Diagnosis of a rotator cuff tear

Various examination options are available for the diagnosis of a rotator cuff rupture.As a rule, a functional shoulder joint examination is started. Among other things, this examination includes checking the force development of the rotator cuff by lifting the arm sideways (abduction) against resistance, by external rotation (rotation) against resistance with the arm hanging and the elbow bent, and by internal rotation of the arm against resistance. While the abduction reflects the functionality of the supraspinatus muscle, the functional test, which checks the external rotation against resistance, refers to the teres minor and infraspinatus muscles.

The test of the powerful internal rotation of the arm controls the functionality of the subscapularis muscle. In addition to the functional shoulder joint examination, imaging techniques such as: are available. X-rays cannot directly detect a tear in the rotator cuff because tendons and muscles are part of the soft tissues of the body and are radiolucent to X-rays, i.e. they are not imaged.

However, since the absence of the rotator cuff causes the humeral head to rise below the acromion, observation of this phenomenon is an indirect indication of the presence of a severe rotator cuff tear. However, smaller tears do not cause this phenomenon. More importantly, however, an x-ray can reveal concomitant diseases (e.g. omarthrosis = arthrosis of the glenohumeral joint, tendinosis calcarea) and provide information on the cause of the rotator cuff tear.

An example would be a bony spur under the acromion (subacromial spur = impingement syndrome), which may have torn a hole in the rotator cuff. The great advantage of sonography is its easy availability and applicability as well as the possibility of dynamic shoulder examination, in that the arm can be moved during the examination. It is therefore possible to examine the rotator cuff “at work”.

Even small holes in the rotator cuff can be detected by an experienced examiner. An MRI of the shoulder is increasingly used when a rotator cuff tear is suspected. Tears in the rotator cuff can be reliably detected.

In addition, the tendon quality and retraction (pulling back of the tendon after the tear) can be assessed well by MRI, which can have direct consequences on the doctor’s therapy recommendation. A suspected diagnosis can be confirmed by a shoulder joint endoscopy (arthroscopy). Here, the extent of the rotator cuff lesion can also be assessed (partial or total rupture) and, if necessary, therapy can be performed simultaneously (rotator cuff suture = suture of the torn tendon).

X-ray image
Sonography (ultrasound)
Magnetic resonance imaging of the shoulder (MRT, NMR)

In the MRI, soft tissue structures such as tendons and muscles can be better visualized in comparison to CT and X-rays. A torn rotator cuff can be seen in the MRI at the point where the continuous structure of the tendon filaments ends abruptly. The radiologist can see edema (fluid) at the corresponding location and also along the rest of the muscle, which may be light or dark, depending on the setting of the MRI.

The extent and location of the rotator cuff tear can be described in more detail on the MRI and statements can already be made on how to proceed surgically – for example, whether a tendon plastic should be inserted. In addition, accompanying problems such as impingement (shoulder stenosis) or arthrosis can also be recorded here. Compared to other examinations, however, MRI of the shoulder is significantly more expensive and also more time-consuming.

In the case of a rotator cuff tear, the tear makes the function of the affected muscle painful or can only be performed to a limited extent. In most cases, the supraspinatus muscle is affected. This muscle is responsible for lifting (abduction) the shoulder.

If this muscle tears or tears, lifting the shoulder is only possible with pain. Movements that are often difficult are overhead movements or putting on jackets. With complete and also fresh tears, it may be that the initial lifting of the shoulder is no longer possible.

In the case of a rotator cuff tear that has existed for a long time, some patients complain that the entire shoulder becomes stiff over time. There are two common causes of rotator cuff tears. One is the tear caused by trauma and the other is wear and tear.Patients in whom wear is the cause of rotator cuff tear tend to be older patients (55 years and older).

If the patients indicate that no adequate trauma has occurred, such as a fall or a heavy load, then it is very likely that the rotator cuff tear is due to wear. An ultrasound or MRI examination, which are frequently performed as part of the diagnostic process, can provide a good assessment of the condition of the tendon. If the visible parts, the torn tendon, show signs of thinning and calcification, this indicates a wear process.

Furthermore, the patient’s history of wear-related rotator cuff tear is often conspicuous. The fact that the patient is younger (50 and significantly younger) speaks in favor of a tear caused by an injury. At this age, closure may already occur – but is not so pronounced that a tear would occur.

If patients report an accident involving the shoulder and after which corresponding complaints of the shoulder have occurred, then an injury is likely to be the cause of the rotator cuff tear. If arthroscopy, ultrasound and MRI show that the tendon looks rather unremarkable and healthy except for the tear, wear and tear can be ruled out as the cause. In elderly people who have wear and tear and who suffer an accident, it is probably a combination of both that causes the rotator cuff tear.

With regard to various diagnostic possibilities, some functional tests have already been described to check the functionality of the shoulder joint. In addition, there are further examination options that should be consulted as part of a physical (clinical) examination. This examination usually includes the differentiation of two clinical pictures, the impingement syndrome and the rupture of the rotator cuff.

The triggering of the so-called painful arc (= painful bow). For this purpose the arm is passively lifted over the side. Between 60 and 120°, the arc passes through a constriction in the case of impingement syndrome, which causes pain when impingement syndrome is present.
This examination can thus be used to diagnose symptoms caused by a constriction under the acromion.
If the pain is so severe that independent movement of the arm is not possible, an anesthetic is injected into the bursa. If the patient is not able to actively move the arm despite the sedative, a rotator cuff tear can be assumed. A pseudoparalysis is when the symptoms are not only related to the loss of function, but also resemble paralysis.