Introduction
Several treatment modalities, such as bone grafting, vascularized local or free bone transfer, and distraction osteogenesis, have been recently used for large segmental bone defects of the tibia [
1‐
8]. Although satisfactory results have been reported with these techniques, a limitation of joint motion due to long-term immobilization and non–weight bearing due to weak grafts are problems [
4,
6]. Also, when autogenous iliac bone graft and fibular bone grafts are impossible due to multiple fractures, there are few treatment options for large segmental bone defect.
We present two patients with open pilon fractures with large bone defects treated successfully with fibular strut allografts. The patients were initially treated by massive irrigation, wound debridement, and temporary external fixation. After complete wound healing, the bone defects were managed. Because autologous iliac crest or fibular bone grafts were impossible to be harvested due to multiple fractures, the bone defects were reconstructed with fibular strut allografts. Fixation was performed with a periarticular distal tibia locking plate. At 2 months postoperatively, the patients ambulated with partial weight-bearing; at 6 months, they had full range of motion of the ankle joint and full weight-bearing.
Discussion
Because most pilon fractures are caused by high-energy trauma, the pattern of fractures is complex and the adjacent soft tissues are damaged. Therefore, the treatment outcomes are often not satisfactory, and complications such as infections remain significant [
9,
10]. Also, pilon fractures should obtain accurate reduction due to invading the articular surface. Accordingly, the pilon fracture is difficult to be properly treated. In most cases, pilon fractures are associated with bone defects. In cases of a small-sized defect, the treatment can only be an iliac bone graft. However, the management of pilon fractures with large bone defects is challenging. Several methods have been used to manage these defects. In recent years, methods such as bone grafting, vascularized local or free bone transfer, and distraction osteogenesis have been frequently used. In particular, the free vascularized osteocutaneous fibula graft is helpful for obtaining a sufficient length of the grafted bones [
11]. With a synchronous transplantation of soft tissues, such as skin and muscle, one-stage surgery can resolve the defects of soft tissue. There are advantages to these techniques, and satisfactory treatment outcomes can be obtained with them. However, there are disadvantages such as the fatigue fracture of the grafted tibia, complete and incomplete necrosis of a flap, morbidity of the donor site, and functional deficits due to long-term immobilization (e.g., ankle ROM limitation) [
11‐
14]. In addition, most cases of pilon fractures resulted from fall injury are accompanied by fractures in the pelvis and fibula. Thus, we cannot use autogenic iliac bones and fibulas for large segmental bone defects. Therefore, in cases of pilon fractures with large segment bone defects accompanied by multiple fractures, we suggest that the use of fibular strut allograft could be a good treatment of choice.
A structural allograft has previously been used for a bone defect, but it has mainly been used for tumors or for revision surgery of total joint replacements [
2]. In 1995, Chmell et al. [
2] used a structural allograft for a large segmental defect >10 cm in size. But, a structural allograft has been used as an end-stage method for limb salvage of the femur or proximal tibia. As shown in our cases, there were no cases in which initial management was performed for the pilon fracture. Besides, this method does not sacrifice the fibula. We obtained rigid fixation using a periarticular distal tibia locking plate after impaction of the fibular strut allograft. This procedure is effective for patients to perform early articular movement and weight-bearing, and it might be effective for achieving earlier rehabilitation. Also, in our cases, partial weight-bearing ambulation was performed at the 2nd postoperative month. Approximately 6 months later, almost all normal function was recovered. In particular, the distal tibia is a region in which a great deal of force is concentrated per unit area. Rigid fixation was obtained using a fibular strut allograft, by which the weight-bearing could be done at earlier times. A recent study reported that a long segmental defect was treated with a cylinder mesh cage [
15]. However, that defect was in the humerus, which is not a weight-bearing bone. A good result was also reported for the simultaneous treatment of tibia and soft tissue defects with the Ilizarov method [
16], but weight-bearing was much delayed in that case.
We aimed for the second-staged surgery with the fibular allograft and ORIF when complete wound healing without infection was obtained, because an allograft is very vulnerable to infection; we could treat successfully without infections.
When treating a open pilon fracture in which there is an extension of the fracture to the tibial diaphysis along with a large segmental bone defect >7 cm in size and there is the concurrent presence of fibular or pelvic fractures (which rules out bone grafting from these sites), fibular strut allografts and ORIF using periarticular distal tibia locking plates are effective reconstruction options.
Conflict of interest
No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.