Orthopedic Emergencies: Expert Management for the Emergency Physician 1st Ed.

Chapter 5. Foot and ankle emergencies

Brian Tscholl

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

·        Positive Thompson test

o   Lie the patient prone on the examination table with shoes and socks removed from both feet

o   With the knee bent to 90° on the uninvolved extremity, the ankle should have a resting plantar-flexion posture

o   When the calf is squeezed, the ankle will plantar flex

o   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

o   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

o   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

o   The wound should be irrigated and dressed by the ED provider to help reduce the risk of infection

o   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

o   The surface landmark is the tibialis anterior tendon

o   The injection can be done just medial to this landmark

o   A soft spot is often palpable to help guide the proper area to start

·        To reduce the fracture:

o   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

o   Apply longitudinal traction and restore the bone to its normal position

o   An assistant can hold counter-traction to the proximal tibia or distal femur

·        Post reduction, immobilize the joint

o   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

o   A stable fracture should be placed in a simple posterior splint

o   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:

o   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

o   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

o   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

o   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.



Figure 5.4 Plain radiograph with arrow indicating a medial talus fracture. These injuries have a high rate of non-union and will need operative repair. (Image courtesy of Michael Abraham, MD.)



Figure 5.5 A: Image of a fifth metatarsal fracture in an 11-year- old. White arrow highlights the fracture. B: Same patient 1 month later after conservative treatment. (Images courtesy of Michael Abraham, MD.)

Diagnostic work-up

·        Physical examination should include a neurovascular assessment as well as documentation of any breaks in the skin

·        Any injury which involves an axial load pattern of injury should prompt evaluation of the ipsilateral knee, hip, pelvis, and lumbar spine

·        Obtain plain radiographs of the foot. AP, oblique, and lateral films are standard

o   In cases of a calcaneus fracture, a Harris axial view should also be obtained

o   When evaluating for a Lisfranc injury, a fleck sign can be seen at the medial base of the second metatarsal

§  This is a small piece of bone pulled off by the stout Lisfranc ligament and should alert the practitioner to the possibility of a more serious injury

o   Weight-bearing radiographs are helpful in suspected Lisfranc injuries

§  However, they may be hard to obtain in the acute setting because of patient discomfort

o   A CT is useful to further delineate the extent of talus and calcaneus fractures, and in cases where the plain films may not be diagnostic but the index of suspicion is high

Treatment

·        Immobilization and non-weight-bearing with a prompt referral to orthopedics is the mainstay of treatment

·        Calcaneus fractures

o   Require a soft bulky dressing with or without a posterior slab splint

o   Traditionally, surgery was delayed 10–20 days to allow for swelling to resolve. However, surgeons are often now choosing to treat these fractures within 24–48 hours, before the swelling reaches maximum

o   Urgent orthopedic consultation or follow-up

·        Talus fractures

o   Displaced fractures of the talar neck require urgent fixation, usually within 24 hours

o   Posterior splinting with ice and elevation are necessary to stabilize the joint prior to surgery

o   Emergent orthopedic consultation in the ED

·        Lisfranc injury

o   Recognition of the Lisfranc injury and distinguishing it from a simple “foot sprain” is the key to treatment

o   Immobilize in a posterior splint

o   Urgent orthopedic consultation or follow-up

·        Metatarsal fractures

o   Proximal avulsion injuries of the fifth metatarsal can be treated with a hard-soled shoe and weight-bearing as tolerated

·        Jones fractures

o   Place in a posterior splint with strict non-weight-bearing

o   Urgent orthopedic consultation or follow-up as these patients often require ORIF

PEARL: Talar fractures will often require operative repair in 24 hours. Admission and frequent neurovascular checks are warranted.

Prognosis

·        The prognosis for fractures of the talus and calcaneus is more guarded than for ankle fractures. Often patients require surgical intervention to restore the normal anatomy, but this often will only delay the onset of post-traumatic arthritis

·        Non-weight-bearing status for 4–12 weeks can be expected

·        Patients should be informed that a complete return to pre-injury function is not expected with calcaneus and talus injuries

·        Lisfranc injuries are the exception. With prompt recognition and anatomic restoration of the tarsometatarsal complex, return to pre-injury status and sports can often be accomplished

Foreign bodies

Presentation

·        A common complaint

·        Often patients are barefoot at the time of injury, though it is common for foreign bodies to puncture through a shoe

·        Patients often make attempts at removal, but are unable to remove all of the foreign body

Diagnostic evaluation

·        Obtain a thorough history

o   Ask what the foreign body is (e.g., glass, wood, metal)

o   Document whether the patient was wearing footwear and what type

o   Document the patient’s tetanus immunization status

·        Complete a physical examination of the area

o   Document the entrance wound, including its size, color, any odor, and whether a foreign body can be visualized

o   Note the location of any loss of sensation or range of motion

·        Plain radiographs are helpful if the foreign body is radiopaque (e.g., metal, some plastics, and glass), but should be ordered on all patients

o   This helps exclude radiopaque foreign bodies as well as evaluate for any subcutaneous air

o   It is helpful to place two or three radiographic markers, or pellets, on the surface of the skin prior to obtaining the radiographs. By noting the location of the pellets on two orthogonal radiographs, the radiographs can then help to triangulate the foreign body removal

·        Ultrasound is also helpful in confirming the presence of radiolucent foreign bodies

o   Ultrasound can document the location and depth of the body

o   When possible, a marker should be on the skin after the ultrasound is complete to note the location and depth of the retained foreign body

PEARL: Ultrasound is helpful for identifying a foreign body but also for removal using real-time visualization.

