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Orthopaedic Journal of Sports Medicine May 2021The axillary nerve is at risk for iatrogenic injuries in surgical procedures involving the lateral aspect of the shoulder joint. To date and to our knowledge, there have...
BACKGROUND
The axillary nerve is at risk for iatrogenic injuries in surgical procedures involving the lateral aspect of the shoulder joint. To date and to our knowledge, there have been no studies that have compared the relevant distances in the common arm abduction positions used in these types of surgery as well as the relative risks of each position.
PURPOSE
To evaluate the effect of arm abduction position on the distance from the acromion process to the axillary nerve in the common abducted arm positions.
STUDY DESIGN
Descriptive laboratory study.
METHODS
The shoulders of 10 fresh-frozen, full-body cadaveric specimens were used. A saber incision was made at the anterolateral edge of the acromion, and the anterior branch of the axillary nerve was identified. The distance between the anterolateral edge of the acromion process and the axillary nerve was measured 3 times in each of 4 positions: with the arm at the side as well as at 30°, 60°, and 90° of abduction. Then, the same procedure was performed from the midlateral and the posterolateral edges of the acromion process. The distances of the acromion process to the axillary nerve in the 4 positions were compared using 2-way analysis of variance.
RESULTS
The mean distances from the anterolateral edge of the acromion process to the anterior branch of the axillary nerve were 52.76 ± 4.64 mm with the arm at the side, 49.48 ± 4.77 mm at 30° of abduction, 46.00 ± 4.75 mm at 60° of abduction, and 42.88 ± 4.59 mm at 90° of abduction. There was a significant decrease in the distance from the anterolateral edge of the acromion process to the axillary nerve as the abduction angle of the arm increased from 0° to 60°, 0° to 90°, and 30° to 90° ( < .05).
CONCLUSION
The distances from the acromion process to the axillary nerve were shorter in all abducted arm positions than with the arm at the side.
CLINICAL RELEVANCE
To avoid iatrogenic axillary nerve injuries, surgeons should be aware of the safe zone based on the shortest distance from the acromion process to the axillary nerve to ensure no accidental damage to this structure instead of using the mean distance of 5 cm.
PubMed: 34095326
DOI: 10.1177/23259671211008834 -
BMC Musculoskeletal Disorders Jan 2023To evaluate the shoulder anatomical characteristics in asymptomatic Chinese adults.
BACKGROUND
To evaluate the shoulder anatomical characteristics in asymptomatic Chinese adults.
METHODS
The prospective study enrolled individuals without shoulder pain at Beijing Tiantan Hospital Affiliated to Capital Medical University between January 2019 and January 2020. Six radiographic parameters were measured and analyzed, including glenoid plane to the acromion (GA), glenoid plane to the lateral aspect of the humeral head (GH), acromion index (AI), lateral acromial angle (LAA), acromion-humeral interval (AHI), and critical shoulder angle (CSA).
RESULTS
103 participants (51 males and 52 females) were enrolled. The mean values of GA, GH, AI, CSA, LAA, and AHI were 32.88 ± 5.68 mm, 47.16 ± 4.82 mm, 0.70 ± 0.11, 37.45 ± 6.00°, 6.32 ± 3.99°, and 9.611.86 mm, respectively. Females had lower GA (30.78 ± 5.06 vs. 35.01 ± 5.51 mm, P < 0.001) and GH (44.28 ± 3.67 vs. 50.11 ± 4.02 mm, P < 0.001) than males and LAA was significantly smaller in the Bigliani flat type compared with the curved type and the hooked type (5.07 ± 2.31° vs 12.33 ± 5.46°vs 10.00 ± 3.37, P = 0.001).
CONCLUSIONS
Females had lower GA and GH than males in asymptomatic Chinese Han adults. Asymptomatic Chinese Han subjects with Bigliani flat type had lower LAA. CSA appears lager in Chinese Han individuals. Curve type of acromion performed lager LAA. The results may help establish an anatomical model of the shoulder joint and elucidate the anatomy features of the shoulder joint in asymptomatic Chinese Han adults.
Topics: Male; Female; Adult; Humans; Shoulder Joint; Rotator Cuff Injuries; Prospective Studies; East Asian People; Shoulder; Acromion
PubMed: 36709290
DOI: 10.1186/s12891-023-06172-9 -
Experimental Brain Research May 2017During goal-directed arm movements, the eyes, head, and arm are coordinated to look at and reach the target. We examined whether the expectancy of visual information...
