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Shoulder impingement syndromes
European Journal of Radiology 27 (1998) S42 – S48
Shoulder impingement syndromes Folco Rossi * Italian Olympic Committee Sports Science Institute, Via Campi Sporti6i 46, 00197 Rome, Italy
Abstract Objective: Not all shoulder pain conditions are a consequence of rotator cuff injuries secondary to anterior subacromial impingement. Additional causative forms have been identified and classified as posterosuperior glenoid rim, subcoracoid and suprascapular nerve (at spinoglenoid notch) impingement syndromes. Material and methods: We reviewed 206 consecutive magnetic resonance examinations carried out with conventional T1- and T2-weighted spin-echo and gradient-echo sequences in patients complaining of shoulder pain. Adjunctive sequences were acquired with the involved arm positioned in abduction and external rotation. Results: Anterior subacromial impingement is only one of the possible causes of shoulder disorders. Posterosuperior glenoid rim impingement is the most frequent cause of shoulder pain in young throwers. Subcoracoid and spinoglenoid notch suprascapular nerve impingement are additional forms that must be considered in the differential diagnosis because of their frequent occurrence in routine clinical practice. Conclusion: Magnetic resonance imaging is the most useful diagnostic modality for shoulder disorders. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Shoulder impingement; Soft tissue; Magnetic resonance imaging
1. Introduction The shoulder impingement syndrome is usually a painful condition in which the soft tissues of the subcromial space (bursa, rotator cuff tendons, biceps tendon) are chronically entrapped between the humeral head and the coracoacromial arch (anterior acromion, coracoacromial ligament, acromioclavicular joint). However, this syndrome, suggested by Codman and demonstrated by Neer, does not always account for the whole of shoulder conditions and additional symptomatic impingement syndromes have been hypothesized, identified and finally classified. The four main and most frequent types are: (1) anterior subacromial impingement [1]; (2) posterosuperior glenoid rim impingement [2]; (3) subcoracoid impingement [3]; and (4) suprascapular nerve (at spinoglenoid notch) impingement [4]. Various imaging modalities, especially magnetic resonance imaging (MRI), have yielded very good results in * Present address: Via S. Agatone Papa 34, I-00165 Roma, Italia. Tel.: + 39 6 634859.
the study of these different friction and impingement disorders and this is the subject of our presentation.
2. Materials and methods The images presented in the paper were selected from 206 consecutive MR examinations performed last year in patients who had had shoulder pain for more than 3 months before the first consultation. The patients were 16–70 years old (mean: 41). MR studies were carried out with a .2T permanent magnet and a solenoid collar-shaped receiver coil, the patients positioned supine with the arm in neutral position. T1-weighted spin-echo (TR 500, TR 20) and T2weighted gradient-echo (TR 500, TE 25, FA 50°) were always acquired. The matrix was 256× 256 and the FOV 240 mm; slice thickness was 4–5 mm with no interslice gap. The images were acquired on obliquecoronal, axial and oblique-sagittal planes. The images with the arm totally abduced and extrarotated were acquired, on an axial scout image, on
0720-048X/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII S0720-048X(98)00042-4
F. Rossi / European Journal of Radiology 27 (1998) S42– S48
the sagittal plane. These 4-mm Tl-weighted SE sequences clearly depict and characterize supraspinatus tendon partial tears, as well as labrum and bone injuries. All MR findings were confirmed surgically. 3. Diagnostic considerations and images
3.1. Anterior subacromial impingement syndrome [1,5,6] The shape and orientation of the acromion process and osteophyte at the acromioclavicular joint are usually considered favoring factors. The presence of ossification of the coracoacromial ligament or of an ‘os acromiale’ (Fig. 1) are unusual favoring factors. Three progressive lesion stages have been classified: Stage 1. Occurs in young patients. Histologically, it exibits edema and hemorrhage in the rotator cuff tendons (especially the supraspinatus) and synovial reaction in the bursa (Fig. 2). Stage 2. Generally occurs in patients 20 – 40 years old. Disorders consist of fibrosis and thickening of the bursa and rotator cuff tendons including microscopic and partial tears (Fig. 3).
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Stage 3. Is common in patients over 40. It features complete rotator cuff tears (small, moderate, large, massive) and biceps tendon changes (Fig. 4).
