Rotator Cuff Tear

Abstract

Rotator cuff tear occurs because of direct trauma or degeneration and can involve partial- or full-thickness. Degenerative rotator cuff tear tends to occur in adults over 40 years of age and its pathological changes include increased fibroblast cellularity, neovascularity, thinning or loss of collagen matrix, and fatty infiltration. The biceps tendon can be affected in lieu of a rotator cuff tear. Superior migration of humeral head can be seen in massive rotator cuff tear and rotator cuff tear arthropathy may ensue as result of repetitive cartilage wear. Patients with rotator cuff tear complain of shoulder pain, loss of range of motion, weakness, and limitations in self-care and overhead activities. Magnetic resonance imaging (MRI) is the most commonly used imaging modality to diagnose rotator cuff tear and it can provide information on tear thickness, size, fatty infiltration, muscle atrophy, and tendon retraction. Ultrasound visualizes cuff tear as an area of hypoechogenicity and can achieve diagnostic sensitivity and specificity comparable to MRI; however, it is operator dependent. Magnetic resonance angiography is an invasive imaging modality and indicated when labrum tear is suspected. Both conservative and operative treatments can be used for rotator cuff tear but strong evidence for decision-making is still lacking. Surgery is preferred for acute traumatic tear and chronic symptomatic full-thickness tear, non-responsive to conservative treatment. Nonoperative treatment entails pharmacological treatment, physical therapy, and procedures. Pain control can be achieved by nonsteroidal anti-inflammatory drugs, selective cyclooxygenase 2 inhibitor, acetaminophen, and cryotherapy. Ultrasound guided corticosteroid/lidocaine injection can be performed for symptom relief.

Keywords

MRI, Rotator cuff tear, Tendon rupture, Ultrasound

Synonyms
Shoulder tear Torn shoulder
ICD-10 Codes
M75.100	Unspecified rotator cuff tear or rupture of unspecified shoulder, nontraumatic
M75.101	Unspecified rotator cuff tear or rupture of right shoulder, nontraumatic
M75.102	Unspecified rotator cuff tear or rupture of left shoulder, nontraumatic
S43.421	Sprain of right rotator cuff
S43.422	Sprain of left rotator cuff
S43.429	Sprain of unspecified rotator cuff

Definition

Shoulder pain is the third most common musculoskeletal complaint (behind back and knee pain) in the United States. In the United States, shoulder symptoms accounted for an estimated 10.7 million ambulatory care visits to physician offices in 2013. There were an estimated 272,148 ambulatory rotator cuff surgeries performed in the United States in 2006.

The rotator cuff is composed of supraspinatus, subscapularis, infraspinatus, and teres minor ( Fig. 17.1 ). Rotator cuff tears are categorized as partial- or full-thickness. Rotator cuff tears are measured based on their longitudinal or transverse tear size. Rotator cuff tears can occur from a traumatic incident (such as falling off a ladder or motor vehicle accident) or can be secondary to degenerative changes within the tendon. Degenerative rotator cuff tears tend to occur in adults over 40 years of age. In patients with degenerative rotator cuff tears, histological tendon changes such as increased fibroblast cellularity, neovascularity, thinning or loss of collagen matrix, and fatty infiltration have been described. In patients with rotator cuff tear, the muscles of the rotator cuff and surrounding scapulothoracic stabilizers may become weak over time. Under these conditions, the muscles can fatigue early, resulting in altered biomechanics. In patients with a large rotator cuff tear, over time, the humeral head migrates superiorly because of the unopposed action of the deltoid and lack of downward compressive forces from the supraspinatus and infraspinatus. From this abnormal motion, impingement of the rotator cuff is more likely to occur. It occurs particularly during forward flexion when the anterior portion of the acromion impinges on the supraspinatus tendon.

The long head of biceps is often affected in patients with rotator cuff tears. Repetitive trauma resulting from impingement leads to wear of the shoulder joint, commonly involving anterior-superior margin of glenoid bone, and the occurrence of rotator cuff tear arthropathy. It was proposed the loss of motion and pathologic change of periarticular structure accelerate the process of bone and cartilage atrophy.

Symptoms

Patients usually present with shoulder pain, weakness, and loss of range of motion resulting in impaired shoulder function. Pain may occur with internal and external rotation and may affect daily self-care and overhead activities. The patient can be awoken by pain in the shoulder, which impairs sleep.

Physical Examination

The shoulder examination for rotator cuff tears is similar to that for rotator cuff tendinopathy and consists of inspection, palpation, range of motion, and strength testing as described in Chapter 16 . It includes inspection, palpation, range of motion, muscle strength testing, and performance of special tests of the shoulder as clinically indicated.

Special Tests

There are more than 25 special tests reported to evaluate the rotator cuff. In this chapter, we describe the ones having been more rigorously assessed for sensitivity and specificity and most useful in clinical practice ( Table 17.1 ). Tests for impingement are described in Chapter 16 .

