Operative Techniques in Orthopaedic Surgery (4 Volume Set) 1st Edition

365. Subscapularis Repair, Coracoid Recession, and Biceps Tenodesis

Steven Milos and Allen Deutsch

DEFINITION

images Subscapularis tears are less common than supraspinatus or infraspinatus tears. They occur in 2% to 8% of rotator cuff tears and are often missed.5,12

images Subscapularis tears can be.

images Isolated tears (partial or complete)

images Partial-thickness tears

images Anterosuperior (involving the supraspinatus)

images Rotator interval lesions (with associated biceps tendon injury)

images There is a high association of concomitant biceps tendon pathology.12,18

ANATOMY

images The subscapularis is innervated by the upper and lower subscapular nerves (C5–C8). Its origin is at the subscapularis fossa, and the upper two thirds inserts onto the lesser tuberosity, while the inferior third inserts onto the humeral metaphysis.

images The subscapularis is the strongest of the rotator cuff muscles. It acts to internally rotate the humerus along with the teres major, latissimus dorsi, and pectoralis major muscles. It resists anterior and inferior translation of the humeral head.10,17

images The upper fibers of the subscapularis and the anterior fibers of the supraspinatus contribute to the rotator interval as well as the transverse humeral ligament.

images The coracohumeral ligament is the roof of the rotator interval and blends with the supraspinatus and subscapularis. The coracohumeral ligament and the superior glenohumeral ligament are the primary stabilizers of the biceps.2

images The biceps muscle is innervated by the musculocutaneous nerve (C5–C6). It is composed of a long head, which originates from the supraglenoid tubercle, and a short head, which originates from the coracoid process. Both heads insert onto the bicipital tuberosity of the radius and the ulnar fascia of the forearm.

images The long head of the biceps tendon provides superior shoulder stability when the arm is abducted. It also provides posterior shoulder stability when the arm is in midranges of elevation.14,21

images The coracoid is located just anterior to the superior border of the subscapularis. It projects laterally, anteriorly, and inferiorly toward the glenoid.

images The subcoracoid bursa does not communicate with the glenohumeral joint but can communicate with the subacromial bursa.

PATHOGENESIS

images In the young patient, subscapularis tears occur as a result of trauma. The typical mechanisms include hyperextension of an externally rotated arm or forced external rotation of an adducted arm.5,8

images In older patients a tear is typically degenerative in nature, although it may be the result of a glenohumeral dislocation or other trauma.13,15,16

images Frequently, there is associated long head of the biceps pathology. This may include tenosynovitis, subluxation, dislocation, degeneration, or complete rupture.12,19

images Subcoracoid impingement may also be a cause of subscapularis tendon tears.

NATURAL HISTORY

images Isolated subscapularis tendon ruptures are relatively rare. Subscapularis tears are often associated with tears of the supraspinatus and infraspinatus.

images One study found that subscapularis tears occur in 8% of rotator cuff tears.7

images An MRI study was performed on 2167 patients with rotator cuff tears.12

images 2% of the patients had subscapularis tendon tears.

images 27% of those tears were partial-thickness tears and 73% were full-thickness tears.

images One study found a high correlation between subscapularis tendon tears and medial biceps subluxation, biceps tendinopathy, superior labral pathology, and fluid within the subscapular recess or the subcoracoid space.12,18

images The above-listed MRI study found that 25 of the 45 patients with subscapularis tendon tears had associated biceps pathology.

PHYSICAL FINDINGS

images Patients with complete tears of the subscapularis have increased passive external rotation compared with the unaffected shoulder.

images Several muscles contribute to internal rotation of the shoulder, including the pectoralis major, latissimus dorsi, and teres major, and can compensate for loss of the subscapularis.

images Passive external rotation: Increased passive external rotation may indicate a complete rupture of the subscapularis.

images Passive forward flexion, external rotation, and internal rotation: Limited passive range of motion is indicative of adhesive capsulitis.

images Active forward flexion: Limited active forward flexion is indicative of a possible large rotator cuff tear.

images The lift-off test isolates the subscapularis muscle. Inability to lift the hand off the back is a positive test.

