You are in: eMedicine Specialties >
Emergency Medicine > TRAUMA AND ORTHOPEDICS
Dislocation, Foot
Article Last Updated: Apr 3, 2006
AUTHOR AND EDITOR INFORMATION
Section 1 of 10
Author: Christopher M McStay, MD, Assistant Professor, Department of Emergency Medicine, New York University, Bellevue Hospital Center
Christopher M McStay is a member of the following medical societies: American College of Emergency Physicians and Wilderness Medical Society
Coauthor(s):
Moira Davenport, MD, Attending Physician, Departments of Emergency Medicine and Orthopedic Surgery, Allegheny General Hospital;
Martin J Carey, MD, MB, BCh, MPH, FACEM, FRCS, Program Director, Assistant Professor, Department of Emergency Medicine, University of Arkansas for Medical Sciences
Editors: James E Keany, MD, FACEP, Medical Director, JetWest International Air Ambulance, Van Nuys, California; Consulting Staff, Department of Emergency Services, Mission Hospital Regional Medical Center, Mission Viejo, California; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; David B Levy, DO, FACEP, FAAEM, Chairman, Department of Emergency Medicine, St Elizabeth Health Center; Associate Professor of Emergency Medicine, Northeastern Ohio Universities College of Medicine; John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center; Rick Kulkarni, MD, Medical Director, Assistant Professor of Surgery, Section of Emergency Medicine, Yale-New Haven Hospital
Author and Editor Disclosure
Synonyms and related keywords:
hindfoot, talus, calcaneus, midfoot, navicular, cuboid, cuneiforms, forefoot, metatarsals, phalanges, subtalar joint, foot dislocation, dislocation foot
Background
Dislocations of the foot are uncommon but potentially incapacitating injuries. The mechanism of injury may vary from a simple fall to a major motor vehicle collision (MVC). The foot is a complex structure, and injuries often occur in patients who sustain multiple trauma. The clinician must understand common patterns of injury and maintain a high index of suspicion in examining the appropriate radiographs to avoid missing foot dislocations.
Pathophysiology
Anatomy
The foot consists of 26 bones and 57 articulations. Three functional and anatomic regions make up the foot. The hindfoot consists of the talus and the calcaneus. The midfoot consists of the navicular, the cuboid, and the 3 cuneiforms. The forefoot contains the 5 metatarsals and 14 phalanges.
The foot also contains a number of accessory centers of ossification that are occasionally mistaken for avulsion injuries. The presence of a smooth cortical surface and lack of associated soft-tissue edema helps to differentiate these normal variants from fractures.
The articulations between the hindfoot and the midfoot are the midtarsal or Chopart joints. These joints are the talonavicular and the calcaneocuboid joints. The articulations between the midfoot and the forefoot are termed the Lisfranc joints and consist of the 5 tarsometatarsal joints.
The subtalar joint, between the talus and the calcaneus, accounts for the majority of inversion and eversion injuries to the hindfoot. Adduction and abduction of the forefoot occurs primarily through the midtarsal joints. Flexion and extension occurs primarily at the metatarsophalangeal (MTP) and interphalangeal (IP) joints.
Frequency
United States
All dislocations in the foot (with the exception of simple dislocations of the toes) are uncommon injuries. The most common of these injuries is a dislocation that involves the Lisfranc joint complex. The rarity of these injuries makes diagnosis difficult. A significant proportion of the more subtle dislocations are not diagnosed on initial presentation. Dislocations through the Lisfranc joint complex are thought to have an incidence of about 1 in 50,000 persons with orthopedic trauma per year, representing fewer than 1% of all dislocations.
International
No information is available on international injury rates.
Mortality/Morbidity
Dislocations of the foot are commonly associated with other significant injuries sustained during falls or MVCs. Delay in recognition of dislocations is common because of the distracting effect of the associated injuries or because of the subtle nature of these injuries. Early reduction and immobilization may reduce morbidity. Many complications, including avascular necrosis, compartment syndrome, and degenerative arthritis, have been reported. Additionally, residual pain and loss of function is common as a consequence of the complex biomechanics of the foot.
