Internal Impingement of the Shoulder

Internal impingement of the shoulder is a pathologic condition characterized by excessive or repetitive contact of the greater tuberosity of the humeral head with the posterosuperior aspect of the glenoid when the arm is abducted and externally rotated. This arm positioning leads to rotator cuff and glenoid labrum impingement by the bony structures of the glenohumeral joint. Although some degree of contact between these structures occurs under normal conditions, to date most of the orthopaedic literature has focused on internal impingement as a disease state that affects overhead athletes and is characterized by the development of articular-sided rotator cuff tears and posterosuperior labral lesions. The precise cause of these impingement lesions remains unclear. However, it is believed that varying degrees of glenohumeral instability, posterior capsular contracture, and scapular dyskinesis may play a role in the development of symptomatic internal impingement. The purpose of this article is to review the pathomechanics, clinical complaints, physical examination findings, and imaging findings that are associated with internal impingement. The results of treatment will be reviewed, and a diagnostic and therapeutic algorithm for the management of internal impingement is presented.

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The Area of Impingement in the Throwing Versus Nonthrowing Shoulder of Collegiate Baseball Players: An MRI Study of the Simulated Late-Cocking Phase of Throwing

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967121992133 ◽

2021 ◽

Vol 9 (3) ◽

pp. 232596712199213

Author(s):

Makoto Takahashi ◽

Koji Iwamoto ◽

Masahiko Monma ◽

Hirotaka Mutsuzaki ◽

Masafumi Mizukami

Keyword(s):

Rotator Cuff ◽

Glenohumeral Joint ◽

External Rotation ◽

Rotator Cuff Tears ◽

Shoulder Abduction ◽

Baseball Players ◽

Greater Tuberosity ◽

Internal Impingement ◽

Collegiate Baseball ◽

Cystic Changes

Background: During shoulder abduction and external rotation, internal impingement can occur when compressive forces between the greater tuberosity and the posterior glenoid rim pinch the undersurface of the rotator cuff. Previous studies on internal impingement have focused on qualitative results such as pathological findings; however, few studies have quantified the area of impingement (AOI) of the rotator cuff muscles between the greater tuberosity and the posterior glenoid rim. Purpose: To compare the AOI between the throwing and nonthrowing shoulders of baseball players. Study Design: Controlled laboratory study. Methods: A total of 14 asymptomatic male collegiate baseball players participated in this study. The AOI in both the throwing and the nonthrowing shoulders was calculated using magnetic resonance imaging (MRI) scans. The MRI measurements were collected with the shoulder at 90° of abduction and at 90° and 100° of external rotation. The area, width, and depth of impingement as well as cystic changes in the greater tuberosity and degeneration in the posterior labrum were compared between the throwing and nonthrowing shoulders. Results: The AOI was significantly greater in the throwing shoulders than in the nonthrowing shoulders (90° of external rotation: 32.4 vs 19.1 mm2, respectively; 100° of external rotation, 28.0 vs 15.6 mm2, respectively; P < .001 for both). Compared with the nonthrowing shoulders, there were more positive findings in the throwing shoulders regarding greater tuberosity cystic changes (0 vs 7, respectively; P = .006) and posterior labral degeneration (3 vs 13, respectively; P < .001). Conclusion: The AOI and the number of lesions in the greater tuberosity and posterior labrum were greater in throwing shoulders than in nonthrowing shoulders. Therefore, damage to the insertion of the rotator cuff muscles may affect internal impingement. Clinical Relevance: Lesions in the greater tuberosity and posterior labrum in throwing shoulders may increase the AOI by expanding the joint gap behind the glenohumeral joint. Impingement of the greater tuberosity and the posterior glenoid rim may lead to rotator cuff tears.

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Supraspinatus-to-Glenoid Contact Occurs During Standardized Overhead Reaching Motion

Orthopaedic Journal of Sports Medicine ◽

10.1177/23259671211036908 ◽

2021 ◽

Vol 9 (10) ◽

pp. 232596712110369

Author(s):

Gaura Saini ◽

Rebekah L. Lawrence ◽

Justin L. Staker ◽

Jonathan P. Braman ◽

Paula M. Ludewig

Keyword(s):

