Field Management of Displaced Ankle Fractures: Techniques for Successful Reduction

Orthopedic trauma is the most common subset of injuries encountered by the wilderness medical provider, making up 70 to 80% of acute trauma sustained during outdoor and wilderness activities. Fractures and dislocations of the extremities are by far more common than more severe and morbid injuries to the axial skeleton (spine and pelvis). Although not commonly life threatening, appropriate initial assessment and subsequent management of extremity injuries are critical in order to maximize long-term outcomes in terms of patient pain and function in the months and years after injury. Anatomic reduction of fractures and dislocations, although generally a procedure not often performed by urban and suburban prehospital medical providers, is an essential skill for medical personnel who anticipate managing orthopedic injuries in a wilderness setting in which prolonged evacuation time is often the norm. I offer a technique for reducing ankle fracture/dislocations that works well both in the wilderness and in the emergency department setting but that may not be well known among wilderness medical providers.

Fracture/dislocations of the ankle are caused by combined supination/pronation stress and rotational torque on the ankle joint. Usually these injuries are sustained by slip and fall accidents from standing or from an awkward landing after a fall from a height. Ankle fractures are most commonly seen in persons older than 55 years, and indeed multiple epidemiological studies have demonstrated a recent increased incidence of these injuries in developed nations consistent with the increase in the proportion of older adults.

Patients who sustain this type of injury will complain of immediate severe pain and an inability to bear weight on the affected lower extremity. All injured patients should be initially assessed after advanced trauma life support protocols have been carried out. Once the patient is deemed stable from cardiopulmonary and hemodynamic standpoints, focused examination of the effected lower extremity should be performed. Obvious deformity at the ankle with associated soft-tissue swelling indicates a fracture/dislocation. A thorough neurovascular exam should be performed consisting of assessment of both the posterior tibial and the dorsalis pedis pulses and sensation to light touch on the plantar, dorsal, medial, lateral, and first dorsal webspace regions of the foot. Any abnormalities should prompt an even more urgent reduction of the ankle deformity. The remainder of the affected extremity should be examined for tenderness to palpation, crepitance, deformity, soft-tissue injury, or pain with motion of the knee or hip.

Any time that evacuation to a definitive care facility will be longer than 2 hours or if neurovascular compromise to the foot is suspected, prompt reduction of displaced ankle fractures should be attempted. Anatomic reduction accomplishes many important goals: 1) compression and/or tension on neurovascular structures is alleviated, often restoring blood flow and neurological function that was lost while the ankle was deformed; 2) realignment of joint contact surfaces decreases the chance of articular cartilage damage from friction against jagged bone edges; 3) pain levels are usually significantly decreased for the patient once anatomic realignment is achieved; and 4) edema and inflammation of the injured area are reduced, which could have important implications for timing of surgical management once a definitive care facility is reached.

In the emergency department setting, reductions are often achieved while the patient is consciously sedated by intravenous medications. Sedation allows maintenance of a high level of analgesia and affords partial relaxation of tense and often spastic muscles contributing to the deforming forces of the displaced ankle. In this situation, a physician is free to manipulate the ankle as needed to achieve a near-anatomic reduction of a displaced ankle fracture. However, this freedom comes at a price, because sedation requires intravenous access, the training and experience of a physician familiar with sedation techniques and protocols, and the constant vigilance of a one-on-one nurse. Further, real-time physiological monitoring of blood pressure, oxygen saturation, end-tidal Co_2, and cardiac rhythm is usually required. These resources are rarely available in a wilderness or expedition setting. Thus, alternative techniques are clearly indicated in these environments.

The hematoma block is an effective technique requiring injection of 1% lidocaine, without epinephrine, into the fracture hematoma. This simple technique can effectively numb the entire region around the fracture. When administered correctly, a hematoma block provides sufficient anesthesia to allow a fully awake and alert patient to tolerate surprisingly vigorous manipulation of the fractured ankle. Adequate analgesia is achieved with the injection of approximately 2 to 2.5 mg/kg of lidocaine, a dose that results in circulating plasma concentrations well below the toxic threshold of 5000 ng/mL. Although used more commonly for distal radius fracture reductions, the hematoma block is extremely effective for ankle injuries. Two studies have demonstrated that in terms of patient satisfaction and ease of reduction, ankle hematoma block is comparable to conscious sedation.^, Similarly, it has been demonstrated that intra-articular injection of dislocated shoulders with lidocaine is as effective as conscious sedation. Because all ankle fractures are intra-articular, hematoma block is an ideal technique for use in the wilderness setting. All of the required supplies for performing this technique may be found in well-stocked expedition medical kits (lidocaine, sterile skin prep, syringe, and needle). The technique is safe and relatively minimally invasive, easy to master, and very effective.

