Cruciform part of fibrous sheath of digit of hand
Pars cruciformis vaginae fibrosae digiti manus
- Latin synonym: Pars cruciformis I-III
- Synonym: Cruciform part 1-3; C band 1-3
- Related terms: Cruciform part of fibrous sheath
Definition
The cruciform part of fibrous sheath of digit of hand consists of three crossed (X-shaped) fibrous bands, also known as the cruciform pulleys or cruciate pulleys (C1–C3). These lie between the annular pulleys along the palmar surface of each finger.
The cruciate pulleys are thin and flexible, allowing the fibrous sheath to fold and stretch during finger flexion and extension without restricting movement. This way, they maintain alignment of the long flexor tendons while permitting flexibility of the sheath, as the fingers bend and straighten.
Locations
C1: Between the A2 and A3 pulleys.
C2: Between the A3 and A4 pulleys.
C3: Between the A4 and A5 pulleys.
References
Hauger, O., Chung, C.B., Lektrakul, N., Botte, M.J., Trudell, D., Boutin, R.D. and Resnick, D., 2000. Pulley system in the fingers: normal anatomy and simulated lesions in cadavers at MR imaging, CT, and US with and without contrast material distention of the tendon sheath. Radiology, 217(1), pp.201-212.