During goal-directed arm movements, the eyes, head, and arm are coordinated to look at and reach the target. We examined whether the expectancy of visual information about the target modifies Anticipatory Postural Adjustments (APAs). Ten standing subjects had to (1) move the eyes, head and arm, so as to reach, with both gaze and index-finger, a target of known position placed outside their visual field (Gaze-Reach); (2) look at the target while reaching it (Reach in Full Vision); (3) keep the gaze away until having touched it (Reach then Gaze) and (4) just Gaze without Reach the target. We recorded eye, head, right arm, and acromion kinematics, EMGs from upper- and lower-limb muscles, and forces exerted on the ground. In Gaze-Reach, two coordination strategies were found: when gaze preceded arm muscle recruitment (Gaze-first) and when the opposite occurred (Reach-first). APAs in acromion kinematics, leg muscles, and ground forces started significantly earlier in Gaze-first vs. Reach-first (mean time advance: 44.3 ± 8.9 ms), as it was in Reach in Full Vision vs. Reach then Gaze (39.5 ± 7.9 ms). The Gaze-first to Reach-first time-shift was similar to that between Reach in Full Vision and Reach then Gaze (p = 0.58). Moreover, Gaze without Reach data witnessed that the head-induced postural actions did not affect the APA onset in Gaze-first and Reach-first. In conclusion, in Gaze-first, the central control of posture considers visual information while planning the movement, like in Reach in Full Vision; while Reach-first is more similar to Reach then Gaze, where vision is not required.
Topics: Adult; Analysis of Variance; Electromyography; Feedback, Sensory; Female; Fixation, Ocular; Functional Laterality; Humans; Male; Motion Perception; Movement; Postural Balance; Posture; Psychomotor Performance; Reaction Time; Young Adult
PubMed: 28213690
DOI: 10.1007/s00221-017-4898-3 -
Asia-Pacific Journal of Sports... Apr 2020A hooked acromion on an outlet view and a keeled acromion on Rockwood tilt radiographs are associated with rotator cuff tears. The identification of the acromial...
BACKGROUND
A hooked acromion on an outlet view and a keeled acromion on Rockwood tilt radiographs are associated with rotator cuff tears. The identification of the acromial morphology may be helpful for acromioplasty planning with regarding the acromial types.
METHODS
Descriptive Laboratory Study. Three-dimensional computed tomography scans models of 108 shoulders in 91 patients with; (1) Normal shoulders, (2) Shoulders with osteoarthritis, and (3) Irreparable rotator cuff tears; were created and adjusted manually to provide the proper supraspinatus outlet and Rockwood views. The acromial morphology/spurs were analyzed, classified and tested for reliability.
RESULTS
The intra-observer reliability of supraspinatus outlet view had a weak-to-strong agreement [0.828 (95%CI: 0.716-0.945, p-value<0.001), and 0.475 (95%CI: 0.288-0.672, p-value<0.001 from 2 evaluators]. The inter-rater of the supraspinatus outlet view has a minimal-to-moderate agreement [0.782 (95%CI: 0.662-0.907, p-value<0.001), and 0.344 (95%CI: 0.157-0.539, p-value<0.001) in the first and second readings]. The intra-observer reliability of the Rockwood view has a moderate-to-almost-perfect agreement [0.752 (95%CI: 0.652-0.860, p-value<0.001), and 0.903 (95%CI: 0.833-0.974, p-value<0.001) from 2 evaluators]. The inter-observer reliability of the Rockwood view has a moderate-to-strong agreement [0.854 (95%CI: 0.777-0.936, p-value<0.001), and 0.737 (95%CI: 0.634-0.847, p-value<0.001) in the first and second readings].
CONCLUSION
The classification of acromion morphology under Three-dimensional computed tomography in the supraspinatus outlet view has poor reliability. The Rockwood caudal tilt view model results in moderate-to-almost-perfect reliability that can be developed to the plain radiographic classification to determine the need for acromioplasty in rotator cuff surgery.
PubMed: 32095430
DOI: 10.1016/j.asmart.2020.02.001 -
Journal of Clinical and Diagnostic... Aug 2015Owing to its many variations, scapula became one of the most interesting bones of the human skeleton.
