Distal Radius Fractures

Summarized by: Niharika Shahi, M.D.

Reviewed by: Prasaanthan Gopee-Ramanan, M.D.

Original publication details

Authors: Paul M. Bunch, Scott E. Sheehan, George S. Dyer, Aaron Sodickson, Bharti Khurana 

DOI: https://doi.org/10.1007/s10140-015-1363-0

Reference: Bunch, P. M., Sheehan, S. E., Dyer, G. S., Sodickson, A., & Khurana, B. (2015). A biomechanical approach to distal radius fractures for the emergency radiologist. Emergency Radiology, 23(2), 175–185.

Anatomy

Distal forearm is divided into three columns

Radial column (radial styloid and scaphoid fossa)

Intermediate column (lunate fossa and sigmoid notch of radius)

Ulnar column (distal ulna, triangular fibrocartilage complex [TFCC], and distal radioulnar joint [DRUJ])

Radiographic evaluation

Standard views: Posteroanterior (PA), Lateral, PA oblique views

Scaphoid fracture → PA view with the wrist in ulnar deviation can be obtained. 

Additional views: radiocarpal joint, carpal boss, and carpal tunnel.

Measurements

Radial length

Measured on the PA radiograph.

Normal radial length: 10-13 mm

Ulnar variance

Measured on the PA radiograph. More than 5 mm of radial shortening (or positive ulnar variance) is a relative indication for operative treatment.

Relative indication for operative treatment: >5mm radial shortening

Radial inclination

Measured on the PA radiograph. Normal radial inclination is 21° to 25°. Radial inclination < 15° is a relative indication for operative management.

Normal radial inclination: 21º - 25º

Relative indication for operative management: <15º

Volar/Palmer tilt

Measured on the correctly positioned lateral radiograph. > 5° to 10° of dorsal tilt is a relative indication for operative management.

Relative indication for operative management: >5º- 10º of dorsal tilt

Standard evaluation for distal radius fractures → radiography. 

CT aids in: 

Diagnosis of negative or equivocal radiographs 

Improves detection of radiocarpal and distal radioulnar joint articular surface involvement 

More reliably quantifies articular surface gap and step-off deformities, and improves detection of comminution and impaction

Particularly useful for the casted wrist - fine osseous detail less obscured 

Types

  • Extra-articular fractures divided into dorsal and volar bending subtypes.

    Dorsal bending injuries most common type [Colles fracture]

    Less common volar bending injury [Smith fracture]

  • Divided into volar and dorsal shear injuries, with volar shear fractures being far more common.

  • Axial loading of the carpus and wrist. Both the radial and intermediate columns usually disrupted.

  • Strong association with radiocarpal fracture-dislocations and ligamentous injuries.

Post-reduction radiographs

Extra-articular distal radius fractures:

Closed reduction considered acceptable if no > 5 mm radial shortening, radial inclination is maintained to at least 15°, no > 5° of dorsal tilt, and < 2 mm of articular step-off. 

Fracture fragment characteristics favoring instability - initial displacement > 1 cm, dorsal comminution, osteoporosis, associated distal ulnar fracture, radial shortening > 5 mm, and initial dorsal tilt > 20°.

Citation


Bunch, P. M., Sheehan, S. E., Dyer, G. S., Sodickson, A., & Khurana, B. (2015). A biomechanical approach to distal radius fractures for the emergency radiologist. Emergency Radiology, 23(2), 175–185. https://doi.org/10.1007/s10140-015-1363-0