceps brachii muscle, the lateral heads demonstrated arborization between 4/10 and 7/10. The authors recommend targeting these regions, where maximum arborization occurs, as the optimal and safest points for injecting botulinum toxin.

Study of the impact of using the industrial exoskeleton to support the upper limbs on the condition of the arms and shoulder girdle muscles

Introduction. The level of occupational morbidity associated with the effects of physical overload and overstrain of individual organs and systems indicates the need for timely and effective prevention, one of the means of which is the introduction of a promising type of PPE — industrial exoskeletons. Since there are no clear requirements and criteria of their safety and efficiency, all the researches in this field are of experimental character, which dictates the necessity of testing each particular type of exoskeleton in relation to the performance of certain labor operations.&#x0D; The study aims assess the influence of using industrial exoskeleton for support of upper limbs on the arm and shoulder girdle muscles fatigue.&#x0D; Materials and methods. The researchers used the presented industrial exoskeleton designed to reduce the load on the upper limbs when performing work above the level of the user's head. Eleven healthy volunteers participated in the study. In laboratory conditions, the authors simulated labor activity similar to work on an automobile conveyor with a gravity class 3.2.&#x0D; During the work, both without the use of an industrial exoskeleton and with its use, scientists measured the bioelectric activity of the muscles of the upper extremities and shoulder girdle on both sides using surface EMG. In addition, before and after the work, the authors performed myotonometry and dynamometry in order to register the biomechanical properties of the studied muscles, as well as strength and endurance of the hands.&#x0D; Results. As a result of recording the EMG-signal, scientists found that the activity of the anterior deltoid muscle on the right and the biceps muscle of the shoulder on the right when using an industrial exoskeleton in work is reduced by more than 50%. The indicators of endurance and strength recorded during dynamometry decreased after performing work both with and without an exoskeleton, from 1% to 36%, but their dynamics did not fully correspond to classical ideas about the development of muscle fatigue. The analysis of myotonometry data did not show statistically significant changes in the parameters of the studied muscles.&#x0D; Limitations. The limitations of this study are: a small sample size (eleven volunteers), the lack of calculation of the sample size, the use of a small set of used biomedical methods for assessing the human condition.&#x0D; Conclusion. The use of the studied industrial exoskeleton when performing simulated labor operations reduces the bioelectric activity of the main muscles involved in the work, which proves its effectiveness. The developed technique of surface EMG can be used in the future when carrying out such work. Dynamometry and myotonometry did not show sufficient sensitivity in the study, which necessitates the development of special techniques for solving similar problems.&#x0D; Ethics. The Local Ethics Committee of Izmerov Research Institute of Occupational Health have approved the Protocol of the study (the protocol No.3 dated 04/20/2022).

Parameter mapping of hemiplegic shoulder electrical stimulation for motor function: A scoping review.

Electrical stimulation (ES) of the shoulder is effective in treating subluxation and shoulder pain. However, few studies have reported on ES of the hemiplegic shoulder with motor function as an outcome; thus, the method remains unclear. We aimed to map the existing evidence and identify the parameters for ES of the hemiplegic shoulder for motor function in stroke patients. A literature search was performed through PubMed and Scopus to retrieve original articles from 1975 to March 2023 using the terms "stroke", "shoulder", and "electricity". We selected studies in which ES was performed on hemiplegic shoulders after stroke, parameters were described, and upper extremity motor functional assessment was included as an outcome. The extracted data included study design, phase, sample size, electrode position, parameters, intervention period, evaluation frequency, outcomes, and results. Of the 449 titles identified, 25 fulfilled the inclusion and exclusion criteria. Nineteen were randomized controlled trials. The most common electrode positions and parameters (frequency and pulse width) were over the posterior deltoid and the supraspinatus (upper trapezius) muscles, 30 Hz, and 250μs, respectively. The intervention period was 30-60 minutes per day, 5-7 days per week, for 4-5 weeks in over half of the studies. Stimulation positions and parameters for electrical stimulation of the hemiplegic shoulder are inconsistent. Whether ES represents a significant treatment option remains unclear. Establishing universal ES methods is necessary to improve the motor function of hemiplegic shoulders.

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

BackgroundRotator 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 MethodsTwenty-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.ResultsMuscle 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.ConclusionsRotator 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).

