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Journal of Clinical Medicine Mar 2023Over 35 years ago, the pioneer Paul Grammont from Lyon published his ideas of a reversed semi-constraint prosthesis improving the moment arm of the deltoid by...
Over 35 years ago, the pioneer Paul Grammont from Lyon published his ideas of a reversed semi-constraint prosthesis improving the moment arm of the deltoid by medializing the center of rotation and lengthening of the arm and thus increasing deltoid muscle tension [...].
PubMed: 36902731
DOI: 10.3390/jcm12051945 -
The Israel Medical Association Journal... Aug 2021Cervical spinal surgery is considered safe and effective. One of the few specific complications of this procedure is C5 nerve root palsy. Expressed primarily by deltoid...
BACKGROUND
Cervical spinal surgery is considered safe and effective. One of the few specific complications of this procedure is C5 nerve root palsy. Expressed primarily by deltoid muscle and biceps brachii weakness, it is rare and has been related to nerve root traction or to ischemic spinal cord damage.
OBJECTIVES
To determine the clinical and epidemiological traits of C5 palsy. To determine whether C5 palsy occurs predominantly in one specific surgical approach compared to others.
METHODS
A retrospective study of patients who underwent cervical spine surgery at our medical center during a consecutive 8-year period was conducted. The patient data were analyzed for demographics, diagnosis, and surgery type and approach, as well as for complications, with emphasis on the C5 nerve root palsy.
RESULTS
The study group was comprised of 124 patients. Seven (5.6%) developed a C5 palsy following surgery. Interventions were either by anterior, by posterior or by a combined approach. Seven patients developed this complication. All of whom had myelopathy and were older males. A combined anteroposterior (5 patients) and posterior access (2 patients) were the only approaches that were associated with the C5 palsy. None of the patients who were operated via an anterior approach did develop this sequel.
CONCLUSIONS
The incidence of the C5 root palsy in our cohort reached 5.6%. Interventions performed through a combined anterior-posterior access in older myelopathic males, may carry the highest risk for this complication.
Topics: Cervical Plexus; Cervical Vertebrae; Decompression, Surgical; Deltoid Muscle; Female; Humans; Intraoperative Complications; Israel; Male; Middle Aged; Muscle Weakness; Outcome and Process Assessment, Health Care; Paresis; Postoperative Complications; Retrospective Studies; Risk Assessment; Spinal Cord Ischemia
PubMed: 34392627
DOI: No ID Found -
Frontiers in Endocrinology 2023Resistance exercise can significantly increase serum steroid concentrations after an exercise bout. Steroid hormones are involved in the regulation of several important...
INTRODUCTION
Resistance exercise can significantly increase serum steroid concentrations after an exercise bout. Steroid hormones are involved in the regulation of several important bodily functions (e.g., muscle growth) through both systemic delivery and local production. Thus, we aimed to determine whether resistance exercise-induced increases in serum steroid hormone concentrations are accompanied by enhanced skeletal muscle steroid concentrations, or whether muscle contractions per se induced by resistance exercise can increase intramuscular steroid concentrations.
METHODS
A counterbalanced, within-subject, crossover design was applied. Six resistance-trained men (26 ± 5 years; 79 ± 8 kg; 179 ± 10 cm) performed a single-arm lateral raise exercise (10 sets of 8 to 12 RM - 3 min rest between sets) targeting the deltoid muscle followed by either squat exercise (10 sets of 8 to 12 RM - 1 min rest) to induce a hormonal response (high hormone [HH] condition) or rest (low hormone [LH] condition). Blood samples were obtained pre-exercise and 15 min and 30 min post-exercise; muscle specimens were harvested pre-exercise and 45 min post-exercise. Immunoassays were used to measure serum and muscle steroids (total and free testosterone, dehydroepiandrosterone sulfate, dihydrotestosterone, and cortisol; free testosterone measured only in serum and dehydroepiandrosterone only in muscle) at these time points.
