The scaphoid receives its arterial supply mainly through vessels that enter the bone at the distal pole and dorsal ridge. Fractures through the waist therefore endanger the proximal fragment because the blood flow to it is:

• A Antegrade, from vessels entering the tuberosity
• B Derived entirely from the anterior interosseous artery
• C Retrograde, running from distal to proximal within the bone ✓
• D Derived from the ulnar artery through the radioscapholunate ligament

Explanation

Most of the scaphoid blood supply comes from branches of the radial artery entering the distal pole and dorsal ridge, with intraosseous flow directed retrograde toward the proximal pole. A waist fracture interrupts this retrograde flow, placing the proximal fragment at high risk of avascular necrosis and nonunion. The tuberosity supplies only a minor portion of the bone, and neither the anterior interosseous nor the ulnar artery provides the dominant supply.

Reference: Rockwood and Green's Fractures in Adults, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.