Page 89 - Orthopedic Casting Manual

2.1 Fracture Type(s) for Short Arm

Cast

Or thopedic c asting remains a cor nerstone in the management of var ious fractures, p ar ticular ly those that require
immobilization to promote he aling while maintaining functional alignment. This section provides a detailed
analysis of specific fracture t ypes commonly tre ated with c asting, addressing clinic ally relevant anatomy,
epidemiologic al and etiologic al considerations, clinic al character istics, diagnostic processes, differential
diagnoses, and tre atment appro aches.

Distal Radius Fractures
✓ Clinic ally Relevant Anatomy: The distal radius is the largest bone of the fore ar m and ar ticulates with the c ar p al
bones to for m the wr ist joint. This anatomic al structure plays a cr itic al role in wr ist motion and lo ad
transmission from the hand to the fore ar m. Key anatomic al landmar ks include the radial st yloid, sigmoid
notch, and the volar and dorsal sur faces, which are often the sites of fracture involvement. The integr it y of the
radioulnar and radioc ar p al joints is essential for maintaining wr ist function LCour t-Brown & McQueen, 2016M.
✓ Epidemiology / Etiology / Mechanism of Injur y: Distal radius fractures are the most common fractures seen in
or thopedic practice, accounting for 18% of all adul t fractures. The pr imar y mechanism of injur y involves a fall
onto an outstretched hand LFOOSHM, often occur r ing in elder ly individuals with osteoporotic bone or in young
adul ts exposed to high-energy trauma. Subt ypes of distal radius fractures include Colles and Smith fractures,
which differ in their mechanism and fracture displacement LMulders et al., 2019M.
✓ Clinic al Character istics/Presentation: Patients with distal radius fractures t ypic ally present with loc alized p ain,
swelling, and defor mit y around the wr ist. A Colles fracture, c aused by a fall onto an ex tended hand, presents
with the character istic "dinner for k" defor mit y, where the distal radius is dorsally displaced. Conversely, a
Smith fracture, c aused by a fall onto a flexed hand, resul ts in volar displacement of the distal radius,
producing a "garden sp ade" defor mit y. Both fractures may exhibit tender ness, reduced range of motion, and
potential neurovascular compromise.
✓ Fracture Diagnosis Process: Radiographic imaging is essential for diagnosing distal radius fractures. Standard
views include postero anter ior LPAM, lateral, and oblique views, which help evaluate radial height, radial
inclination, and volar til t. Advanced imaging techniques, such as CT sc ans, are useful for assessing intra-
ar ticular ex tension and complex fracture p atter ns. Colles fractures often demonstrate dorsal angulation and
displacement, while Smith fractures show volar angulation and displacement LBer trand et al., 2018M.
✓ Differential Diagnosis/Associated Injur ies: Distal radius fractures c an be associated with ulnar st yloid

fractures, TFCC te ars, and ligamentous injur ies. Differential diagnoses include sc aphoid fractures, lunate
disloc ations, and c ar p al instabilit y. I t is impor tant to evaluate the p atient for concomitant injur ies that may
require additional inter vention.
✓ Tre atment / Management Considerations: The tre atment of distal radius fractures depends on the stabilit y and
displacement of the fracture. Stable, minimally displaced Colles and Smith fractures are managed with closed
reduction and immobilization in a shor t ar m c ast. The wr ist is positioned in slight flexion and ulnar deviation
for Colles fractures, while neutral or slight ex tension is prefer red for Smith fractures. Unstable fractures or
those with signific ant displacement often require surgic al fixation to restore anatomic al alignment and function
LMulders et al., 2019M.