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.
The head of the more proximal phalanx articulates with the base of the more distal phalanx
- limited by the palmar and collateral ligaments
Each joint is enclosed by a fibrous capsule which attaches to the margins of the articular surfaces and is lined by a synovial membrane.
- two collateral ligaments
- strengthen the capsule on each side 1, 2
- 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 phalanx1, 2
Deep digital arteries from the superficial palmar arch
Digital nerves from the ulnar and median nerves