Distal Triceps Tendon Rupture

A distal triceps tendon rupture is the least common upper-limb tendon rupture. The triceps muscle on the back of your upper arm attaches to the bony point at the tip of your elbow (the olecranon) — its job is to straighten your arm. The tendon usually tears from a fall onto an outstretched arm, or from a sudden eccentric load while pushing off (think bench press or push-up gone wrong). Risk factors include anabolic steroid use, repeated corticosteroid injections near the tendon, kidney failure, and hyperparathyroidism. With a complete tear, you can't straighten your elbow against gravity.

You'll feel a sudden sharp pain at the back of your elbow during a forceful push or after a fall. There may be a pop. Swelling and bruising develop quickly over the back of the elbow, and you may notice a soft gap just above the bony point (the olecranon) where the tendon should be.

The defining symptom is weakness or inability to straighten your elbow against gravity — pushing yourself up from a chair or doing a push-up becomes impossible. With a partial tear, you may still extend the elbow but with noticeably less power and a sense that something is wrong at the back of the joint.

Pain and swelling at the back of the elbow after the injury, plus weakness or inability to straighten your elbow. In a complete tear your surgeon can often feel a soft gap right above the bony tip of the elbow. X-rays sometimes show a tiny chip of bone pulled off where the tendon attached (the flake sign). MRI confirms the diagnosis and shows how much of the tendon is torn.

Complete tears — where you can't straighten your elbow — should be repaired promptly. The longer you wait, the more the tendon retracts up the arm and scars to surrounding tissue, making the eventual repair harder and the result less reliable.

External patient-education references and related OSI pages for additional background:

• Britannica — Tendon
• Britannica — Joint (anatomy)
• AAOS OrthoInfo — patient education library
• OSI glossary — orthopedic terminology in plain language