Fractures to the fingers and hands are common. Mallet finger is a deformity caused from a blow to the finger at the DIP joint. Patient is unable to straighten the DIP due to avulsion injury.
Most often mallet finger injuries can be treated without surgery. Treatment is given by applying a splint to immobilize the fingertip in extension. Movement should be allowed in the PIP joint. Surgery may be necessary if more than 50% of the joint is involved or there is subluxation of the joint to restore the function of the extensor tendon.
Middle and proximal phalangeal fractures:
The normal relaxed cascade of the hand should form a straight alignment of the fingers. When holding a relaxed cascade, the fingers should normally point towards the region of the scaphoid. Malrotation of the finger will cause the affected finger to deviate from its normal rotational direction.
If there is no rotational deformity, the finger is treated by buddy taping the injured finger to the adjacent normal finger for 2-3 weeks. If rotational deformity is present, a digital block is given and the fracture is reduced in a volar splint. The MCP is held in 70 degrees of flexion for proximal phalanx fractures for 2-3 weeks. The splint holds the DIP and PIP in 0 degrees extension in middle phalanx fractures. Then buddy tape for additional 2 weeks.
The wrist should be immobilized in 20 degrees extension and the MCP in 60-70 degrees of flexion.
The fingers should be kept free in order to check for rotation. Finger fractures means stiffness of the fingers.
Indication for surgery:
- Rotational deformity
- Open fracture
- Multiple unstable fractures
- Significant angulation or deformity.
- Articular displacement
- Metacarpal shortening especially with the middle and index fingers.
If the fracture is displaced or unstable, closed reduction and K-wire is an option for fixation.
Plating is another option for fixation however it is rare.
In phalanx fractures treated by ORIF, adhesions of the extensor tendon may occur. Patient may have decreased range of motion of the PIP which is called extrinsic tightness.
The patient will have greater passive PIP flexion with MP extension compared to when MP is flexed.