3.2. Posterosuperior glenoid rim impingement syndrome [2,7,8] Humeral retrotorsion much lower than the normal 25–30°, seems to be a favoring pathogenetic factor. This syndrome is frequently complained of by the athletes who practice sports involving repeated forceful overhead abduction and external rotation. Mostly posterior shoulder pain is the main clinical feature, while glenohumeral bone degeneration is seen at radiography (Fig. 5); supraspinatus tendon deep surface tears and posterosuperior glenoid rim and labrum changes (Fig. 6), are also depicted.
3.3. Subcoracoid impingement syndrome [3,9,10] The most important favoring factors are inherent abnormalities in orientation and length of the coracoid process and acquired bone changes in the coracohumeral space components resulting from lesser tuberosity or coracoid process displaced fractures especially if healed in pseudoarthrosis (Fig. 7). Anterior pain over the coracoid results from repeated arm flexion and internal rotation. The continous contact between the coracoid tip and the most prominent part of the lesser tuberosity causes progressive bone degeneration, inflammation of the subscapularis bursa and substance damage of the subscapularis tendon that may develop and result in isolated partial or complete tear (Fig. 8).
3.4. Suprascapular ner6e (at the spinoglenoid notch) impingement syndrome [4,11,12]
Fig. 1. Anterior subacromial impingement syndrome; favoring factors. (A) acromial hook; (B) acromioclavicular osteophyte; (C) coracoacromial ligament ossification; (D) os acromiale.
A calcified or hypertrophic spinoglenoid ligament and excessive nerve angulation, when it curves entering the infraspinatus fossa, are considered important pathogenetic factors of this syndrome. Nerve entrapment from ganglion cysts at the spinoglenoid notch or consequent to local trauma has been reported (Fig. 9). This syndrome has been reported in volleyball players of both genders. Infraspinatus muscle atrophy, decreased strength in external rotation and pain in the posterior and lateral dominant arm are found in 20% of professional players. The syndrome results from gradual frictional degeneration and stretching over the terminal branches of the nerve against the base of the notch during service to try to give the ball a floating trajectory (Fig. 10).
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F. Rossi / European Journal of Radiology 27 (1998) S42– S48
Fig. 2. Stage 1: (A) subacromial bursitis; (B) tendinitis; (C) subacromial subdeltoid bursitis; (D) advanced tendinitis.
Fig. 3. Stage 2: (A) bursal fibrosis; (B) tendinosis; (C–E) rotator cuff partial tear: bursar surface, intratendinous, articular surface.
F. Rossi / European Journal of Radiology 27 (1998) S42– S48
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Fig. 4. Stage 3: Complete rotator cuff tears: (A – D) small, moderate, large, massive (see ‘geyser sign’).
Fig. 5. Posterosuperior glenoid rim impingement syndrome; X-ray features. (A – C) Degenerative glenohumeral bony changes shown in lateral glenoid view.
4. Conclusion Rotator cuff disorders, causing painful shoulder disability, do not always result from the attritional degeneration beneath the coracoacromial arch as described by Neer [1,5]. Other forms of impingement have thus been suggested to try to explain the actual cause of different symptomatic shoulder injuries.
These additional impingement syndromes are much more frequent than it is commonly thought, especially in the posterosuperior glenoid rim which is the most frequent cause of shoulder pain in young sportsmen and women in our experience. MR high diagnostic accuracy has always been confirmed.
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F. Rossi / European Journal of Radiology 27 (1998) S42– S48
Fig. 6. Coronal oblique and sagittal sequences in abduction and extrarotation demonstrate the partial tears of the articular surface of the supraspinatus, the glenoid rim and labrum damage.
Fig. 7. Subcoracoid impingement syndrome favoring factors. (A,B) Inherent coracoid process abnormalities. (C,D) Reduced coracohumeral space from lesser tuberosity and coracoid tip displaced fractures.
F. Rossi / European Journal of Radiology 27 (1998) S42– S48
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Fig. 8. (A,B) Tip coracoid osteophytes and traumatic geodes caused by repeated microtraumas. (C,D) Traumatic subscapularis tendon tear with dislocation of the long biceps tendon (coracohumeral normal width 8.7mm).
Fig. 9. Suprascapular nerve impingement syndrome at spinoglenoid notch. (A) Infraspinatus muscle atrophy in a volleyball player. (B) Synovial ganglion cyst at spinoglenoid notch. (C) Infraspinatus muscle and tendon tear.
