Finger Sprains and Deformities

Question 1

Boutonniere deformity

Answer 1

the finger postures PIP flexion and DIP extension
-involves a disruption of the central slip of the extensor tendon that causes the lateral bands to slip volar to the PIP joint axis creating flexor forces of the PIP joint

Question 2

Swan neck deformity

Answer 2

the finger postures with PIP hyperextension and DIP flexion

can be caused by injury to DIP, PIP, or MP joint

Question 3

Skier’s thumb

Answer 3

UCL injury

• FOOSH with thumb in ABduction
• acute UCL injuries of the thumb MP joint usually involve detachment of the ligament from its proximal phalanx insertion