Digital flexor tendon sheath: an anatomic study.

The flexor sheath of 72 fresh human cadaver digits was examined under the operating microscope utilizing fiberoptic and polarizing light sources. Magnifications of eight to 25 times were used during the dissection. The vascular system was injected with latex material, and longitudinal and cross sections of the tissues were studied histologically. The flexor sheath is seen to be a contained bursal environment with specialized anatomy to provide for flexion and extension. The formerly perplexing pulley system is now seen to be an orderly repeating system of proximal and distal pulleys. The anatomic relationships of the vessels to the proximal cul-de-sac and vincular system are described.