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F. Rossi / European Journal of Radiology 27 (1998) S42– S48
Fig. 10. Different degrees of infraspinatus muscle atrophy are shown by axial sequences.
References [1] Neer CS. Anterior acromioplasty for the chronic impingement syndrome in the shoulder: a preliminary report. J Bone Jt Surg Ser A 1972;54:41 – 49. [2] Walch G, Liotard JP, Boileau P, Noel E. Le conflit glenoidien posterosuperieur: un autre conflit de l’epaule. Rev Chir Orthop 1991;77:571 – 574. [3] Goldthwait JE. An anatomic and mechanical study of the shoulder joint, explaining many of the cases of pain shoulder, recurrent dislocations and brachial neuralgias. Am J Orthop Surg 1909;6:579 – 606. [4] Thomas A. La paralyse du muscle susepineux. La Presse Medic 1936;64:1283 – 1284. [5] Neer CS. Impingement lesions. Clin Orthop 1983;173:71 – 77. [6] Sartoris DJ. Principles of Shoulder Imaging. New York: McGraw-Hill, 1995.
.
[7] Rossi F, Ternamian PJ, Cerciello G, Walch G. Il conflitto glenoideo posterosuperiore nell’atleta: valve diagnostico della radiologia tradizionale e della RM. Radiol Med 1994;87:22–27. [8] Tirman PFJ, Bost FW, Garvin GJ, et al. Posterosuperior glenoid impingement of the shoulder: findings at MR imaging and MR arthrography with arthroscopy correlation. Radiology 1994;193:431 – 436. [9] Gerber C, Terrier F, Ganz R. The role of the coracoid process in the chronic impingement syndrome. J Bone Jt Surg Ser A 1985;67B:703 – 708. [10] Patte D. The subcoracoid impingement. Clin Orthop Rel Res 1990;254:55 – 59. [11] Ferretti A, Cerullo G, Russo G. Suprascapular neuropathy in volleyball players. J Bone Jt Surg Ser A 1987;69A:260–263. [12] Rossi F, Barile A. Nervous diseases: spinal and peripheral nerve entrapments. In: Masciocchi C, editor. Radiological Imaging of Sports Injuries. Berlin: Springer Verlag, 1998.
Shoulder impingement syndromes Folco Rossi * Italian Olympic Committee Sports Science Institute, Via Campi Sporti6i 46, 00197 Rome, Italy
Abstract Objective: Not all shoulder pain conditions are a consequence of rotator cuff injuries secondary to anterior subacromial impingement. Additional causative forms have been identified and classified as posterosuperior glenoid rim, subcoracoid and suprascapular nerve (at spinoglenoid notch) impingement syndromes. Material and methods: We reviewed 206 consecutive magnetic resonance examinations carried out with conventional T1- and T2-weighted spin-echo and gradient-echo sequences in patients complaining of shoulder pain. Adjunctive sequences were acquired with the involved arm positioned in abduction and external rotation. Results: Anterior subacromial impingement is only one of the possible causes of shoulder disorders. Posterosuperior glenoid rim impingement is the most frequent cause of shoulder pain in young throwers. Subcoracoid and spinoglenoid notch suprascapular nerve impingement are additional forms that must be considered in the differential diagnosis because of their frequent occurrence in routine clinical practice. Conclusion: Magnetic resonance imaging is the most useful diagnostic modality for shoulder disorders. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Shoulder impingement; Soft tissue; Magnetic resonance imaging
1. Introduction The shoulder impingement syndrome is usually a painful condition in which the soft tissues of the subcromial space (bursa, rotator cuff tendons, biceps tendon) are chronically entrapped between the humeral head and the coracoacromial arch (anterior acromion, coracoacromial ligament, acromioclavicular joint). However, this syndrome, suggested by Codman and demonstrated by Neer, does not always account for the whole of shoulder conditions and additional symptomatic impingement syndromes have been hypothesized, identified and finally classified. The four main and most frequent types are: (1) anterior subacromial impingement [1]; (2) posterosuperior glenoid rim impingement [2]; (3) subcoracoid impingement [3]; and (4) suprascapular nerve (at spinoglenoid notch) impingement [4]. Various imaging modalities, especially magnetic resonance imaging (MRI), have yielded very good results in * Present address: Via S. Agatone Papa 34, I-00165 Roma, Italia. Tel.: + 39 6 634859.
the study of these different friction and impingement disorders and this is the subject of our presentation.