Rotator Cuff ◽

Pearson Correlation ◽

Supraspinatus Tendon ◽

Contact Angles ◽

Magnetic Resonance Images ◽

Rotator Cuff Tears ◽

Internal Impingement ◽

Glenoid Morphology ◽

Minimum Distances ◽

The Relationship

Background: Rotator cuff tears may result from repeated mechanical deformation of the cuff tendons, and internal impingement of the supraspinatus tendon against the glenoid is one such proposed mechanism of deformation. Purpose: To (1) describe the changing proximity of the supraspinatus tendon to the glenoid during a simulated overhead reaching task and (2) determine the relationship between scapular morphology and this proximity. Additionally, the patterns of supraspinatus-to-glenoid proximity were compared with previously described patterns of supraspinatus-to-coracoacromial arch proximity. Study Design: Descriptive laboratory study. Methods: Shoulder models were created from magnetic resonance images of 20 participants. Standardized kinematics were imposed on the models to simulate functional reaching, and the minimum distances between the supraspinatus tendon and the glenoid and the supraspinatus footprint and the glenoid were calculated every 5° between 0° and 150° of humerothoracic elevation. The angle at which contact between the supraspinatus and the glenoid occurred was documented. Additionally, the relationship between glenoid morphology (version and inclination) and the contact angle was evaluated. Descriptive statistics were calculated for the minimum distances, and glenoid morphology was assessed using Pearson correlation coefficients and simple linear regressions. Results: The minimum distances between the tendon and the glenoid and between the footprint and the glenoid decreased as elevation increased. Contact between the tendon and the glenoid occurred in all participant models at a mean elevation of 123° ± 10°. Contact between the footprint and the glenoid occurred in 13 of 20 models at a mean of 139° ± 10°. Less glenoid retroversion was associated with lower tendon-to-glenoid contact angles ( r = –0.76; R 2 = 0.58; P < .01). Conclusion: This study found that the supraspinatus tendon progressively approximated the glenoid during simulated overhead reaching. Additionally, all participant models eventually made contact with the glenoid by 150° of humerothoracic elevation, although anatomic factors influenced the precise angle at which contact occurred. Clinical Relevance: Contact between the supraspinatus and the glenoid may occur frequently within the range of elevation required for overhead activities. Therefore, internal impingement may be a prevalent mechanism for rotator cuff deformation that could contribute to cuff pathology.

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Common upper limb musculoskeletal lesions

Oxford Handbook of Rheumatology ◽

10.1093/med/9780198728252.003.0020 ◽

2018 ◽

pp. 595-604

Author(s):

Gavin Clunie ◽

Nick Wilkinson ◽

Elena Nikiphorou ◽

Deepak R. Jadon

Keyword(s):

Rotator Cuff ◽

Upper Limb ◽

Glenohumeral Joint ◽

Tennis Elbow ◽

Adhesive Capsulitis ◽

Lateral Epicondylitis ◽

Glenohumeral Instability ◽

Suprascapular Notch ◽

Long Head ◽

Musculoskeletal Lesions

This chapter introduces readers to some common upper limb musculoskeletal lesions, including subacromial (shoulder) impingement syndrome, adhesive capsulitis, and lateral epicondylitis (tennis elbow). The epidemiology, aetiopathogenesis, clinical presentation, and management of these conditions are presented. Algorithms for their management are provided. Other disorders presenting with a subacromial impingement pattern of pain are detailed and optimal diagnostic imaging methods proposed. These include supraspinatus/cuff tendonitis, subacromial bursitis, rotator cuff tear, long head of biceps tendonitis, osteophyte impingement on the rotator cuff tendon, glenohumeral instability due to labral trauma (e.g. SLAP lesion), arthritis of the glenohumeral joint, enthesitis related to spondyloarthritis, and lesions at the suprascapular notch.

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Prevalence and Site of Rotator Cuff Lesions in Shoulders With Recurrent Anterior Instability in a Young Population

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967119849876 ◽

2019 ◽

Vol 7 (6) ◽

pp. 232596711984987 ◽

Cited By ~ 1

Author(s):

Yusuke Ueda ◽

Hiroyuki Sugaya ◽

Norimasa Takahashi ◽

Keisuke Matsuki ◽

Morihito Tokai ◽

...

Keyword(s):

Rotator Cuff ◽

Arthroscopic Surgery ◽

Case Series ◽

Supraspinatus Tendon ◽

Rotator Cuff Tears ◽

Anterior Instability ◽

Glenohumeral Instability ◽

Anterior Border ◽

Level Of Evidence ◽

Rotator Cuff Lesions

Background: Partial articular supraspinatus tendon avulsion (PASTA) lesions are often seen in shoulders of throwing athletes. PASTA lesions in anterior instability are also found in recurrent anterior glenohumeral instability. Purpose: To investigate the prevalence and location of rotator cuff tears (RCTs), including PASTA lesions, in shoulders with recurrent anterior instability. Study Design: Case series; Level of evidence, 4. Methods: A total of 842 shoulders in 801 patients with recurrent anterior instability (647 men, 154 women; mean age, 24 years; age range, 13-40 years) who underwent arthroscopic surgery at the age of 40 years or younger were enrolled. During surgery, the thickness and the sites of RCTs as well as patient factors associated with RCTs were examined. Results: RCTs were found in 57 shoulders (7%) in 56 patients. There were 4 shoulders with full-thickness RCTs and 53 shoulders with PASTA lesions. All lesions but 1 involved the anterior border of the supraspinatus (SSP). Participation in high-level athletics and older age at injury were associated with RCTs. Conclusion: The incidence of RCTs was 7% in shoulders with recurrent anterior instability at age 40 years or younger. Most RCTs were PASTA lesions that involved the anterior border of the SSP.

