Chapter 5 – Foot and ankle emergencies



Chapter 5 Foot and ankle emergencies




Brian Tscholl



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



  • Positive Thompson test




    • 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





Figure 5.1 PA (A), oblique (B), and lateral (C) views of a trimalleolar fracture This is a very unstable injury that will require operative repair. The fibula has a Weber C fracture.


(Image courtesy of Michael Abraham, MD.)



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.





Figure 5.2 Images show a Maisonneuve fracture pattern of a distal tibial fracture (A) and a proximal fibular fracture (B). Distal tibial injuries always require evaluation of the fibular head to rule out this type of injury.


(Images courtesy of Michael Abraham, MD.)




Figure 5.3 Fracture and dislocation of the ankle. Notice the lateral dislocation of the tibia on the talus and the complete disruption of the ankle mortise.


(Image courtesy of Michael Abraham, MD.)



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:




    • Calcaneus fractures




      • 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




    • Lisfranc injuries




      • 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.

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Jan 19, 2021 | Posted by in EMERGENCY MEDICINE | Comments Off on Chapter 5 – Foot and ankle emergencies
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