Jersey Finger

Jersey finger is when the deep flexor tendon — the one that bends the tip of your finger — pulls completely off the bone at the fingertip. The ring finger is by far the most often affected. The classic mechanism: you're grabbing onto someone's jersey or clothing during a tackle and your finger gets forcibly straightened while you're trying to grip — the tendon snaps off the bone.

You won't be able to bend the tip of the affected finger. The torn end of the tendon often retracts up into the palm — so the bump or tender spot might be felt much higher than the fingertip.

The hallmark of jersey finger is the sudden inability to bend the tip of the affected finger — typically the ring finger. You may feel a pop during the injury, followed by pain and swelling along the palm side of the finger.

The torn tendon often retracts toward the palm, so tenderness and a palpable lump may appear in the finger, palm, or even the base of the finger rather than at the fingertip itself. Bruising along the palm side of the finger is common. Grip strength drops noticeably, and you may struggle to hold objects between the affected finger and your thumb.

Your surgeon checks whether you can bend just the tip of the finger when the rest of the finger is held straight — if you can't, that's the diagnosis. Tenderness may be at the tip, along the finger, or as far up as the palm depending on how far the tendon has retracted. X-rays show whether a small chunk of bone came off with the tendon (an avulsion fragment). MRI locates the retracted tendon end when X-rays are negative.

Jersey finger is almost always repaired surgically — and time matters. The torn tendon quickly loses blood supply once it retracts, and the longer it scars and contracts in its new position the harder the repair becomes. Prompt repair, ideally within a couple of weeks of the injury, is strongly preferred.

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

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