Mallet Finger

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Definition

-  Injury of extensor digitorum tendon at distal interphallangeal joint +/- fracture of distal phallange

 

Features

-  Patients often present month post injury

-  Most common closed tendon injury in atheletes

 

Mechanism

-  Forcible flexion (hyperflexion) of extended DIP

-  Finger jammed by ball (basketball..)

 

Associated S/S

-  Sustained flexion at DIP joint: unopposed flexion of flexor digitorum profundus (FDP)

-  Inability to extend DIP joint

-  Swan neck deformity may develop from tendon pull imbalance (hyperextension)

 

 

Ix

-  Hand exam

-  X-ray

-  +/- fracture of dorsal base of distal phallange

 

 

Mx

-  Splint

-  Mallet splint (DIP splint) 6-10 weeks

-  PIP joint NOT immobilised

-  Avoid flexion (at any time) for 6 weeks then R/V

-   If extensor lag present splint up to 10 weeks

-   If not then night splint 2-3 weeks

-  Poor response if Swan neck deformity

-  K-wire

-  Indicted if

-   Volar subluxation w >30% joint surface involvement

-   Open fracture

-  6 weeks then night splint 4 weeks

-  Direct repair

-  Tendon repair

-  +/- K-wire

 

 

 

 

References

 

Wheeless Textbook of Orthopaedics: www.wheelessonline.com/ortho/mallet_deformity_baseball _finger

emedicine.medscape.com/article/98168-overview

Pic (Splint): langergrp.com/mallet-finger-plastic-p-1378.html

Pic (finger): www.chanorthopaedics.com.sg/patient-educations/hand-pain/mallet-finger

Pic (x-ray): myradnotes.wordpress.com/2008/06/19/mallet-finger-fracture/