2. Materials and methods The images presented in the paper were selected from 206 consecutive MR examinations performed last year in patients who had had shoulder pain for more than 3 months before the first consultation. The patients were 16–70 years old (mean: 41). MR studies were carried out with a .2T permanent magnet and a solenoid collar-shaped receiver coil, the patients positioned supine with the arm in neutral position. T1-weighted spin-echo (TR 500, TR 20) and T2weighted gradient-echo (TR 500, TE 25, FA 50°) were always acquired. The matrix was 256× 256 and the FOV 240 mm; slice thickness was 4–5 mm with no interslice gap. The images were acquired on obliquecoronal, axial and oblique-sagittal planes. The images with the arm totally abduced and extrarotated were acquired, on an axial scout image, on
0720-048X/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII S0720-048X(98)00042-4
F. Rossi / European Journal of Radiology 27 (1998) S42– S48
the sagittal plane. These 4-mm Tl-weighted SE sequences clearly depict and characterize supraspinatus tendon partial tears, as well as labrum and bone injuries. All MR findings were confirmed surgically. 3. Diagnostic considerations and images
3.1. Anterior subacromial impingement syndrome [1,5,6] The shape and orientation of the acromion process and osteophyte at the acromioclavicular joint are usually considered favoring factors. The presence of ossification of the coracoacromial ligament or of an ‘os acromiale’ (Fig. 1) are unusual favoring factors. Three progressive lesion stages have been classified: Stage 1. Occurs in young patients. Histologically, it exibits edema and hemorrhage in the rotator cuff tendons (especially the supraspinatus) and synovial reaction in the bursa (Fig. 2). Stage 2. Generally occurs in patients 20 – 40 years old. Disorders consist of fibrosis and thickening of the bursa and rotator cuff tendons including microscopic and partial tears (Fig. 3).
S43
Stage 3. Is common in patients over 40. It features complete rotator cuff tears (small, moderate, large, massive) and biceps tendon changes (Fig. 4).
3.2. Posterosuperior glenoid rim impingement syndrome [2,7,8] Humeral retrotorsion much lower than the normal 25–30°, seems to be a favoring pathogenetic factor. This syndrome is frequently complained of by the athletes who practice sports involving repeated forceful overhead abduction and external rotation. Mostly posterior shoulder pain is the main clinical feature, while glenohumeral bone degeneration is seen at radiography (Fig. 5); supraspinatus tendon deep surface tears and posterosuperior glenoid rim and labrum changes (Fig. 6), are also depicted.
3.3. Subcoracoid impingement syndrome [3,9,10] The most important favoring factors are inherent abnormalities in orientation and length of the coracoid process and acquired bone changes in the coracohumeral space components resulting from lesser tuberosity or coracoid process displaced fractures especially if healed in pseudoarthrosis (Fig. 7). Anterior pain over the coracoid results from repeated arm flexion and internal rotation. The continous contact between the coracoid tip and the most prominent part of the lesser tuberosity causes progressive bone degeneration, inflammation of the subscapularis bursa and substance damage of the subscapularis tendon that may develop and result in isolated partial or complete tear (Fig. 8).
3.4. Suprascapular ner6e (at the spinoglenoid notch) impingement syndrome [4,11,12]
Fig. 1. Anterior subacromial impingement syndrome; favoring factors. (A) acromial hook; (B) acromioclavicular osteophyte; (C) coracoacromial ligament ossification; (D) os acromiale.
A calcified or hypertrophic spinoglenoid ligament and excessive nerve angulation, when it curves entering the infraspinatus fossa, are considered important pathogenetic factors of this syndrome. Nerve entrapment from ganglion cysts at the spinoglenoid notch or consequent to local trauma has been reported (Fig. 9). This syndrome has been reported in volleyball players of both genders. Infraspinatus muscle atrophy, decreased strength in external rotation and pain in the posterior and lateral dominant arm are found in 20% of professional players. The syndrome results from gradual frictional degeneration and stretching over the terminal branches of the nerve against the base of the notch during service to try to give the ball a floating trajectory (Fig. 10).
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F. Rossi / European Journal of Radiology 27 (1998) S42– S48
Fig. 2. Stage 1: (A) subacromial bursitis; (B) tendinitis; (C) subacromial subdeltoid bursitis; (D) advanced tendinitis.
