The subscapularis is a powerful internal rotator which contribute significantly to the shoulder motion but its pathology has only recently been recognized. The injury can occur after trauma or by degenerative aging process. The diagnosis can be made with careful patient assessment including physical examinations and the advanced imaging. The management of the subscapularis tear is dependent on the size and clinical findings but the functional demand of the patient should be considered. Nonoperative treatment is sufficient for partial injury in older patients. However, the patient with full thickness tears with functional loss is need for surgical repair. The prompt dagnosis and the early operation could provide excellent results.
Keywords: Subscapularis; Tears; Diagnosis; Management
Subscapularis tendon tears
Sang Ha Park, Suenghwan Jo, Mohamed Attia, Young Lae Moon
Department of Orthopedics, Chosun University Hospital, Gwangju, Korea
Copyright © 2015 Korean Arthroscopy Society and Korean Orthopedic Society for Sports Medicine. All rights reserved.
CC This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/
by-nc/4.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received June 8, 2015; Revised June 10, 2015; Accepted June 10, 2015
Correspondence to: Young Lae Moon, Department of Orthopedics, Chosun University Hospital, 365 Pilmun-daero, Dong-gu, Gwangju 501-717, Korea. Tel: +82-62-220-3147, Fax: +82-62-226-3379, E-mail: [email protected]
Arthroscopy and Orthopedic Sports Medicine
AOSM
INTRODUCTION
The incidence of subscapularis tear is relatively low (2.1%
to 27.4%) as compare to the tears of supraspinatus or in- fra spinatus and as the treatment of rotator cuff has tra- di tionally focused on supraspinatus tendon, the tear of sub scapularis tendon was less appreciated when the shoulder pathologies were assessed [1,2]. However, with the advent of diagnostic tools such as magnetic resonance imaging (MRI) or ultrasonography, the reported incidence of subscapularis tear has increased rapidly and currently there are growing interest in the diagnosis and the treatment of its pathology [3].
ANATOMY
The subscapularis muscle is the largest and the strongest of the rotator cuff muscles which forms the anterior portion of the rotator cuff and bounded by the axillary space and the coracobrachialis bursa anteriorly [4]. The muscle arises from the anterior scapula at the subscapularis fossa and inserts into the humeral lesser tuberosity by trapezoidal musculotendinous insertion (approximately
60%) superiorly and muscle (approximately 40%) in fe- riorly (Fig. 1) which is divided by anterior humeral cir- cumflex vessels [4,5]. The subscapularis tendon footprint length is about 2.5 cm with mean superior width of 18 mm and inferior width of 3 mm [6].
The superficial layer of the subscapularis has parallel collagen but the deep fibers of the upper subscapularis tendon forms divergent fascicles and the deep layer of the upper group insert into the floor of the bicipital groove [7].
The superior-most insertion which is the lateral portion of the cranial part of the intramuscular tendons, forms a stru- cture that provide direct contact with the biceps tendon and is believed to support the biceps tendon like a trochlea [8]. However, this is also where the most load transmission occurs and the tears are usually initiated from the upper insertion [6].
FUNCTION
The primary role of subscapularis is internally rotating the shoulder which is aided by latissimus dorsi, pec- toralis major and teres major. Another important role is stabilizing the glenohumeral joint by preventing anterior
subluxation and depressing the humeral head [9,10].
The subscapularis, specially the upper portion, is com- posed of dense collagenous framework which enables short excursion and thus the muscle play a role as a passive restraint to external rotation [11]. Together with the supraspinatus and infraspinatus, subscapularis aid shoulder elevation function of the deltoid by restricting shear force. The subscapularis is known to play bigger role in the professional pitchers as compare to amateur throwers implicating the function could differ according to how it is trained [12].
DIAGNOSIS
The diagnosis should be made with careful evaluation of patient history, physical examination and require
advanced radiographic examinations. The detail patient history should be first retrieved. The subscapularis tears are usually presented with anterior shoulder pain and the patients commonly complains of difficulty in reaching for objects or tucking in shirts. The tenderness is typically noted at the coracoid tip. The causes of subscapularis tendon tears are mostly degenerative in nature [13]. However, the tear can also occur from trauma by direct blow, fall on extended shoulder position, hyper- extension on abducted position and after dislocation therefore history of traumatic event should be taken into consideration [14,15].
