Which hand deformity is characterized by MCP flexion, PIP hyperextension, and DIP flexion?

The hand deformity characterized by MCP flexion, PIP hyperextension, and DIP flexion is known as Swan Neck Deformity. This condition typically arises from certain underlying issues, such as rheumatoid arthritis or damage to the volar plate, which affects the stability of the PIP joint.

In Swan Neck Deformity, the MCP joint is flexed while the PIP joint hyperextends, leading to a distinctive appearance of the fingers. The DIP joint then flexes in response to the altered positioning of the PIP joint. This combination creates the characteristic "Swan Neck" shape, resembling the neck of a swan.

Understanding the mechanics of Swan Neck Deformity is crucial for clinicians, particularly for developing appropriate treatment plans and interventions. This could include splinting, exercises, or possibly surgical options, depending on the severity and underlying cause of the condition.