Managing Dislocations of the Hip, Knee, and Ankle in the Emergency

Home , Hip dislocation, Knee dislocation, Patellar dislocation

December 2017 Managing Dislocations of the Volume 19, Number 12 Authors Hip, Knee, and Ankle in the Caylyne Arnold, DO Clinical Faculty, Emergency Department, Naval Medical Center San Diego, San Diego, CA Emergency Department Zane Fayos, MD Resident Physician, Emergency Medicine, Naval Medical Center San Diego, Abstract San Diego, CA David Bruner, MD, FAAEM Staff Physician, Scripps Mercy Hospital San Diego, San Diego, CA Dislocation of the major joints of the lower extremities—hip, Dylan Arnold, DO knee, and ankle—can occur due to motor-vehicle crashes, falls, Assistant Professor of Military and Emergency Medicine, Uniformed Services and sports injuries. Hip dislocations are the most common, University of the Health Sciences; Assistant Program Director, Emergency Medicine Residency, Naval Medical Center San Diego, San Diego, CA and they require emergent management to prevent avascular necrosis of the femoral head. Knee dislocations are uncommon Peer Reviewers but potentially dangerous injuries that can result in amputa- Melissa Leber, MD, FACEP Assistant Professor of Emergency Medicine and Orthopedics, Director of tion due to the potential for missed secondary injury, especially Emergency Department Sports Medicine, Icahn School of Medicine at Mount if they are reduced spontaneously. Isolated ankle dislocations Sinai, New York, NY are relatively rare, as most ankle dislocations involve an associ- Christopher R. Tainter, MD, RDMS ated fracture. This review presents an algorithmic approach to Associate Clinical Professor, Department of Anesthesiology, Division of Critical Care, Department of Emergency Medicine, University of California management that ensures that pain relief, imaging, reduction, San Diego, San Diego, CA vascular monitoring, and emergent orthopedic consultation are carried out in a timely fashion. Prior to beginning this activity, see “Physician CME Information” on the back page. This issue is eligible for 4 trauma CME credits.

Editor-In-Chief Daniel J. Egan, MD Shkelzen Hoxhaj, MD, MPH, MBA Alfred Sacchetti, MD, FACEP Joseph D. Toscano, MD Andy Jagoda, MD, FACEP Associate Professor, Department Chief Medical Officer, Jackson Assistant Clinical Professor, Chairman, Department of Emergency Professor and Chair Emeritus, of Emergency Medicine, Program Memorial Hospital, Miami, FL Department of Emergency Medicine, Medicine, San Ramon Regional Director, Emergency Medicine Thomas Jefferson University, Medical Center, San Ramon, CA Department of Emergency Medicine; Eric Legome, MD Residency, Mount Sinai St. Luke's Philadelphia, PA Director, Center for Emergency Chair, Emergency Medicine, Mount Medicine Education and Research, Roosevelt, New York, NY Sinai West & Mount Sinai St. Luke's; Robert Schiller, MD International Editors Icahn School of Medicine at Mount Nicholas Genes, MD, PhD Vice Chair, Academic Affairs for Chair, Department of Family Medicine, Peter Cameron, MD Sinai, New York, NY Associate Professor, Department of Emergency Medicine, Mount Sinai Beth Israel Medical Center; Senior Academic Director, The Alfred Emergency and Trauma Centre, Emergency Medicine, Icahn School Health System, Icahn School of Faculty, Family Medicine and Monash University, Melbourne, Associate Editor-In-Chief of Medicine at Mount Sinai, New Medicine at Mount Sinai, New York, NY Community Health, Icahn School of Medicine at Mount Sinai, New York, NY Australia Kaushal Shah, MD, FACEP York, NY Keith A. Marill, MD Associate Professor, Department of Assistant Professor, Department Scott Silvers, MD, FACEP Giorgio Carbone, MD Emergency Medicine, Icahn School Michael A. Gibbs, MD, FACEP of Emergency Medicine, Harvard Associate Professor and Chair, Chief, Department of Emergency of Medicine at Mount Sinai, New Professor and Chair, Department Medical School, Massachusetts Department of Emergency Medicine, Medicine Ospedale Gradenigo, York, NY of Emergency Medicine, Carolinas Medical