BACKGROUND
Owing to its many variations, scapula became one of the most interesting bones of the human skeleton.
AIM
To measure acromial and glenoid morphology in to describe their anatomical patterns and variations in Egyptians to establish possible morphofunctional correlations related to race, geographic region and literature data.
MATERIALS AND METHODS
One hundred and sixty scapulae of unknown age and sex were studied. Morphological shapes of the tip of the acromion; types of acromion; and morphological shapes of the glenoid were evaluated. Length and width of the scapulae, length, breadth and thickness of the acromion process and distances of the acromio-coracoid and acromio-glenoid in addition to glenoid diameters were measured.
STATISTICAL ANALYSIS
The morphometric values of the two sides were analysed using an unpaired t-test. Statistical significance was set p≤ 0.05.
RESULTS
The intermediate shape of the acromion presented with the highest incidence, while the cobra shaped presented with the lowest distribution in both sides. The oval shaped glenoid cavity presented with the highest incidence while the inverted coma shaped showed the lowest incidence. These results are in match with other population. However, the morphometric values of the scapula, acromion process and glenoid cavity were higher than reported in Turkish and Indians.
CONCLUSION
Our data are important to compare Egyptian scapulae to those from various other races that could contribute to demographic studies of shoulder disease probability and management in Egyptian population.
PubMed: 26435934
DOI: 10.7860/JCDR/2015/14362.6386 -
JSES International Nov 2022Small changes in deltoid tension and moment arm due to glenosphere lateralization may be associated with an increase in acromion or scapular spine strain in reverse...
BACKGROUND
Small changes in deltoid tension and moment arm due to glenosphere lateralization may be associated with an increase in acromion or scapular spine strain in reverse shoulder arthroplasty (RSA), which can lead to stress fracture. The coracoacromial ligament (CAL) may be protective and lower the strain seen on the acromion or scapular spine. This biomechanical study investigated the impact of glenosphere lateralization and CAL integrity on acromion and scapular spine strain after RSA.
METHODS
Ten cadaveric specimens were tested on a custom dynamic shoulder frame. Acromial and scapular spine strain were measured at 0°, 30°, and 60° of abduction using strain rosettes fixed to the acromion (Levy Type 2) and the scapular spine (Levy Type 3). Specimens were first tested with a standard commercially available RSA implant with zero lateralization and then subsequently with the +3 and +6 lateralizing glenospheres for that implant. The CAL was then cut in each specimen and testing was repeated with the 0, +3, and +6 glenospheres. Maximal strain was recorded at both the acromion and scapular spine and analysis of variance compared strain across various abduction angles and glenospheres with and without CAL transection.
RESULTS
In the intact CAL group, maximal strain decreased significantly at the acromion with abduction from 0° to 30° and 0° to 60°, however, at the scapular spine abduction did not significantly impact strain. Maximal strain decreased significantly with increasing abduction from 0 to 30 and 0 to 60 at both the acromion and scapular spine in the cut CAL group. Average strain at the acromion was significantly higher in the cut group (844.7 με) versus the intact group (580.3 με), a difference of 31.3% ( = .0493). Average strain at the scapular spine, did not differ in the cut group (725 με) compared with the intact group (787 με) ( = .3666). There were no statistically significant differences in acromial or scapular spine strain between various levels of glenosphere lateralization in either the cut or intact state.
CONCLUSION
In this biomechanical study, arm abduction decreased acromial and scapular spine strain following RSA. Cutting the CAL significantly increased strain at the acromion, and did not significantly alter strain at the scapular spine for all angles of abduction, differing from prior literature. Glenosphere lateralization did not have a significant effect on strain at the levels studied regardless of CAL status. Continued study of the complexion relationship between surgical and implant factors on strain following RSA is needed.
PubMed: 36353428
DOI: 10.1016/j.jseint.2022.08.010 -
Orthopaedics & Traumatology, Surgery &... Apr 2022Critical shoulder angle (CSA)>35° correlates significantly with primary rotator cuff tear and re-tear after repair. Acromial axial orientation varies between...
INTRODUCTION
Critical shoulder angle (CSA)>35° correlates significantly with primary rotator cuff tear and re-tear after repair. Acromial axial orientation varies between individuals. The present study aimed to assess the impact of strictly anterior acromioplasty on CSA.
HYPOTHESIS
CSA is reduced by arthroscopic anterior acromioplasty.
