Chapter 5 Foot and ankle emergencies
Orthopedic Emergencies, ed. Michael C. Bond, Andrew D. Perron, and Michael K. Abraham. Published by Cambridge University Press. © Cambridge University Press 2013.
Achilles tendon injuries
Presentation
Achilles injuries often present as a sudden onset of pain in the posterior aspect of the ankle, without direct trauma
The typical patient is male, 30–40 years old who has begun new activities such as jumping sports, known colloquially as a “Weekend Warrior”
Often patients can ambulate, but with poor balance and with pain
Physiology
The rupture typically occurs 2 to 5 cm proximal to the insertion of the Achilles within the calcaneus. This is the “watershed zone” of diminished vascularity
These injuries have been associated with recent fluoroquinolone use
PEARL: Have a high index of suspicion for an Achilles tendon injury in patients complaining of ankle pain without direct or commensurate trauma.
Diagnostic work-up
The physical examination is the key to diagnosis
The patient will often maintain the ability to plantar flex their ankle because of the continuity of the flexor hallux longus and the flexor digitorum longus
There will often be weakness of plantar-flexion and tenderness with resisted plantar-flexion
Palpation in the posterior aspect of the ankle and Achilles may reveal a palpable gap
Ecchymosis and swelling in this area is common
Lie the patient prone on the examination table with shoes and socks removed from both feet
With the knee bent to 90° on the uninvolved extremity, the ankle should have a resting plantar-flexion posture
When the calf is squeezed, the ankle will plantar flex
On the side with an Achilles tendon rupture, the ankle will stay bent essentially to 90° when the knee is bent. In addition, when the calf is squeezed, the ankle will not move
This failure of the ankle to move when the calf is squeezed is what constitutes a positive Thompson test
Plain radiographs of the foot or ankle are necessary to ensure there is not an avulsion fracture of the calcaneus
PEARL: Diagnosis of an Achilles tendon injury is best made by physical examination, and the gold standard test for confirmation is the Thompson test.
Treatment
Place the patient in a posterior slab splint with the ankle in resting plantar-flexion
A “CAM” boot with 15° of plantar-flexion can also be used if available
Crutches and non-weight-bearing status are required
Prognosis
The long-term outcome of Achilles ruptures is quite good
Historically, patients were operatively repaired within 1 to 2 weeks. However, newer literature indicates equally good outcomes in eligible patients who undergo non-operative treatment with progressive casting and functional rehabilitation
In general, patients are able to return to sporting activities in 4–6 months after an Achilles rupture
Ankle fractures and dislocations
Presentation
Ankle fractures can have a variety of histories, from a simple twist and fall to a violent motor vehicle collision
For most ankle fractures, patients present with the inability to weight-bear
They will often complain of pain over the medial or lateral malleolus
Physiology
Ankle fractures can be the result of rotational injuries or of axial loads
In a rotational injury, often the injury will be the result of an inversion or eversion stress to the ankle
During an inversion event, the injury will often start over the distal tip of the fibula (the lateral malleolus), and progress in a circular fashion to the posterior aspect of the ankle (posterior malleolus) and then to the medial distal portion of the ankle (medial malleolus) or deltoid ligament (Figure 5.1 A, B, C)
Similarly, an eversion event will often start with an injury over the medial malleolus or deltoid ligament, then progress to the posterior malleolus and then the lateral malleolus
Conversely, a pilon fracture results from an axial load being placed upon the foot. This can occur either from a sudden deceleration (fall from height) or from a direct impact (head on motor vehicle collison). The talus is essentially forced into the distal tibial plafond, resulting in a fracture of the entire distal tibia
Diagnostic evaluation (Figures 5.2A, B and 5.3)
Obtain plain radiographs of the joint
These should include PA, lateral, and mortise views
The mortise view is an AP view with the ankle internally rotated approximately 20° such that the medial and lateral malleolus are in the same frontal plane
Especially in cases of fractures with dislocation, the diagnosis is often immediately evident
The physical examination should focus on skin breaks, motor function, and vascular status
The vascular examination is important on the initial evaluation but even more important after reduction of any dislocation or manipulation
Similarly, sensation to light touch often can improve after the reduction of a fracture
PEARL: Beware of isolated fractures of the medial malleolus. This may indicate a rotational-type injury where the energy of the fracture travels up the syndesmosis (before exiting the proximal fibula); a Maisonneuve fracture. Isolated fractures of the medial malleolus should also be evaluated with plain radiographs of the tibia/fibula to exclude this injury.
