Long head of biceps dislocation grading.

(Adapted from Resnick24) Normal: Graphic depicting the biceps pulley region from an oblique axial perspective, perpendicular to the course of the LHBT just superior and medial to the bicipital groove. The coracohumeral ligament (CHL) is the most superficial layer of the biceps pulley mechanism and extends over the subscapularis (SScT) and supraspinatus (SST) tendons. The superior glenohumeral ligament fuses with the CHL laterally and forms a ligament layer between the biceps tendon (BT) and the superior-most inserting subscapularis tendon (SScT) at the lesser tuberosity (LT).

Type I: Tendon displacement-subscapularis tendon (SScT) tear alone. Medial shift or minor subluxation of the biceps tendon secondary to a partial intrasubstance or anterior tear of the subscapularis tendon with intact medial ligament component of the biceps pulley.

Type II: Tendon displacement-medial ligament tears alone. Slightly greater medial subluxation of the biceps tendon through the torn portion of the ligaments, but the intact subscapularis tendon fibers prevent medial dislocation.

Type III: Extra-articular tendon dislocation-tears of the medial ligaments and subscapularis tendon. A partial intrasubstance tear of the subscapularis tendon allows the biceps tendon to dislocate medially without entering the joint because of intact deep fibers of the subscapularis tendon.

Type IV: Extra-articular tendon dislocation-tears of the lateral limbs of the ligaments with an intact subscapularis tendon. The biceps tendon dislocates anteriorly becoming located anterior to the intact subscapularis tendon. This pattern has a high association with partial or full-thickness tears of the supraspinatus tendon. Although a full-thickness tear of the subscapularis is not required for this pattern, partial articular-sided, bursal-sided, and interstitial tears may be seen.

Type V: Intra-articular tendon dislocation-Tears of the medial and lateral limbs of the coracohumeral and superior glenohumeral ligaments with a full-thickness tear of the subscapularis allows medial dislocation of the LHBT into the joint. Most commonly the superior subscapularis tendon demonstrates a full-thickness tear while the lower portion of the tendon remains attached along the inferior portion of the lesser tuberosity and surgical neck. The course of the LHBT moves from a dislocated intra-articular position superiorly to an extra-articular location anterior to the intact subscapularis fibers inferiorly.

Type VI: Intra-articular tendon dislocation-tear of the medial limbs of the ligaments and detachment of the subscapularis from the lesser tuberosity. Bridging fibers from the subscapularis to the greater tuberosity remain intact. Medial dislocation of the biceps tendon remains deep to the subscapularis and enters the glenohumeral joint.