Loss of Supination Force with Partial Distal Biceps Avulsion

In the May 5, 2021 issue of JBJS, Tomizuka et al. report the results of mechanical testing in which they quantified the loss of supination and flexion strength after a series of surgical releases designed to simulate traumatic avulsions of the short and long head of the distal biceps tendon.

Reflecting on the clinical implications of their study, the authors note:

Partial tears of the distal biceps tendon can cause substantial disability, yet the mechanical effect of such ruptures is not fully understood. This study showed that a simulated complete short-head tear significantly decreased (p ≤ 0.043) the supination moment arm by 24% in pronation and 10% in neutral.

A mechanical case can be made for early repair of a partial distal biceps tendon tear when the rupture is ≥75% of the distal insertion site.”

Click here for the full JBJS report.

A JBJS Clinical Summary on distal biceps tendon rupture can be found here.