Association between the Critical Shoulder Angle and Non-traumatic Rotator Cuff Tears

Background: Moor et al. developed a critical shoulder angle (CSA) as a radiological parameter for the development of rotator cuff injury and degenerative changes of the glenohumeral joint. The objective of this study is to evaluate the association between CSA and the development of non-traumatic rotator cuff tears (RCTs) to further validate this study. Materials and Methods: The study was performed as an observational study dividing subjects into control and study groups, differing in the presence of non-traumatic RCT. The study group comprised 50 subjects with 40 subjects in the control group. All acceptable radiographs were evaluated, to measure the CSA in accordance with Moor et al. Results: The mean CSA of control subjects was 31.79° (± 1.89°), while that of study subjects were 37.85° (± 2.25°). The relative variability in the control group was about 6% and that in the study group was also 6%, indicating internal homogeneity of the study groups. Chi-square test applied to the distribution gave a P = 0.00001, representing an excellent association between the study groups and the CSA. Conclusion: There is a significant association between larger CSA and RCTs (P = 0.00001). Individual (quantitative) anatomical parameters may imply altered biomechanics, which are likely to induce RCTs, independent of trauma and degenerative glenohumeral joint disease.

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Risk Factors, Pathobiomechanics and Physical Examination of Rotator Cuff Tears

The Open Orthopaedics Journal ◽

10.2174/1874325001610010277 ◽

2016 ◽

Vol 10 (1) ◽

pp. 277-285 ◽

Cited By ~ 6

Author(s):

Samuel G. Moulton ◽

Joshua A. Greenspoon ◽

Peter J. Millett ◽

Maximilian Petri

Keyword(s):

Risk Factors ◽

Rotator Cuff ◽

Physical Examination ◽

Diagnostic Accuracy ◽

Literature Search ◽

Glenohumeral Joint ◽

Rotator Cuff Tears ◽

Critical Shoulder Angle ◽

Common Risk Factors ◽

Shoulder Angle

Background: It is important to appreciate the risk factors for the development of rotator cuff tears and specific physical examination maneuvers. Methods: A selective literature search was performed. Results: Numerous well-designed studies have demonstrated that common risk factors include age, occupation, and anatomic considerations such as the critical shoulder angle. Recently, research has also reported a genetic component as well. The rotator cuff axially compresses the humeral head in the glenohumeral joint and provides rotational motion and abduction. Forces are grouped into coronal and axial force couples. Rotator cuff tears are thought to occur when the force couples become imbalanced. Conclusion: Physical examination is essential to determining whether a patient has an anterosuperior or posterosuperior tear. Diagnostic accuracy increases when combining a series of examination maneuvers.

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Could superior capsule findings be used as a predictor for partial bursal-sided rotator cuff tears?

Journal of Orthopaedic Surgery ◽

10.1177/2309499019895153 ◽

2020 ◽

Vol 28 (1) ◽

pp. 230949901989515 ◽

Cited By ~ 1

Author(s):

Ulunay Kanatlı ◽

Tacettin Ayanoglu ◽

Erdinc Esen ◽

Baybars Ataoglu ◽

Mustafa Ozer ◽

...

Keyword(s):

