An X-ray usually cannot show a rotator cuff tear because the rotator cuff is made of tendons and other soft tissues that do not appear clearly on plain X-rays. However, an X-ray can reveal bone problems, such as arthritis, bone spurs, a fracture, or a shoulder that is out of place. If a tear is suspected, ultrasound or MRI may help show it.
Why Can't an X-Ray Show a Rotator Cuff Tear?
The rotator cuff is a group of four muscles and their tendons that help keep the shoulder stable and allow the arm to lift and rotate. A tear occurs when one or more of these tendons becomes partly or completely damaged. Because tendons are soft tissues, they do not appear clearly on a standard X-ray, which primarily shows bones.
According to Mayo Clinic, a rotator cuff tear will not show up directly on an X-ray. This means that an X-ray may look normal even when a tendon injury is present. The test remains useful because shoulder pain can have several causes, and examining the bones helps healthcare professionals investigate other possible explanations.
What Can a Shoulder X-Ray Show Instead?
Although an X-ray cannot directly display a torn rotator cuff tendon, it can help identify bone and joint problems that may contribute to shoulder pain. Depending on the findings, the image may reveal:
- Arthritis: Changes in the shoulder joint that may be associated with pain and stiffness.
- Bone spurs: Extra areas of bone growth that may be relevant to shoulder symptoms.
- Fractures: Broken bones following a fall, accident, or other injury.
- Dislocation: An abnormal position of the bones that form the shoulder joint.
The American Academy of Orthopaedic Surgeons (AAOS) explains that X-rays are commonly used to examine the shoulder bones and look for other causes of pain, including arthritis. These findings can help guide the next steps in an evaluation, but they do not by themselves confirm or exclude a rotator cuff tear.
Which Imaging Tests Can Detect a Rotator Cuff Tear?
When a tendon injury remains a concern after an examination or X-ray, a healthcare professional may recommend ultrasound or magnetic resonance imaging (MRI). Both tests can provide information about the rotator cuff itself, which a standard X-ray cannot adequately show. The choice depends on the clinical findings, the information needed, and the availability of suitable imaging.
Ultrasound of the Shoulder
An ultrasound uses sound waves to create images of soft tissues, including muscles and tendons. It can help identify a rotator cuff tear and allows the examiner to assess tendon movement while the shoulder is moving. Ultrasound does not use ionizing radiation and generally does not require the patient to remain completely still throughout the examination.
RadiologyInfo.org, which provides patient information reviewed by radiology professional organizations, explains that musculoskeletal ultrasound can be used to evaluate tendon tears, including those affecting the rotator cuff. The quality and accuracy of the examination can depend on the experience of the person performing it and the structures that need to be assessed.
MRI of the Shoulder
An MRI uses a strong magnetic field and radio waves to produce detailed images of the shoulder's soft tissues. It can help identify a rotator cuff tear and show its location and size. MRI can also provide information about the surrounding tendons and muscles, which may help clinicians understand the injury and consider appropriate treatment options.
MRI may be especially useful when a detailed assessment of the tendon and nearby structures is needed. However, it is not automatically necessary for every person with shoulder pain. A healthcare professional considers the symptoms, examination findings, previous imaging, and whether the results are likely to affect management before selecting further tests.
What Does a Normal Shoulder X-Ray Mean?
A normal X-ray means that the images have not shown a significant abnormality that can be identified with that examination. It does not establish that every structure in the shoulder is healthy, because many soft-tissue injuries are not visible on plain X-rays.
For example, ongoing shoulder pain or weakness may still need further assessment when the X-ray shows no fracture or obvious bone abnormality. According to RadiologyInfo.org's guidance on acute shoulder pain and imaging, additional imaging may be considered when an X-ray does not explain a suspected injury. Depending on the situation, this may include an ultrasound or MRI.
How Do Healthcare Professionals Decide Which Test Is Needed?
Imaging results are considered alongside the person's medical history and physical examination. A healthcare professional may ask when the pain started, whether it followed an injury, which movements are difficult, and whether the shoulder feels weak. The examination may include checking tenderness, movement, and muscle strength.
The reason for the test also matters. After a significant injury, an X-ray may be useful for checking for a fracture or dislocation. If the main concern is a torn tendon, ultrasound or MRI may provide information that the X-ray cannot. Not everyone needs every type of imaging, and the most suitable approach depends on the clinical situation.
When Should You Have a Shoulder Injury Assessed?
Arrange a healthcare assessment if shoulder pain persists, worsens, interferes with sleep or everyday activities, or occurs with ongoing weakness or difficulty raising the arm. These problems can have several causes, so an examination can help determine whether imaging or other evaluation is appropriate.
Seek prompt medical attention after a significant injury, particularly if there is sudden loss of shoulder function, marked weakness, or an obvious change in the shoulder's shape. A normal X-ray should not be the only reason to dismiss continuing symptoms when the clinical findings suggest that further assessment may be needed.