Functional Anatomy of the Vagina Fibrosa of the Flexors of the Fingers

The flexor tendon sheaths of 40 fingers were investigated to determine which classification of the annular and cruciform pulleys seems to be justified. The classification of Kleinert et al. (1981) into five annular and four cruciform pulleys was the most consistent with our results. The constant presence of the mid-phalangeal annular pulleys in zones III and VII shows their major role in preventing the tendons from bow-stringing. The cruciform pulleys seem to allow the tendon sheath to deform during flexion.