Rotator Cuff ◽

Glenohumeral Joint ◽

Arthroscopic Treatment ◽

Rotator Cuff Tears ◽

Subacromial Impingement Syndrome ◽

Control Group ◽

Study Group ◽

Coracoacromial Ligament ◽

Cuff Tear ◽

Significant Difference

Purpose: The purpose of this study was to investigate the relationship between the superior capsule tear patterns and synovitis with subacromial pathologies, such as bursal-sided rotator cuff tear and subacromial impingement syndrome. Methods: Fifty patients who underwent arthroscopic treatment for isolated bursal-sided tear were included in the study. Fifty more patients who underwent arthroscopic treatment for isolated Superior Labrum Anterior Posterior (SLAP) 2 lesion without pathology in the rotator cuff were included in the control group. Firstly, superior capsule tear and common synovitis on the rotator cable were assessed during glenohumeral joint examination. Coracoacromial Ligament (CAL) degeneration grading was performed according to the Royal Berkshire Hospital classification. Bursal-sided partial tear grading was done using Ellman classification. Whether or not there was a relationship between synovitis, classic capsule tear, plus reverse flap capsule tear, and partial bursal-sided tear existence. Results: There were 21 patients with reverse flap capsule tear in the study group and 3 patients in the control group. In addition, there were 13 patients with synovitis in the study group and 4 in the control group. Compared to the control group, there was also a significant positive correlation in the presence of both synovitis and reverse flap capsule tear with the presence of bursal-sided tear in the study group ( p = 0.000). There was, however, no significant difference between the presence of classical capsule tear and the presence of bursal-sided tear ( p = 0.485). Conclusion: This study shows that the presence of reverse flap capsule tear and synovitis was associated with partial bursal-sided tears. Therefore, if the reverse flap capsule tear or synovitis is detected in the superior capsule, the rotator cuff should be evaluated in more detail during subacromial bursoscopy in order not to miss a bursal-sided partial cuff tear.

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Critical shoulder angle is associated with full-thickness rotator cuff tears in patients with glenohumeral osteoarthritis

Journal of Shoulder and Elbow Surgery ◽

10.1016/j.jse.2017.05.020 ◽

2017 ◽

Vol 26 (12) ◽

pp. e376-e381 ◽

Cited By ~ 22

Author(s):

Matthew T. Mantell ◽

Ryan Nelson ◽

Jeremiah T. Lowe ◽

Donald P. Endrizzi ◽

Andrew Jawa

Keyword(s):

Rotator Cuff ◽

Rotator Cuff Tears ◽

Full Thickness ◽

Critical Shoulder Angle ◽

Glenohumeral Osteoarthritis ◽

Shoulder Angle

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Relationship Between Deltoid and Rotator Cuff Muscles During Dynamic Shoulder Abduction: A Biomechanical Study of Rotator Cuff Tear Progression

The American Journal of Sports Medicine ◽

10.1177/0363546518768276 ◽

2018 ◽

Vol 46 (8) ◽

pp. 1919-1926 ◽

Cited By ~ 13

Author(s):

Felix Dyrna ◽

Neil S. Kumar ◽

Elifho Obopilwe ◽

Bastian Scheiderer ◽

Brendan Comer ◽

...

Keyword(s):

Rotator Cuff ◽

Dynamic Testing ◽

Correlation Coefficients ◽

Biomechanical Study ◽

Rotator Cuff Tears ◽

Shoulder Abduction ◽

Mean Values ◽

Critical Shoulder Angle ◽

Anterior Deltoid ◽

Shoulder Angle

Background: Previous biomechanical studies regarding deltoid function during glenohumeral abduction have primarily used static testing protocols. Hypotheses: (1) Deltoid forces required for scapular plane abduction increase as simulated rotator cuff tears become larger, and (2) maximal abduction decreases despite increased deltoid forces. Study Design: Controlled laboratory study. Methods: Twelve fresh-frozen cadaveric shoulders with a mean age of 67 years (range, 64-74 years) were used. The supraspinatus and anterior, middle, and posterior deltoid tendons were attached to individual shoulder simulator actuators. Deltoid forces and maximum abduction were recorded for the following tear patterns: intact, isolated subscapularis (SSC), isolated supraspinatus (SSP), anterosuperior (SSP + SSC), posterosuperior (infraspinatus [ISP] + SSP), and massive (SSC + SSP + ISP). Optical triads tracked 3-dimensional motion during dynamic testing. Fluoroscopy and computed tomography were used to measure critical shoulder angle, acromial index, and superior humeral head migration with massive tears. Mean values for maximum glenohumeral abduction and deltoid forces were determined. Linear mixed-effects regression examined changes in motion and forces over time. Pearson product-moment correlation coefficients ( r) among deltoid forces, critical shoulder angles, and acromial indices were calculated. Results: Shoulders with an intact cuff required 193.8 N (95% CI, 125.5 to 262.1) total deltoid force to achieve 79.8° (95% CI, 66.4° to 93.2°) of maximum glenohumeral abduction. Compared with native shoulders, abduction decreased after simulated SSP (–27.2%; 95% CI, –43.3% to –11.1%, P = .04), anterosuperior (–51.5%; 95% CI, –70.2% to –32.8%, P < .01), and massive (–48.4%; 95% CI, –65.2% to –31.5%, P < .01) cuff tears. Increased total deltoid forces were required for simulated anterosuperior (+108.1%; 95% CI, 68.7% to 147.5%, P < .01) and massive (+57.2%; 95% CI, 19.6% to 94.7%, P = .05) cuff tears. Anterior deltoid forces were significantly greater in anterosuperior ( P < .01) and massive ( P = .03) tears. Middle deltoid forces were greater with anterosuperior tears ( P = .03). Posterior deltoid forces were greater with anterosuperior ( P = .02) and posterosuperior ( P = .04) tears. Anterior deltoid force was negatively correlated ( r = −0.89, P = .01) with critical shoulder angle (34.3°; 95% CI, 32.0° to 36.6°). Deltoid forces had no statistical correlation with acromial index (0.55; 95% CI, 0.48 to 0.61). Superior migration was 8.3 mm (95% CI, 5.5 to 11.1 mm) during testing of massive rotator cuff tears. Conclusion: Shoulders with rotator cuff tears require considerable compensatory deltoid function to prevent abduction motion loss. Anterosuperior tears resulted in the largest motion loss despite the greatest increase in deltoid force. Clinical Relevance: Rotator cuff tears place more strain on the deltoid to prevent abduction motion loss. Fatigue or injury to the deltoid may result in a precipitous decline in abduction, regardless of tear size.

