- Discussion: 
- spiral band is continuation of
pretendinous cord;
- at a point just distal to the
superficial transverse palmar ligament (which is
just proximal to the metacarpal heads), the pretendinous cord bifurcates
to form the
spiral bands;
- spiral band passes deep to the N/V bundle and then forms a coalescence with
the natatory liagment;
- proximally the spiral bands dives deeply into palm, and twist 90 deg as they
pass across the metacarpal head and ends up lying in the saggital plane;
- spiral band winds around the N/V bundle to reach lateral digital sheet (thickening of
superficial fascia on side of finger);
- lateral digital sheet receives fibers from
natatory ligament & spiral band;
- more distally, the lateral digital sheet passes distally along the side
of the digit, lying lateral to the neurovascular bundle;
- Surgical Considerations:
- when resection
Dupuytren's contracture, the neurovascular bundles are
especially at risk ath the level of the MP joint;
- spiral cords are most responsible for distorted position of N/V bundle;
- the spiral cords may pull the N/V bundle in a superficial and central
direction, making them vulnerable during the dissection;
- unlike the palm, there may be no overlying fascial cover;
