Rotator cuff tears are one of the most common causes of shoulder pain.
Prevalence of tear increases with age. Most significant findings are impingement and "arc of pain" sign (pain during descent of abducted arm) 1. Supraspinatus weakness, night pain and weakness of external rotation (seen in infraspinatus tear) are also seen.
Important causes of rotator cuff tear are
- trauma (acute, chronic repetitive)
- subacromial impingement
- tendon degeneration
Specific sub types
The original Codman classification system published in 1930 was as
- full thickness rotator cuff tear (FTRCT)
- partial thickness rotator cuff tear (PTRCT)
Exact features depend on the type of tear, general features include
- may show a decreased acromiohumeral distance i.e. less than 2 mm ( on an 'active abduction' view)
- may show decreased supraspinatus opacity and decreased bulk due to atrophy, may be seen in chronic cases (on an 'outlet view')
- humeral subluxation superiorly may be seen in late cases
- may show features of acromial impingement -
- spur formation on the undersurface of acromioclavicular joint
- acromion with an inferolateral tilt (type III acromion) seen on outlet view i.e. modified 'Y' view
- secondary degenerative changes - sclerosis, subchondral cysts, osteolysis, and notching or pitting of greater tuberosity
In the hands of good radiologist, ultrasound may have up to 90% sensitivity and specificity. It can also reveal other mimics like tendinosis, calcific tendinitis, subacromial subdeltoid bursitis, greater tuberosity fracture and adhesive capsulitis.
Full-thickness tears extend from bursal to articular surface, while partial thickness tears are focal defects in the tendon that involve either the bursal or articular surface. Full-thickness appear on ultrasound as hypoechoic/anechoic defects in the tendon. Due to the fluid replacing tendon, cartilage shadow gets accentuated giving a 'double cortex' or 'cartilage interface sign'. Also, due to the defect, overlying peribursal fat dips down into the tendon gap, creating a 'sagging peribursal fat' sign1.
In summary, direct signs are - non-visualization of supraspinatus tendon and hypoechoic discontinuity in tendon. Indirect signs are - double cortex sign, sagging peribursal fat sign, compressibility and muscle atrophy.
Secondary associated signs are - cortical irregularity of greater tuberosity, shoulder joint effusion, fluid along biceps tendon, fluid in axillary pouch and posterior recess.
Complete tears are easier to diagnose on MRI than full-thickness tear 2 . Hyperintense signal area within the tendon on T2W, fat-suppressed and GRE sequences, usually corresponding to fluid signal is seen.
Partial tears are extending to either bursal or articular surface, and sometimes intrasubstance. Retraction of tendinous fibers from the distal insertion into the greater tuberosity may also be considered partial tear.
Complete tears extend from articular to bursal surface, most commonly in supraspinatus tendon. Presence of tendon defect filled with fluid is most direct sign of rotator cuff tear. Tendon retraction may also be present. Indirect signs on MRI are - subdeltoid bursal effusion, medial dislocation of biceps, fluid along biceps tendon, and diffuse loss of peribursal fat planes. Muscle atrophy is seen in chronic cases. Chronic tears have degenerative changes at acromioclavicular joint, acromioclavicular joint cysts, as well as intramuscular cysts.
MR arthrography may enhance the detection of rotator cuff tears, especially complete tears.
General imaging differential considerations include
- calcific tendinitis
- subacromial subdeltoid bursitis
- greater tuberosity fracture
- adhesive capsulitis
- supraspinatus tendinitis
- 1. Moosikasuwan JB, Miller TT, Burke BJ. Rotator cuff tears: clinical, radiographic, and US findings. Radiographics. 25 (6): 1591-607. doi:10.1148/rg.256045203 - Pubmed citation
- 2. Stoller DW, Fritz RC. Magnetic resonance imaging of impingement and rotator cuff tears. Magn Reson Imaging Clin N Am. 1993;1 (1): 47-63. - Pubmed citation
- 3. Kaplan P. Musculoskeletal MRI. W B Saunders Co. (2001) ISBN:0721690270. Read it at Google Books - Find it at Amazon
- 4. Haaga JR, Boll D. CT and MRI of the whole body. Mosby. (2009) ISBN:0323053750. Read it at Google Books - Find it at Amazon
- 5. Tuite MJ, Turnbull JR, Orwin JF. Anterior versus posterior, and rim-rent rotator cuff tears: prevalence and MR sensitivity. Skeletal Radiol. 1998;27 (5): 237-43. Pubmed citation
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Rotator cuff tears||✗|
|Tears of the rotator cuff||✗|