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Critical shoulder angle is an effective radiographic parameter that is associated with rotator cuff tears and osteoarthritis: a systematic review

Journal of ISAKOS Joint Disorders & Orthopaedic Sports Medicine ◽

10.1136/jisakos-2018-000255 ◽

2019 ◽

Vol 4 (2) ◽

pp. 113-120

Author(s):

Gabriel Kuper ◽

Ajaykumar Shanmugaraj ◽

Nolan S Horner ◽

Seper Ekhtiari ◽

Nicole Simunovic ◽

...

Keyword(s):

Systematic Review ◽

Rotator Cuff ◽

Predictive Value ◽

Rotator Cuff Tears ◽

Radiographic Parameter ◽

Rater Reliability ◽

Critical Shoulder Angle ◽

Patient Reported ◽

Shoulder Angle ◽

Shoulder Pathologies

ImportanceThe critical shoulder angle (CSA) is a relatively new radiographic parameter correlated with pathologies such as rotator cuff tears and osteoarthritis.ObjectiveThe purpose of this systematic review was to: (1) determine the degree of correlation between the CSA and shoulder pathologies, (2) determine the reliability of measuring CSA between (inter-rater reliability) and within (intrarater reliability) clinicians, (3) assess the accuracy of different imaging modalities used for measuring the CSA and (4) determine the association of CSA with patient outcomes after surgery.Evidence reviewThe electronic databases MEDLINE, EMBASE and PubMed were searched in March 2018 for relevant studies. The results are presented in a narrative summary.FindingsA total of 26 studies and 4563 patients satisfied the inclusion criteria. The majority of CSAs were measured using radiographs (98.2%) in neutral rotation (72.9%). Significant associations (p<0.05) were found between lower CSAs (<30°) and osteoarthritis, and higher CSAs (>35°) with primary rotator cuff tears and the risk of re-tear following a repair. The CSA has excellent intrarater (intraclass correlation coefficient (ICC) 0.903 to 0.996) and inter-rater reliability (ICC 0.869 to 0.980) when measured with radiographs. High variability in measurements was found when using MRI. The CSA, however, is not a clear, significant independent predictor (p>0.05) of outcomes after the surgical management of shoulder pathologies.Conclusions and relevanceThe CSA is an effective radiographic parameter that is associated with rotator cuff tears and osteoarthritis. Lower CSAs (<30°) are associated with osteoarthritis, whereas higher CSAs (>35°) are associated with primary rotator cuff tears and re-tear after arthroscopic repair. Currently, there is a limited predictive value of the CSA in patient-reported outcomes after rotator cuff repair. The CSA is measured with high intrarater and inter-rater reliability for both radiographs and CT scans. Measuring the CSA using radiographs with the arm in the neutral rotation is currently recommended. Future studies are required to further investigate how best use the CSA to guide patient management and its predictive value.Level of evidenceIV.

