Emergency department external fixation for provisional treatment of pilon and unstable ankle fractures.

Unstable ankle fractures and impacted tibial pilon fractures often benefit from provisional external fixation as a temporizing measure prior to definitive fixation. Benefits of external fixation include improved articular alignment, decreased articular impaction, and soft tissue rest. Uniplanar external fixator placement in the Emergency Department (ED ex-fix) is a reliable and safe technique for achieving ankle reduction and stability while awaiting definitive fixation. This procedure involves placing transverse proximal tibial and calcaneal traction pins and connecting the pins with two external fixator rods. This technique is particularly useful in austere environments or when the operating room is not immediately available. Additionally, this bedside intervention prevents the patient from requiring general anesthesia and may be a cost-effective strategy for decreasing valuable operating time. The ED ex-fix is an especially valuable procedure in busy trauma centers and during mass casualty events, in which resources may be limited.

BACKGROUND

Displaced ankle fractures and impacted pilon fractures are optimally treated with open reduction and internal fixation. Immediate surgical fixation is not always optimal, as soft tissue swelling may preclude immediate fixation. Additionally, operating room availability is not always immediate, thus closed reduction in the emergency room is often necessary to improve alignment and to relieve pressure on the skin. When closed reduction fails to maintain fracture reduction, external fixation is an invaluable tool.

The use of an emergency department external fixator (ED ex-fix) is an effective temporizing procedure for improving alignment and length of tibial pilon[1] and unstable ankle fracture/dislocations.[2] This device can be applied safely and quickly by orthopedic physicians, and is immediately effective in relieving pressure on a compromised soft-tissue envelope or endangered articular cartilage. This construct was initially described as “traveling traction” by Watson et al.,[3] who placed a uniplanar ankle spanning external fixator connecting horizontal calcaneal and proximal tibial metaphyseal Steinman pins. The original technique involved immediate placement of a calcaneal traction pin in the emergency department followed by conversion to a spanning external fixator in the operating room.[3]

At our institution, the ED ex-fix is applied for a variety of fracture patterns in which immediate operative intervention is not possible. First, the ED ex-fix can be used to temporize pilon fractures with articular impaction by effectively distracting the tibiotalar joint surface and preventing further chondral pressure injury. Second, when a splint or cast cannot maintain the reduction of an unstable ankle fracture-dislocations, as in the case of a large posterior malleolar fracture fragment, the ED ex-fix can help to achieve a satisfactory reduction. Lastly, pilon or ankle fractures with a threatened soft tissue envelope not alleviated by splinting or casting can be treated with an ED ex-fix to prevent further soft-tissue compromise.

Technique

Depending on local resources and provider preference, the ED ex-fix can be placed utilizing local anesthetic, with or without conscious sedation with commonly available instruments. Figure 1 illustrates the equipment required for this technique. Mini C-arm fluoroscopy is not necessary, but may assist with pin placement and accurate fracture reduction.

Figure 1

Supplies necessary for ED ex-fix placement

Initially, local anesthetic is injected into the lateral and medial aspect of the tibia 3 cm distal to the tibial tubercle. The calcaneus is then injected medially and laterally in the middle of the tuber, taking care to infiltrate sub-periosteally. The proximal leg and heel are sterilely prepped with betadine or chlorhexidine solution.

The proximal tibial traction pin is placed through a 1 cm longitudinal incision on the lateral aspect of the tibia, 3 cm below the tibial tubercle through the center of the tibia. A 1 cm incision is made on the medial side as the pin penetrates the skin. At our institution, a hand drill is used in order to avoid thermal necrosis of the bone.

Next, a 1 cm longitudinal incision is placed in the middle of the calcaneal tuber. A transfixion pin is placed from medial to lateral over the flat area of the calcaneal tuber posterior and inferior to the neurovascular bundle.[4] Again an incision is made on the lateral side of the calcaneus as the pin penetrates the skin.

A uniplanar Stryker Hoffman II external fixator frame (Stryker, Cambridge, MA) is then applied. The frame is locked proximally leaving enough room on the bars to apply traction. The fracture and/or tibiotalar joint is then closed reduced by applying longitudinal traction and manipulated to minimize angulation, translation and rotation [Figure 2]. Once reduction of the tibiotalar joint and fracture is adequate, the distal aspect of the ex-fix is tightened. It is sometimes helpful to use a mini C-arm to fine-tune the reduction and prevent multiple flat plate radiographs. Gauze dampened with sterile saline is applied to the pin sites. Then, a well-padded posterior splint is placed to keep the ankle in neutral flexion and prevent equinus contracture.

Figure 2

Photograph of ED ex-fix apparatus in place

In cases of unstable ankles with large posterior malleolar fractures, a traction rope can be used to suspend the calcaneal pin from the traction bed frame to prevent the ankle from dislocating posteriorly. In all cases the skin should be monitored closely for blistering, pressure points and to assess when the soft tissues are ready for definitive fixation. Patients should be monitored for compartment syndrome and neurapraxia. Overdistraction of the ankle joint should be avoided to prevent neurapraxia. The bed should be gatched with the extremity iced and elevated. If the leg is suspended from the traction bed, the patient should be placed on bed rest, otherwise, the patient can be mobilized out of bed to a chair with the extremity elevated.

