How Are Rotator Cuff Tears Diagnosed?
Edited by Guy Slowik MD FRCS. Last updated on June 28th 2011
Physicians use a variety of tests to diagnose and evaluate the severity of a rotator cuff tear. These include:
Physical Examination
The doctor will:
- Inspect the shoulder for muscle wasting, swelling and the general contour of the shoulder.
- Assess range of motion of the shoulder and at what height the pain commences
- Look for signs of weakness, instability, and pain during specific movements. Some of these simple tests are designed to figure out whether the rotator cuff is being pinched between the upper arm bone and the acromion (impingement).
- Assess the strength of resisted movements of the shoulder and if these type of movements are painful
- Possibly inject an anesthetic, or painkiller, into the injured shoulder in an attempt to localize the problem (is the pain coming from the rotator cuff or possibly from another area of the shoulder). The degree of pain relief or change in movement after the injection may help determine the nature of the problem.
X-ray
Because x-rays do not show soft tissue such as tendons, they will not expose a partially or completely torn rotator cuff. X-rays are used to rule out other causes of shoulder pain, particularly arthritis (osteo or degenerative arthritis) of the nearby acromio-clavicular joint which may be a contributory cause to the shoulder pain or even a contributory cause to the tear of the rotator cuff.
The x-ray can also show whether the space between the humerus (arm bone) and the acromion has narrowed, possibly resulting in impingement. X-rays can also reveal the presence of calcium deposits,
Magnetic Resonance Imaging (MRI)
A magnetic resonance imaging (MRI) scan is one of the most powerful diagnostic tools available to doctors. An MRI scan uses magnetic waves and computers to create detailed images of the interior of the shoulder. An MRI can reveal even small, partial tears of the rotator cuff. An MRI is painless and has, for the most part, replaced the arthrogram for the diagnosis of rotator cuff tears.
For more information about MRI, go to MRI.
Sometimes the physician may opt to inject dye into the shoulder joint before doing the MRI scan. This is called an MRI arthrogram. One will get better pictures and learn a lot more about the shoulder joint (if there is a tear the dye will be seen leaking through the tear)
Ultrasound
Ultrasound tests use sound waves to examine the inside of the shoulder. This is now commonly used to diagnose a tear of the rotator cuff. It is not as sensitive or as reliable as an MRI scan.
An ultrasound scanner emits harmless waves; the returning echoes are recorded by a computer which produces an image of the part of the body scanned.
For more information about ultrasound, go to Ultrasound.
Diagnostic Arthroscopy
This is a surgical procedure. Nowadays its done after the MRI scan, once it has been confirmed that a rotator cuff tear is present. Sometimes, its clear from clinical examination that the problem is a tear of the rotator cuff. An arthroscopy is then done to confirm the rotator cuff tear and deal with the problem at the same time (repair the tear). During arthroscopy, a physician makes a small cut in the shoulder, then inserts a thin tube that contains a miniature video camera. This camera allows the physician to see whether the rotator cuff has been torn. This procedure is usually done under general anaesthetic.
For detailed information about shoulder arthroscopy, go to Arthroscopy Of The Shoulder.