Fig. 3. Stage 2: (A) bursal fibrosis; (B) tendinosis; (C–E) rotator cuff partial tear: bursar surface, intratendinous, articular surface.
F. Rossi / European Journal of Radiology 27 (1998) S42– S48
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Fig. 4. Stage 3: Complete rotator cuff tears: (A – D) small, moderate, large, massive (see ‘geyser sign’).
Fig. 5. Posterosuperior glenoid rim impingement syndrome; X-ray features. (A – C) Degenerative glenohumeral bony changes shown in lateral glenoid view.
4. Conclusion Rotator cuff disorders, causing painful shoulder disability, do not always result from the attritional degeneration beneath the coracoacromial arch as described by Neer [1,5]. Other forms of impingement have thus been suggested to try to explain the actual cause of different symptomatic shoulder injuries.
These additional impingement syndromes are much more frequent than it is commonly thought, especially in the posterosuperior glenoid rim which is the most frequent cause of shoulder pain in young sportsmen and women in our experience. MR high diagnostic accuracy has always been confirmed.
S46
F. Rossi / European Journal of Radiology 27 (1998) S42– S48
Fig. 6. Coronal oblique and sagittal sequences in abduction and extrarotation demonstrate the partial tears of the articular surface of the supraspinatus, the glenoid rim and labrum damage.
Fig. 7. Subcoracoid impingement syndrome favoring factors. (A,B) Inherent coracoid process abnormalities. (C,D) Reduced coracohumeral space from lesser tuberosity and coracoid tip displaced fractures.
F. Rossi / European Journal of Radiology 27 (1998) S42– S48
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Fig. 8. (A,B) Tip coracoid osteophytes and traumatic geodes caused by repeated microtraumas. (C,D) Traumatic subscapularis tendon tear with dislocation of the long biceps tendon (coracohumeral normal width 8.7mm).
Fig. 9. Suprascapular nerve impingement syndrome at spinoglenoid notch. (A) Infraspinatus muscle atrophy in a volleyball player. (B) Synovial ganglion cyst at spinoglenoid notch. (C) Infraspinatus muscle and tendon tear.
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F. Rossi / European Journal of Radiology 27 (1998) S42– S48
Fig. 10. Different degrees of infraspinatus muscle atrophy are shown by axial sequences.
References [1] Neer CS. Anterior acromioplasty for the chronic impingement syndrome in the shoulder: a preliminary report. J Bone Jt Surg Ser A 1972;54:41 – 49. [2] Walch G, Liotard JP, Boileau P, Noel E. Le conflit glenoidien posterosuperieur: un autre conflit de l’epaule. Rev Chir Orthop 1991;77:571 – 574. [3] Goldthwait JE. An anatomic and mechanical study of the shoulder joint, explaining many of the cases of pain shoulder, recurrent dislocations and brachial neuralgias. Am J Orthop Surg 1909;6:579 – 606. [4] Thomas A. La paralyse du muscle susepineux. La Presse Medic 1936;64:1283 – 1284. [5] Neer CS. Impingement lesions. Clin Orthop 1983;173:71 – 77. [6] Sartoris DJ. Principles of Shoulder Imaging. New York: McGraw-Hill, 1995.
.
[7] Rossi F, Ternamian PJ, Cerciello G, Walch G. Il conflitto glenoideo posterosuperiore nell’atleta: valve diagnostico della radiologia tradizionale e della RM. Radiol Med 1994;87:22–27. [8] Tirman PFJ, Bost FW, Garvin GJ, et al. Posterosuperior glenoid impingement of the shoulder: findings at MR imaging and MR arthrography with arthroscopy correlation. Radiology 1994;193:431 – 436. [9] Gerber C, Terrier F, Ganz R. The role of the coracoid process in the chronic impingement syndrome. J Bone Jt Surg Ser A 1985;67B:703 – 708. [10] Patte D. The subcoracoid impingement. Clin Orthop Rel Res 1990;254:55 – 59. [11] Ferretti A, Cerullo G, Russo G. Suprascapular neuropathy in volleyball players. J Bone Jt Surg Ser A 1987;69A:260–263. [12] Rossi F, Barile A. Nervous diseases: spinal and peripheral nerve entrapments. In: Masciocchi C, editor. Radiological Imaging of Sports Injuries. Berlin: Springer Verlag, 1998.