Anatomic and biomechanical analysis of the short and long head components of the distal biceps tendon

Anatomic repair of the distal biceps tendon cannot be consistently performed through a classic single-incision suture anchor technique

“…However, the short head loses this advantage in full supination when the cam effect of the bicipital tuberosity is gone, and then, the long head (which is attached more ulnar) becomes a stronger supinator. 19 The same authors showed, in a biomechanical model, that reattachment of the tendon in a nonanatomic position (radial to the tuberosity) had a minimal effect on strength with the forearm pronated. In contrast, the greatest effect of the repair was seen in full supination.…”

“…Interestingly, it is surprisingly a stronger supinator when the arm is in a pronated or neutral position. The authors 19 hypothesized that the short head has a bigger surface area and attaches closer to the apex of the tuberosity, which increases its lever action compared with the long head. However, the short head loses this advantage in full supination when the cam effect of the bicipital tuberosity is gone, and then, the long head (which is attached more ulnar) becomes a stronger supinator.…”

Distal biceps tendon injuries

“…From a biomechanical standpoint, the short head of biceps will have a higher moment arm, with the forearm in neutral and pronation, and likely contributes more to elbow flexion. 7,8 In contrast, the long head of biceps will have a higher moment arm in supination due to the fact that its insertion is more proximal and farther away from the radial axis of rotation. 7,8 When repairing the DBT, the medial aspect of the tendon must be secured distally, and the lateral aspect of the tendon laterally; this may be facilitated by using medial and lateral sutures of different colours or lengths.…”

Endoscopic-assisted Distal Biceps Footprint Repair

“…Hence, in full supination, when the biceps is taught, the tendon drapes around the radial tuberosity. 6 The aim of surgical repair is to recreate the native anatomy to restore normal, full function. All current fixation methods strive to repair the tendon to the most ulna aspect of the tuberosity, however, despite these efforts, current techniques still repair the biceps to the volar aspect of the radial tuberosity.…”

“…6 If the tendon is repaired anterior to the footprint, the supination torque is reduced, especially in the fully supinated position. 6 The aim of this technique is to restore the biceps tendon to its true anatomic footprint, and therefore reestablish the forearm supination function.…”