Sex
The male-to-female ratio is 6:1. This differential is largely due to the higher number of young males sustaining significant trauma.
Age
Injury may occur at any age, although the more severe forms of dislocation associated with MVCs are more common in young adult males.
History
Both a detailed medical history and a history of the events surrounding the injury or appearance of symptoms are essential to identifying the type of injury and predisposition to complicating factors.
- What was the exact mechanism of injury?
- Has the patient been able to bear weight since the injury?
- Does the patient have an underlying medical condition, especially a history of diabetes mellitus?
- People with diabetes mellitus may have denervation of the foot and are prone to develop Charcot joints. Charcot joints are joints that demonstrate a grossly disorganized structure, deformity, edema, extreme hypermotility, and often remarkably little pain. Function is generally good.
- Early, accurate recognition of foot injury is particularly important in patients with diabetes mellitus because a delayed diagnosis is associated with the development of Charcot joints.
- Does the patient have a history of foot surgery or prior injury to the affected foot? (This may make interpretations of radiographs difficult.)
- In general, patients who experience dislocations of the foot have other injuries related to the mechanism of injury. A full history of the event should be obtained from the patient or prehospital caregivers.
- Occasionally, these injuries may occur with minimal trauma. This is especially true with athletes. The history in these cases is usually of increasing pain and edema over a few days, resulting in a significant limitation of mobility/decreased performance. Often, the patient gives no definitive history of a single traumatic event.
- The presumed mechanism of injury responsible for each type of dislocation is discussed with that dislocation.
Physical
Examination of the foot usually reveals an obvious deformity; however, some dislocations are accompanied by substantial soft-tissue edema. The exact nature of the injury may be unclear until radiographs are taken.
- Neurovascular examination is critical both prior to and after any reduction.
- Assess the vascular status. If no pulse is palpable, urgent reduction of the dislocation is required. Confirm the absence of a pulse with Doppler studies in the emergency department (ED) if possible. Mark the position of the pulse on the skin. This simple measure confirms that a pulse was taken and that it was palpable. It also indicates the ideal anatomic location for reassessment. Loss of a previously palpable pulse is a sign that urgent reduction is needed.
- Perform a thorough neurologic examination of the foot.
- Check for any breaks in the skin. Check for any tenting of the skin, which may necessitate urgent reduction.
- Lisfranc dislocations
- In persons presenting with foot pain from a Lisfranc dislocation where no single major traumatic event has occurred findings may be subtle and nonspecific.
- Edema and tenderness over the joint are usually present. Ecchymoses may develop after a few days.
- Vascular compromise is rare.
Causes
- The risk factors for dislocation of the foot are the same as those for any major trauma (ie, youth, alcohol intake, drug intake). Dislocations of the foot, however, can result from an apparently simple fall (eg, twisting one's foot in a hole in the ground when jogging).
- A number of different types of dislocations of the foot exist. These dislocation types are discussed below with a review of their causes.
- Subtalar or peritalar dislocation
- This is a simultaneous dislocation of the talocalcaneal and talonavicular joints. Note that the talus remains in the ankle mortise. It typically is caused by falls from a height, MVCs, and severe twisting injuries such as in basketball players who land on an inverted and plantar-flexed foot.
- The dislocation is typically medial or lateral (rarely anterior or posterior), although medial dislocation is more common (80%). Inversion injuries result in medial dislocations and eversion injuries result in lateral dislocations. The navicular bone and forefoot are displaced medially with a medial subtalar dislocation and laterally with a lateral dislocation. These dislocations are frequently associated with fractures of the involved bones and a small percentage are open.
- Total talar dislocation
- A rare dislocation, this injury typically results from very high-energy trauma. The talus is completely out of the ankle mortise and is rotation such that the inferior articulation points posteriorly with the talar head pointing medially.
