Swan Neck deformities A swan neck deformity of the hand is characterized by hyperextension of the proximal interphalangeal joint and flexion of the distal interphalangeal joint.
Swan Neck deformities A swan neck deformity of the hand is characterized by hyperextension of the proximal interphalangeal joint and flexion of the distal interphalangeal joint. These patients will complain of difficulty grasping an object due to the hyperextension of the proximal interphalangeal joint. They will also be unable to make a fist.
Swan neck deformity of second and third digit There are three etiologies of a swan neck deformity. The primary issue of the different etiologies is the development of an imbalance of the extensor tendon. The first cause is an extrinsic injury to the finger.
This would include a tear of the terminal extensor tendon or development of a metacarpophalangeal joint flexion contracture. An unrepaired mallet finger can lead to unopposed action of the flexor digitorum profundus, which causes flexion of the DIP. These injuries differ from Boutonniere deformities, which are ruptures of the central slip.
Mechanism of swan neck deformity The second cause of swan neck deformities are intrinsic causes, which include chronic metacarpophalangeal joint volar subluxation, an ischemic contracture, or a tendon adhesion. The final etiology is an articular source, which includes volar plate/capsular injury or disruption of the flexor digitorum superficialis. An injury to the volar plate causes overactivity of the extensor mechanism, resulting in the swan neck deformity.
Anatomy of extensor complex The assessment of a suspected swan neck deformity includes an evaluation for inflammatory arthritis verse a posttraumatic swan neck deformity. Providers should evaluate the other joints of the hands and wrist to evaluate for synovitis. Assessing for tendon rupture with flexion and extension of the DIP, PIP, and MCP joints are recommended as well.
If you are experiencing symptoms that may be related to swan neck deformities, it is important to see a sports medicine physician. Early evaluation and treatment typically lead to better outcomes. Do not ignore pain or symptoms that are limiting your activity.
*This article is for educational purposes only and does not substitute for professional medical advice. Always consult a qualified healthcare provider.*
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