The Case
An athlete presents to the ED with an injured pinky finger. He says that he struck it on a teammate during practice and “it bent back.” The pinky finger is abducted and jutting out at an extreme angle. It is making dad nauseous. The XRay shows the following:
Diagnosis
This is a Salter-Harris II fracture of the proximal 5th phalanx. The physis is stressed during impact and it is fractured because of the pull of the collateral ligament. You will often see an abducted, angulated digit. This is the most common proximal finger fracture in children. When it occurs in the 5th digit as seen in this example it is known as an extra-octave fracture. The term alludes to abducting the pinky finger to try to reach piano keys that are too far away.
The initial degree of angulation can be severe, often 60 to 90 degrees. You should also make sure that there is no rotational deformity, which can be better appreciated if the patient makes a fist.
Management
In general, any fracture angulated >10 degrees needs to be reduced. This fracture requires emergent involvement of a Hand Surgeon if:
- The fracture is open
- Tendon, nerve or vascular injury
- Intraarticular fracture that is unstable or significantly angulated/rotated
Angulation is more tolerated at the MCP joint as opposed to the PIP and DIP. The MCP joint is built to allow for a degree of side to side motion. Thus, following reduction <10 degrees of angulation is OK. However, there should be ZERO rotational deformity. Reduction should occur only after appropriate analgesia. Sedation is not necessary if the patient is cooperative and appropriate local/regional anesthesia applied. For the case example an Ulnar Nerve Block could be a good option. This procedure can be performed via ultrasound guidance.
Reduction is achieved by applying traction to the digit, gently flexing the MCP joint and then adducting the distal phalanx. After reduction patients should be splinted with radial or ulnar gutter splints (depending on the injured finger). For the young man in the case example an ulnar gutter would suffice. The MCP joint should be in 70-90 degrees of flexion in the properly applied splint. The PIP joint should be extended.
Patients that undergo successful reduction should be reevaluated in one week. The Hand Specialist will look for post-reduction displacement, shortening, angulation and rotation. Fractures with any of those findings may require operative intervention. Follow up for stable injuries will then occur at 1-2 week intervals until healing is satisfactory – often 4-6 weeks.