- These dislocations are commonly open and result in avascular necrosis of the talus, loss of ankle motion due to traumatic arthritis, and ischemic skin loss from underlying skin pressure.
- Lisfranc dislocation
- Dislocation fractures of the tarsometatarsal joints are referred to as Lisfranc injuries. This type of dislocation is caused by several mechanisms including rotational forces about a fixed forefoot, axial loading in a plantar flexed foot, and crush injuries. These injuries may also be a manifestation of a developing neuropathic or Charcot joint arthropathy.
- Tremendous energy usually is required to subluxate or dislocate the Lisfranc joint complex. This energy frequently results in extensive soft-tissue injury. Occasionally, minor rotational injuries may cause this problem. This is particularly well described in athletes and in older patients.
- The clinician must be careful not miss these injuries. Evaluate the alignment of the metatarsal bones with their corresponding tarsal bones on radiographs. The first, second, and third metatarsals should line up with the medial, middle, and lateral cuneiforms respectively. The fourth and fifth metatarsals should line up with the cuboid.
- A good starting point for evaluation is to inspect the medial aspect of the middle cuneiform to be directly inline with the medial aspect of the second metatarsal. Any disruption is indicative of a dislocation (may have reduced spontaneously).
- Lisfranc dislocations are classified according to the direction of injury in the horizontal plane.
- Homolateral, in which all 5 metatarsals move in the same direction
- Partial, or isolated, in which 1 or 2 metatarsals are displaced from the others
- Divergent, in which the first metatarsal displaces medially, while 1 or more of the other metatarsals are displaced laterally
- Some studies estimated that 20% of Lisfranc injuries are missed on initial presentation to the ED. Subtle injuries to the Lisfranc joint do occur and may be difficult to diagnose. Slight widening (2-5 mm) of the space between the first and second metatarsals may be seen, as well as a widening of the space between the middle and medial cuneiforms.
- Metatarsophalangeal (MTP) and interphalangeal (IP) dislocation
- First MTP dislocations, although rare given the inherent stability of the joints, typically result from large forces. These dislocations are typically dorsal and are often open.
- Dislocations of the other metatarsophalangeal joints are not unusual and typically are caused by trauma. The dislocation is most frequently a lateral or dorsal displacement of the digit on the metatarsal head.
- IP dislocations are less common than MTP dislocations. Most occur in the first toe as a direct result of axial loading.
- Other, very rare, dislocations in the foot have also been described.
- Isolated fracture dislocation of the navicular on the talus has been described. It occurs following a fall from a height and is usually treated with open reduction and internal fixation.
- Cuboid and cuneiform fractures are sometimes associated with tarsometatarsal dislocations, but they may present as isolated fracture-dislocation. They are unstable frequently and require open reduction and internal fixation.
Ankle Injury, Soft Tissue
Compartment Syndrome, Extremity
Dislocations, Ankle
Dislocations, Interphalangeal
Fractures, Ankle
Fractures, Foot
Lab Studies
- Laboratory studies are generally not indicated for diagnosing foot dislocations. However, if an intravenous line is being placed for conscious sedation purposes, routine preoperative laboratory samples may be drawn to facilitate definitive management of foot dislocations.
Imaging Studies
- Routine radiography of the foot should include 3 views: anteroposterior, lateral, and 45-degree internal oblique.
- The hindfoot is assessed via the lateral projection and the midfoot and forefoot via the anteroposterior and oblique projections.
- Any identified hindfoot injury should prompt standard imaging of the ankle.
- Additional views, such as the Harris (axial) view to evaluate the subtalar joint and calcaneus, can be obtained to improve imaging of certain areas of the foot.
- Weightbearing views may reveal subtle Lisfranc abnormalities.
- Increasingly, CT scanning is being used to help evaluate fractures and dislocations in the foot and in particular to help evaluate calcaneal and talar fractures.
- MRI is often used to diagnose stress fractures and to evaluate the various tendons and ligaments of the foot.
Other Tests
- Detection of pulses via Doppler may be performed.