images Internal rotation lag sign11 : The examiner measures the lag between maximal internal rotation and the amount the patient can maintain. A positive sign shows increased sensitivity over the classic lift-off test.

images Belly press (Napoleon test)8 : A positive test is the inability to bring the elbow forward. An intermediate test is the ability to bring the elbow forward partially. A positive test indicates a complete rupture, while an intermediate test indicates a partial tear of the subscapularis.

images The bear hug test1 : If the examiner is able to lift the hand off the shoulder, then the patient likely has a partial or complete tear of the upper subscapularis tendon. This is perhaps the most sensitive test for a subscapularis tear.

images Coracoid impingement6 : Reproduction of pain or a painful click indicates a positive test. A positive test indicates impingement of the coracoid onto the subscapularis.

images Speed’s test4 : If the maneuver produces pain or tenderness, the test is positive, which may indicate bicipital pathology, although the test is not specific.

images Yerguson test22 : The patient will experience pain as the biceps tendon subluxes out of the groove with a positive test; this indicates biceps instability.

images Pain may inhibit a patient from maneuvering the arm behind the body into the lift-off position, thereby preventing assessment.

images A complete rupture of the long head of the biceps tendon will result in an obvious cosmetic deformity in the anterior arm as the muscle retracts distally.

images Tests used to diagnose superior labral lesions will be discussed in a separate section.

IMAGING AND DIAGNOSTIC STUDIES

images Anteroposterior (AP), outlet, and axillary view radiographs should be obtained to rule out any fractures or associated injuries.

images In chronic cases of subscapularis tears, anterior subluxation of the humeral head may be noted on the axillary view.18

images MRI is the modality of choice for diagnosing subscapularis tears (FIG 1).

images MR arthrography improves the study accuracy to detect partial-thickness tears.

images Fatty degeneration of the subscapularis correlates with poor tendon quality.20

images Although not sensitive, these signs are highly specific for subscapularis tears15 :

images Leakage of contrast material onto the lesser tuberosity

images Fatty degeneration of the subscapularis muscle

images Abnormalities in the course of the long biceps tendon

images Biceps dislocation deep to the subscapularis tendon is pathognomonic for a subscapularis tear.

images Ultrasound is a noninvasive method for assessing the subscapularis and can be performed in the office. It is less expensive than MRI, but results are operator-dependent.

DIFFERENTIAL DIAGNOSIS

images Impingement syndrome

images Subscapularis tendinitis

images Bicipital tendinitis

images Posterosuperior rotator cuff tear (supraspinatus, infraspinatus, teres minor)

images Biceps pathology

images Coracoid impingement

images Labral tear

images Glenoid fracture

images Glenohumeral instability

images Glenohumeral arthritis

images Pectoralis major injury

images Contusion

images Cervical radiculopathy

NONOPERATIVE MANAGEMENT

images For subscapularis tears, nonoperative management is reserved for some chronic and atraumatic, degenerative, and asymptomatic tears.

images Treatment includes activity modification, anti-inflammatory medications, and physical therapy.

images Corticosteroid injections may be performed in the bicipital groove or subcoracoid bursa to treat biceps tendinitis and coracoid impingement.

images It is likely that some degenerative subscapularis tendon tears are successfully treated nonsurgically without ever being diagnosed.

images In most cases, an acute symptomatic subscapularis tear should be managed operatively and whenever possible within the first 6 to 8 weeks, when retraction and scarring are minimal, to reduce the risks of dissection in the axillary recess.

images In young, active patients, attempts are made to repair acute biceps ruptures.

images In older, less active patients and in cases of chronic biceps ruptures more than 8 weeks old, biceps repair is discouraged.

SURGICAL MANAGEMENT

Preoperative Planning

images Physical therapy or a home exercise program emphasizing range of motion may be used to prevent stiffness and improve range of motion before surgery.

images All imaging studies are reviewed.

images An examination under anesthesia is performed before beginning surgery to evaluate for instability, increased external rotation, or decreased range of motion.