Center, University of North General Hospital, Boston, MA Mayo Clinic, Jacksonville, FL Torino, Italy Editorial Board Carolina School of Medicine, Chapel Charles V. Pollack Jr., MA, MD, Corey M. Slovis, MD, FACP, FACEP Suzanne Y.G. Peeters, MD Saadia Akhtar, MD Hill, NC FACEP Professor and Chair, Department Attending Emergency Physician, Associate Professor, Department of Steven A. Godwin, MD, FACEP Professor and Senior Advisor for of Emergency Medicine, Vanderbilt Flevo Teaching Hospital, Almere, Emergency Medicine, Associate Dean Professor and Chair, Department Interdisciplinary Research and University Medical Center, Nashville, TN The Netherlands Clinical Trials, Department of for Graduate Medical Education, of Emergency Medicine, Assistant Hugo Peralta, MD Emergency Medicine, Sidney Kimmel Ron M. Walls, MD Program Director, Emergency Dean, Simulation Education, Chair of Emergency Services, Medical College of Thomas Jefferson Professor and Chair, Department of Medicine Residency, Mount Sinai University of Florida COM- Hospital Italiano, Buenos Aires, University, Philadelphia, PA Emergency Medicine, Brigham and Beth Israel, New York, NY Jacksonville, Jacksonville, FL Women's Hospital, Harvard Medical Argentina Michael S. Radeos, MD, MPH William J. Brady, MD Joseph Habboushe, MD MBA School, Boston, MA Dhanadol Rojanasarntikul, MD Associate Professor of Emergency Professor of Emergency Medicine Assistant Professor of Emergency Attending Physician, Emergency Medicine, Weill Medical College and Medicine; Chair, Medical Medicine, NYU/Langone and Critical Care Editors Medicine, King Chulalongkorn of Cornell University, New York; Emergency Response Committee; Bellevue Medical Centers, New York, Memorial Hospital, Thai Red Cross, Research Director, Department of William A. Knight IV, MD, FACEP Medical Director, Emergency NY; CEO, MD Aware LLC Thailand; Faculty of Medicine, Emergency Medicine, New York Associate Professor of Emergency Management, University of Virginia Chulalongkorn University, Thailand Gregory L. Henry, MD, FACEP Hospital Queens, Flushing, NY Medicine and Neurosurgery, Medical Medical Center, Charlottesville, VA Clinical Professor, Department of Director, EM Advanced Practice Stephen H. Thomas, MD, MPH Emergency Medicine, University Ali S. Raja, MD, MBA, MPH Provider Program; Associate Medical Calvin A. Brown III, MD Vice-Chair, Emergency Medicine, Professor & Chair, Emergency Director of Physician Compliance, of Michigan Medical School; CEO, Director, Neuroscience ICU, University Medicine, Hamad Medical Corp., Medical Practice Risk Assessment, Massachusetts General Hospital, of Cincinnati, Cincinnati, OH Credentialing and Urgent Care Boston, MA Weill Cornell Medical College, Qatar; Services, Department of Emergency Inc., Ann Arbor, MI Scott D. Weingart, MD, FCCM Emergency Physician-in-Chief, Medicine, Brigham and Women's John M. Howell, MD, FACEP Robert L. Rogers, MD, FACEP, Associate Professor of Emergency Hamad General Hospital, Hospital, Boston, MA Clinical Professor of Emergency FAAEM, FACP Medicine; Director, Division of ED Doha, Qatar Medicine, George Washington Assistant Professor of Emergency Critical Care, Icahn School of Medicine Peter DeBlieux, MD Edin Zelihic, MD University, Washington, DC; Director Medicine, The University of at Mount Sinai, New York, NY Professor of Clinical Medicine, Head, Department of Emergency of Academic Affairs, Best Practices, Maryland School of Medicine, Interim Public Hospital Director Medicine, Leopoldina Hospital, Inc, Inova Fairfax Hospital, Falls Baltimore, MD Senior Research Editors of Emergency Medicine Services, Schweinfurt, Germany Church, VA Louisiana State University Health Aimee Mishler, PharmD, BCPS Science Center, New Orleans, LA Emergency Medicine Pharmacist, Maricopa Medical Center, Phoenix, AZ Case Presentations cine Database, SportDiscus, and Google Scholar using the search terms hip dislocation, anterior hip A 25-year-old man is brought in by ambulance after dislocation, posterior hip dislocation, knee dislocation, being involved in a