Prehospital Care
- When the dislocated foot is seen as one of a number of injuries in a patient with major trauma, management of the other potentially life-threatening injuries takes priority.
- When the dislocation is an isolated injury, immobilize the limb to make the patient as comfortable as possible and transport the patient promptly.
- Control bleeding with direct pressure, and cover any open dislocation with a sterile dressing.
Emergency Department Care
- Immediate management may be dictated by concomitant injuries. Assess the neurovascular status of the foot as part of the secondary survey. Consider an urgent reduction of any dislocation causing significant neurovascular compromise.
- In cases of isolated injury, assess and record neurovascular status. Urgent radiographs should be obtained. Make arrangements for referral to an orthopedic specialist for reduction of the dislocation and further management as appropriate.
- Remember the possibility of compartment syndrome developing after severe injuries to the foot. Often the signs of compartment syndrome may be initially masked by the severe pain related to the injury. Failure to diagnose this problem can result in serious long-term sequelae for the patient including contractures, deformities, and chronic pain. A high index of suspicion for this complication is required, and measurement of compartment pressures in the foot should be instituted if any findings suggest that this complication is present.
- Any open dislocation associated with or without a fracture should typically not be reduced in the ED. Appropriate prophylactic antibiotics should be administered, and the tetanus status of the patient should be updated. Sterile dressings should be applied.
- Subtalar and total talar dislocation
- Most subtalar dislocations can be treated with closed reduction under appropriate analgesia and sedation. The interposition of soft tissues may prevent reduction, necessitating open reduction. Consider an urgent reduction if significant neurovascular compromise is evident.
- Total talar dislocations are often open and as such should not be reduced in the ED. If a closed injury exists or if urgent reduction is necessary secondary to neurovascular compromise, reduction may be attempted ideally with appropriate consultation available.
- With the knee flexed, apply longitudinal traction at the foot. Initial accentuation of the injury followed by reversal of the deformity with pressure over the talus may result in reduction. For example, after distraction, apply an abduction force for a medical dislocation.
- Lisfranc dislocation: Dislocations at the Lisfranc joint frequently require operative reduction. An orthopedic surgeon should be involved in the care of these injuries. ED care typically involves appropriate analgesia, ice, and elevation.
- Metatarsophalangeal (MTP) and interphalangeal (IP) dislocation: Dislocations of the toes often can be reduced under local anesthesia (digital block) in the ED with simple longitudinal traction. Dislocations of the first toe may be difficult to reduce.
Consultations
Urgent ED orthopaedic consultation is indicated for subtalar, total talar, and Lisfranc dislocations. Additionally, first MTP and IP dislocations that are open or not reducible require orthopedic consultation. Most other MTP and IP dislocations are easily managed by the ED physician.
Administer analgesia as appropriate. Ensure adequate coverage against tetanus. If dislocation is compound, broad-spectrum IV antibiotics are required. Generally, a cephalosporin is the drug of choice. Dirty wounds may need the addition of an aminoglycoside to target gram-negative organisms. Injuries heavily contaminated with soil or farmyard waste require penicillin to protect against Clostridium perfringens.
Drug Category: Analgesics
Pain control is essential to quality patient care. It ensures patient comfort, promotes pulmonary toilet, and aids physical therapy regimens. Many analgesics have sedating properties that benefit patients who have sustained injuries.
| Drug Name | Fentanyl citrate (Duragesic, Sublimaze) |
| Description | More potent narcotic analgesic with much shorter half-life than morphine sulfate. DOC for conscious sedation analgesia. With short duration (30-60 min) and easy titration, excellent choice for pain management and sedation. Easily and quickly reversed by naloxone. After initial dose, subsequent doses should not be titrated more frequently than q3h or q6h. |
| Adult Dose | 0.5-1 mcg/kg/dose IV/IM q30-60 min |
| Pediatric Dose | <2 years: 2-3 mcg/kg/dose IV/IM q30-60min 2-12 years: 1-2 mcg/kg/dose q60min >12 years: Administer as in adults |
| Contraindications | Documented hypersensitivity; hypotension; potentially compromised airway in which establishing rapid airway control would be difficult |
| Interactions | Phenothiazines may antagonize analgesic effects; tricyclic antidepressants may potentiate adverse effects |
| Pregnancy | C - Safety for use during pregnancy has not been established.