The tear of the subscapularis muscle is often difficult to detect with one specific physical examination as this is not the sole structure contributing to internal rotation.
Also, the subscapularis tear usually occur in combination Fig. 1. Illustratation of subscapularis tendon (A) and its footprint (B).
A B
Fig. 2. Physical examinations of sub sca- pu laris tear: belly-press test (A) and lift off test (B).
A B
with supraspinatus tear and often extend to biceps long head which confuses examiner for specific diagnosis.
The clinical examination findings are those of increased passive external rotation and decreased internal rotation strength in comparison to the normal side. There are several physical exams useful in diagnosis of sub sca- pularis injury (Fig. 2) [16]. The upper and lower portions of the subscapularis muscles are respectively activated by specific belly-press and lift-off tests [17].
The lift-off test should be performed after identifying that the patient do not have limitation of internal rotation as the exam start with the hand placed on patient’s back at the mid lumbar spine [18]. The hand is slowly paused away from the body while the pain and the strength is monitored. In the other hand, the belly-press test requires less internal rotation to start with and the patient usually feels more comfortable. The wrist and the elbow should be locked while the patient press against the belly and if the patient complains of pain or requires wrist flexion during the exam, subscapularis pathology should be considered [14]. Similar test can be done with the hand positioned on the belly and pushing elbow anteriorly (Napoleon test).
Lastly, the bear hug test can be performed by bringing the hand over to the opposite shoulder. The patient pushes the hand against the examiner’s hand on the opposite shoulder to check if the pain is provocated [19]. The patient with subscapularis tear typically feels pain or weakness during the examination. However, the diagnosis of partial subscapularis tear or tear involving only superior portion has relatively low diagnostic specificity with the physical examination.
Full radiographic evaluations such as plain radiographs, MRI (Fig. 3), ultrasonography can further aid diagnosis [20].
The routine shoulder X-rays including anteroposterior, axillary, lateral and outlet views are often nonspecific. The MRI is recognized to be the imaging study of choice but the preoperative diagnosis of subscapularis is reported to be as low as 31% even with the advanced imaging [21]. As intact cuff fibers may persist in the partial thickness tears or as the regenerated scar tissue, it is important to review the images in multiple planes [15,21]. Abnormally high signal intensity in T2-weighted MRI is indicative of tear but the diagnosis should not be made without complete discontinuity of the tendon as simple tendinosis can be misdiagnosed as tear. As with the diagnosis of other rotator cuff pathologies, magnetic resonance arthro- graphy could increase the sensitivity and the specificity of detecting subscapularis lesions [22]. Also, at the time of the diagnosis, the muscle atrophy and fatty degeneration should be noted as they are the important predictors of the surgical outcome [2,23].
The use of ultrasound is a relatively inexpensive, less time-consuming study that can provide dynamic evalua- tion but the diagnostic accuracy depends largely on the skill of the surgeon/radiologist.
THE ROLE OF BICEPS
Due to the close anatomical relationship, subscapularis tendon tear is often associated with biceps long head pa thologies [11]. The most important stabilizer of the biceps long head is reported to be the reflection pulley
Fig. 3. Magnetic resonance imaging of subscapularis tendon tear (arrows): axial section (A) and oblique coronal section (B).
A B
which is consist of superior glenohumeral ligament and coracohumeral ligament [24,25]. As this pulley is in direct contact with the superior-most insertion of the subscapularis tendon as was described previously, it is evident that this portion of the subscapularis support the biceps tendon. According to the previous literature, the degenerative tear of the subscapularis initiates from the upper portion and it is likely that the subscapularis tendon tear would be accompanied by biceps instability [8,26].
Multiple studies showed close correlation between sub- scapularis tear and the unstable biceps tendons [27,28].
CLASSIFICATION
Numerous classification has been proposed to classified the subscapularis tear depending on size of the tear, presence of coracoid impingement and fatty degeneration.
Current classification systems for subscapularis tears focus on involvement of the tendinous insertion in the form of partial thickness (articular, bursal side, intratendinous) or full thickness tears and depends on the tear size (Table 1) [29,30].