Positioning

images The patient is placed in a low beach chair position with the arm draped free.

images A McConnell arm holder (McConnell Orthopedic Manufacturing Co., Greenville, TX) is useful for maintaining arm positions throughout the case (FIG 2).

images

FIG 1 • Axial T2-weighted MR images of right shoulders with an intact subscapularis tendon (Aarrow) and a complete rupture of the subscapularis tendon.

Approach

images  Both the deltopectoral and anterolateral deltoid-splitting approaches have been described.20

images  The anterolateral deltoid-splitting approach is useful for partial tears of the upper subscapularis and tears associated with supraspinatus tears. It is not recommended for large, retracted full-thickness subscapularis tears.

images  The deltopectoral approach provides greater visualization and access to the inferior portion of the subscapularis. It also allows for concomitant biceps tenodesis and coracoplasty.

images

FIG 2 • Positioning for a subscapularis repair. The patient is placed in a beach chair position with the arm stabilized in a McConnell holder.

TECHNIQUES

INCISION AND DISSECTION

images  The deltopectoral approach is started just proximal to the coracoid process and extended distally 8 to 10 cm.

images  Adducting the arm identifies the major axillary crease.

images  The cephalic vein and deltoid muscle are carefully retracted laterally and the pectoralis muscle is retracted medially to facilitate exposure (TECH FIG 1A).

images  Once the deltopectoral interval is developed, the clavipectoral fascia is identified.

images  The clavipectoral fascia is divided at the lateral aspect of the conjoined tendon.

images  Avoid excessive retraction on the conjoined tendon to avoid injuring the musculocutaneous nerve.

images  The tendon of the subscapularis is often retracted inferiorly and medially and requires mobilization.

images  A layer of scar tissue may be seen overlying the lesser tuberosity, which can mimic the subscapularis tendon.

images  If the subscapularis tendon cannot be brought back to the lesser tuberosity easily, then the subscapularis requires systematic release from the glenohumeral ligaments.

images  Begin by releasing the superior aspect of the tendon from the coracohumeral ligament. The rotator interval is opened from the glenoid to the bicipital groove to facilitate the release.

images  Next release the inferior portion of the tendon from the capsular attachments. Care must be taken to identify and protect the axillary nerve and vascular supply inferiorly.

images  Finally, release the remaining capsular attachments on the undersurface of the subscapularis (TECH FIG 1B).

images

TECH FIG 1 • A. Deltopectoral interval in a right shoulder. The deltoid muscle (D) and cephalic vein are retracted laterally and the pectoralis muscle (P) is retracted medially. B. The subscapularis is released from the capsule to facilitate mobilization of the tendon. Note the proximity of the axillary nerve inferiorly.

BICEPS TENODESIS

images  If a biceps tenotomy is performed, it is important to warn the patient of the resultant cosmetic deformity when the biceps retracts distally.

images  Indications for biceps tenodesis include the following.

images Tears involving more than 50% of the biceps tendon

images Medial subluxation of the biceps tendon

images  Open the bicipital groove from the medial side to expose the biceps tendon.

images  The biceps tendon is released from the superior glenoid with curved scissors.

images  The tendon is retracted distally from the bicipital groove.

images  To ensure proper tensioning of the biceps tendon, the proximal portion of the tendon is resected to leave about 20 to 25 mm of tendon proximal to the musculotendinous junction.

images  Running locking Krakow or whipstitches are placed up and down the proximal 15 mm of the biceps tendon.

images  Abrade the bicipital groove to develop a bleeding surface.

images  A burr hole the size of the biceps tendon is made in the bicipital groove about 15 mm from the articular surface. Two smaller 3.2-mm holes are made 15 mm distal to the burr hole in a triangular configuration.

images  The tendon end is passed into the proximal hole by pulling the sutures out the distal holes. The sutures are then passed through and tied over the overlying biceps tendon (TECH FIG 2A,B).

images  Another fixation option is to use a biotenodesis screw for the biceps tendon.

images The tendon is prepared as above.

images An 8-mm reamer is used to make a 25-mm-deep bone tunnel about 15 mm from the articular surface.

images An 8 × 23-mm Arthrex Bio-Tenodesis screw is used for fixation.

images One end of the suture is passed through the biotenodesis screw while the other suture passes outside of the screw. This ensures that the tendon will be pulled into the hole as the screw is advanced.

images When the screw is flush with the bone tunnel, the sutures are tied over the screw (TECH FIG 2C). This provides both an interference fit and suture anchor stability.

images

TECH FIG 2 • A,B. The tunnel technique uses bone tunnels to fix the biceps tendon upon itself. C. A biceps tenodesis with interference screw fixation.