|
| Precautions | Caution in hypotension, respiratory depression, constipation, nausea, emesis, and urinary retention; idiosyncratic reaction, known as chest wall rigidity syndrome, may require neuromuscular blockade in order to increase ventilation |
| Drug Name | Oxycodone and acetaminophen (Percocet) |
| Description | Drug combination indicated for relief of moderately severe to severe pain. DOC for aspirin-hypersensitive patients. |
| Adult Dose | 1-2 tab or cap PO q4-6h prn |
| Pediatric Dose | 0.05-0.15 mg/kg/dose oxycodone PO q4-6h prn; not to exceed 5 mg/dose of oxycodone |
| Contraindications | Documented hypersensitivity |
| Interactions | Phenothiazines may decrease analgesic effects; CNS depressants or tricyclic antidepressants increase toxicity |
| Pregnancy | C - Safety for use during pregnancy has not been established.
|
| Precautions | Duration of action may increase in elderly persons; be aware of total daily dose of acetaminophen patient is receiving; do not exceed 4000 mg/24 h of acetaminophen; higher doses may cause liver toxicity |
| Drug Name | Oxycodone and aspirin (Percodan) |
| Description | Drug combination indicated for relief of moderately severe to severe pain. |
| Adult Dose | 1-2 tab or cap PO q4-6h prn |
| Pediatric Dose | 0.05-0.15 mg/kg/dose oxycodone PO q4-6h prn; not to exceed 5 mg/dose of oxycodone |
| Contraindications | Documented hypersensitivity; liver damage; hypoprothrombinemia; vitamin K deficiency; bleeding disorders; asthma Because of association with Reye syndrome, do not use in children ( <16 y) who have flu |
| Interactions | Phenothiazines may decrease analgesic effects; CNS depressants or tricyclic antidepressants increase toxicity; may potentiate anticoagulant effects of warfarin |
| Pregnancy | D - Unsafe in pregnancy
|
| Precautions | Duration of action may increase in elderly persons; caution in renal or liver impairment, peptic ulcer disease, and erosive gastritis |
| Drug Name | Hydrocodone bitartrate and acetaminophen (Vicodin ES) |
| Description | Drug combination indicated for relief of moderately severe to severe pain. |
| Adult Dose | 1-2 tab or cap PO q4-6h prn |
| Pediatric Dose | <12 years: 10-15 mg/kg/dose acetaminophen PO q4-6h prn; not to exceed 2.6 g/d acetaminophen or 5 mg of hydrocodone bitartrate/dose >12 years: 750 mg acetaminophen q4h; not to exceed 5 doses/d acetaminophen or 10 mg of hydrocodone bitartrate/dose |
| Contraindications | Documented hypersensitivity; high-altitude cerebral edema; elevated intracranial pressure |
| Interactions | Phenothiazines may decrease analgesic effects; CNS depressants or tricyclic antidepressants increase toxicity |
| Pregnancy | C - Safety for use during pregnancy has not been established.
|
| Precautions | Tablets contain metabisulfite, which may cause hypersensitivity; caution in patients dependent on opiates since this substitution may result in acute opiate withdrawal symptoms; caution in severe renal or hepatic dysfunction |
Drug Category: Anxiolytics
Patients with painful injuries usually experience significant anxiety. Anxiolytics allow the clinician to administer a smaller analgesic dose to achieve the same effect.