Treatment
In cases of open fractures, an orthopedic consult is emergent
The wound should be irrigated and dressed by the ED provider to help reduce the risk of infection
Consider starting antibiotics (i.e., cefazolin) to reduce the risk of infection
Dislocation of an ankle fracture should be promptly managed. Often the talus will sublux or dislocate laterally, which compromises the integrity of the skin medially. The goal of the reduction is to get the talus to sit under the distal tibia (ankle mortise) and to relieve pressure over the skin
Reduction can be accomplished with procedural sedation, intra-articular injection of a local anesthetic (without epinephrine), or with a forceful and longitudinal traction of quick duration
In cases of intra-articular injection, there is often a large space just medial to the talus, assuming a lateral dislocation of the talus within the ankle mortise
The surface landmark is the tibialis anterior tendon
The injection can be done just medial to this landmark
A soft spot is often palpable to help guide the proper area to start
To reduce the fracture:
Over-exaggerate the fracture
In cases of a lateral dislocation, this would involve tipping the ankle into greater valgus after shifting the ankle laterally
Having the knee flexed is often helpful as this will help relax the gastrocnemius muscle
Apply longitudinal traction and restore the bone to its normal position
An assistant can hold counter-traction to the proximal tibia or distal femur
Post reduction, immobilize the joint
A fracture–dislocation should be placed in a posterior split plus a stirrup splint for medial and lateral stability
This combination prevents dorsiflexion, plantar flexion, inversion, and eversion
A stable fracture should be placed in a simple posterior splint
Distal fibular fractures (Weber A) can be immobilized with a posterior splint or CAM walking boot and most are immediately weight-bearing as tolerated by the patient
Post-reduction radiographs are a necessity to ensure the ankle is reduced and aligned properly
Fibular fractures above the malleolus (Weber B and C) will require operative repair
Discharge instructions should include elevation, ice, and non-weight-bearing status
Prognosis
The outcome of ankle fractures is as varied as the presentations, and depends on both the amount of energy involved and the presence of any associated soft-tissue injuries
Some fractures require surgical intervention with open reduction and internal fixation, while other fractures are treated conservatively with splinting and casting
In general, ankle fractures that require surgical intervention require 6–12 weeks of non-weight-bearing
Hind foot and mid-foot injuries
Presentation
Injuries in this group entail a variety of injuries, including:
Result from axial load injuries, similar to ankle pilon fractures
With any axial load injury, it is important to evaluate for injuries at the knee, hip, pelvis, and lumbar spine
Patients will be unable to bear weight on the heel
Talus fractures (Figure 5.4)
Result from an axial load with forced dorsiflexion of the ankle
These are often the result of high-energy trauma and must be recognized promptly for optimal management because of the tenuous blood supply of the talar neck
Avascular necrosis of the talus is a common long-term complication even if properly managed
The result of an axial load placed on to the heel of a foot that is plantar flexed
A common example is a football player whose toes are planted into the ground but whose heel is off the ground. Often another player rolls on to the heel, causing an injury to the Lisfranc joint
The Lisfranc joint is located between the cuneiforms and the first and second metatarsal bases
The Lisfranc ligament connects the medial cuneiform with the base of the second metatarsal
This injury is often missed in the ED and failure to diagnose is one of the most common reasons for litigation later
Metatarsal injuries (Figure 5.5 A, B)
Commonly caused by inversion/eversion injuries or direct trauma
Fifth metatarsal fractures are the most common
Can be divided into avulsion or “pseudo Jones” and distal or “Jones” fractures
Jones fractures require more aggressive follow-up and management because of the increased risk of malunion, non-union, and avascular necrosis
PEARL: Prior to making the diagnosis of a “foot sprain” consider the diagnosis of a Lisfranc injury and disposition the patient accordingly. This injury is often missed in the ED and failure to diagnose is one of the most common reasons for litigation later.