TREATMENT
Management of subscapularis tendon tears is dependent
on the size and clinical findings but more importantly, functional demand of the patient should be taken into account. Conservative management include cold or heat therapy, pain medications such as nonsteroidal anti- inflammatory drugs, local injections, or physiotherapy is indicated for low demand and elderly patients with partial subscapularis tendon tears. In the patients with significant pain and disability even after conservative management for 3 to 6 months, chronic subscapularis tendon tear and full thickness tendon tear, open or arthroscopic surgical repair is indicated [31]. It should be noted that the fatty degeneration and the muscle atrophy can result in poor result and like in supraspinatus the partial subscapularis lesion is opt to progress to larger tear. Therefore, early ope- rative intervention may provide better result in properly selected patients [2].
The subscapularis tendon tears can be particularly diffi- cult to repair for 3 reasons. First, the chronic subscapularis tear tends to retract. Second, scar against the coracoids from retracted torn tendons are in close proximity to important neurovascular structures. Third, arthroscopic manipulation in the tightly constricted subcoracoid space can be a hard tasks [32–34].
The open repair can be performed with the patient in a beach chair or supine position and using deltopectoral or deltoid splitting approach. Arthroscopic technique for subscapularis repair can be performed with patient in a lateral recumbent position or in beach chair position. The arthroscope is introduced from a posterior portal [35], and through working ventral and anterosuperolateral portals, the initial diagnostic arthroscopy is carried out. The foot print of the subscapularis can be visualized with the
Fig. 4. Arthroscopic finding of subscapularis tendon tear.
Table 1. Classification of subscapularis tendon tears
Grade Size of tear (mm) % of tendon thickness I
II III
< 3 3–6
> 6
< 25 25–50
> 50
shoulder in abducted and internally rotated position. The use of 70 degree scope or utilizing “posterior lever push”
maneuver as described by Burkhart et al could improve visualization of lesion [32]. The subscapularis tendon is than mobilized and prepared at the insertion site (Fig. 4) [36]. Subsequently, a suture anchor is inserted through the anterior portal. The senior author (Y.L.M.) recommend the repair using mattress suture technique to stitch the tendon firmly to the lesser tuberosity (Fig. 5) [35,37]. The treatment of the retracted subscapularis is often difficult to manage with arthroscopy and may require additional procedures. The coracoid tip and the neck can be skele- tonized to free attachments of the retracted tendons and
“interval slide in continuity” maneuver can be used by resecting rotator interval and coracohumeral ligament [38].
Recent study by Ide et al. [39] recommended coracoplasty when coracohumeral interval is less than 6 mm to prevent impingement.
As was described previously, subscapularis tendon tears is commonly associated with biceps pathologies and therefore it is important to assess the bicipital groove during the arthroscopic procedure [40]. In a case with severe tendinopathy or medial dislocation, biceps teno- tomy or tenodesis can be performed [41]. Tenotomy is the procedure of choice for inactive patients 60 years or older with a ruptured biceps tendon [42]. Tenodesis is a reasonable option for patients younger than 60 years, as well as active patients, athletes, manual laborers [43].
Following the repair, the patients are placed in abduc- tion brace and limit external rotation for 4 to 6 weeks. The
gradual increase in range of motion and the strengthening exercise is then followed.
The result of the subscapularis tear treatments are satisfactory with poor result in significantly older and ten- don retracted patients. However the results were superior using when arthroscopic technique was used (80% to 92%
satisfactory) as compare to open surgical method (42%
satisfactory) [14,27,33,39,44–46].
CONCLUSION
Subscapularis tendon tears can frequently cause mor- bi dity in a wide range of individuals. There are many options for managing subscapularis tear but the treat- ment modality should depend on the size and site of the tear as well as individual patient needs. Nonoperative treat ment in the form of pain medications and physio- therapy is sufficient for partial tendon tears. However in the case with significant pain, disability, full thickness subscapularis tendon tears surgical repair maybe nece- ssary. In such cases, early recognition and repair can provide excellent results. Although technically deman- ding, arthroscopic management can provide better visu- ali zation and decreased morbidity.
CONFLICT OF INTEREST
No potential conflict of interest relevant to this article was reported.
Fig. 5. Anchor sutures for subscapularis tendon repair. After anchor insertion (A) and after subscapularis repair (B).
A B
1. Flury MP, John M, Goldhahn J, Schwyzer HK, Simmen BR.
Rupture of the subscapularis tendon (isolated or in combination with supraspinatus tear): when is a repair indicated? J Shoulder Elbow Surg 2006;15:659-64.