| Drug Name | Midazolam (Versed) |
| Description | DOC for procedural sedation to aid in reduction of anxiety associated with fractures or dislocations. Provides antegrade amnesia. Dose q1-2h. |
| Adult Dose | 1 mg IV slowly q2-3min |
| Pediatric Dose | 6 months to 5 years: 0.05-0.1 mg/kg IV; not to exceed total dose of 0.6 mg/kg 6-12 years: 0.025-0.05 mg/kg IV; not to exceed total dose of 0.4 mg/kg |
| Contraindications | Documented hypersensitivity; preexisting hypotension; narrow-angle glaucoma; sensitivity to propylene glycol (diluent) |
| Interactions | Sedative effects may be antagonized by theophyllines; narcotics and erythromycin may accentuate sedative effects due to decreased clearance |
| Pregnancy | D - Unsafe in pregnancy
|
| Precautions | Caution in congestive heart failure, pulmonary disease, renal impairment, and hepatic failure |
Drug Category: Sedative hypnotics
Procedural sedation for reductions may require a sedative hypnotic.
| Drug Name | Propofol (Diprivan) |
| Description | Phenolic compound. Sedative hypnotic agent used for induction and maintenance of sedation or anesthesia. |
| Adult Dose | Procedural sedation: 0.5 mg/kg IV infused over 3-5 min initially |
| Pediatric Dose | Procedural sedation: 0.5-1 mg/kg IV push infused over 2 min initially |
| Contraindications | Documented hypersensitivity to propofol or allergy to soybean oil, egg yolk, glycerol, or disodium edentate |
| Interactions | Reduce propofol dose when administered concomitantly with benzodiazepines, opiates, phenothiazines, ethanol, and narcotics; propofol may potentiate neuromuscular blockade of vecuronium; theophylline may weaken effects of propofol, and dose increase may be needed |
| Pregnancy | B - Usually safe but benefits must outweigh the risks.
|
| Precautions | Patients may develop apnea and may experience a decrease in systemic vascular resistance leading to hypotension Do not administer with blood or blood products using same IV catheter |
Drug Category: Antibiotics
Prophylaxis is given to patients with compound dislocations.
| Drug Name | Cefazolin (Ancef, Kefzol, Zolicef) |
| Description | First-generation semisynthetic cephalosporin that binds to one or more penicillin-binding proteins, arrests bacterial cell wall synthesis, and inhibits bacterial replication. Primarily active against skin flora, including Staphylococcus aureus. Total daily dosages are same for IV and IM routes. |
| Adult Dose | 2 g IV/IM; not to exceed 12 g/d |
| Pediatric Dose | 25-100 mg/kg/d IV/IM; not to exceed 6 g/d |
| Contraindications | Documented hypersensitivity |
| Interactions | Probenecid prolongs effect; aminoglycosides may increase renal toxicity; may yield false-positive urine dip test result for glucose |
| Pregnancy | B - Usually safe but benefits must outweigh the risks.
|
| Precautions | Adjust dose in renal impairment; superinfections and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy |
| Drug Name | Gentamicin (Gentacidin, Garamycin) |
| Description | Aminoglycoside antibiotic used for gram-negative bacterial coverage. Commonly used in combination with both an agent against gram-positive organisms and one that covers anaerobes. Used in conjunction with ampicillin or vancomycin for prophylaxis in patients with compound dislocations. Dosing regimens numerous and adjusted based on CrCl and changes in volume of distribution. May be given IV or IM. |
| Adult Dose | 1.5 mg/kg IV; not to exceed 80 mg |
| Pediatric Dose | <5 years with normal renal function: 2.5 mg/kg/dose IV/IM q8h >5 years: 1.5-2.5 mg/kg/dose IV/IM q8h or 6-7.5 mg/kg/d IV/IM divided q8h |
| Contraindications | Documented hypersensitivity; non–dialysis-dependent renal insufficiency |
| Interactions | Other aminoglycosides, cephalosporins, penicillins, and amphotericin B may increase nephrotoxicity; enhance effects of neuromuscular blocking agents, thus prolonged respiratory depression may occur; loop diuretics may increase auditory toxicity—possible irreversible hearing loss of varying degrees may occur (monitor regularly) |
| Pregnancy | C - Safety for use during pregnancy has not been established.
