Relationship of deep structures of the hand and wrist to topographical landmarks

The relationship of topographical landmarks to the deep structures of the wrist and hand has not been clearly defined and would be of benefit to surgeons performing endoscopic carpal tunnel surgery. To this end, 10 fresh cadaveric wrist specimens had radiopaque markers placed adjacent to key anatomic structures within the wrist and hand. A new technique for localizing the hook of the hamate was established. We found that the thick segment of the flexor retinaculum, often defined as the transverse carpal ligament, was 2.2 cm in length. Its distal border was 1 cm distal to the distal aspect of the hook of the hamate. The proximal ligamentous portion had a mean length of 1.2 cm, whereas the distal aponeurotic portion (distal to the hook of the hamate) had a mean length of 1.0 cm. The position of the superficial palmar arch was 2.7 cm distal to the hook of the hamate or at a line bisecting three‐fourths of the distance from the distal flexor wrist crease to the proximal palmar crease. The relationship of the superficial palmar arch to topographical landmarks was more consistent than it was when the standard reference of Kaplan's cardinal line was used. © 1993 Wiley‐Liss, Inc.