CORACOPLASTY

images  The conjoined tendons are identified.

images  Care is taken not to retract vigorously on the conjoined tendons to avoid injury to the musculocutaneous nerve.

images  The coracoacromial ligament is released from the coracoid.

images  The posterior aspect of the coracoid is exposed by removing the overlying soft tissue. The posterolateral portion is then resected in line with the subscapularis muscle with an osteotome (TECH FIG 3). Alternatively, a burr may be used to accomplish the same resection. Protect the neurovascular structures by placing a retractor on the posterior aspect of the coracoid.

images  A rasp is then used to smooth out the bony surface.

images  The goal is a 7to 10-mm clearance between the coracoid and subscapularis.

images  Confirmation of adequate decompression can be determined by manipulating the arm into the impingement position and confirming that there is adequate clearance for the subscapularis.

images

TECH FIG 3 • The posterolateral portion of the coracoid is resected, leaving the conjoined tendon attached. The goal is a 7to 10-mm clearance space for the subscapularis.

SUBSCAPULARIS REPAIR

images  The residual soft tissue is cleaned from the lesser tuberosity. A burr is then used to expose bleeding bone for the tendon to heal to.

images  To recreate the anatomic footprint of the subscapularis insertion, four suture anchors are used for the repair.

images  Two anchors are placed at 1-cm intervals along the medial aspect of the lesser tuberosity and two are placed at the lateral aspect of the lesser tuberosity (TECH FIG 4A).

images  The sutures from the medial anchors are passed in a mattress fashion near the musculotendinous junction of the subscapularis (TECH FIG 4B).

images  The sutures from the lateral anchor are passed through the lateral edge of the tendon in a simple fashion and tied down to the lesser tuberosity.

images  After repair of the subscapularis tendon, the shoulder is taken through a gentle range of motion to determine the safe arcs for postoperative rehabilitation.

images  The lateral aspect of the rotator interval is closed while maintaining about 30 degrees of external rotation of the arm to prevent overtightening of the subscapularis repair.

images

TECH FIG 4 • A. Four suture anchors are placed for the repair of the completely torn subscapularis tendon. Two anchors are placed medially and two laterally. B. The sutures from the two medial anchors have been passed in a mattress fashion through the subscapularis tendon (S). C. The diagram shows the suture configuration for the subscapularis repair with mattress sutures at the musculotendinous junction and simple sutures at the lateral tendon insertion. D. Once the subscapularis tendon has been repaired, it is important to close the rotator interval. Wide straight arrows indicate the tied mattress sutures; narrow straight arrows point to the tied simple sutures; and the curved arrow indicates the rotator interval.

images

POSTOPERATIVE CARE

images The most important postoperative management for subscapularis tears is limitation of external rotation for 6 weeks to avoid stressing the repair.

images Complete tears are not allowed to externally rotate past 0 degrees.

images Partial tears are allowed to externally rotate 20 to 30 degrees.

images At 6 weeks the patient may begin active and active-assisted external rotation exercises, as well as overhead stretching.

images At 12 weeks strengthening exercises are initiated for partial tears. At 16 weeks strengthening exercises are initiated for complete tears.

OUTCOMES

images Isolated subscapularis tears have favorable surgical outcomes.

images At 2 years of follow-up, good or excellent results were reported in 13 of 14 isolated subscapularis tears.4

images Another study demonstrated good or excellent results in 13 of 16 patients with acute traumatic subscapularis tears at 43 months of follow-up. The Constant scores were 82% of age-matched controls.8

images Poor prognostic factors include chronic tears (symptoms for more than 6 months), fatty degeneration of the subscapularis muscle, and anterosuperior tears (combination of subscapularis and supraspinatus tears).19

images Comparative outcomes between open and arthroscopic techniques remain to be determined.