MATERIAL AND METHODS
A single-center retrospective study included patients receiving isolated arthroscopic acromioplasty between January 2016 and December 2017. Exclusion criteria comprised history of surgery and fracture or dislocation of the shoulder. Pre- and post-operative AP shoulder radiographs were taken. The angle subtended by a line between the inferior and superior edges of the glenoid and a line between the inferior edge of the glenoid and the most lateral point on the acromion was measured.
RESULTS
One hundred and two patients were included: mean age, 50.5±10.1 years (range, 23-82 years). Mean CSA was 34.7±4.4° (range, 26-48°) preoperatively and 31.7±3.7° (range, 23-40°) postoperatively (p<0.001). In the group with CSA >35°, the decrease was significant: 34.4±3.2° (range, 28-40°) versus 38.9±2.8° (range, 36-48°) (p<0.001), with 64% CSA <35° after isolated anterior acromioplasty.
DISCUSSION
CSA was decreased by arthroscopic acromioplasty. However, in 36% of cases with preoperative CSA >35°, CSA was not normalized.
CONCLUSION
Anterior arthroscopic acromioplasty significantly reduced CSA in the overall population, and especially in case of high CSA.
LEVEL OF EVIDENCE
IV; retrospective study.
Topics: Acromion; Adult; Arthroscopy; Humans; Middle Aged; Retrospective Studies; Rotator Cuff Injuries; Shoulder; Shoulder Joint
PubMed: 34389495
DOI: 10.1016/j.otsr.2021.103040 -
Knee Surgery, Sports Traumatology,... Aug 2021The critical shoulder angle (CSA) and the acromion index (AI) are measurements of acromial shape reported as predictors of degenerative rotator cuff tears (RCT) and...
PURPOSE
The critical shoulder angle (CSA) and the acromion index (AI) are measurements of acromial shape reported as predictors of degenerative rotator cuff tears (RCT) and glenohumeral osteoarthritis (GH OA). Whether they are the cause or effect of shoulder pathologies is uncertain since pre-morbid radiographs most often are lacking. The main aim of this study was to investigate if CSA or AI were related to the development of RCT or GH OA after 20 years. A secondary aim was to investigate if the CSA and AI had changed over time.
METHODS
In the hospital archive, 273 preoperative plain shoulder radiographs were found of patients scheduled for elective surgery other than cuff repair and arthroplasty. Forty-five images fulfilled the strict criteria published by Suter and Henninger (2015) and were used to measure CSA and AI with two independent assessors. No patient had any sign of OA in the index radiographs or any information in the medical records indicating RCT. After a median of 20 (16-22) years, 30 of these patients were radiologically re-examined with bilateral true frontal views and ultrasound of the rotator cuff. There were 19 men (20 study shoulders) and 11 females (12 study shoulders).
RESULTS
Mean age at follow-up was 56 (32-78) years. There was no correlation between CSA (r = 0.02) (n.s) or AI (r = - 0.13) (n.s) in the primary radiographs and OA at follow-up. Nor was any correlation found between index CSA (r = 0.12) (n.s) or AI (r = - 0.13) (n.s) and RCT at follow-up. Mean difference in CSA was - 1.7 (- 10-3) degrees and mean AI difference was - 0.04 (- 0.13-0.09) between the first and the second radiographs, 20 years later. Bilaterally, mean CSA was 32 and AI 0.61 at follow-up.
CONCLUSION
In this study, no correlation between the CSA, AI and development of OA or RCT could be found. The mean CSA and AI decreased over a 20-year period but the difference was very small. No difference was found between the study shoulders and the contralaterals. These findings question previously reported etiological associations between scapular anatomy and the development of OA or RCT and thereby the use of these calculations as the basis of treatment.
LEVEL OF EVIDENCE
III.
Topics: Acromion; Female; Humans; Male; Rotator Cuff; Rotator Cuff Injuries; Shoulder; Shoulder Joint
PubMed: 34009456
DOI: 10.1007/s00167-021-06602-y -
Frontiers in Public Health 2023In recent studies, individual scapular anatomy has been found to be related to degenerative full-thickness rotator cuff tears. However, research on the relationship...
BACKGROUND
In recent studies, individual scapular anatomy has been found to be related to degenerative full-thickness rotator cuff tears. However, research on the relationship between the anatomical characteristics of shoulder radiographs and bursal-sided partial-thickness rotator cuff tears (PTRCTs) is limited, and the risk factors for this pathology still need to be determined.
