Mateusz Gładysz FESSH prep

FESSH prep Anatomy Scaphoid anatomy

Scaphoid anatomy and vascular supply

Last reviewed v2.0

FESSH-025Anatomy●○○ basic

Regarding the anatomy, articulations and vascular supply of the scaphoid:

  1. 1.The principal intra-osseous blood supply to the scaphoid is delivered by dorsal ridge branches of the radial artery, with the entire proximal pole supplied retrograde from the distal entry points.

  2. 2.The scaphoid articulates with five other carpal bones.

  3. 3.Approximately 80% of the scaphoid's surface is covered by articular cartilage, leaving a narrow non-articular dorsal ridge through which the principal vascular pedicle enters.

  4. 4.In a displaced waist fracture, the proximal pole is at disproportionate risk of avascular necrosis because of the scaphoid's retrograde intraosseous flow.

  5. 5.The proximal pole is the most common site of scaphoid fracture.

FESSH marking: +1 per correct statement, 0 for blank, −1 for incorrect. Click the same TRUE/FALSE button twice to clear it.

Question ID
FESSH-025
First published
Last reviewed
Version
v2.0
Answer key and explanations — open after answering

  1. 1. The principal intra-osseous blood supply to the scaphoid is delivered by dorsal ridge branches of the radial artery, with the entire proximal pole supplied retrograde from the distal entry points.

    True

    Gelberman and Menon's cadaveric injection-clearing work demonstrated that 70–80% of intra-osseous vascularity, including the entire proximal pole, derives from dorsal ridge branches of the radial artery, while the remaining 20–30% supplies the distal tubercle via volar radial branches. The intraosseous flow is therefore predominantly retrograde from distal to proximal, which underlies the disproportionate burden of avascular necrosis in proximal pole injuries.

    • Gelberman RH, Menon J. The vascularity of the scaphoid bone. J Hand Surg Am. 1980;5(5):508-513. PMID 7430591

  2. 2. The scaphoid articulates with five other carpal bones.

    False

    The scaphoid articulates with four carpal bones — the lunate, capitate, trapezium and trapezoid — and with the radius proximally. The radius is not a carpal bone.

    • Berger RA. The anatomy of the scaphoid. Hand Clin. 2001;17(4):525-532, vii. PMID 11775465

  3. 3. Approximately 80% of the scaphoid's surface is covered by articular cartilage, leaving a narrow non-articular dorsal ridge through which the principal vascular pedicle enters.

    True

    The scaphoid is approximately 80% covered by articular cartilage, which constrains both vascular entry and surgical exposure. The non-articular dorsal ridge accommodates the principal vascular pedicle and forms the operative landmark for dorsal mini-open or arthroscopic-assisted fixation.

    • Gelberman RH, Menon J. The vascularity of the scaphoid bone. J Hand Surg Am. 1980;5(5):508-513. PMID 7430591

  4. 4. In a displaced waist fracture, the proximal pole is at disproportionate risk of avascular necrosis because of the scaphoid's retrograde intraosseous flow.

    True

    Vessels enter the scaphoid through the dorsal ridge at the waist and distal pole and supply the proximal fragment in a distal-to-proximal direction. A waist or proximal-third fracture devascularises the proximal fragment, with the risk approaching 100% in fractures isolating the proximal fifth.

    • Gelberman RH, Menon J. The vascularity of the scaphoid bone. J Hand Surg Am. 1980;5(5):508-513. PMID 7430591
    • Filan SL, Herbert TJ. Herbert screw fixation of scaphoid fractures. J Bone Joint Surg Br. 1996;78(4):519-529. PMID 8682813

  5. 5. The proximal pole is the most common site of scaphoid fracture.

    False

    Waist fractures account for approximately 65% of acute scaphoid fractures in defined-population series, with proximal third around 25% and distal third around 10%; the often-quoted textbook figure of 70–80% derives from older institutional series and over-represents the bone's contribution. The Edinburgh cohort by Duckworth and colleagues showed Herbert B2 (complete waist) injuries in 36% of acute fractures.

    • Duckworth AD, Jenkins PJ, Aitken SA, Clement ND, Court-Brown CM, McQueen MM. Scaphoid fracture epidemiology. J Trauma Acute Care Surg. 2012;72(2):E41-E45. PMID 22439232
    • Hove LM. Epidemiology of scaphoid fractures in Bergen, Norway. Scand J Plast Reconstr Surg Hand Surg. 1999;33(4):423-426. PMID 10614752