2. Warner JJ, Higgins L, Parsons IM 4th, Dowdy P. Diagnosis and treatment of anterosuperior rotator cuff tears. J Shoulder Elbow Surg 2001;10:37-46.
3. Goldberg B. Minimally invasive shoulder and elbow surgery. Med Sci Sports Exerc 2007;39:1679.
4. Hinton MA, Parker AW, Drez D Jr, Altcheck D. An anatomic study of the subscapularis tendon and myotendinous junction. J Shoulder Elbow Surg 1994;3:224-9.
5. Scheibel M, Habermeyer P. Subscapularis dysfunction following anterior surgical approaches to the shoulder. J Shoulder Elbow Surg 2008;17:671-83.
6. Richards DP, Burkhart SS, Tehrany AM, Wirth MA. The sub sca- pularis footprint: an anatomic description of its insertion site.
Arthroscopy 2007;23:251-4.
7. Clark JM, Harryman DT 2nd. Tendons, ligaments, and capsule of the rotator cuff. Gross and microscopic anatomy. J Bone Joint Surg Am 1992;74:713-25.
8. Arai R, Sugaya H, Mochizuki T, Nimura A, Moriishi J, Akita K.
Subscapularis tendon tear: an anatomic and clinical investigation.
Arthroscopy 2008;24:997-1004.
9. Morag Y, Jamadar DA, Miller B, Dong Q, Jacobson JA. The sub- scapularis: anatomy, injury, and imaging. Skeletal Radiol 2011;
40:255-69.
10. Inman VT, Saunders JB, Abbott LC. Observations of the function of the shoulder joint. 1944. Clin Orthop Relat Res 1996;(330):3- 12.
11. Lyons RP, Green A. Subscapularis tendon tears. J Am Acad Orthop Surg 2005;13:353-63.
12. Gowan ID, Jobe FW, Tibone JE, Perry J, Moynes DR. A compara- tive electromyographic analysis of the shoulder during pitching.
Professional versus amateur pitchers. Am J Sports Med 1987;
15:586-90.
13. Kreuz PC, Remiger A, Lahm A, Herget G, Gächter A. Comparison of total and partial traumatic tears of the subscapularis tendon. J Bone Joint Surg Br 2005;87:348-51.
14. Gerber C, Hersche O, Farron A. Isolated rupture of the sub sca- pularis tendon. J Bone Joint Surg Am 1996;78:1015-23.
15. Deutsch A, Altchek DW, Veltri DM, Potter HG, Warren RF. Trau- matic tears of the subscapularis tendon. Clinical diagnosis, magnetic resonance imaging findings, and operative treatment.
Am J Sports Med 1997;25:13-22.
16. Levine WN, Blaine TA, Ahmad C. Minimally invasive shoulder and elbow surgery. Med Sci Sports Exerc 2007;39:1679.
17. Tokish JM, Decker MJ, Ellis HB, Torry MR, Hawkins RJ. The belly- press test for the physical examination of the subscapularis muscle: electromyographic validation and comparison to the lift- off test. J Shoulder Elbow Surg 2003;12:427-30.
18. Gerber C, Krushell RJ. Isolated rupture of the tendon of the subscapularis muscle. Clinical features in 16 cases. J Bone Joint Surg Br 1991;73:389-94.
19. Barth JR, Burkhart SS, De Beer JF. The bear-hug test: a new and sensitive test for diagnosing a subscapularis tear. Arthroscopy 2006;22:1076-84.
20. Stevenson JH, Trojian T. Evaluation of shoulder pain. J Fam Pract 2002;51:605-11.
21. Tung GA, Yoo DC, Levine SM, Brody JM, Green A. Subscapularis tendon tear: primary and associated signs on MRI. J Comput Assist Tomogr 2001;25:417-24.
22. Pfirrmann CW, Zanetti M, Weishaupt D, Gerber C, Hodler J.
Subscapularis tendon tears: detection and grading at MR arthrography. Radiology 1999;213:709-14.
23. Goutallier D, Postel JM, Bernageau J, Lavau L, Voisin MC. Fatty muscle degeneration in cuff ruptures. Pre- and postoperative evaluation by CT scan. Clin Orthop Relat Res 1994;(304):78-83.
