Commentary & Perspective

Commentary & Perspective on
"External Fixation of Distal Radial Fractures: Four Compared with Five Pins.
A Randomized Prospective Study"
by K.-D. Werber, MD, et al.

Commentary & Perspective by
Jesse B. Jupiter, MD*,
Orthopaedic Hand Service, Massachusetts General Hospital, Boston, MA

External skeletal fixation is well recognized as a versatile adjunct in the management of unstable fractures of the distal part of the radius. External fixation may be used as a joint distraction device, a frame that neutralizes the fracture, a buttress, or even as a device that compresses fracture fragments. Regrettably, the literature devoted to this technique is difficult to interpret because in many reports stratification of the fractures is inadequate, application techniques vary, associated soft-tissue problems are poorly documented, and the outcomes instruments are either too variable or are inappropriate. In this issue of The Journal, Werber et al. provide a welcome addition to our literature with their clearly presented report of a well thought-out and carefully controlled study.

The results of this study support an observation that has been reported by a number of investigators, i.e., distraction of unstable distal radial fractures (commonly defined as "ligamentotaxis") alone may not be sufficient either to reduce some fractures with restoration of the normal palmar tilt or to maintain the reduction over the course of healing^1-3.

Although the number of patients and the length of follow-up were both limited, the study by Werber et al. highlights several important components of the successful management of unstable distal radial fractures with use of external skeletal fixation. First, the surgeons performed direct manipulation of the displaced fragments, including disimpaction of articular fragments with use of Kirschner wires. Their achievement of articular realignment as well as the restoration of normal palmar tilt was directly related to use of this intervention.

Second, the authors used a "fifth pin" to maintain the reduction of the articular fragments that was achieved through direct manipulation.

For a number of years, it has been our impression that external fixation functions best as a "neutralization" device that protects percutaneous Kirschner-wire fixation of the distal fragment(s) of radial fractures from displacement by axial loads across the radiocarpal joint^4,5. Similar results may be achieved by placing external fixation pins only into the distal fracture fragments and the more proximal part of the radius, thus avoiding the need to "bridge" the radiocarpal joint. While the assessment of the outcomes of these "nonbridging" techniques will require additional clinical trials, the results of Werber et al. may provide more support for the premises underlying their use.

The third notable feature of the authors' technique is the loosening of the longitudinal traction in both study groups at three weeks after application of the fixator. A major concern of spanning external fixation has been a potential for the development of wrist stiffness from prolonged distraction across the radiocarpal joint. However, one could argue that the loosening of the longitudinal distraction had a negative impact on the maintenance of the fracture reduction in the cohort without the additional pin, thus constituting a deviation from the usual method of employing ligamentotaxis for a minimum of six weeks or more.

It is interesting that the external fixation was maintained in place for nine weeks, substantially longer than in most previous reports^1,2,6. The apparent absence of adverse effects on wrist mobility, problems with patient compliance, and pin complications challenges accepted concepts of this type of external fixation and could also be a factor in the ability to maintain the anatomic reduction.

The six-month follow-up may be too short to assess accurately the functional outcome. Additionally, the reader must bear in mind that the vast majority of the fracture patterns in this study were relatively simple and represented low-energy injuries so that many of the soft-tissue injuries associated with more complex fracture patterns were not a factor. Thus, we should be somewhat cautious in comparing the results reported by Werber et al. with those of other studies of external fixation of distal radial fractures.

*The author did not receive grants or outside funding in support of the research or preparation of this manuscript. He did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the author is affiliated or associated.

References

1. Leung KS, Shen WY, Tsang HK, Chiu KH, Leung PC, Hung LK. An effective treatment of comminuted fractures of the distal radius. J Hand Surg [Am]. 1990;15:11-7.
2. Seitz WH Jr, Froimson AI, Leb R, Shapiro JD. Augmented external fixation of unstable distal radius fractures. J Hand Surg [Am]. 1991;16:1010-6.
3. Wolfe SW, Swigart CR, Grauer J, Slade JF 3rd, Panjabi MM. Augmented external fixation of distal radius fractures: a biomechanical analysis. J Hand Surg [Am]. 1998;23:127-34.
4. Clancey GJ. Percutaneous Kirschner-wire fixation of Colles fractures. A prospective study of thirty cases. J Bone Joint Surg Am. 1984;66:1008-14.
5. Wolfe SW, Austin G, Lorenze M, Swigart CR, Panjabi MM. A biomechanical comparison of different wrist external fixators with and without K-wire augmentation. J Hand Surg [Am]. 1999;24:516-24.
6. Kaempffe FA, Wheeler DR, Peimer CA, Hvisdak KS, Ceravolo J, Senall J. Severe fractures of the distal radius: effect of amount and duration of external fixator distraction on outcome. J Hand Surg [Am]. 1993;18:33-41.