Peculiarities of Acromioplasty in Patients with Chronic Massive Rotator Cuff Ruptures

Background. According to the literature, from 14% to 28% of patients with rotator cuff tendon ruptures have unsatisfactory results of treatment and require a reverse shoulder joint arthroplasty in the future.&#x0D; Objective: to compare the results of open rotator cuff repair of chronic massive rotator cuff tears in groups with standard subacromial decompression and subacromial decompression with resection of the lateral part of the acromion.&#x0D; Materials and Methods. The study included 58 patients who underwent an open rotator cuff repair of chronic massive rotator cuff tears (supraspinatus and infraspinatus tendons) and who underwent a rehabilitation program and follow-up up to 12 months after surgery. The age of the patients ranged from 30 to 60 years. All patients were divided into 2 groups: group 1 – classic subacromial decompression, group 2 – classic subacromial decompression complemented by resection of 5 mm of the lateral end of the acromion. Shoulder joint function was assessed using the Constant Shoulder Score and VAS scales before surgery, 6 and 12 months after surgery.&#x0D; Results. Six months after surgery, the mean functional result on the Constant Shoulder Score scale in group 1 was slightly worse (24.5 ± 16.2 points) than in group 2 (18.5 ± 6.1 points); p = 0.131. Twelve months after surgery, the mean functional score on the Constant Shoulder Score was 21.1 ± 5.6 points in group 1 and 10.1 ± 6.1 points in group 2 (p = 0.031). Six months after surgery, the average score on the VAS scale was worse in group 1 than in group 2 and ranged from 3.5 ± 1.2 points. Twelve months after surgery, the mean score on the VAS scale was also worse in group 1 than in group 2 (p = 0.05). Conclusions. Resection of the lateral part of the acromion during the open rotator cuff repair of chronic massive rotator cuff tendons tears allows to obtain better average functional results of treatment both 6 months and 12 months after the surgery. Resection of the lateral end of the acromion changes the vector of the total force of the rotator cuff and deltoid muscles during shoulder elevation. This reduces the probability of the subacromial conflict syndrome development and thus reduces the load on the area of the rotator cuff tendon suture.

The use of the Classic and Modified Transfer of the Lower Trapezius Muscle (Elhassan Transfer) as a Primary or Secondary Method for Surgical Reconstruction of the Abduction and External Rotation of the Shoulder in Brachial Plexus Injury

Background. Brachial plexus injury (BPI) leads to severe dysfunction of the upper extremity (UE). Elbow flexion and multiaxial movements in glenohumeral joint (MGHJ) are prioritized in reconstruction strategy. Time-dependent (&lt; 6 months) nerve transfers (NT) allow effective restoring of MGHJ. Late (&gt; 6 months) reconstruction of MGHJ remains completely dependent on transfers of the functional tendon-muscle complexes.&#x0D; Objective: to compare the outcomes of the classic Elhassan (c) and modified (m) transfer of the lower trapezius muscle (LTT) on recovery of monoaxial MGHJ.&#x0D; Materials and Methods. Patient (P.) #3 with M4+ recovery of the deltoid muscle (DM) after NT and P. #4 without spontaneous recovery (SR) of DM – forward flexion (FF) was 170° and 0°, respectively, received cLTT. Patient #1 with M4+ recovery of DM after NT and P. #2 with M4+ SR of DM (FF was 160° and 50°, respectively), received mLTT – distal fixation point has been changed from the tendon of the infraspinatus to the tendon of supraspinatus muscle.&#x0D; Results. Shoulder abduction (ABD) has been restored to 50° in P. #1 and P. #2, while the recovery of the external rotation (ER) has not been achieved – upper arm remained internally rotated (IR). ABD has been restored to 40° and 80° in P. #3 and P. #4; simultaneously +15° and +70° of ER has been restored.&#x0D; Conclusions. The use of mLTT leads to more effective recovery of monoaxial MGHJ – ABD – 50° vs. 40° after cLTT. The use of cLTT leads to more effective recovery of another monoaxial MGHJ – ER – +15° and +70° vs. IR after mLTT; LTT should only be considered as a complementary surgical procedure, which utilization should cohere with a patient’s requirements to the MGHJ.

Maintaining the Sporting Shoulder after Injury; a Case Report on the Journey of Rehabilitation Exercise after Revision Rotator Cuff Repair

Surgical treatment of complete or full thickness tear of rotator cuff is a common treatment. However, the number of postoperative re-tear is increasing, and repetition of such surgical treatment causes various complications. Therefore, the importance of conservative rehabilitation exercise treatment has been emphasized, but there is no established rehabilitation protocol that shows a definite functional recovery of complete rotator cuff tear. The patient is a 46-year-old male patient who has already undergone an arthroscopic rotator cuff repair once due to a full thickness tear of the right supraspinous tendon. The patient visited the hospital after performing a second arthroscopic repair after diagnosing the re-tear of the supraspinous tendon. He visited the department of rehabilitation medicine and performed rehabilitation excise under physician supervision at cooperative rehabilitation center for 7 years, and showed complete functional recovery after rehabilitation treatment. The MRI without contrast performed 7 years after the surgery showed the maintenance of supraspinatus muscle and hypertrophy of surrounding muscles (especially deltoid muscle). And there is no functional limitation or pain. Therefore, functional recovery can be promoted through effective rehabilitation exercise protocol in complete or full thickness tear of rotator cuff, and even re-tear.