Partial vs Full-Thickness Rotator Cuff Tear on MRI

“Partial-thickness tear” or “full-thickness tear” in your report

A partial-thickness tear goes only part of the way through the tendon, from the joint side (articular-sided) or the bursal side, or sits inside it. A full-thickness tear goes all the way through, so the joint and the bursa above connect. Reports then describe depth or width, retraction and fatty atrophy of the muscle.

How radiologists phrase it

• “Low-grade partial-thickness articular-sided tear of the supraspinatus”
• “High-grade bursal-sided partial-thickness tear involving more than 50% of the tendon”
• “Intrasubstance (interstitial) tear”
• “Full-thickness, partial-width tear of the supraspinatus”
• “Full-thickness tear measuring 1.5 cm with retraction to the humeral head; Goutallier grade 2 fatty infiltration”

Reading the numbers

• Low grade and high grade compare the depth of a partial tear with the tendon's thickness. Ellman's scale grades depth as under 3 mm, 3 to 6 mm, or over 6 mm, which is more than half the tendon.
• “Full-thickness, partial-width” means the tear goes all the way through but only across part of the tendon from front to back.
• Retraction is how far the torn end has pulled back from the bone. Patte staged it from near the insertion, to the humeral head, to the glenoid.
• Fatty atrophy or fatty infiltration (Goutallier grade 0 to 4) describes fat replacing muscle; higher grades are linked with poorer results after repair.

Does it change the plan?

Cuff tears are common in shoulders that do not hurt. One ultrasound study found tears in 13% of people aged 50 to 59 and in 51% of those over 80 without shoulder symptoms, so a report is read alongside pain, strength and function. For full-thickness tears, size, retraction and fatty atrophy are the details surgeons weigh when judging whether a tendon can be repaired.

What to ask at your follow-up

• Is my tear partial or full thickness, and on which side of the tendon?
• How wide is it, and how far has the tendon retracted?
• What grade of fatty change does the muscle show?
• Could my symptoms come from something else on the scan?

Rotator cuff tears are classified using several grading systems that describe the depth, size, location, and tissue quality of the injury. Understanding these classifications helps you interpret your MRI report, have meaningful conversations with your surgeon, and understand the treatment options available for your specific tear type.

This guide covers the major classification systems used for rotator cuff tears, including the distinction between partial and full-thickness tears, the Ellman classification for partial tears, and the Patte classification for tendon retraction. For guidance on reading your shoulder MRI, see our article on how to read shoulder MRI.