Table 17.1

Special Tests for Rotator Cuff Disease

Subject	Test	Procedure	Interpretation
Subscapularis ( Fig. 17.1 )	Lift-off test	The examiner assists the patient to get in a position where he/she touches their lower back with the arm fully extended and internally rotated.	The test is positive if the patient is unable to lift the dorsum of his hand off his/her back.
	Passive lift-off test	The examiner brings the arm behind the body into maximal internal rotation (around the lower back region and pull it backwards away from the back).	The test is positive if the patient cannot maintain this position.
	Belly-press test	The examiner requests the patient to presses the abdomen with the hand flat and attempts to keep the arm in maximum internal rotation.	A positive test is when the elbow drops back behind the trunk.
	Belly-off sign	The examiner will passively bring the arm of the patient into flexion and maximum internal rotation with the elbow 90 degrees flexed. The elbow of the patient is supported by one hand of the examiner while the other hand brings the arm into maximum internal rotation placing the palm of the hand on the abdomen. The patient is then asked to keep the wrist straight and actively maintain the position of internal rotation as the examiner releases the wrist.	The test is positive if the patient cannot maintain the above position, lag occurs, and the hand lifts off the abdomen.
	Bear hug test	The examiner requests the patient to place the palm of the involved side on the opposite shoulder, extend the fingers (so that the patient could not resist by grabbing the shoulder), and position the elbow anterior to the body. The examiner then asks the patient to hold that position (resisted internal rotation) as the examiner tries to pull the patient’s hand from the shoulder with an external rotation force applied perpendicular to the forearm.	The test is positive if the patient could not hold the hand against the shoulder or if he or she shows weakness of resisted internal rotation of greater than 20% compared with the opposite side.
Infraspinatus and teres minor ( Fig. 17.2 )	External rotation lag sign at 0 degree	The patient is seated on an examination couch with his or her back to the physician. The elbow is passively flexed to 90 degrees, and the shoulder is held at 20 degrees elevation (in the scapular plane) and near maximum external rotation (i.e., maximum external rotation −5 degrees to avoid elastic recoil in the shoulder) by the examiner. The patient is then asked to actively maintain the position of external rotation as the examiner releases the wrist while maintaining support of the limb at the elbow.	The sign is positive when a lag, or angular drop, occurs.
	External rotation lag sign at 90 degrees (drop sign)	The patient is seated on an examination couch with his or her back to the examiner, who holds the affected arm at 90 degrees of elevation (in the scapular plane) and at almost full external rotation, with the elbow flexed at 90 degrees. The patient is asked to actively maintain this position as the physician releases the wrist while supporting the elbow.	The sign is positive if a lag or “drop” occurs. (The maintenance of the position of external rotation of the shoulder is a function mainly of infraspinatus.)
	Hornblower’s sign	The examiner supports the patient’s arm at 90 degrees of abduction in the scapular plane with elbow flexed at 90 degrees. The patient then attempts external rotation of the forearm against resistance of the examiner’s hand.	The test is positive if the patient cannot externally rotate, then he or she assumes a characteristic position.
Supraspinatus ( Fig. 17.3 )	Jobe test (empty can test)	It is performed by first assessing the deltoid with the arm at 90 degrees of abduction and neutral rotation. The shoulder is then internally rotated and angled forward 30 degrees; the thumbs should be pointing toward the floor. Manual muscle testing against resistance is performed with the examiner pushing down at the distal forearm.	The test is positive if there is weakness to resistance with the second maneuver as compared with the first maneuver.
	Full can test	With the arm in 90 degrees of elevation in the scapular plane and 45 degrees of external rotation, manual muscle testing against resistance is performed with the examiner pushing down at the distal forearm.	A positive test is when there is weakness to resistance.
	Drop arm test	The examiner abducts the patient’s shoulder to 180 degrees passively and then observes as the patient slowly lowers the arm to the waist.	The test is positive if the arm drops to the side. A positive result indicates a tear of the rotator cuff.
Biceps ( Fig. 17.4 )	Speed test	The patient flexes his shoulder (elevates it anteriorly) against resistance (from the examiner) while the elbow is extended and the forearm supinated.	The test is positive when pain is localized to the bicipital groove.
Acromioclavicular joint	Cross-chest adduction	The patient’s arm forward flexes to 90 degrees, the examiner forcibly adducts the arm across the chest.	If the patient reports pain, it is a positive test.

Testing of the scapula rotators, the trapezius, and the serratus anterior is also important. The serratus anterior can be tested by having the patient lean against a wall; winging of the scapula as the patient pushes against the wall indicates weakness. The cervical spine should be examined to assess for pathology. Suprascapular neuropathy results in weakness of the rotator cuff or the scapular stabilizers and can be isolated or accompany a rotator cuff tear.

Functional Limitations

The greatest limitation that patients complain of is performing overhead activities. Patients with rotator cuff tear complain of difficulty with overhead activities (e.g., throwing a baseball, painting a ceiling), greatest above 90 degrees of abduction, secondary to pain or weakness. Internal and external rotation may be compromised and may affect daily self-care activities. Women typically have difficulty hooking the bra in back. Work activities, such as filing, hammering overhead, and lifting, will be affected. The patient can be awakened by pain in the shoulder, which impairs their sleep.

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