Infiltration of 1% lidocaine into the ankle is accomplished by injection using a 20- to 22-gauge needle through an anteromedial approach. Palpable landmarks used to define the injection point consist of the tibialis anterior tendon and the medial malleolus (Figure 1). Although the anatomy may be distorted in a severely displaced fracture, these landmarks are usually still identifiable. After the skin is sterilized, the needle is inserted approximately midway between these 2 landmarks angled in a slightly lateral and cephalad direction. As the needle is advanced, it is common to impact the talar dome. Simple repositioning of the needle in a more cephalad angle allows penetration of the joint and fracture hematoma. Once dark blood is aspirated, confirming the correct needle position, 10 to 15 mL of lidocaine should easily flow into the ankle with little resistance. Allow 5 to 10 minutes for adequate analgesia to take effect. If the lidocaine was injected into the correct area, the patient should tolerate significant manipulation of the ankle.

Reduction is accomplished by grasping the calcaneous and midfoot area and producing axial traction, followed by manipulation of the talus back into anatomical position under the weight-bearing articular surface of the distal tibia. If the talus is displaced laterally, then gentle internal rotation of the foot may facilitate the reduction and help stabilize the ankle once reduced. Conversely, if the talus is medially displaced, then external rotation may assist with postreduction stabilization. After reduction is achieved, a repeat neurovascular examination should be performed. Immobilization of a reduced ankle fracture is critical to prevent redisplacement of the ankle with subsequent articular surface damage, potential neurovascular compromise, and severe soft-tissue swelling. Many methods of improvised immobilization have been described using materials readily available in expedition medical kits and in camping/mountaineering supplies. Regardless of the immobilization method used, the ankle should be splinted at neutral (90°) to maximize tibio-talar stability. If at all possible, no weight should be placed on the injured extremity. When able, elevation and icing of the ankle should be carried out to decrease soft-tissue swelling and associated pain.

If the reduction is difficult to achieve after several attempts at manipulating the ankle back into an anatomic position, the traction method described by Quigley may be easily used. The injured lower extremity is simply suspended encased in a tubular fabric sheath that extends the length of the leg out beyond the toes. The weight of the leg stretching the fabric creates both an axial and internal or external rotatory force on the ankle and allows for gradual reduction of the fracture. After a hematoma block is administered, the extremity may be allowed to hang for 20 to 40 minutes in this position. I have found this method to be very successful in achieving anatomic reduction in ankle fracture/dislocations that were not amenable to reduction by direct manipulation. Presumably the protracted and constant forces created by the traction allow for gradual relaxation of deforming muscle forces and edema and allow the ankle to “reduce itself.” In the hospital setting, Quigley's traction is generally set up using tubular stockinette rolled up to the mid-thigh and secured with tape. Two to three feet of excess stockinette extends beyond the toes and is tied to an intravenous pole, and the leg is allowed to hang with the foot in a plantar-flexed position. This arrangement can be easily improvised in the field with the use of any relatively tight-fitting pants (Figure 2) or even long socks. After successful reduction, the ankle should be stabilized as previously discussed. Quigley's traction also facilitates splinting of the injured ankle with minimal assistance because splint material may be applied while the extremity is hanging in traction.

Ankle fracture/dislocations will become more common in wilderness and outdoor situations as the large population of Baby Boomers continues to remain active even at advanced ages. Successful management of these injuries begins in the field, where accurate reduction of a displaced fracture may restore lost neurovascular function, decrease pain, restore articular alignment, and reduce soft-tissue swelling. The use of an intra-articular hematoma block easily allows pain-free reduction, and the use of improvised Quigley's traction may facilitate reduction of displaced fractures not amenable to reduction by direct manipulation. Reduced fractures should be immobilized in a neutral position and kept nonweightbearing until definitive care can be reached.