To the Editor:

Bone transport using distraction histogenesis (the Ilizarov concept) is certainly one alternative in the treatment of ununited fractures associated with bone defects; however, the appeal of the technique has been limited by the cumbersome nature of the frame, the challenge to the patient who must operate the frame correctly and deal with pin track infections and other problems, and the frequent docking site nonunions that require secondary open procedures.

Dr. Calif describes the need for a “limited open exposure for surgical debridement, and removal of hardware” and expresses concern regarding “the surgical invasiveness and the resultant devascularization”. Our data demonstrate that these concerns may be overstated. The difference between a “limited open exposure” and a larger exposure for plate and screw application is limited in terms of bone vascularity if the surgeon takes care to keep the periosteum and muscle attachments intact as much as possible. When it is described that “large deficits are subsequently addressed by bone grafting after full restoration of bone length” this sounds as if techniques similar to the ones we described are being used—large cancellous bone grafts bridging defects and protected by fixation devices (in this case an external frame?).

We have used the techniques of Ilizarov(1, 2), but prefer plate and screw fixation and bridging bone grafts(3, 4) because they are easier for the patient and the surgeon and the results may be superior(1).

References

1. Ring D, Jupiter JB, Gan BS, Israeli R, Yaremchuk M. Infected nonunion of the tibia. Clin Orthop 1999;369:302-311.

2. Ring D, Jupiter JB, Labropoulous PA, Guggenheim JJ, Stanitski DF, Spencer DM. Limb deformity in osteogenesis imperfecta treated by the method of distraction histogenesis. J Bone Joint Surg 1996;78A:220-225.

3. Ring D, Jupiter JB, Quintero J, Sanders RA, Marti RK. Atrophic ununited diaphyseal fractures of the humerus with a bony defect: treatment by wave-plate osteosynthesis. J Bone Joint Surg [Br] 2000;82B:867-871.

4. Ring D, Jupiter JB, Sanders RA, Quintero J, Santoro VM, Ganz R, et al. Complex nonunion of fractures of the femoral shaft treated by wave- plate osteosynthesis. J Bone Joint Surg 1997;79B:289-294.

To The Editor:

We wish to congratulate Dr. Ring and colleagues for their contribution, "Ununited diaphyseal forearm fractures with segmental defects: plate fixation and autogenous cancellous bone-grafting" (2004;86:2440-5); one of the largest reported series of forearm nonunions, which will certainly help guide the management of this intricate problem.

Concomitant compounding factors including active infection, failed previous fixation, bone deficit, or inadequate soft tissue coverage further complicate the problem of nonunion and constitute a surgical challenge. In our practice, we refrain from employing the plating technique in such cases. We have, however, a rewarding experience in utilizing the hybrid external fixation, based on the Ilizarov's concept, as an efficient therapeutic modality. Following limited exposure for surgical debridement, and removal of hardware, if any, the bones are fixated with a hybrid Ilizarov-AO frame. An isolated external fixation frame is applied to each bone, thus sparing the mobility of radio-ulnar joints. Each frame is transfixed to the bone with threaded mini-Schanz pins and Kirschner wires. Restoration of length is crucial, but is not always readily attainable long after injury. This is achieved postoperatively by gradual distraction through the fracture site at a rate of 1mm/day. Small bone deficits are usually bridged by bony tissue through distraction osteogenesis, while large deficits are subsequently addressed by bone grafting after full restoration of bone length. Early mobilization of the elbow, forearm, and wrist is encouraged postoperatively, thus achieving complete osseous union and good functional outcome.

The hybrid frame offers favorable conditions for healing of both the bony and soft tissues by providing stable fixation, while still allowing axial micro-movements at the fracture site. Furthermore, this configuration minimizes the surgical invasiveness and the resultant devascularization. The transfixing pins and wires are inserted extra- focally, obviating the need for embedding hardware and nonvascularized bone in a dysvascular and potentially septic location.

This promising modality poses a surgical alternative to plating and bone grafting. However, it requires patient's compliance and may be technically demanding.