Articular-sided rotator cuff tear
Articular-sided rotator cuff tears commonly occur in athletes with overhead activity .
They are more common than bursal-sided tears and most common in overhead athletes , but according to cadaver studies less common than intra-substance tears in the general population .
- throwing sports
- overhead sport activity
Internal impingement is thought to have a significant role in the occurrence of a partial articular-sided rotator cuff tear and another extrinsic factor is glenohumeral instability. Intrinsic factors include the relative hypovascularity of the distal parts of tendon and the footprint and a decreased overall strength in relation to the bursal side, due to a more random fiber orientation . In addition trauma either as a single event or repetitive microtrauma is also thought to have a role in the development of articular sided tears .
- an articular-sided rim rent tear or articular-sided tendon avulsion of the footprint, most commonly the tendon insertion of the supraspinatus tendon is called PASTA lesion.
- a partial articular-sided rim rent tear, extending into the tendon substance is called PAINT lesion (partial articular tear with intratendinous extension)
- PASTA lesions are most commonly found in the anterior supraspinatus tendon
- focal hypoechoic or anechoic defect of the rotator cuff, extending from the articular side into the tendon substance
- focal non-transmural articular-sided defect of fluid signal intensity of the rotator cuff on fat-saturated T2- weighted or intermediate-weighted images with intact residual fibers
MR arthrography is preferred over CT arthrography since it is also able to depict bursal-sided or intrasubstance tears .
MR and CT arthrography can depict articular-sided tears with intraarticular contrast extending into the tear. The ABER (abduction and external rotation) position is particularly useful to demonstrate intratendinous extensions or PAINT lesion because the tendon fibers become loose when the muscles relax and the contrast fills the delaminated space .
Treatment and prognosis
Partial-articular sided tears can be initially treated conservatively for 2-3 months, especially if symptoms are minor or even asymptomatic and include cessation of throwing activities, physical therapy with the focus on rotator cuff strengthening and range of motion .
Surgery is indicated for patients, who failed conservative treatment and younger patients with a single acute injury and include debridement and repair the latter especially in larger tears, where more than 75% of the tendon diameter is affected . PAINT lesions might need more extensive debridement or can be treated with non-absorbable mattress sutures .