Rotator Cuff Tendinitis

The etiology of rotator cuff tendinitis is still under debate. The intrinsic, extrinsic, and overuse mechanisms have been proposed as etiological factors.

The degeneration in rotator cuff tendinitis occurs in response to chronic overuse of the tendon without giving it time to rest and heal, disrupting the balance between protective and regenerative mechanisms and overuse pathologic changes. The end result is weakness, pain, and loss of shoulder motion [1] [2].

The symptoms of rotator cuff tendinitis can be acute, occur after an injury to the shoulder, or be associated with overuse. Symptoms are often insidious in elderly patients. The pain is usually felt as a dull ache on the anterolateral part of the shoulder and is aggravated by overhead activities. It is worse on shoulder abduction or flexion between 60° and 120° and is frequently minimal or absent outside of this range. Passive abduction causes less pain, however, abduction against resistance may aggravate the pain. Feeling pain during the night is common, especially if the patient lies on the affected side.

Obtaining a detailed history is essential for ruling out other diagnoses such as referred pain from cervical spine or serious symptoms of cardiac origin. Shoulder examination should be systematical. The shoulder must be exposed entirely. Inspection, palpation, motor strength, the range of movement (ROM), and special tests should be performed.

Tenderness is often localized to the greater tuberosity and subacromial bursa. Active and passive ROM in all planes has to be evaluated as part of the physical examination. Strength assessment can help isolating the relevant muscles.

Two techniques have been described in the literature to test the supraspinatus muscle:

1. Thumbs down position: elbow extended, shoulder in full internal rotation, the arm in the scapular plane [3].
2. Thumbs up position: test in the prone position, elbow extended, shoulder abduction to 100° with external rotation while the patient lifts in abduction [4].

Although both of these techniques activate the supraspinatus muscle, neither of them can truly isolate it since other muscles are also active during the evaluation [5]. Subtle weakness during either position can represent early degeneration in the rotator cuff.

• Neer impingement test: In this special examination, the shoulder is forcibly flexed forward and rotated internally, therefore the greater tuberosity will jam against the anterior inferior surface of the acromion. Pain during this test indicates a positive result which reveals an overuse injury to supraspinatus or biceps tendon.
• Hawkins-Kennedy impingement test: Another special type of assessment, in which the shoulder and elbow are flexed forward to 90° and the shoulder is forcibly rotated internally. Pain reflects a positive test and identifies greater tuberosity and supraspinatus tendon impingement under the coracoacromial ligament and the coracoid process.

Plain radiography of the shoulder in a true anteroposterior (AP) view, an axillary view, and supraspinatus outlet view is very helpful in the diagnosis of rotator cuff tendinitis. Magnetic resonance imaging (MRI) is extremely sensitive and specific while being non-invasive. It has the ability to detect the characteristics, size, and location of the pathology. Ultrasonography can also be employed to evaluate the rotator cuff muscles. it is less costly but as it is operator-dependent, the sensitivity and specificity of the results obtained may vary [6] [7] [8] [9].

1. Bass E. Tendinopathy: Why the Difference Between Tendinitis and Tendinosis Matters. Int J Ther Massage Bodywork. 2012;5(1):14–17.
2. Andres BM, Murrell GAC. Treatment of Tendinopathy: What Works, What Does Not, and What is on the Horizon. Clin Orthop Relat Res. 2008;466(7):1539-1554. doi:10.1007/s11999-008-0260-1.
3. Jobe FW, Moynes DR. Delineation of diagnostic criteria and a rehabilitation program for rotator cuff injuries. Am J Sports Med. 1982 Nov-Dec. 10(6):336-9.
4. Blackburn TA, White B, McLeod WD, Wofford L. EMG analysis of posterior rotator cuff exercises. Athl Training. 1990. 25:40-5.
5. Malanga GA, Bowen JE, Nadler SF, Lee A. Nonoperative management of shoulder injuries. J Back Musculoskeletal Rehab. 1999. 12:179-89.
6. Teefey SA, Hasan SA, Middleton WD, Patel M, Wright RW, Yamaguchi K. Ultrasonography of the rotator cuff. A comparison of ultrasonographic and arthroscopic findings in one hundred consecutive cases. J Bone Joint Surg Am. 2000 Apr. 82(4):498-504.
7. Read JW, Perko M. Shoulder ultrasound: diagnostic accuracy for impingement syndrome, rotator cuff tear, and biceps tendon pathology. J Shoulder Elbow Surg. 1998;7(3):264–271.
8. Paavolainen P, Ahovuo J. Ultrasonography and arthrography in the diagnosis of tears of the rotator cuff. J Bone Joint Surg Am. 1994;76(3):335–340.
9. Teefey SA, Middleton WD, Yamaguchi K. Shoulder sonography. State of the art. Radiol Clin North Am. 1999;37(4):767–785.