Use of Cross-Leg Flap for Wound Complications Resulting From Open Pilon Fracture

Discussion

Fractures of the distal tibia are commonly known as pilon or plafond fractures. They represent up to 10% of all tibial fractures. The injury consists of an intra-articular fracture of the tibiotalar joint with varying degrees of proximal extension into the tibial metaphysis. The etiology is an axial load on the tibia with or without a rotational force.¹ Treatment is challenging. The literature includes many reports of wound and soft-tissue complications after ORIF. In 1969, Rüedi and Allgöwer² published recommendations that have become the standard for treatment of pilon fractures. Twelve percent of the 84 fractures included in their study were associated with wound complications. In 2004, Sirkin and colleagues³ suggested that wound problems associated with ORIF of pilon fractures may be caused by attempts at immediate fixation through swollen soft tissue. They postulated that staging the procedure and waiting for decreased soft-tissue swelling may reduce the incidence of wound complications. In their series, only 2.9% of closed pilon fractures and only 9.1% of open fractures had any wound complications, and none of their patients required skin grafts, rotation flaps, or free tissue transfers.

However, soft-tissue complications still remain a significant threat in the treatment of pilon fracture, and cases that require additional procedures for soft-tissue coverage are common. In some cases, wound necrosis may lead to below-knee amputation.⁴ There are several coverage options, including local rotational flaps using the soleus muscle^5,6 as well as free flaps using the latissimus dorsi, gracilis, or rectus abdominis muscles.⁷ These options require a sufficient blood supply to the region.

Many high-energy pilon fractures may be associated with vascular injury, and therefore flap survival may be compromised. We have reported such a case in the present article. Our patient’s preoperative angiogram indicated he had 1-vessel runoff to the distal leg—a situation incompatible with free tissue transfer. It is not clear whether this finding is secondary to trauma to the leg or is caused by an anatomical anomaly. Nevertheless, the poor vascularity posed a challenge to providing soft-tissue coverage. Cross-finger⁸ and cross-foot⁹ flaps have been described in upper and lower extremity injuries. In 2006, Zhao and colleagues¹⁰ reported on 5 patients with tibia and/or hardware exposure after operative fixation of tibia fractures. These patients had poor local soft tissue around the wound and therefore underwent cross-leg flap for coverage. It is not clear where the soft-tissue defects were located and whether any studies were performed to assess the local blood flow.

From our patient’s case, we learned that multiple factors should be considered when assessing such high-energy injuries. First, respecting the soft tissues is of paramount importance. Our initial management on presentation consisted of irrigation and débridement of the wound, fixation of the fibula, and application of an external fixator to allow for soft-tissue healing before definitive fixation of the pilon. Although ultimately the patient required soft-tissue coverage, soft-tissue healing and viability are important in preventing unnecessary soft-tissue procedures, and therefore we would not have handled our initial treatment differently.

Patient selection is also important. The ideal candidate for a cross-leg flap is a young, healthy person who is compliant and has a strong support system to help with activities of daily living. Unfortunately, because of financial issues and lack of home support, our patient remained hospitalized during his treatment course. For a patient who has support, it is possible to be discharged either home or to a rehabilitation facility once flap viability has been confirmed after surgery.

Another consideration is type of immobilization. Immobilization options include casting, use of Kirschner wires (K-wires), and use of rigid external fixation. For cross-leg flaps, external fixation is superior to casting and K-wires, as it provides a more rigid construct and easier access to the flap for serial evaluation. Further, it is easier for the patient to maintain personal hygiene, and it can provide heel rises to avoid pressure ulcers.

Conclusion

To our knowledge, there have been no reports of using a cross-leg flap for wound complications in high-energy pilon fractures. As already mentioned, many of these fractures may be associated with severe soft-tissue injury and may need flap coverage. A cross-leg flap with external fixation of both legs provides a limb salvage option with satisfactory patient outcomes.