RESULTS
In the serum, only cortisol significantly increased after the HH protocol. There were no significant changes in muscle steroid concentrations after the protocols.
DISCUSSION
Our study provides evidence that serum steroid concentration increases (cortisol only) seem not to be aligned with muscle steroid concentrations. The lack of change in muscle steroid after protocols suggests that resistance-trained individuals were desensitized to the exercise stimuli. It is also possible that the single postexercise timepoint investigated in this study might be too early or too late to observe changes. Thus, additional timepoints should be examined to determine if RE can indeed change muscle steroid concentrations either by skeletal muscle uptake of these hormones or the intramuscular steroidogenesis process.
Topics: Humans; Male; Dihydrotestosterone; Hydrocortisone; Muscle, Skeletal; Steroids; Testosterone; Cross-Over Studies
PubMed: 37077354
DOI: 10.3389/fendo.2023.1081056 -
Annals of Medicine and Surgery (2012) Oct 2022Full-thickness rotator cuff tear is common in the older population. The incidence of traumatic deltoid tears post-surgery is well addressed. However, non-traumatic...
BACKGROUN
Full-thickness rotator cuff tear is common in the older population. The incidence of traumatic deltoid tears post-surgery is well addressed. However, non-traumatic spontaneous injury is not well recognized despite a few case reports and previous studies. The aim of the study is to determine the incidence and association of deltoid tear among patients with non-traumatic full-thickness rotator cuff tear using shoulder magnetic resonance imaging.
METHODS
A retrospective cross-sectional study was conducted of 271 shoulders magnetic resonance imaging examinations with full-thickness rotator cuff tear between 2012 and 2022. The analyzed variables were full-thickness rotator cuff tear size, tear grading (small, medium, large, and massive), muscle fatty degeneration, and deltoid tear. Acromio-humeral interval was also recorded and analyzed on the anteroposterior projection of shoulder radiographs.
RESULTS
The incidence of deltoid tear was 7% (19 cases), encountered in eleven females (6.4%) and eight males (8%) with a mean age of 65 years. Deltoid tears were located on the right side in fifteen patients (9.4%) and on the left side in four patients (3.6%). The Man-Whitney test indicated a significant association between deltoid tears and full-thickness rotator cuff tear, P < 0.001. The deltoid tear was more notably associated with large and massive full-thickness rotator cuff tear (16.7% and 42.3%, respectively), P < 0.001. Acromio-humeral interval showed a significant difference between the deltoid and non-deltoid cases, P = 0.045.
CONCLUSION
The incidence and association of deltoid tears with full-thickness rotator cuff tear with no prior surgical intervention or traumatic insults were considered significant, with a positive impact of large and massive tear size and association of muscle fatty degeneration. This association is statistically significant and should be adequately evaluated by the radiologist.
PubMed: 36268451
DOI: 10.1016/j.amsu.2022.104621 -
PloS One 2022Evaluation of surgical skills during minimally invasive surgeries is needed when recruiting new surgeons. Although surgeons' differentiation by skill level is highly...
Evaluation of surgical skills during minimally invasive surgeries is needed when recruiting new surgeons. Although surgeons' differentiation by skill level is highly complex, performance in specific clinical tasks such as pegboard transfer and knot tying could be determined using wearable EMG and accelerometer sensors. A wireless wearable platform has made it feasible to collect movement and muscle activation signals for quick skill evaluation during surgical tasks. However, it is challenging since the placement of multiple wireless wearable sensors may interfere with their performance in the assessment. This study utilizes machine learning techniques to identify optimal muscles and features critical for accurate skill evaluation. This study enrolled a total of twenty-six surgeons of different skill levels: novice (n = 11), intermediaries (n = 12), and experts (n = 3). Twelve wireless wearable sensors consisting of surface EMGs and accelerometers were placed bilaterally on bicep brachii, tricep brachii, anterior deltoid, flexor carpi ulnaris (FCU), extensor carpi ulnaris (ECU), and thenar eminence (TE) muscles to assess muscle activations and movement variability profiles. We found features related to movement complexity such as approximate entropy, sample entropy, and multiscale entropy played a critical role in skill level identification. We found that skill level was classified with highest accuracy by i) ECU for Random Forest Classifier (RFC), ii) deltoid for Support Vector Machines (SVM) and iii) biceps for Naïve Bayes Classifier with classification accuracies 61%, 57% and 47%. We found RFC classifier performed best with highest classification accuracy when muscles are combined i) ECU and deltoid (58%), ii) ECU and biceps (53%), and iii) ECU, biceps and deltoid (52%). Our findings suggest that quick surgical skill evaluation is possible using wearables sensors, and features from ECU, deltoid, and biceps muscles contribute an important role in surgical skill evaluation.