COMPLICATIONS

images Repair failure

images Infection

images Loss of motion

images Axillary nerve injury

images Vascular injury

REFERENCES

1.     Barth JRH, Burkhart SS, DeBeer JF. The bear hug test: the most sensitive test for diagnosing a subscapularis tear. Arthroscopy 2006;22: 1076–1084.

2.     Burkhead WZ Jr, Arcand MA, Zeman C, et al. The biceps tendon. In: Rockwood CA Jr, Matsen FA III, Wirth MA, Lippitt SB, eds. The Shoulder, 3rd ed. Philadelphia: Saunders, 2004;1059–1119.

3.     Constant CR, Murley AH. A clinical method of functional assessment of the shoulder. Clin Orthop Relat Res 1987;214:160–164.

4.     Crenshaw AH, Kilgore WE. Surgical treatment of bicipital tenosynovitis. J Bone Joint Surg Am 1966;48A:1496–1502.

5.     Deutsch A, Altchek DW, Veltri DM, et al. Traumatic tears of the subscapularis tendon: clinical diagnosis, magnetic resonance imaging findings, and operative treatment. Am J Sports Med 1997;25:13–22.

6.     Dines DM, Warren RF, Inglis AE, et al. The coracoid impingement syndrome. J Bone Joint Surg Br 1990;72B:314–316.

7.     Frankle MA, Cofield RH. Rotator cuff tears including the subscapularis [abstract]. Fifth International Conference of Surgery of the Shoulder, Paris, France, 1992:52.

8.     Gerber C, Krushell RJ. Isolated rupture of the tendon of the subscapularis muscle: clinical features in 16 cases. J Bone Joint Surg Br 1991;73B:389–394.

9.     Gerber C, Rippstein R. Combined lesions of the subscapularis and supraspinatous tendons: a multi-center analysis of 56 cases [abstract]. Fifth International Congress of Surgery of the Shoulder, Paris, France, 1992:51.

10. Halder AM, Itoi E, An KN. Anatomy and biomechanics of the shoulder. Orthop Clin North Am 2000;31:159–176.

11. Hertel R, Ballmer F, Lombert SM, et al. Lag signs in the diagnosis of rotator cuff rupture. J Shoulder Elbow Surg 1996;5:307–313.

12. Li XX, Schweitzer ME, Bifano JA, et al. MR evaluation of subscapularis tears. J Comput Assist Tomogr 1999;23:713–717.

13. Neviaser RJ, Neviaser TJ. Recurrent instability of the shoulder after age 40. J Shoulder Elbow Surg 1995;4:416–418.

14. Pagnani MJ, Deng XH, Warren RF, et al. Role of the long head of the biceps brachii in glenohumeral stability: a biomechanical study in cadavers. J Shoulder Elbow Surg 1996;5:255–262.

15. Pfirrmann CW, Zanetti M, Weishaupt D, et al. Subscapularis tendon tears: detection and grading at MR arthrography. Radiology 1999; 213:709–714.

16. Symeonides PP. The significance of the subscapularis muscle in the pathogenesis of recurrent anterior dislocations of the shoulder. J Bone Joint Surg Br 1972;54B:276–283.

17. Tillett F, Smith M, Fulcher M, et al. Anatomic determination of humeral head retroversion: the relationship of the central axis of the humeral head to the bicipital groove. J Shoulder Elbow Surg 1993; 2:255–256.

18. Travis RD, Burkhead WZ, Doane R. Technique for repair of the subscapularis tendon. Orthop Clin North Am 2001;32:495–500.

19. Tung GA, Yoo DC, Levine SM, et al. Subscapularis tendon tear: primary and associated signs on MRI. J Comput Assist Tomogr 2001; 25:417–424.

20. Warner JJ, Higgins L, Parsons IM, et al. Diagnosis and treatment of anterosuperior rotator cuff tears. J Shoulder Elbow Surg 2001;10:37–46.

21. Warner JJ, McMahon PJ. The role of the long head of the biceps brachii in superior stability of the glenohumeral joint. J Bone Joint Surg Am 1995;77A:366–372.

22. Yergason RM. Supination sign. J Bone Joint Surg Am 1931;13A:60.



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