In 1814, Abraham Colles wrote the definitive description of this fracture, which consequently bears his name.1 The injury is defined as a fracture of the distal radius approximately 20-to-35 mm proximal to the articular surface, with posterior angulation of the distal fragment. More than 60% will have an accompanying fracture of the ulnar styloid process.1 The usual mechanism is a fall on an outstretched, extended hand. The physical appearance of the fractured distal forearm and wrist has led to its being called the dinner fork deformity.
The incidence of the fracture increases with age, and this increase is so rapid in women that, by age sixty-five, the lesion is six times more common in women than in men.2 Osteoporosis appears to be the underlying influencing factor. Complications are common and may be severe.2
The radiologic features are distinctive and relatively consistent.2
- Fracture Line. Usually transverse and comminuted, it is normally readily visible. A variable degree of impaction is apparent on the dorsal surface at the fracture site.
- Radial Contour. A sharp cortical overlap is seen at the fracture site, especially visible on the frontal projection, due to the proximal migration of the distal fragment.
- Radial Length. The overall length of the radius is decreased due to the proximal migration of the distal fragment.
- Angulation. The distal fragment is tilted dorsally, as evidenced by the altered angle of the articular surface, which is seen on the lateral projection. Normally, there is a five-to fifteen degree palmar angulation of the articular surface.
- Soft tissue. The distorted skin contour is apparent. The pronator quadratus fat plane will usually be altered. TAC
Dr. Terry R. Yochum is a second-generation chiropractor and a cum laude graduate of the National College of Chiropractic, where he subsequently completed his radiology specialty. He is currently Director of the Rocky Mountain Chiropractic Radiological Center, in Denver, CO, an Adjunct Professor of Radiology at the Los Angeles College of Chiropractic, as well as instructor, Skeletal Radiology, University of Colorado School of Medicine, Denver, CO. Dr. Yochum is, also, a consultant to Health Care Manufacturing Company that offers a Stored Energy system. For more information, Dr. Yochum can be reached at: (303) 940-9400 or by e-mail at [email protected].