Answer :
Final answer:
The described condition, characterized by flexion at the PIP joint and hyperextension at the DIP joint, is known as a Swan-neck deformity, most commonly associated with rheumatoid arthritis but also resulting from injuries, so the correct option is (a).
Explanation:
The condition described, where the client's proximal interphalangeal (PIP) joint appears flexed, and the distal interphalangeal (DIP) joint appears to be hyper-extended, is best described as a Swan-neck deformity. This type of deformity is characterized by an abnormal bending posture of the fingers, where the PIP joint is in hyperextension and the DIP joint in flexion, resembling the neck of a swan. It's a common condition seen in patients with rheumatoid arthritis, but can also result from injuries or other forms of arthritis.
Swan-neck deformity is distinctly different from other finger deformities, such as Boutonniere deformity, which involves the opposite bending posture of the PIP and DIP joints (PIP flexed and DIP extended), Mallet finger, where the DIP joint cannot be straightened, and Trigger finger, characterized by the finger being stuck in a bent position as if squeezing a trigger.
The understanding of deformities like the Swan-neck is crucial for healthcare professionals, especially those specializing in physical and occupational therapy, as it informs the treatment and management strategies for affected patients. Knowledge of the anatomy and function of the metacarpophalangeal joints, which are examples of condyloid joints, and other specific joints of the hand, is foundational in identifying such conditions.
