Answer :
Final answer:
Swan neck deformity: Hyperextension of PIP joint and flexion of DIP joint; Boutonniere deformity: PIP flexion and DIP hyperextension; Ulnar deviation: lateral finger deviation associated with conditions like rheumatoid arthritis.
Explanation:
Sure, here's a detailed explanation of each hand deformity:
Swan Neck Deformity:
This deformity is characterized by hyperextension of the proximal interphalangeal (PIP) joint and flexion of the distal interphalangeal (DIP) joint.It is caused by a combination of intrinsic muscle tightness and extrinsic muscle imbalance, particularly the flexor muscles of the metacarpophalangeal (MCP) joint and the extensor muscles of the PIP joint.
Contraction of the flexor muscles of the MCP joint leads to hyperextension of the PIP joint, while the intrinsic muscles and the stretched volar plate of the PIP joint cause flexion of the DIP joint.
Swan neck deformity can result from conditions such as rheumatoid arthritis, trauma, or ligamentous laxity.
Boutonniere Deformity:
In this deformity, there is flexion of the PIP joint and hyperextension of the DIP joint.It occurs due to disruption or weakening of the central slip of the extensor tendon, which normally extends the PIP joint.
When the central slip is damaged, the lateral bands of the extensor mechanism pull the PIP joint into flexion, while the unopposed action of the intact terminal tendon causes hyperextension of the DIP joint.
Boutonniere deformity can result from traumatic injuries, such as ruptures of the central slip or inflammatory conditions like rheumatoid arthritis.
Ulnar Deviation:
Ulnar deviation refers to the lateral deviation of the fingers towards the ulnar (pinky finger) side of the hand.It is often associated with conditions such as rheumatoid arthritis, where inflammation and damage to the joint structures lead to instability and deviation of the fingers.
Weakening or imbalance of the extensor carpi ulnaris muscle, which runs along the ulnar side of the forearm, can contribute to ulnar deviation.
Over time, ulnar deviation can lead to progressive deformity and functional impairment of the hand, particularly in gripping and fine motor tasks.
These deformities can cause significant functional limitations and discomfort for individuals affected by them. Treatment options may include splinting, physical therapy, medication, or surgical intervention, depending on the severity and underlying cause of the deformity.
Your correct question is: 1. Swan neck - contraction of the flexor muscles of the MCP 2. Boutonniere - flexion of the PIP and hyperextension of the DIP due to weakening of the extrinsic extensor tendon. 3. Ulnar deviation - weakening of extensor carpi ulnaris.
