Hand Orthopedics Colles Fracture Criteria Calculator

About Colles fractures

A Colles fracture breaks the distal radius, roughly an inch (2-3 cm) proximal to the wrist, and the distal fragment displaces and angulates dorsally. It ranks among the most common fractures, and the classic mechanism is a fall onto an outstretched hand with the wrist in dorsiflexion. On the surface you get that characteristic "dinner fork" deformity. An ulnar styloid fracture often tags along, and dorsal comminution shows up frequently too.

Clinical criteria and how it is assessed

You assess it both clinically and on imaging. The radiographic parameters and instability criteria this calculator works with are:

• Dorsal tilt (angulation) of the distal fragment; once it passes about 20°, that points toward instability.
• Radial inclination; watch out when it drops below about 15°.
• Radial shortening; more than about 5 mm against the uninjured side points toward instability.
• How much dorsal comminution there is, plus any intra-articular extension into the radiocarpal and/or distal radioulnar joint.
• Classification systems such as AO and Frykman to describe the pattern and prognosis.

On exam the wrist hurts, swells, looks deformed and moves poorly. Don't skip the neurovascular check, the median nerve in particular.

Who uses this

Orthopedic and hand surgeons rely on these criteria, along with emergency physicians, radiologists, residents and physiotherapists. They use them to judge stability and to choose between closed reduction with casting and surgical fixation.

FAQ

What is a "dinner fork" deformity? With the dorsal displacement and angulation, the forearm takes on a profile that looks like an upturned fork.

How is it different from a Smith fracture? A Colles fracture displaces dorsally. A Smith, sometimes called a "reverse Colles", displaces toward the palm (volar).

This tool is educational only and does not replace a medical evaluation. If a distal radius fracture is suspected, a qualified clinician still has to examine it, order radiographs and decide on treatment.