-Definition: A mallet fracture is an “avulsion fracture of the distal phalanx with a bone fragment on the terminal extensor tendon, resulting in unopposed flexion and the inability to actively extend the distal interphalangeal (DIP) joint.”
-Will splint the distal interphalangeal (DIP) joint in extension for 8 weeks.
-Will keep the joint in full extension the entire time for optimal healing. Any flexion of the finger may negatively affect healing and extend the treatment time.
“If the finger fracture involves >30% of the intra-articular surface, referral to a hand or orthopedic surgeon can be considered. However, conservative therapy appears to have outcomes similar to those of surgical treatment and therefore is generally preferred.” ABFM

Mechanism of Injury

“These fractures are caused by an axial load to the tip of an extended finger that causes forced flexion at the distal interphalangeal (DIP) joint. This leads to a fracture at the dorsal surface of the proximal distal phalanx where the terminal finger extensor mechanism inserts.” ABFM

Conservative treatment consists of immobilization of the DIP joint in extension for 8 weeks and is recommended for most cases of mallet fracture. If the joint is allowed to flex at any time during that period, then the treatment period must be extended. Immobilization of the proximal interphalangeal (PIP) joint is not required. Surgical pinning may be indicated in more complicated fractures or with failure of conservative therapy.

Reference

Borchers JR, Best TM: Common finger fractures and dislocations. Am Fam Physician 2012;85(8):805-810.

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