Upper limb
Synovial digital flexor sheaths of hand
Vaginae synoviales digitorum manus
- Origin
- Commence at the level of the metacarpophalangeal (MCP) joints (A1 pulley level)
- Insertion
- Extend distally to the base of the distal phalanges of digits II, III, and IV
- Function
- Provides synovial lubrication and metabolic support via vincula tendinum for FDS and FDP tendons
- Innervation
- Proper palmar digital nerves
- Movement & chain
- Smooth bidirectional tendon glide during finger curling and uncurling
- Palpation
- Palpable along the volar aspects of the phalanges during flexor tenosynovitis
- Clinical
- Trigger finger (stenosing tenosynovitis at the A1 pulley causing painful locking/snapping in flexion); suppurative flexor tenosynovitis
- Segmental innervation
- C7–T1 spinal segments
- In clinical practice
- Trigger finger management includes night splinting, corticosteroid injection around the A1 pulley, or surgical A1 pulley release
- Region in the model
- Upper limb