|
| Precautions | Narrow therapeutic index (not intended for long-term therapy); caution in renal failure (not on dialysis), myasthenia gravis, hypocalcemia, and conditions that depress neuromuscular transmission; adjust dose in renal impairment |
| Drug Name | Vancomycin (Vancocin) |
| Description | Potent antibiotic directed against gram-positive organisms and active against enterococcal species. Used to treat septicemia and skin-structure infections. Used in conjunction with gentamicin for prophylaxis in penicillin-allergic patients with compound dislocations. May need to adjust dose in patients with renal impairment. |
| Adult Dose | 1 g IV infusion over 1 h |
| Pediatric Dose | Administer as in adults |
| Contraindications | Documented hypersensitivity |
| Interactions | Erythema, histaminelike flushing, and anaphylactic reactions may occur when administered with anesthetic agents; with aminoglycosides, risk of nephrotoxicity may increase above that with aminoglycoside monotherapy; effects in neuromuscular blockade may be enhanced when coadministered with nondepolarizing muscle relaxants |
| Pregnancy | C - Safety for use during pregnancy has not been established.
|
| Precautions | Caution in renal failure, neutropenia; red man syndrome caused by too rapid IV infusion (dose given over a few minutes) but rarely happens when dose given over 2 h or by PO or IP route; red man syndrome not an allergic reaction |
| Drug Name | Ampicillin (Omnipen, Marcillin) |
| Description | Used along with gentamicin for prophylaxis in patients with compound dislocations. Interferes with bacterial cell wall synthesis during active replication, causing bactericidal activity against susceptible organisms. Given in place of amoxicillin in patients unable to take medication orally. |
| Adult Dose | 2 g IV/IM |
| Pediatric Dose | 50 mg/kg IV/IM |
| Contraindications | Documented hypersensitivity |
| Interactions | Probenecid and disulfiram elevate levels; allopurinol decreases effects and has additive effects on ampicillin rash; may decrease effects of oral contraceptives |
| Pregnancy | B - Usually safe but benefits must outweigh the risks.
|
| Precautions | Adjust dose in renal failure; evaluate rash and differentiate from hypersensitivity reaction |
| Drug Name | Penicillin G (Pfizerpen) |
| Description | Interferes with synthesis of cell wall mucopeptide during active replication, resulting in bactericidal activity against susceptible microorganisms. |
| Adult Dose | 2.4 million U IM as single dose in 2 injection sites |
| Pediatric Dose | 50,000 U/kg IM; maximum of 2.4 million U |
| Contraindications | Documented hypersensitivity |
| Interactions | Probenecid can increase effects; tetracyclines can decrease effects |
| Pregnancy | B - Usually safe but benefits must outweigh the risks.
|
| Precautions | Caution in impaired renal function |
Further Inpatient Care
- Reduction of some foot dislocations, especially isolated dislocations of the talus or some of the more complex dislocations of the Lisfranc joint complex, can be very difficult and inadvisable in the ED. In all these cases, consulting an orthopedic specialist is always wise. Closed reduction is frequently insufficient and open reduction and internal fixation are required.
- Urgent reduction of a dislocation in the ED is often necessary to prevent further vascular or neurological compromise. Whenever possible, ensure adequate analgesia; conscious sedation may be required. The joint should be reduced using gentle traction and the limb then immobilized. Further therapy or operative intervention may be required after this initial reduction.
Further Outpatient Care
- As noted above, except for simple dislocations of the toes, these injuries frequently require the services of an orthopedic surgeon, who is responsible for the long-term follow-up of these patients.
In/Out Patient Meds
- Analgesia is very important. Narcotics may be required. If the dislocation is open, antibiotics are essential.
Transfer
- Most of these injuries, with the exception of simple MTP or IP dislocations, should be managed by an orthopedic specialist. If a specialist is not available, patients should be transferred to the nearest institution able to offer this service.
