What is the flexor retinaculum?
A fibrous band on the palmar side of the hand near the wrist. It arches over the carpal bones, covering them and forming the carpal tunnel.
What is a boutonniere deformity?
Characterized by PIP flexion and DIP extension
How does a boutonniere deformity occur?
Rupture of the extensor tendon or central slip, so the finger can’t perform active extension.
What are the three componenets of a Boutonniere deformity?
Central slip rupture
Triangular ligament attenuation
Lateral Band Volar migration
What are the four stages of a Boutonniere deformity?
Injury to central slip leading to lack of extension of PIP
Triangular ligament, lateral band separation, and volar migration causing flexion force on the PIP and extension on DIP
Retinacular ligament contracture
PIP and DIP capsular contracture
What is the treatment for actue Boutonniere deformity?
Finger 8 splint for 6 weeks.
What is the cause of a mallet finger
Rupture or avulsion of the terminal extensor tendon
What does a patient present with when they have mallet finger?
Inability to extend distal phalanx
What is swan neck deformity?
Hyperextension of PIP joint and flexed DIP joint
What is the cause of swan neck deformity?
Volar plate laxity of injury (PIP)
Subluxation (MP)
