Interphalangeal joint of the hand
Interphalangeal (IP) joints of the hand are hinge-type synovial joints between adjacent phalanges. The thumb has a single interphalangeal joint, and the second to fifth digits each have a proximal and a distal interphalangeal joint.
Gross anatomy
Articulation
The head of the more proximal phalanx articulates with the base of the more distal phalanx.
Movement
- flexion
- extension
- limited by the palmar and collateral ligaments
Joint capsule
Each joint is enclosed by a fibrous capsule which attaches to the margins of the articular surfaces and is lined by a synovial membrane.
Ligaments
- two collateral ligaments
- strengthen the capsule on each side
- palmar ligament (volar ligament)
- a thick, fibrocartilaginous plate that connects the collateral ligaments and attaches firmly to the base of the more distal phalanx and attaches loosely to the head of the more proximal phalanx
Blood supply
Deep digital arteries from the superficial palmar arch.
Innervation
Digital nerves from the ulnar and median nerves.
Related pathology