METHODS
The bursal-sided PTRCTs group included 102 patients without a history of shoulder trauma who underwent arthroscopy between January 2021 and October 2022. A total of 102 demographically matched outpatients with intact rotator cuffs were selected as the control group. Radiographs were used to measure the lateral acromial angle (LAA), critical shoulder angle (CSA), greater tuberosity angle (GTA), β-angle, acromion index (AI), acromiohumeral distance (AHD), acromial tilt (AT), acromial slope (AS), acromial type, and acromial spur by two independent observers. Multivariate analyses of these data were used to identify potential risk factors for bursal-sided PTRCTs. Receiver operating characteristic (ROC) analysis was performed to assess the sensitivity and specificity of CSA, GTA, and AI for this type of pathology.
RESULT
The β-angle, AHD, AS and acromion type showed no difference between bursal-sided PTRCTs and controls ( = 0.009, 0.200, 0.747 and 0.078, respectively). CSA, GTA and AI were significantly higher in bursal-sided PTRCTs ( < 0.001). LAA, β-angle and AT were significantly lower in bursal-sided PTRCTs. Multivariate logistic regression analysis demonstrated significant correlations between the acromial spur ( = 0.024), GTA ( = 0.004), CSA ( = 0.003) and AI ( = 0.048) and bursal-sided PTRCTs. The areas under the ROC curves for AI, CSA, and GTA were 0.655 (95% CI 0.580-0.729), 0.714 (95% CI 0.644-0.784), and 0.695 (95% CI 0.622-0.767), respectively.
CONCLUSION
Acromial spur, GTA, CSA, and AI were independent risk factors for bursal-sided PTRCTs. Furthermore, CSA was the most powerful predictor of bursal-sided PTRCTs compared to GTA and AI.
Topics: Humans; Shoulder; Rotator Cuff Injuries; Prognosis; Multivariate Analysis; Outpatients
PubMed: 37304102
DOI: 10.3389/fpubh.2023.1189003 -
Journal of Shoulder and Elbow Surgery 1995One hundred consecutive magnetic resonance imaging (MRI) studies of the shoulder obtained for the purpose of evaluating rotator cuff symptoms were retrospectively...
One hundred consecutive magnetic resonance imaging (MRI) studies of the shoulder obtained for the purpose of evaluating rotator cuff symptoms were retrospectively reviewed to assess the relationship between acromion morphologic appearance and rotator cuff disease. The studies were reviewed simultaneously by two authors. Each cuff was assigned a tendon grade and an overall cuff score with MRI criteria previously described in the literature. A newly described "lateral acromion angle" was measured from a specified oblique coronal cut on each MRI study and was correlated with the corresponding MRI-determined rotator cuff score and supraspinatus tendon grade. Observed correlations were analyzed by using statistical methods. The average measured lateral acromion angle was 78 degrees, with a range from 64 degrees to 99 degrees. Eight shoulders had angles less than or equal to 70 degrees, and all eight of these patients were found to have full-thickness rotator cuff tears. As the lateral acromion angle decreased, a statistically significant increase in rotator cuff disease was noted (p < 0.0001). A significant correlation between increasing age and rotator cuff disease was also observed (p < 0.0001). Multiple regression analysis confirmed that both the lateral acromion angle and the age of the patient were independent predictors of rotator cuff score. Finally, although a trend was noted suggesting a correlation between acromion type (I--flat, II--curved, and III--hooked) and MRI-determined rotator cuff disease, this trend did not reach statistical significance (p = 0.12). Surgical correlation with MRI rotator cuff findings in 35 patients showed an MRI sensitivity of 100% and specificity of 83%. A statistically significant correlation between the lateral acromion angle and MRI-determined rotator cuff disease has been noted. The described angle may be a useful adjuvant in the evaluation and management of rotator cuff disease.
Topics: Acromioclavicular Joint; Acromion; Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Bone Diseases; Female; Forecasting; Humans; Joint Diseases; Magnetic Resonance Imaging; Male; Middle Aged; Regression Analysis; Retrospective Studies; Rotator Cuff; Rupture, Spontaneous; Sensitivity and Specificity; Shoulder Joint; Tendinopathy; Tendons
PubMed: 8665291
DOI: 10.1016/s1058-2746(05)80038-2