The three cruciate pulleys (C1, C2, C3) are the X-shaped flexible components of the finger flexor sheath, located between the annular pulleys (A2-A4). They allow the sheath to accordion during finger flexion without buckling while providing circumferential constraint. Unlike the annular pulleys, cruciate pulleys have minimal biomechanical role in force transmission and can be released without affecting bowstringing.
| Origin | Lateral sides of the fibrous flexor sheath |
|---|---|
| Insertion | Cross-connecting the lateral walls of the flexor sheath in an X pattern |
| Actions | Maintain sheath flexibility during finger flexion by allowing sheath to fold |
|---|
Cruciate pulleys are routinely released or excised during flexor tendon repair without functional consequence — only the A2 and A4 annular pulleys must be preserved to prevent bowstringing. During Dupuytren fasciectomy, cruciate pulley excision may be required to excise involved digital fascia. Their release is a standard step in four-strand flexor tendon repair to allow tendon passage.
Cruciate pulley release during flexor tendon repair to facilitate tendon passage without compromising the A2 and A4 critical pulleys.
