Which among the following is TRUE regarding mallet finger?
The mallet finger deformity is characterized by a loss of full active distal interphalangeal joint extension with full passive ROM evident. The mallet finger reflects the loss of normal extensor force transmission the terminal tendon inseion onto the distal phalanx. The unopposed flexor digitorum profundus pulls the distal joint into flexion. The usual mechanism of injury involves sudden passive flexion of the actively extended distal interphalangeal joint. Disruption of the terminal tendon may be entirely confined to the tendon or may involve an avulsed fracture fragment from the dorsal lip of the distal phalanx proximal aicular surface. Ref: Bednar M.S., Light T.R. (2006). Chapter 10. Hand Surgery. In H.B. Skinner (Ed), CURRENT Diagnosis & Treatment in Ohopedics, 4e.
Avulsion of tendon at the base of the middle phalanx
Avulsion of extensor tendon at the base of the distal phalanx
Fracture of distal phalanx
Fracture of the proximal phalanx