Distal biceps rupture: the coil sign.

Delayed repair of the distal biceps brachii tendon can lead to the formation of scar tissue and coiling of the tendon. Dissection of the scar tissue and unraveling of the tendon may allow for anatomic repair to the radial tuberosity. A 50-year-old man had a distal biceps brachii tendon tear with an intact lacertus fibrosis. Surgery was performed 22 days after injury. On inspection, the distal biceps tendon was coiled, encased in scar tissue, and unable to be reduced to the radial tuberosity. Dissection of the scar tissue and unraveling of the tendon provided additional length, allowing anatomic repair. Postoperatively, the patient regained full range of motion and strength and returned to work without restrictions. After a distal biceps brachii tear in which the lacertus fibrosis remains intact, the coiled tendon may become enveloped in a sheath of scar tissue. Dissection of the "pseudosheath" unveils the native tendon and allows reduction to the radial tuberosity. Cadaveric analysis shows that the pseudosheath may conceal 6 cm of coiled tendon. When the lacertus fibrosis remains intact after distal biceps tendon rupture, the tethered tendon stump may coil, become encased in scar tissue, and resemble the native tendon. Failure to identify the native tendon could result in the loss of 6 cm of tendon.