Topics: Bayes Theorem; Electromyography; Machine Learning; Muscle, Skeletal; Wearable Electronic Devices
PubMed: 35657912
DOI: 10.1371/journal.pone.0267936 -
Orthopaedic Journal of Sports Medicine Jan 2023Despite advances in surgical management of acromioclavicular (AC) joint reconstruction, many patients fail to maintain sustained anatomic reduction postoperatively.
BACKGROUND
Despite advances in surgical management of acromioclavicular (AC) joint reconstruction, many patients fail to maintain sustained anatomic reduction postoperatively.
PURPOSE
To determine the biomechanical support of the deltoid and trapezius on AC joint stability, focusing on the rotational stability provided by the muscles to posterior and anterior clavicular rotation. A novel technique was attempted to repair the deltoid and trapezius anatomically.
STUDY DESIGN
Controlled laboratory study.
METHODS
Twelve human cadaveric shoulders (mean ± SD age, 60.25 ± 10.25 years) underwent servohydraulic testing. Shoulders were randomly assigned to undergo serial defects to either the deltoid or trapezius surrounding the AC joint capsule, followed by a combined deltotrapezial muscle defect. Deltotrapezial defects were repaired with an all-suture anchor using an anatomic technique. The torque (N·m) required to rotate the clavicle 20° anterior and 20° posterior was recorded for the following conditions: intact (native), deltoid defect, trapezius defect, combined deltotrapezial defect, and repair.
RESULTS
When compared with the native condition, the deltoid defect decreased the torque required to rotate the clavicle 20° posteriorly by 7.1% ( = .206) and 20° anteriorly by 6.1% ( = .002); the trapezial defect decreased the amount of rotational torque posteriorly by 5.3% ( = .079) and anteriorly by 4.9% ( = .032); and the combined deltotrapezial defect decreased the amount of rotational torque posteriorly by 9.9% ( = .002) and anteriorly by 9.4% ( < .001). Anatomic deltotrapezial repair increased posterior rotational torque by 5.3% posteriorly as compared with the combined deltotrapezial defect ( = .001) but failed to increase anterior rotational torque ( > .999). The rotational torque of the repair was significantly lower than the native joint in the posterior ( = .017) and anterior ( < .001) directions.
CONCLUSION
This study demonstrated that the deltoid and trapezius play a role in clavicular rotational stabilization. The proposed anatomic repair improved posterior rotational stability but did not improve anterior rotational stability as compared with the combined deltotrapezial defect; however, neither was restored to native stability.
CLINICAL RELEVANCE
Traumatic or iatrogenic damage to the deltotrapezial fascia and the inability to restore anatomic deltotrapezial attachments to the acromioclavicular joint may contribute to rotational instability. Limiting damage and improving the repair of these muscles should be a consideration during AC reconstruction.
PubMed: 36743723
DOI: 10.1177/23259671221119542 -
Journal of Shoulder and Elbow Surgery Mar 2021Adequate deltoid and rotator cuff elongation in reverse shoulder arthroplasty is crucial to maximize postoperative functional outcomes and to avoid complications....
