That Rotator Cuff Tear Might Actually Be….

Many other injuries can present remarkably similar to rotator cuff tears. So if a patient presents with shoulder pain, what should you consider? Here’s everything you need to know for a rotator cuff differential diagnosis.

If it looks like a duck, walks like a duck, and quacks like a duck, then it’s a duck. Right? Not always. In an orthopedic setting, many different common injuries can present in the same way. That’s why differential diagnosis is such an important tool. Specifically, rotator cuff injuries have many “copycats.”

Typically, rotator cuff tears cause shoulder pain, weakness, and limited range of motion. However, many other shoulder injuries can present in a remarkably similar way. So if a patient presents with shoulder pain, what should you consider besides a rotator cuff tear? Here’s everything you need to know for a rotator cuff differential diagnosis.

Other Rotator Cuff Injuries

First, we’ll consider other rotator cuff injuries. It may still be the rotator cuff, but instead of a tear, the tendons may be irritated or damaged. Many of the same symptoms still apply – pain at activity and rest, radiating from the shoulder down the side of the arm. The pain may increase with specific movements and eventually progress to loss of strength or range of motion.

What might these injuries include?

• Rotator cuff tendinitis
• Shoulder impingement syndrome
• Rotator cuff bursitis
• Biceps tendinitis
• Other kinds of tears

Other Shoulder Tears

Alternatively, something may be torn, but it may not be the rotator cuff. The complex shoulder joint hosts several tendons, muscles, and surrounding tissues. These tears can lead to pain, decreased mobility, weakness, and sometimes a catching feeling when moving the shoulder.

Your rotator cuff differential diagnosis should consider these common shoulder tears:

• Biceps tendon tear: Although often associated with the rotator cuff, the biceps tendon is not officially part of the grouping. However, the long head of the biceps tendon helps attach the humerus to the scapula and works closely with the rotator cuff tendons. As a result, a biceps tendon tear will closely mimic the rotator cuff tear symptoms.
• SLAP tear: Superior Labrum from Anterior to Posterior tear, named for the type and direction of the tear involved.
• Bankart tear: This tear is caused by dislocation, instead of the other way around. The labrum tears, but in a different direction than a SLAP tear. After tearing, it is weaker and cannot stabilize the shoulder. This weakness may lead to repeated shoulder dislocations.

Completely Different Shoulder Injuries

Yet another possibility to consider is an entirely different type of shoulder problem. Rather than the soft tissue, there could be a dysfunction of the joint itself. These injuries will still cause pain, loss of range of motion, and grinding sensations or crepitus.

Though there are plenty of other shoulder injuries to consider as part of a rotator cuff differential diagnosis. Some of the most common are:

• Shoulder fracture: Typically more acute, accompanied by severe pain, and often swelling, bruising, and deformity.
• Dislocation: Anterior or posterior, often occurring after a specific trauma.
• Adhesive Capsulitis (frozen shoulder): Generally presents as pain that gradually increases and leads to a drastic or complete loss of range of motion.
• Osteoarthritis: Typically located more posteriorly and deep within the joint, compared to rotator cuff injuries.

Nerve Conditions

In addition to the tissue and joint issues above, some nerve conditions can present similarly to rotator cuff injuries. Typical rotator cuff tear symptoms can be replicated by pinched or damaged nerves. If your patient is presenting with shoulder pain, limited range of motion, and weakness, you may also want to look into the following:

• Fibromyalgia
• Rheumatoid Arthritis
• Complex Regional Pain Syndrome
• Thoracic Outlet Syndrome
• Neuropathy
• Brachial Plexus Injury
• Cervical Radiculopathy

Diagnostic Tools for Rotator Cuff Differential Diagnosis

The most definitive way to establish an accurate shoulder pain diagnosis is via arthroscopy or operative findings. However, other testing methods are less extreme and can help us determine what a patient is dealing with.

Physical Testing and Exam

A thorough evaluation begins with a patient history and physical exam. A complete history can often be the determining factor in a correct diagnosis. Standardized tests, such as the DASH or the COPM can help us to find quantifiable answers to our questions about pain and daily function.

Range of motion and strength testing provide important baseline measurements. If you use objective evaluation tools, you can later compare results to show progress over time. Palpation of bony prominences, tendon heads, and other surrounding “landmarks” can give a clear picture of the level of involvement.

Clinical testing can also help to determine the type and extent of rotator cuff involvement. While there are many special tests to assess rotator cuff tear types, some can also give an idea of other diagnoses. For example, Neer’s sign can determine impingement. Learn more about specific clinical tests in this article: Rotator Cuff Evaluation: Standardized Tests, Strength, ROM, and Questionnaires.

Imaging

MRI and ultrasound are the most common diagnostic tools in evaluating rotator cuff tears. As the more sensitive tool, MRIs can identify the tear, measure its severity, and provide information on the surrounding tissue. MRIs are also helpful in determining anomalies in the labrum, ligaments, and other tendons.

In contrast, ultrasound is more helpful in examining soft tissues. Ultrasound can help to assess subacromial impingement syndrome, bursitis, and degenerative arthritic changes.

A third option, X-rays, can help rule out other diagnoses. For example, a chest X-ray may reveal bone spurs surrounding the rotator cuff tendons. These may be causing rotator cuff tendinitis or impingement. An X-ray is also the most common way to rule out a shoulder fracture and can indicate degenerative changes caused by arthritis.

Nerve Studies

A nerve study is another method to evaluate the function of the shoulder joint. Nerve conduction studies (NCS) and needle electromyography (NEMG) can determine the functional abilities of the nerves that innervate the shoulder muscles. They can provide diagnostic information on nerve injury, impingement, entrapment, radiculopathy, and thoracic outlet syndrome (TOS).

Conclusion

Although rotator cuff tears are the leading cause of shoulder pain in the United States, they are not always to blame! A rotator cuff differential diagnosis will help us consider many other possible causes of shoulder pain, weakness, and loss of mobility. By utilizing a comprehensive physical exam, a complete patient history, incorporating special tests, and ordering imaging and nerve studies as appropriate, we can ensure we get our patients the help they need.

Sydney Moninger, COTA/L is an Occupational Therapy Assistant and freelance writer. She has more than 10 years of clinical experience working in pediatric, orthopedic, and geriatric settings. Most recently, she has been helping patients at a pain management center for orthopedic injuries. Sydney is passionate about patient education and increasing health literacy in the community, which is what got her started in her writing in the first place. She loves discovering new perspectives that improve her clinical practice, and connecting with others on LinkedIn or her Upwork page.

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