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Effect of biceps rerouting technique to restore glenohumeral joint stability for large irreparable rotator cuff tears: a cadaveric biomechanical study

Journal of Shoulder and Elbow Surgery ◽

10.1016/j.jse.2019.11.015 ◽

2020 ◽

Vol 29 (7) ◽

pp. 1425-1434 ◽

Cited By ~ 1

Author(s):

Sang-Yup Han ◽

Thay Q. Lee ◽

David J. Wright ◽

Il-Jung Park ◽

Maniglio Mauro ◽

...

Keyword(s):

Rotator Cuff ◽

Glenohumeral Joint ◽

Biomechanical Study ◽

Rotator Cuff Tears ◽

Joint Stability

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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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In situ repair of partial-thickness rotator cuff tears: a critical analysis review

EFORT Open Reviews ◽

10.1302/2058-5241.5.190010 ◽

2020 ◽

Vol 5 (3) ◽

pp. 138-144

Author(s):

Luciano A. Rossi ◽

Maximiliano Ranalletta

Keyword(s):

Rotator Cuff ◽

Functional Outcomes ◽

Rotator Cuff Tears ◽

Return To Sports ◽

Overhead Athletes ◽

Partial Thickness ◽

Long Term Follow Up ◽

Tendon Thickness ◽

In Situ Repair

After failed conservative management, operative intervention is typically indicated for patients with partial-thickness rotator cuff tears (PTRCTs) with persistent pain and disability symptoms. For PTRCTs involving < 50% of the tendon thickness, debridement with or without acromioplasty resulted in favourable outcomes in most studies. For PTRCTs involving > 50% of the tendon thickness, in situ repair has proven to significantly improve pain and functional outcomes for articular and bursal PTRCTs. The few available comparative studies in the literature showed similar functional and structural outcomes between in situ repair and repair after conversion to full-thickness tear for PTRCTs. Most non-overhead athletes return to sports at the same level as previous to the injury after in situ repair of PTRCTs. However, rates of return to preinjury level of competition for overhead athletes have been generally poor regardless of the utilized technique. During long-term follow-up, arthroscopic in situ repair of articular and bursal PTRCTs produced excellent functional outcomes in most patients, with a low rate of revision. Cite this article: EFORT Open Rev 2020;5:138-144. DOI: 10.1302/2058-5241.5.190010

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Irreparable Rotator Cuff Tears: A Biomechanical Comparison of Superior Capsuloligamentous Complex Reconstruction Techniques and an Interpositional Graft Technique

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967119864590 ◽

2019 ◽

Vol 7 (8) ◽

pp. 232596711986459 ◽

Cited By ~ 1

Author(s):

Tim Leschinger ◽

Katharina Besch ◽

Cansu Aydin ◽

Manfred Staat ◽

Martin Scaal ◽

...

Keyword(s):

Rotator Cuff ◽

Glenohumeral Joint ◽

Supraspinatus Tendon ◽

Rotator Cuff Tears ◽

Neutral Position ◽

Management Options ◽

Significant Difference ◽

Intact Condition ◽

Point Condition ◽

Biomechanical Comparison

Background: Irreparable rotator cuff tears lead to superior translation of the humeral head. Numerous surgical management options are available to treat the condition. Purpose: To compare superior capsule stability among different types of patch grafting in irreparable rotator cuff tears. Methods: Six cadaveric shoulders were tested in a custom-designed shoulder testing system. Superior translation of the humerus and subacromial contact pressure were quantified in an intact condition (condition 1), after cutting the supraspinatus tendon (condition 2), and after additionally cutting the superior capsuloligamentous complex (condition 3). The results were compared among 3 types of patch grafting, in which capsule reconstruction was achieved by glenoidal 3-point (condition 4) or 2-point (condition 5) fixation or by affixing a graft below the acromion (condition 6). Results: No significant difference in subacromial pressure was measured by reconstruction with 2 or 3 anchors compared with conditions 1 and 2 ( P > .05). However, with 3-point fixation, lower levels of pressure were measured than with 2-point fixation. Moreover, superior translation values were lower with 3-point fixation; the same applied for values of the preserved capsule as compared with the torn capsule. In condition 6, a significant increase in pressure in the neutral position was documented ( P < .05). Conclusion: The superior capsuloligamentous complex plays an important role in stabilizing the glenohumeral joint. The results suggest that with additional medial anchoring at the coracoid base, the depressing and centering effect of the superior complex can probably be regained in a more physiological way compared with a reconstructed capsule with 2 glenoid attachments or with an interpositional graft below the acromion.

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