Rupture of Flexor Digitorum Profundus
due to forced extension of flexed finger
Classic in rugby, as a player pulls away from the injured player who is trying to grip his/her jersey
Can occur in all fingers but these injuries are most common in the ring finger which is affected in 3/4 of cases
This may be due to tethering by the lumbrical muscles or that this finger shares a muscle belly with the middle and little fingers
If bony avulsion present, position of tendon end can be seen on xray
On the flexor side, there are 5 zones, also numbered from distal to proximal
Leddy-Packer classification
Type I: tendon retracts into palm
Type II: tendon retracts to PIP joint
Type III: tendon entrapped at A4 pulley
