Rotator cuff tears are diagnosed through a combination of a physical exam and imaging, typically an MRI or ultrasound. No single test confirms a tear on its own. Your doctor will assess your symptoms, move your shoulder through specific positions to test for weakness and pain, and then order imaging to confirm the tear’s size and location.
What makes diagnosis tricky is that rotator cuff tears are surprisingly common and don’t always cause symptoms. About 10% of people with an average age of 44 have full-thickness tears visible on MRI without any pain at all. By age 80, up to half of people have tears. So the diagnostic process isn’t just about finding a tear; it’s about determining whether the tear is actually causing your problem.
What Symptoms Point Toward a Tear
The classic symptom is a deep, dull ache inside the shoulder, not a sharp surface-level pain. It tends to worsen at night, especially if you sleep on the affected side. Everyday tasks that involve reaching become difficult: combing your hair, reaching behind your back, or lifting objects away from your body. Arm weakness often accompanies the pain, particularly when raising your arm to the side or rotating it outward.
A sudden tear from an injury usually causes immediate sharp pain and noticeable weakness. Degenerative tears, which develop gradually from wear over time, tend to start with mild discomfort that slowly worsens over months. Some rotator cuff tears cause no pain at all, which is why imaging is so important when symptoms do appear. Without treatment, tears can lead to permanent loss of motion or weakness in the shoulder joint.
How the Physical Exam Works
Before ordering imaging, your doctor will put your shoulder through a series of specific movements designed to stress different parts of the rotator cuff. These provocative tests isolate individual tendons to see which one is damaged. The results guide which imaging to order and help distinguish a tear from other shoulder conditions.
One of the most common is the Empty Can test, which targets the supraspinatus tendon (the most frequently torn). You’ll raise both arms out to the side at shoulder height, angle them slightly forward, then turn your thumbs downward as if pouring out a can. The examiner pushes down against your arms while you resist. Pain or weakness on one side suggests a supraspinatus injury. Another useful test is the Drop Arm sign: you raise your arm fully overhead, then slowly lower it. If you can’t control the descent and your arm drops suddenly, that points toward a significant tear.
The Neer test checks for impingement, where the examiner raises your straightened arm forward while stabilizing your shoulder blade. Pain during this motion suggests the rotator cuff is being pinched. This test is highly specific (around 97 to 98%), meaning a positive result strongly suggests a real problem. However, its sensitivity is lower (about 40 to 44%), so a negative result doesn’t rule anything out.
No physical exam maneuver is accurate enough to confirm a tear by itself. These tests are screening tools that, taken together, build a clinical picture and justify imaging.
Distinguishing a Tear From Other Shoulder Problems
Several shoulder conditions produce overlapping symptoms, which is part of why diagnosis requires multiple steps. Subacromial bursitis (inflammation of the fluid-filled sac above the rotator cuff) and rotator cuff tendinopathy (irritation without a tear) both cause pain when moving the arm overhead, just like a partial tear. The key difference is weakness. Bursitis and tendinopathy cause pain but generally preserve strength. A complete tear causes both pain and clear weakness, especially with external rotation.
Frozen shoulder is another common mimic. It restricts motion in all directions, including passive movement (when someone else moves your arm for you). With a rotator cuff tear, passive range of motion is usually preserved; it’s the active, self-powered movement that’s limited. Your doctor can often distinguish these during the physical exam by moving your arm for you and noting whether the restriction persists.
MRI, Ultrasound, and Other Imaging
Imaging confirms the diagnosis and reveals the tear’s size, which directly affects treatment decisions. The two primary options are MRI and ultrasound, and for full-thickness tears, they perform almost identically. Both detect full-thickness tears with about 90 to 91% sensitivity and 93 to 95% specificity.
Partial tears are harder to catch. Both MRI and standard ultrasound detect them only about 67 to 68% of the time. MR arthrography, where contrast dye is injected into the joint before the MRI, bumps that detection rate up to 83% while maintaining the same high specificity. If your doctor suspects a partial tear and an initial MRI comes back inconclusive, MR arthrography may be the next step.
Ultrasound has practical advantages: it’s less expensive, doesn’t require you to lie still in a tube, and allows the examiner to watch your shoulder move in real time. The tradeoff is that its accuracy depends heavily on the skill of the person performing it. MRI provides a more standardized, detailed picture of the entire shoulder, including the bone and cartilage, which helps rule out other problems simultaneously.
X-rays don’t show soft tissue like tendons, so they can’t directly reveal a tear. But they’re sometimes ordered first to check for bone spurs, arthritis, or other bony abnormalities that could be contributing to your symptoms or that might affect surgical planning.
Understanding Tear Size on Your Report
Once imaging confirms a tear, it’s classified by size. These categories show up on radiology reports and directly influence whether your doctor recommends physical therapy or surgery:
- Small: under 1 cm
- Medium: 1 to 3 cm
- Large: 3 to 5 cm
- Massive: over 5 cm, typically involving two or more tendons
Small and medium tears often respond well to conservative treatment, especially in people with moderate activity levels. Large and massive tears are more likely to require surgical repair, particularly in younger or more active individuals. But size alone doesn’t determine the plan. A small tear in someone who depends on overhead arm strength for work may warrant surgery, while a large tear in an older adult with minimal symptoms might be managed with physical therapy.
Why Age and Context Matter
Rotator cuff disease affects between 6.8% and 22.4% of people over 40, and tear prevalence increases with every decade of life. This means a tear found on imaging isn’t automatically the source of your pain, especially if you’re over 60. Your doctor will correlate the imaging findings with your symptoms, physical exam results, and activity level before recommending a course of action.
If your symptoms match the location and severity of the tear on imaging, the diagnosis is straightforward. If the imaging shows a tear but your symptoms don’t quite fit, or if the tear looks old and degenerative while your pain is recent, your doctor may investigate other causes like bursitis, a labral tear, or cervical spine problems referring pain to the shoulder. The diagnosis is rarely just about finding the tear. It’s about confirming the tear is the actual problem.