Answer :
Final Answer:
A characteristic statement of a boutonniere deformity is the flexion of the proximal interphalangeal (PIP) joint with hyperextension of the distal interphalangeal (DIP) joint.
Explanation:
Boutonniere deformity is a hand deformity that typically involves the fingers, particularly the middle and ring fingers. The characteristic feature of a boutonniere deformity is the abnormal positioning of the finger joints. The deformity is defined by the following statement:
Flexion of the PIP Joint with Hyperextension of the DIP Joint: In a boutonniere deformity, the proximal interphalangeal (PIP) joint is flexed, meaning it bends toward the palm of the hand. Simultaneously, the distal interphalangeal (DIP) joint hyperextends, leading to a characteristic appearance resembling the shape of a "buttonhole" or "boutonniere." This finger deformity is often associated with conditions such as rheumatoid arthritis or trauma.
Understanding the specific joint involvement and the pattern of deformity is crucial for accurate diagnosis and appropriate management. In the case of boutonniere deformity, the abnormal flexion at the PIP joint and hyperextension at the DIP joint distinguish it from other hand deformities.