Page 109 - ASOP Orthopedic Casting Manual

Sc aphoid Fracture

2.5.1 Fracture Type(s) for Thumb Spica Cast

Sc aphoid Fractures
✓ Clinic al Relevant Anatomy: The sc aphoid is a small c ar p al bone situated on the radial side of the wr ist,
br idging the distal and proximal c ar p al rows. I t plays a cr itic al role in wr ist stabilit y and motion. The blood
supply to the sc aphoid, pr imar ily from the radial ar ter y, is retrograde, incre asing the r isk of avascular necrosis,
p ar ticular ly in proximal pole fractures.
✓ Epidemiology / Etiology / Mechanism of Injur y: Sc aphoid fractures account for approximately 60%]70% of
c ar p al bone fractures LAdams et al., 2020M. They often resul t from a fall on an outstretched hand LFOOSHM,
with the wr ist hyperex tended and radially deviated.
✓ Clinic al Character istics / Presentation: Patients t ypic ally present with p ain and tender ness in the anatomic al
snuffbox, swelling, and reduced wr ist range of motion. Pain exacer b ates with axial lo ading of the thumb or
wr ist ex tension.
✓ Fracture Diagnosis Process: Diagnosis is made through clinic al examination and imaging. Radiographs
(postero anter ior, lateral, and sc aphoid views) are the first step. If initial imaging is inconclusive, advanced
modalities such as MRI or CT sc an c an confir m the diagnosis and assess displacement.
✓ Differential Diagnosis / Associated Injur ies: Distal radius fracture; Tr iangular fibroc ar tilage complex LTFCC)
injur y; Lunate disloc ation
✓ Tre atment / Management Considerations: Non-displaced sc aphoid fractures are tre ated with a thumb spic a
c ast for 6]12 weeks, depending on the loc ation of the fracture. Displaced or proximal pole fractures often
require surgic al fixation.