Wiler, Jennifer L. MD, MBA
Dr. Wiler is the assistant chief of clinical operations in the department of emergency medicine and the medical director of the ED Observation Unit at Washington University and Barnes-Jewish Hospital in St. Louis.
A pilon fracture (also called a tibial plafond fracture) is a comminuted fracture of the distal tibia involving the ankle joint. This injury occurs as the result of a high-energy vertical axial loading (e.g., fall from height, motor vehicle crash) with impaction of the talus onto the tibial plafond, resulting in a long oblique distal metaphyseal tibia fracture, as well as fracture of the tibiotalar articular surface.
The proper descriptive term for these high-energy articular fractures of the distal tibia is somewhat controversial. In French, the distal end of the tibia is called a pilon, meaning pestle or rammer. This injury implies an axial loading (ramming) of the weight-bearing articular surface of the distal tibia (pestle) into the talus. The distal articular surface of the tibia is also referred to as the plafond, originating from the French “plat” (meaning flat) and “fond” (meaning bottom). (Orthopaedic Care Textbook; www.orthopaediccare.net/view/templates/Chapter_Text.asp?chapterid=tmletbpla&p=0.)
Tibial plafond fractures are frequently associated with severe soft tissue injuries and often result in comminution of bone with disruption of the articular cartilage and subchondral bone. It is well known that post-traumatic arthritis is a common complication because of the typical severity of these fractures and intra-articular involvement.
Pilon fractures are relatively uncommon, accounting for only approximately seven percent of all tibial fractures. Clinical presentation will vary depending on the severity of injury impact and duration since onset of injury. The blood supply to the distal leg is provided by branches of the posterior tibial, peroneal, and dorsalis pedis arteries. Patients sustaining trauma resulting in a pilon fracture often have rapid and significant soft tissue swelling that can quickly result in large skin blister formation.
Emergency department evaluation should include identifying and appropriately managing any associated traumatic injuries. A thorough lower extremity skin assessment should be performed to identify the presence or absence of an open injury. Displaced bony fragments violate the skin in 20 percent to 25 percent of cases. The examiner should note the amount of swelling and the presence or absence of fracture blisters around the ankle. Because significant soft tissue damage is common, compartment syndrome is a known complication, and a comprehensive neurovascular examination of the distal lower extremity is prudent.
Associated traumatic injuries should be identified. Concurrent fibula fractures are very common, and found in approximately 85 percent of cases. Five to 10 percent of patients with pilon fractures will have associated bilateral injuries. (Wheeless' Textbook of Orthopaedics; www.wheelessonline.com/ortho/tibial_plafond_fracture.) These include but are not limited to vertebral compression fractures (predominantly L1) and contralateral fractures of the calcaneus, tibial plateau, pelvis, or acetabulum. Physical examination and evaluation should focus on identifying these associated injuries.
A pilon fracture is considered an unstable fracture because of the disruption to the ankle mortise. Significant ankle dislocation associated with the fracture resulting in neurovascular compromise is an indication for emergent reduction. Wounds at an open fracture site should be irrigated with sterile water if grossly contaminated, covered with a sterile dressing, tetanus prophylaxis updated as needed, and antibiotic prophylaxis administered for contaminated wounds. Traumatic fracture blisters should be left intact because once ruptured, blisters are more likely to become contaminated by skin flora. Appropriate analgesia should be administered and measures taken to control active bleeding. Temporary splinting, ice, and elevation may improve comfort while awaiting disposition in the ED.
Plain three-view (anteroposterior, mortice, and lateral) radiographs of the involved ankle and two-view tibia-fibula film should be obtained. Radiographs of the knee, hip, foot, and vertebra may be needed to rule out associated fractures. Lumbar radiographs should be considered for all patients who fall from a significant height to rule out associated compression fractures. Computerized tomography (CT) scanning of the distal tibia and ankle joint is usually mandatory to define the extent of bony injuries and allow for preoperative planning.
A five-part classification system for pilon fractures has been developed by the Arbeitsgemeinschaft fur Osteosynthesefragen-Association for the Study of Internal Fixation and Orthopaedic Trauma Association (www.ota.org/compendium/tibia.pdf) but is of limited use to the emergency physician.
The timing of treatment, method of stabilization, operative repair techniques, and postoperative rehabilitation for pilon fractures are controversial, and must take into account the severity of the underlying fracture and the extent of soft tissue damage. The treatment options for fractures of the tibial plafond include: nonsurgical care (casting); immediate internal fixation; external fixation with or without delayed limited internal fixation; external fixation followed by delayed internal fixation; and primary arthrodesis (ankle/bone fusion). While operative treatment is generally recommended, there are currently not enough conclusive data to determine which treatment option is best for each fracture subtype. (Orthopedic Care Textbook; www.orthopaediccare.net/view/templates/chapter_text.asp?chapterid=tmletbpla&p=10.)
As such, all pilon fractures should be managed in consultation with an orthopedist. The fracture care provided in the ED will depend on the immediate operative versus expectant management decision made by the orthopedist.
The ankle is a poorly vascularized joint with limited muscle and relatively noncompliant surrounding skin. It is not uncommon to have massive soft tissue swelling, which is at increased risk of wound infection (Injury 2007 Nov 28 [Epub ahead of print]), skin necrosis, and sloughing, particularly with premature operative repair strategies. The reported occurrence of wound sloughing and infection ranges from 10 to 50 percent. (Wheeless' Textbook of Orthopaedics; www.wheelessonline.com/ortho/tibial_plafond_fracture.)
Fractures of the tibial plafond, especially those extending into the diaphyses, are slow to unite. Conditions such as diabetes, peripheral vascular disease, and smoking can further delay healing. All patients seen in the ED should be educated about the common occurrence of long-term disability caused by post-traumatic arthritis despite appropriate treatment. (Injury 2007 Nov 28 [Epub ahead of print].)
On average, high-energy pilon fractures with operative treatment will take four months to heal, and 75 percent of patients who do not develop wound complications may expect to have a good result. Unfortunately, the need for a subsequent arthrodesis (ankle fusion) procedure may be as high as 10 percent. (Wheeless' Textbook of Orthopaedics; www.wheelessonline.com/ortho/tibial_plafond_fracture.) This patient was splinted in the ED, with delayed operative repair planned after her soft tissue swelling improved.
© 2008 Lippincott Williams & Wilkins, Inc.