BACKGROUND
Adequate deltoid and rotator cuff elongation in reverse shoulder arthroplasty is crucial to maximize postoperative functional outcomes and to avoid complications. Measurements of deltoid and rotator cuff elongation during preoperative planning can support surgeons in selecting a suitable implant design and position. Therefore, this study presented and evaluated a fully automated method for measuring deltoid and rotator cuff elongation.
METHODS
Complete scapular and humeral models were extracted from computed tomography scans of 40 subjects. First, a statistical shape model of the complete humerus was created and evaluated to identify the muscle attachment points. Next, a muscle wrapping algorithm was developed to identify the muscle paths and to compute muscle lengths and elongations after reverse shoulder arthroplasty implantation. The accuracy of the muscle attachment points and the muscle elongation measurements was evaluated for the 40 subjects by use of both complete and artificially created partial humeral models. Additionally, the muscle elongation measurements were evaluated for a set of 50 arthritic shoulder joints. Finally, a sensitivity analysis was performed to evaluate the impact of implant positioning on deltoid and rotator cuff elongation.
RESULTS
For the complete humeral models, all muscle attachment points were identified with a median error < 3.5 mm. For the partial humeral models, the errors on the deltoid attachment point largely increased. Furthermore, all muscle elongation measurements showed an error < 1 mm for 75% of the subjects for both the complete and partial humeral models. For the arthritic shoulder joints, the errors on the muscle elongation measurements were <2 mm for 75% of the subjects. Finally, the sensitivity analysis showed that muscle elongations were affected by implant positioning.
DISCUSSION
This study presents an automated method for accurately measuring muscle elongations during preoperative planning of shoulder arthroplasty. The results show that the accuracy in measuring muscle elongations is higher than the accuracy in indicating the muscle attachment points. Hence, muscle elongation measurements are insensitive to the observed errors on the muscle attachment points. Related to this finding, muscle elongations can be accurately measured for both a complete humeral model and a partial humeral model. Because the presented method also showed accurate results for arthritic shoulder joints, it can be used during preoperative shoulder arthroplasty planning, in which typically only the proximal humerus is present in the scan and in which bone arthropathy can be present. As the muscle elongations are sensitive to implant positioning, surgeons can use the muscle elongation measurements to refine their surgical plan.
Topics: Arthroplasty, Replacement, Shoulder; Deltoid Muscle; Humans; Humerus; Range of Motion, Articular; Rotator Cuff; Shoulder; Shoulder Joint
PubMed: 32707326
DOI: 10.1016/j.jse.2020.07.007 -
EFORT Open Reviews Mar 2022Variable definitions of pseudoparalysis have been used in the literature. Recent systematic reviews and biomechanical studies call for a grading of loss of force couple... (Review)
Review
Variable definitions of pseudoparalysis have been used in the literature. Recent systematic reviews and biomechanical studies call for a grading of loss of force couple balance and the use of the terms 'pseudoparesis' and 'pseudoparalysis'. Pain should be excluded as the cause of loss of active function. Key players for loss of force couple balance seem to be the lower subscapularis as an anterior inferior checkrein and the teres minor as a posterior inferior fulcrum. Loss of three out of five muscle-tendon units counting upper and lower subscapularis separately is predictive of pseudoparalysis. Shoulder equator concept: loss of all three posterior, or all three superior, or all three anterior muscle-tendon units is predictive of pseudoparalysis (loss of fulcrum for deltoid force). Every effort should be made to prevent propagation of rotator cuff tears into the subscapularis and posterior rotator cuff (infraspinatus and teres minor) to maintain force couple balance (value of partial cuff repair). Clinical assessment of active forward elevation, active external rotation, and active internal rotation is important to define and grade the severity of loss of force couple balance. Additional features such as patient age, traumatic aetiology, chronicity, fatty infiltration, and stage of cuff tear arthropathy are useful for a specific diagnosis with implications for treatment.
PubMed: 35298415
DOI: 10.1530/EOR-21-0069