Deterrence/Prevention
- Many of these injuries are due to MVCs. Strategies to reduce the number of MVCs, such as encouraging and enforcing the drinking and driving laws, will have an impact on the number of these injuries.
Complications
- One of the major complications of dislocations of the foot involves a failure to make the diagnosis. Some of these dislocations can be subtle, especially those around the Lisfranc joint complex. These dislocations often are missed, resulting in significant morbidity.
- Other complications
- Infection as a result of compound dislocations or, occasionally, as a postoperative complication
- Long-term stiffness of the foot
- Foot pain not specifically localized to one area
- Secondary osteoarthritis
- Avascular necrosis, especially of the talus, after a total talar dislocation
- Damage to the medial plantar nerve with associated wasting of the intrinsic muscles of the foot (rare)
- Compartment syndrome
- These injuries are associated with long-term morbidity in a significant proportion of patients. In one study, 48% of patients with midfoot dislocations (Chopart and Lisfranc joints) had a fair or poor result at follow-up 20-56 months after the injury.
- Fair or poor in this classification indicated substantial limitation of activities. The authors found that the quality of the initial reduction was the major determinant for obtaining an excellent long-term result.
Prognosis
- Prognosis generally is good.
Patient Education
Medical/Legal Pitfalls
- Failure to diagnose dislocation of the foot. Some dislocations, at the Lisfranc joint complex particularly, can be subtle. Clues to the diagnosis include severe pain and edema of the foot. Careful examination of the appropriate radiographs should reveal the diagnosis, but in some cases, further investigation with CT scan or MRI may be required. As many as 20% of Lisfranc injuries are thought to be missed on initial presentation.
- Failure to diagnose dislocation of the foot when other, more severe, injuries are present in a multiple-injury victim. The other injuries may be dramatic and distract attention from the foot. A full detailed secondary survey with frequent reassessment is vital in all patients with multiple injuries.
- Bohay DR, Manoli A 2nd. Subtalar joint dislocations. Foot Ankle Int. Dec 1995;16(12):803-8. [Medline].
- Brunet JA. Pathomechanics of complex dislocations of the first metatarsophalangeal joint. Clin Orthop. Nov 1996;(332):126-31. [Medline].
- Davis CA, Lubowitz J, Thordarson DB. Midtarsal fracture-subluxation. Case report and review of the literature. Clin Orthop. Jul 1993;(292):264-8. [Medline].
- Englanoff G, Anglin D, Hutson HR. Lisfranc fracture-dislocation: a frequently missed diagnosis in the emergency department. Ann Emerg Med. Aug 1995;26(2):229-33. [Medline].
- Karasick D. Fractures and dislocations of the foot. Semin Roentgenol. Apr 1994;29(2):152-75. [Medline].
- Milenkovic S, Radenkovic M, Mitkovic M. Open subtalar dislocation treated by distractional external fixation. J Orthop Trauma. Oct 2004;18(9):638-40. [Medline].
- Mulier T, Reynders P, Sioen W. The treatment of Lisfranc injuries. Acta Orthop Belg. Jun 1997;63(2):82-90. [Medline].
- Perron AD, Brady WJ, Keats TE. Orthopedic pitfalls in the ED: Lisfranc fracture-dislocation. Am J Emerg Med. Jan 2001;19(1):71-5. [Medline].
- Prokuski LJ, Saltzman CL. Challenging fractures of the foot and ankle. Radiol Clin North Am. May 1997;35(3):655-70. [Medline].
- Saab M. Lisfranc fracture--dislocation: an easily overlooked injury in the emergency department. Eur J Emerg Med. Jun 2005;12(3):143-6. [Medline].
- Simon JP, Van Delm I, Fabry G. Fracture dislocation of the tarsal navicular. Acta Orthop Belg. 1993;59(2):222-4. [Medline].
- Wagner R, Blattert TR, Weckbach A. Talar dislocations. Injury. Sep 2004;35 Suppl 2:SB36-45. [Medline].
Dislocation, Foot excerpt Article Last Updated: Apr 3, 2006
|