24. Walch G, Nove-Josserand L, Levigne C, Renaud E. Tears of the supraspinatus tendon associated with "hidden" lesions of the rotator interval. J Shoulder Elbow Surg 1994;3:353-60.
25. Gerber C, Sebesta A. Impingement of the deep surface of the subscapularis tendon and the reflection pulley on the antero- superior glenoid rim: a preliminary report. J Shoulder Elbow Surg 2000;9:483-90.
26. Sakurai G, Ozaki J, Tomita Y, Kondo T, Tamai S. Incomplete tears of the subscapularis tendon associated with tears of the supraspinatus tendon: cadaveric and clinical studies. J Shoulder Elbow Surg 1998;7:510-5.
27. Maier D, Jaeger M, Suedkamp NP, Koestler W. Stabilization of the long head of the biceps tendon in the context of early repair of traumatic subscapularis tendon tears. J Bone Joint Surg Am 2007;89:1763-9.
28. Walch G, Nové-Josserand L, Boileau P, Levigne C. Subluxations and dislocations of the tendon of the long head of the biceps. J Shoulder Elbow Surg 1998;7:100-8.
29. Yoo JC, Rhee YG, Shin SJ, et al. Subscapularis tendon tear classi- fication based on 3-dimensional anatomic footprint: a cadaveric and prospective clinical observational study. Arthroscopy 2015;
31:19-28.
30. Matava MJ, Purcell DB, Rudzki JR. Partial-thickness rotator cuff tears. Am J Sports Med 2005;33:1405-17.
31. Iannotti JP, Williams GR. Disorders of the shoulder: diagnosis and management. Philadelphia, PA: Lippincott Williams & Wilkins;
2007.
32. Burkhart SS, Brady PC. Arthroscopic subscapularis repair: surgical tips and pearls A to Z. Arthroscopy 2006;22:1014-27.
33. Adams CR, Schoolfield JD, Burkhart SS. The results of arthro- scopic subscapularis tendon repairs. Arthroscopy 2008;24:1381- 9.
34. Adams CR, Schoolfield JD, Burkhart SS. Accuracy of preoperative magnetic resonance imaging in predicting a subscapularis tendon tear based on arthroscopy. Arthroscopy 2010;26:1427- 33.
35. Musil D, Sadovský P, Stehlík J. Arthroscopic repair of sub scapularis tendon tear. Acta Chir Orthop Traumatol Cech 2010;77:228-34.
36. Apreleva M, Ozbaydar M, Fitzgibbons PG, Warner JJ. Rotator cuff tears: the effect of the reconstruction method on three-
REFERENCES
dimensional repair site area. Arthroscopy 2002;18:519-26.
37. Lajtai G. Shoulder arthroscopy and MRI techniques: 20 tables.
Berlin: Springer Science & Business Media; 2003.
38. Lo IK, Burkhart SS. Arthroscopic repair of massive, contracted, immobile rotator cuff tears using single and double interval slides: technique and preliminary results. Arthroscopy 2004;20:
22-33.
39. Ide J, Tokiyoshi A, Hirose J, Mizuta H. Arthroscopic repair of traumatic combined rotator cuff tears involving the subscapularis tendon. J Bone Joint Surg Am 2007;89:2378-88.
40. Bennett WF. Arthroscopic repair of isolated subscapularis tears:
a prospective cohort with 2- to 4-year follow-up. Arthroscopy 2003;19:131-43.
41. Romeo AA, Mazzocca AD, Tauro JC. Arthroscopic biceps teno-
desis. Arthroscopy 2004;20:206-13.
42. Patton WC, McCluskey GM 3rd. Biceps tendinitis and subluxation.
Clin Sports Med 2001;20:505-29.
43. Burkhart SS, Tehrany AM. Arthroscopic subscapularis tendon repair: technique and preliminary results. Arthroscopy 2002;18:
454-63.
44. Defranco MJ, Higgins LD, Warner JJ. Subscapularis management in open shoulder surgery. J Am Acad Orthop Surg 2010;18:707- 17.
45. Edwards TB, Walch G, Nové-Josserand L, et al. Arthroscopic debridement in the treatment of patients with isolated tears of the subscapularis. Arthroscopy 2006;22:941-6.
46. Lafosse L, Boyle S. Arthroscopic Latarjet procedure. J Shoulder Elbow Surg 2010;19(2 Suppl):2-12.