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The Critical Shoulder Angle is Predictive of Rotator Cuff Tears and Shoulder Osteoarthritis and is Better Assessed with Radiographs over MRI

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967114s00017 ◽

2014 ◽

Vol 2 (3_suppl) ◽

pp. 2325967114S0001

Author(s):

Ulrich Spiegl ◽

Marilee P. Horan ◽

W Sean Smith ◽

Charles P. Ho ◽

Peter J. Millett

Keyword(s):

Rotator Cuff ◽

Rotator Cuff Tears ◽

Shoulder Osteoarthritis ◽

Critical Shoulder Angle ◽

Shoulder Angle

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Lateral acromioplasty for correction of the critical shoulder angle

Obere Extremität ◽

10.1007/s11678-020-00578-w ◽

2020 ◽

Vol 15 (3) ◽

pp. 228-232

Author(s):

Mark Tauber ◽

Peter Habermeyer ◽

Nikolaus Zumbansen ◽

Frank Martetschläger

Keyword(s):

Rotator Cuff ◽

Rotator Cuff Repair ◽

Constant Score ◽

Logical Consequence ◽

Clinical Results ◽

Rotator Cuff Tears ◽

Critical Shoulder Angle ◽

Cuff Repair ◽

Shoulder Angle

Abstract The critical shoulder angle (CSA) was introduced as a radiological parameter associated with a higher incidence of rotator cuff tears. As a logical consequence, correcting the CSA together with rotator cuff repair should prevent re-tear and provide reliable and good clinical results. We present an all-arthroscopic technique resecting the lateral edge of the acromion (lateral acromioplasty) in order to reduce and correct the CSA after preoperative planning. Preliminary results from 20 patients with an average age of 62 years after rotator cuff repair are reported showing good clinical outcome with a Constant score of 88 points and no re-tear after an average follow-up of 16 months. The CSA was reduced from 39.7° to 32.1°. Previous concerns regarding weakening of the deltoid origin were not confirmed and there were no complications linked to lateral acromioplasty.

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Critical shoulder angle is intrinsically associated with the development of degenerative shoulder diseases: A systematic review

Orthopedic Reviews ◽

10.4081/or.2020.8457 ◽

2020 ◽

Vol 12 (1) ◽

Author(s):

Dimitrios Stamiris ◽

Stavros Stamiris ◽

Kyriakos Papavasiliou ◽

Michail Potoupnis ◽

Eleftherios Tsiridis ◽

...

Keyword(s):

Systematic Review ◽

Rotator Cuff Tears ◽

Control Group ◽

Cochrane Central Register ◽

Control Groups ◽

Level Of Evidence ◽

Predisposing Factor ◽

Critical Shoulder Angle ◽

Study Results ◽

Shoulder Angle

Aim of this study was to investigate the potential influence of Critical Shoulder Angle (CSA) as a predisposing factor for the development of degenerative full-thickness rotator cuff tears (DRCT) or primary glenohumeral osteoarthritis (PGOA). A systematic review of the Pubmed, Scopus, Mendeley, ScienceDirect and the Cochrane Central Register of Controlled Trials online databases was performed for literature regarding CSA and its association with DRCT and PGOA. In order to evaluate solely the relationship between CSA as a predisposing factor for the development of the aforementioned degenerative shoulder diseases (DSDs), we precluded any study in which traumatic cases were not clearly excluded. Our search strategy identified 289 studies in total, nine of which were eligible for inclusion based on our pre-established criteria. Quality assessment contacted using the Newcastle Ottawa Scale for case-control studies. There were a total of 998 patients with DRCT and 285 patients with PGOA. The control groups consisted of a total of 538 patients. The mean CSA ranged from 33.9° to 41.01° for the DRCT group, from 27.3° to 29.8° for the PGOA group and from 30.2° to 37.28° for the control group. All studies reported statistically significant differences between the DRCT and PGOA groups and the respective control groups. Our study results showed that there is moderate evidence in the literature supporting an intrinsic role of CSA in the development of DSDs. Level of evidence: IV. Systematic review of diagnostic studies, Level II-IV.

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