Orthopedic Teaching Cases 2023, Jan, 18 | 12:00 am

Shoulder and Elbow cases SLAP tear

A 34-year-old, right-hand-dominant man who works in construction presents to clinic with 3 weeks of right shoulder pain. A few days ago, he was working on a ladder 20 ft off the ground when he fell. As he was falling, he grabbed a nearby tree branch with his right hand. He felt immediate pain in his right shoulder and is now having pain, clicking, and catching with overhead activity. He is otherwise healthy and takes no medications. On examination, his right, upper extremity is neurovascularly intact; his active and passive shoulder range of motion is limited by clicking and catching; and he has a positive compression–rotation test, Neer impingement sign, Hawkin’s sign, and Speed’s test. He also has pain with anterior apprehension test. The rest of the examination is normal. X-rays are normal.

What is the most likely diagnosis?

  1. Acromioclavicular joint arthritis

  2. Full-thickness rotator cuff tear

  3. Subacromial bursitis

  4. Superior labral tear from anterior to posterior (SLAP tear)

  5. Partial-thickness rotator cuff tear

 

Discussion

The correct answer is (D). In an acute shoulder injury caused by a traction mechanism with pain associated with overhead motion and mechanical symptoms such as popping, catching, clicking, or grinding, the most likely injury is a SLAP

tear. A SLAP tear is identified in about 6% of all shoulder arthroscopies. Of these, about 12% to 30% are isolated SLAP tears and 70% to 88% are associated with other shoulder pathologies.

Acromioclavicular (AC) joint arthritis (Answer A) does not usually occur in an acute injury. It typically has an insidious onset and is more common in patients who are weight lifters or overhead throwing athletes. Mechanical symptoms are not typical.

Rotator cuff tears, subacromial bursitis (Answers B, C, and E), and SLAP tears can present almost identically, with pain in overhead motion, pain when lying on the shoulder, and loss of strength. Like patients with rotator cuff disease, a large number of patients with SLAP tears have positive Neer impingement and Hawkin’s signs. In younger patients, rotator cuff tears are less common, but acute avulsion tears do happen. In this patient, however, the presence of the clicking and catching, positive Speed’s test, and pain with anterior apprehension test make a SLAP tear more likely than a rotator cuff tear.

Which of the following is not a usual mechanism by which SLAP tears usually occur?

  1. Fall on an outstretched arm with tensed biceps

  2. Distraction of the glenohumeral joint

  3. Repeated overhead throwing

  4. Military press weight lifting

  5. Shoulder dislocation

 

Discussion

The correct answer is (D). This is a common mechanism of AC joint pathology including distal clavicular osteolysis.

The most common mechanisms by which a SLAP tear occurs are compression (Answer A) and traction (Answer B). Compression generally occurs when a person falls on an outstretched arm that is slightly flexed and abducted with a tensed biceps. Traction can occur in an anterior, superior, or inferior direction. In the case of this patient, he was falling and caught a tree branch, causing traction in a superior direction. Traction can also occur with overhead throwing (Answer C) or with shoulder dislocation (Answer E). Up to 33% of slap tears, however, have insidious onset.

Many studies have been conducted to investigate SLAP tears in the context of overhead throwing. It appears that SLAP tears are most likely to occur during the

late cocking and deceleration phases of throwing due to the increased stress and strain at the superior glenoid/biceps tendon interface and decreased strength of the biceps tendon in these positions. In addition, posterior capsule contracture with consequential increased external rotation and decreased internal rotation of shoulders of overhead throwing athletes can lead to a peel-back phenomenon of the biceps anchor and internal impingement of the rotator cuff between the humerus and the posterosuperior labrum in the late cocking phase, leading to SLAP tears. This is especially true in patients who have over 25 to 30 degrees less internal rotation as compared to the contralateral shoulder.

Which one of the following physical examination maneuvers is not used to diagnose a SLAP tear?

  1. Crank test

  2. Load and shift test

  3. O’Brien’s test

  4. Anterior slide test

  5. Anterior apprehension test

 

Discussion

The correct answer is (B). This test is used to diagnose shoulder instability.

At this time, there is no highly sensitive or specific physical examination finding for SLAP tears. Authors who first describe the findings report good accuracy, but these findings are not replicated by independent examiners. However, there have been many maneuvers described to test for a SLAP tear including the Crank (Answer A), O’Brien (Answer C), anterior slide (Answer D), and anterior apprehension (Answer E) tests.

The O’Brien is one of the most common and is conducted as follows: the shoulder is flexed 90 degrees, internally rotated, and slightly adducted. Resisted shoulder flexion is performed in this position and then repeated with the shoulder externally rotated but still in 90 degrees of flexion and slightly adducted. If pain is experienced with internal rotation that is deep, anterior, and decreased with external rotation, the test is considered positive (see Fig. 2–21A–B).

 

 

Figure 2–21 (A–B) O’Brien’s active compression test. Left: resisted shoulder flexion in pronation. Right: resisted shoulder flexion in supination. (From Tennent TD, Beach WR, Meyers JF. A review of the special tests associated with shoulder examination. Part II: laxity, instability, and superior labral anterior and posterior (SLAP) lesions. Am J Sports Med. 2003;31(2):301–307.)

 

What is the next step in management?

  1. Physical therapy and NSAIDs

  2. Diagnostic arthroscopy

  3. Arthroscopic debridement

  4. Arthroscopic repair

  5. Arthroscopic biceps tenodesis

 

Discussion

The correct answer is (A). Although there have been few studies that have reported on the efficacy of conservative treatment of SLAP tears, it is a good first step in treatment because of the low risk when compared with surgical treatment (Answers C, D, and E) and high potential benefit. Also, as stated above, it is difficult to diagnose a SLAP tear on physical examination, and other shoulder injuries can often exist concomitantly with SLAP tears. Attempting a trial of physical therapy could result in complete resolution of symptoms whether the symptoms are due to a SLAP tear, a different pathology, or multiple pathologies.

A trial of physical therapy should also be attempted before any additional diagnostic testing is performed, such as MRI, MR arthrogram, or diagnostic arthroscopy (Answer B) unless an injury is suspected that requires acute diagnosis and treatment, which is not the case with this patient.

Physical therapy should focus on strengthening the rotator cuff muscles and scapular stabilizers while restoring normal range of motion, especially internal rotation. This trial should be at least 3 months in length with a suspected SLAP tear before surgery is considered to allow for the body to heal itself.

Objectives: Did you learn...?

 

Clinically diagnose a SLAP tear?

 

Treat a clinically-diagnosed SLAP tear?