Lateral bands displace proximally and dorsally = increased extension of PIP.
FDP unopposed
Rheumatoid arthritis
Untreated mallet finger
Laxity of the fibrous plate inside the hand at the base of the fingers or of the finger ligaments
Spasticity from nerve damage
Other arthritis
Ruptured finger tendon
Misalignment in the healing of middle phalanx fracture
Swan neck deformity
Joint volar subluxation
Boutonniere deformity
FDS laceration
Nail avulsion
Intrinsic contracture
Carpal dislocations
Distal finger