MR arthrography of SLAP X tear with rotator interval tear and biceps tendon rupture

Clinical History

A young athlete (Jiu-jitsu player) presented with pain and weakness in the right shoulder 3 months after trauma sustained during a competition. Physical examination revealed severe pain on abduction and inability to adequately flex the biceps muscle.

Imaging Findings

MR arthrography was performed for better delineation of lesions. Axial, sagittal and coronal images confirmed a large superior labral tear extending from 10 o’clock to 2 o’clock. The labrum was completely detached from the underlying glenoid bone with contrast noted between these 2 structures. The detached labrum was also split into fragments.

The rotator interval structures were also involved. Partial tear of the superior glenohumeral ligament was noted with fraying of the fibres. A large tear was also visualised in the coracohumeral ligament best seen on the coronal and sagittal images.

There was also rupture of the long head of biceps tendon with detachment from the biceps-labral complex. The tendon was also retracted into the bicipital groove.

The combination of findings were suggestive of a SLAP X tear and the findings were confirmed on arthroscopy.

Discussion

The superior labrum, rotator interval structures and the intra-articular portion of the long head of biceps tendon are some of the most difficult structures to evaluate by both MRI and arthroscopy. MR Arthrography has become the imaging modality of choice to evaluate these areas over the last decade [1, 2, 3]. In our institution, we use a mixture of 0.2 ml gadolinium, 10 ml iodinated contrast and 10 ml lidocaine to inject either via CT or ultrasound guidance.

Knowledge of anatomy and variants are critical to diagnosing lesions in these areas. The normal superior labral variants that simulate tears are noted from 11 - 3 o’clock. These include sublabral foramen, sublabral recess and Buford complex [1, 4]. The rotator interval consists of the capsule, superior glenohumeral ligament and the coracohumeral ligament between the subscapularis and supraspinatus tendons. It play an important role in preventing inferior and posterior translation at the gleno-humeral joint [5, 6]. These structures also form the biceps pulley while crossing over the biceps tendon and protect the tendon from dislocation [3]. High quality thin section arthrogram images are needed to demonstrate these structures effectively.

SLAP tears were originally classified into 4 types by Snyder depending on the extent of the labral tear and involvement of the adjacent biceps tendon. Over time, the classification has extended to 10 sub-types based on the extent of involvement of adjacent structures [1, 4]. Beltran first described the SLAP X tear in 2000 as a superior labral tear which not only involves the origin of the biceps tendon but also extends to involve the rotator interval structures (CHL and SGHL) with articular side abnormalities as seen in our case. This tear is important to recognise as it requires surgical management.

There are multiple other lesions that can involve the rotator interval and the biceps [7]. These include post-traumatic biceps pulley tears which lead to subluxation/dislocation of the biceps tendon. The tendon can also be affected by partial/complete tears and tendinitis. Adhesive capsulitis is manifested by thickening of the rotator interval capsule and ligaments with loss of normal fat and difficulty in intra-articular contrast injection.

Our case demonstrated a SLAP X tear with rupture of the biceps tendon. Due to the multiple subtypes of SLAP lesions, it is essential to describe the lesions in clock-wise distribution and the additional structures involved. Early operative repair followed by rehabilitation is essential [8].

Differential Diagnosis List

Final Diagnosis

SLAP X tear with rotator interval tear and biceps tendon rupture

URL:	https://eurorad.org/case/14543
DOI:	10.1594/EURORAD/CASE.14543
ISSN:	1563-4086