- Restore proper anatomic parameters; compare to the other side.
- Don't forget about the DRU joint.
- CT can aide in identifying subtle articular depression and severe comminution to change operative management.
- Remember, there still is a role for external fixators; an alternative remains an internal spanning plate.
- Respect the soft tissues, which can aide in reduction, however don't leave the operating room without feeling confident about your fixation.
Distal radius fracture (DRF), a common fracture, accounts for almost one sixth of all emergency department visits. 1 With the advent of emerging technologies and refined technique, treatment options for DRFs have evolved. Although controversy remains regarding nonoperative vs operative treatment of DRFs in the elderly, 2,3 select situations (open injuries, complex high-energy injuries, young age) warrant definitive fixation. Previously, internal fixation options were limited. Current technologies include locked fixed-angle plating, fragment-specific fixation, and locked variable-angle plating. These modalities aid in achieving and maintaining more anatomical fixation. This article summarizes tips, tricks, and planning for definitive external and internal fixation of complex DRFs.
Anatomical Considerations and Classification
The wrist joint, part of the complex articular network that begins at the forearm and ends at the distal interphalangeal joint, is the foundation for fine- and gross-motor skills. Understanding the anatomy of this network can provide a valuable roadmap for operative reconstruction.
At the wrist level, the radius bears most of the weight-bearing, and in some studies exhibits up to 80% of the load. 1,4 The triangular distal radius bears this weight through a biconcave articular surface with facets for the lunate and scaphoid separated by an anteroposterior ridge. 5-7 The radius also articulates with the ulnar head at the sigmoid notch to form the distal radioulnar (DRU) joint. Restoring the relationships of the DRU joint, the triangular fibrocartilage complex, and the ulnar variance is of paramount importance. 1,8,9
Classical teaching calls for restoration of radial inclination to about 23°, volar tilt to 11° to 12°, and radial length to about 11 mm. Especially regarding volar tilt and radial length, however, cadaveric and clinical studies have found more variance, leading to use of the contralateral extremity as an operative template, particularly when closed reduction thought to be adequate deviates significantly from these parameters. 1,4,7
DRF classification based on these principles has led to abundant representation in the literature. 10-13 Many authors have focused on fracture lines, comminution degree, articular surface violation, and other anatomical or radiographic characteristics of DRF classification and operative fixation approach. 10-13 In 2001, Fernandez 9 proposed a classification system focused on energy or mechanism of injury. In comparisons, 14 the Fernandez system had the highest interobserver reliability—higher than that of AO (Arbeitsgemeinschaft für Osteosynthesefragen).
Considerations for Operative Treatment: Column Theory
In the restoration of anatomical alignment in complex DRFs, it is important to consider the 3 joints and the 3 columns—radial, intermediate, and ulnar ( Figure 1 ).In addition, parallels between the distal radius and the tibial plateau can be considered because of similarities in operative goals. Restoration of mechanical axis, length, alignment, rotation, and articular surfaces is paramount. 15 Considering multiple surgical approaches to address "bicolumnar injuries" and reconstructing the "simpler" columnar injury first are common principles. 16
The goals of fracture fixation at the wrist are the same as at any other joint: anatomical reduction, stable fixation, and early range of motion (ROM). Column restoration can result in consistent achievement of those goals. Intuitively, there is a close correlation between anatomical alignment and functional results. 17 Rebuilding the structural foundation of the columns with respect to buttressing and restoring the 3 radial articulations with the ulna, scaphoid, and lunate can consistently yield restoration of length, inclination, and tilt ( Figure 2 ).Next, we discuss the options available and how to use each to an advantage, individually or in hybrid constructs.
External Fixation: Is There Still a Role?
In the setting of highly comminuted, complex fractures, external fixation with Kirschner wires (K-wires) is a reasonable choice, with restoration of motion and strength within 75% to 80% of the uninjured wrist. 18 In a 2-year study of 113 patients with comminuted metaphyseal DRFs randomly assigned to either external fixation or casting, Kreder and colleagues 19 found a trend toward better clinical, functional, and radiographic outcomes with external fixation with or without K-wire fixation. There was improved restoration of radial length and palmar tilt with external fixation. A study of unstable DRF in patients with osteoporosis found that redisplacement was more common after treatment