- Swan neck deformity
Infobox_Disease
Name = Swan neck deformity
Caption = Human hand bones (Joints visible but not labeled.)
DiseasesDB =
ICD10 = ICD10|M|20|0|m|20
ICD9 = ICD9|736.22
ICDO =
OMIM =
MedlinePlus =
eMedicineSubj = Orthoped
eMedicineTopic = 562
MeshID =Swan neck deformity is a deformed position of the
finger , in which the joint farthest from the knuckle is permanently bent toward the palm while the nearest joint is bent away from it (DIPhyperflexion with PIPhyperextension ). It is commonly caused by injury or inflammatory conditions likerheumatoid arthritis .Pathophysiology
Swan neck deformity has many possible causes arising from the DIP, PIP, or even the MCP joints. In all cases, there is a stretching of the
volar plate at the PIP joint to allow hyperextension, plus some damage to the attachment of the extensor tendon to the base of the distal phalanx that produces a hyperflexedmallet finger .Duck bill deformity is a similar condition affecting the thumb (which cannot have true swan neck deformity because it does not have enough joints).External links
* [http://www.wheelessonline.com/ortho/swan_neck_deformity Swan neck deformity] at Wheeless' Textbook of Orthopedics, a technical review of the condition
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