Treatment

·        Irrigation of the wound

o   This is often sufficient for foreign-body removal

o   Consider using a local anesthetic to improve patient comfort

·        In cases of fresh wounds and foreign bodies, the tract made by the foreign body is the only one present

o   After irrigation with a blunt-tipped needle, exploration with a hemostat may be all that is necessary

·        In cases where the wound is several days old, the tract may already have partially healed, and “blind removal” is more difficult

o   After irrigation, a referral to orthopedics for removal with the aid of fluoroscopy is often necessary

·        Tetanus status should always be verified, and updated as needed

·        Antibiotics are given as needed

·        Diabetic patients and patients where the injury occurred through a rubber-soled shoe should be treated prophylactically with a fluoroquinolone

Prognosis

·        The prognosis for foreign bodies is usually good, but can depend on what other structures are injured

·        In diabetic patients, especially those with peripheral neuropathy, a foreign body can lead to osteomyelitis and chronic infections that may ultimately result in an amputation

Infections

Presentation

·        Foot and ankle infections can vary widely in their presentation and clinical significance

·        Onychocryptosis, ingrown toenails, tinea pedis, and athlete’s foot sit at one end of the clinical spectrum whose course is benign, while abscess and diabetic foot infection represent more serious infectious processes

Diagnostic work-up

·        The evaluation of a foot infection will vary based upon the suspected underlying clinical diagnosis

·        Inquire and document any chronic medical conditions. Diabetes should be specifically asked about

o   Elevated blood sugars without any other change in a patient’s routine could indicate an indolent infection

·        Examination should note:

o   The overall appearance and warmth of the foot as well as any areas of fluctuance

o   Distal pulses and light touch sensation is important

o   Erythema should be outlined with a marking pen

·        Notation should also be made of any breaks in the skin, especially between the toes

PEARL: Diabetics presenting to the ED with a red hot swollen foot but without any breaks in the skin may represent an acute Charcot arthropathy not an infection. To help differentiate the two, elevate the affected extremity while the patient is lying on their back. If the patient has cellulitis or an infectious process, the erythema will be unchanged. However, if the redness improves, this may represent a Charcot arthropathy.

·        For patients with more severe presentations obtain laboratory studies

o   CBC, ESR, CRP, HgbA1c, and blood cultures

·        Plain radiographs of the foot and ankle will help evaluate for osteomyelitis, fractures, foreign bodies, and Charcot arthropathy

·        CT or MRI are both helpful in the evaluation of abscess

·        MRI is more specific for osteomyelitis, but rarely required in the ED evaluation

Treatment

·        Ingrown toenails:

o   Placement of a cotton wisp under the painful edge of the nail allows the nail to continue to grow without piercing the dermal edge

o   If the nail is recalcitrant to conservative therapy, a referral to a podiatrist for digital block and partial nail excision is needed

·        Tinea pedis:

o   Treated with over-the-counter anti-fungals

o   These medications should be used for 2–4 weeks, well past the resolution of symptoms

o   Coverage for staph and strep species may be necessary in chronic cases

·        Abscesses:

o   Should be incised when superficial

o   Cultures of the purulent material will help guide future antibiotic treatment

o   Superficial swabs and cultures of chronic wounds are not helpful and should not be done

·        Diabetic foot infections and acute osteomyelitis:

o   Often require a hospital admission for IV broad-spectrum antibiotics

o   Consult podiatry, orthopedics or your soft-tissue surgical service if there are areas that you feel would benefit from debridement

Prognosis

·        Prognosis varies dependent upon the underlying diagnosis

o   Diabetic foot infections are the most common cause of below-knee amputations. Prompt diagnosis and treatment can help avoid this complication

o   Most infections heal well without long-term sequelae

o   Tinea infections are often chronic and frequently relapse

References

Benirschke SK, Meinberg E, Anderson SA, Jones CB, Cole PA. Fractures and dislocations of the midfoot: Lisfranc and Chopart injuries. J Bone Joint Surg Am. 2012;94:1325–37.

Coughlin MJ, Mann RA, Saltzman CL. Surgery of the Foot and Ankle. 8th edn. PA: Mosby. 2007.

Porter DA, Schon LC. Baxter’s The Foot and Ankle in Sport. 2nd edn. PA: Mosby/Elsevier. 2008.

Ross A, Catanzariti AR, Mendicino RW. The hematoma block: a simple, effective technique for closed reduction of ankle fracture dislocations. J Foot Ankle Surg. 2011;50:507–9.

Thakur NA, McDonnell M, Got CJ, et al. Injury patterns causing isolated foot compartment syndrome. J Bone Joint Surg Am. 2012;94:1030–5.

Wedmore IS, Charette J. Emergency Department evaluation and treatment of ankle and foot injuries. Emerg Med Clin North Am. 2000;18:85–113, vi.

White BJ, Walsh M, Egol KA, Tejwani NC. Intra-articular block compared with conscious sedation for closed reduction of ankle fracture–dislocations. A prospective randomized trial. J Bone Joint Surg Am. 2008;90:731–4.

Willits K, Amendola A, Bryant D, et al. Operative versus nonoperative treatment of acute Achilles tendon ruptures: a multicenter randomized trial using accelerated functional rehabilitation. J Bone Joint Surg Am. 2010;92:2767–75.