Scaphoid bone

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Drawing of a left scaphoid bone of the hand showing the articular surfaces
Wrist (schematic):
A – H = carpal bones
  • A scaphoid bone ( scaphoid bone )
  • B moon bone ( os lunatum )
  • C triangular bone ( os triquetrum )
  • D pea bone ( os pisiforme )
  • E large polygonal bone ( trapezium )
  • F small polygonal bone ( os trapezoideum )
  • G headbone ( os capitatum )
  • H hook bone ( os hamatum )
    • 1 spoke ( radius )
    2 ulna ( ulna )
    3 metacarpal bones ( ossa metacarpalia )

    The os scaphoideum ( Latin os , bone, Latin - Greek scaphoideus from Greek σκάφη, skáphe , "tub, cup, boat", thus "boat-shaped bone"; synonyms : navicular bone and os carpi radiale ; earlier also os naviculare ) is a short bone . It is the second largest bone of the eight carpal bones and is one of the proximal ( proximal ) range of. It is located on the thumb or spoke side.

    It is close to the body ( proximal ) with the spoke ( radius ), remote from the body ( distal ) with the small polygonal bone ( os trapezoideum ) and the large polygonal bone ( os trapezium ) and towards the center with the lunar bone ( os lunatum ) and the head bone ( os capitatum) ) in connection. The navicular bone of the wrist can on the palms ( palmar well the) skin be felt as there is a bump ( tubercle ossis scaphoid ) has. This tubercle acts as a hypomochlion for the tendon of the radial hand flexor muscle ( Musculus flexor carpi radialis ). Three quarters of the surface of the scaphoid bone is covered by cartilage and forms joints. The narrow, cartilage-free areas in between contain numerous vascular entry ports of different sizes. Knowledge of the vascular supply to the scaphoid is important for understanding the healing processes and treatment for fractures of this bone ( scaphoid fracture ). The entire bone is supplied by branches of the radial artery ( arteria radialis ). The vascular entry ports are on the flexor side ( palmar ), the spoke side ( radial ) and on the extensor side ( dorsal ). The pole near the body and the adjoining 70 to 80% of the bone are fed by vessels on the extensor side, with the vascular branches running within the bone from remote to the body. The flexor-sided branches of the radial artery supply the tuberculum ossis scaphoidei and the distant 20 to 30% of the bone. These two vascular provinces have no connections ( anastomoses ) with one another within the bone .

    Because of the particular course of the vessels in the navicular bone from distant to the body and because of the lack of connections between the vessels running in the bone, fractures of the navicular bone are at risk of complications, especially if they are located in the portion of the bone near the body. Thus, nonunion ( Kahnbeinpseudarthrosen ) arise, which is usually surgically must be treated.

    In dogs , the navicular bone is fused with the lunar bone to form the os carpi intermedioradiale .

    literature

    • W. Platzer: Pocket Atlas of Anatomy, Volume 1 - Musculoskeletal System. Thieme Verlag, Stuttgart 2005, p. 126. ISBN 3-13-492009-3
    • Franz-Viktor Salomon: Bony skeleton . In: Franz-Viktor Salomon et al. (Ed.): Anatomy for veterinary medicine. Enke-Verlag, Stuttgart 2. Erw. Edition 2008, pp. 37–110. ISBN 978-3-8304-1075-1

    Web links

    Wiktionary: Os scaphoideum  - explanations of meanings, word origins, synonyms, translations

    Individual evidence

    1. ^ HJ Schmidt and U. Lanz (2003): Surgical anatomy of the hand . 2nd, revised and updated edition, p. 44 f. ISBN 3-13-130692-0
    2. ↑ RH Gelberman and J. Menon (1980): The vascularity of the scaphoid bone. In: Journal of Hand Surgery 5, pp. 508-513. PMID 7430591