CASE REPORT

A 73-year-old woman presented with a closed comminuted left pilon and distal fibula fracture in valgus angulation with threatening of the medial skin [Figure 3a]. Attempted closed reduction and application of a posterior plaster splint with side gussets was inadequate in maintaining an acceptable reduction to relieve skin pressure [Figure 3b]. Application of a uniplanar ankle spanning external fixator (ED ex-fix) coupled with axial traction and varus force adequately reduced the fracture and prevented the patient from requiring an immediate operative intervention [Figure 3c-f]. In this case, the tibiotalar joint is mildly distracted, relieving direct pressure on the articular cartilage in the area of comminution involving the medial malleolus and medial plafond.

Figure 3

73-year-old woman with left valgus-angulated pilon fracture with threatened medial skin. (a) Pre-reduction anteroposterior (AP) radiographs (b) Post-reduction AP radiographs revealing failed closed reduction (c-f) Post ED ex-fix AP and lateral radiographs and coronal and sagittal CT scan revealing improved alignment

A 24-year-old hemodynamically unstable polytrauma victim arrived at our institution with a closed comminuted pilon fracture with anterior impaction [Figure 4a and b]. Closed reduction failed to adequately reduce the fracture [Figure 4c and d]. The patient was too medically unstable for the operating room, thus an ED ex-fix was placed, which successfully achieved reduction and temporary stabilization [Figure 4e and f].

Figure 4

24-year-old male with left impacted pilon fracture. (a and b) Pre-reduction anteroposterior (AP) and lateral radiographs (c and d) Post-reduction AP and lateral radiographs revealing failed closed reduction (e and f) Post ED ex-fix AP and lateral radiographs revealing improved alignment

DISCUSSION

The ED ex-fix provides a safe and reliable method for achieving fracture reduction and stabilization in unstable ankle fractures and pilon fractures. It is ideally indicated in situations in which placement of an external fixator in the operating room is not immediately feasible. This scenario may occur at busy trauma centers or in times of mass casualty where materials and OR time can be limited.

Advantages of the ED ex-fix are numerous; by placing the ED ex-fix at the time of initial presentation, the stress on the soft tissue envelope from the fracture displacement is reduced, and the total hospital resources are minimized. It has been shown that the cost of operating room time ranges from $60-180/minute[5] in the United States, thus each procedure performed outside of the operating room rather than in the operating room may save valuable health care dollars. Additionally, ED ex-fix patients are subjected to one less exposure to general anesthesia, as this technique can be performed with local anesthetic and can be done without imaging if needed.

If resources allow and a patient can be taken urgently to the operating room, it is preferable to place an external fixator in this more controlled setting. In the operating room, sterile conditions are optimized, patients are not subjected to an awake intervention, and a more stable construct can be achieved with two 5 mm tibial half pins as well as additional metatarsal or talar pins for control of reduction in multiple planes. This is a clear limitation of the ED ex-fix, which only provides uniplanar control. Furthermore, the ED ex-fix itself may not be ideal for treatment of large posterior malleolus fractures with posterior dislocation of the ankle. Our solution in this situation is to apply longitudinal traction via the ED ex-fix, then to suspend the extremity by hanging the calcaneal transfixion pin from the traction bed frame to counteract the tendency toward posterior tibiotalar dislocation, providing additional anterior to posterior control and simultaneously elevating the extremity. However, this technique forces the patient to be confined to bed. Since malleolar fractures often do not have the degree of soft tissue injury as high-energy pilon fractures, immediate definitive fixation is optimal to restore joint congruency if the soft tissue envelope allows, and the ED ex-fix should only be used when immediate operative fixation or acceptable closed reduction is not possible.

There are several contraindications to ED ex-fix placement. Fractures of the calcaneus or tibial shaft are absolute contraindications. Compromised skin at the site of the transfixion pins, open fracture, and compartment syndrome are also contraindications.

Critics of the ED ex-fix appropriately contend that a superior construct can be placed in the operating room. In addition, some have voiced concern that there is an increased risk of infection due to the fact that this device is not applied in an optimally sterile environment. However, this procedure is equally invasive as the placement of calcaneal and proximal tibial traction pins, which are commonly placed at orthopedic trauma centers in the ED. No existing studies to date have demonstrated an increased infection rate in ED ex-fix patients when compared to those who have an external fixator placed in the operating room.

Some centers may have reliable immediate operating room access, but scenarios will arise even at these centers in which the ED ex-fix can be an invaluable device in preventing exacerbation of an already tenuous soft-tissue envelope. At our institution, external fixators are preferentially placed in the operating room when this can be achieved within several hours from the time of injury. It may not be appropriate to wait longer than several hours for an available OR, as it further jeopardizes the patient's soft tissue envelope and articular cartilage. Therefore, the concept of the ED ex-fix was developed out of necessity. We feel this is a valuable technique which could benefit many orthopedic institutions and help patients when resources are limited.

CONCLUSION

The ED Ex-Fix is a safe and reliable method for achieving temporary stability of unstable ankle injuries and impacted pilon fractures. This technique can expedite the placement of external fixation, and potentially save valuable operating room time and financial resources.