high-speed motor vehicle crash as an ankle dislocation, talar dislocation, subtalar dislocation, unrestrained driver. He is complaining of right hip pain hip reduction, knee reduction, and ankle reduction. A and lower abdominal pain. During his primary trauma total of 163 articles were found regarding hip dislo- survey, you note that his right leg is shortened and inter- cations, 187 on knee dislocations, and 167 on ankle nally rotated. You suspect a native hip dislocation and/or dislocations. The Cochrane Database of Systematic fracture and wonder which diagnostic studies you should Reviews was searched, using the terms hip disloca- obtain and whether you should attempt a reduction before tion, knee dislocation, and ankle dislocation, resulting in consulting orthopedic surgery. 8 articles related primarily to knee dislocations. The Later that evening, an elderly woman arrives with right American College of Emergency Physicians does not hip pain, unable to ambulate. She states, “I was just bend- endorse any guidelines related to lower-extremity ing over to put on my shoes when I felt a ‘pop,’ and then I dislocations. fell to the ground.” She then informs you that she recently The majority of the applicable literature for underwent right total hip arthroplasty. You notice her right lower-extremity dislocations is found in orthopedic leg appears internally rotated, adducted, and shortened. You and trauma surgery journals. ED-specific studies are suspect a dislocation of her prosthesis and wonder whether limited, though the approach and initial manage- you should involve orthopedics or reduce it yourself and, if ment is the same, regardless of location or provider. reduction is successful, whether she can be discharged home. Most of the articles in the literature are case reports, 19-year-old man arrives by EMS, saying that while case series, and retrospective reviews; there are no he was playing a pick-up game of football, he was tackled large randomized trials assessing diagnosis or man- and felt a “pop” in his right knee. His friend told EMS agement strategies for lower-extremity dislocations. that his knee looked like it “bent backwards.” His knee was immobilized by EMS, but it doesn’t look deformed. Etiology and Pathophysiology You are concerned that he may have dislocated and spontaneously reduced his knee and wonder if any diagnostic Hip Dislocation studies are needed. Hip dislocations are the most common lower-ex- A 27-year-old man presents to the ED with right tremity dislocation. The emergency clinician should ankle pain and obvious deformity. He has severe pain and be able to diagnose the various types of dislocations cannot stand after landing awkwardly in a hole with his and assess for associated injuries and complications. right foot when he jumped down from a tree branch. He Good ED management depends on knowing when is unable to bear weight or move his ankle due to severe to reduce a hip dislocation and gauging the urgency pain. He appears to have an ankle dislocation and possible of orthopedic consultation for intraoperative closed fracture; you wonder which takes priority: reduction or reduction or open reduction and internal fixation. imaging? The hip is a ball-and-socket joint, with the femoral head situated within the acetabulum. The hip joint Introduction is extremely stable, due to the cartilaginous labrum, ligamentous hip capsule, ligamentum teres, and large Lower-extremity dislocations are less common in muscle groups of the lower extremity. For this reason, the emergency department (ED) than shoulder and most native hip dislocations are caused by a high- elbow dislocations, and emergency clinicians’ ex- energy traumatic mechanism, with motor-vehicle perience with evaluation and reduction techniques crashes (MVCs) being the most common etiology.1 is often limited. Nonetheless, these dislocations can Over two-thirds of traumatic hip dislocations occur in be serious because of their association with vascu- MVC victims who were not wearing seatbelts.2 Trau- lar injury. Rapid assessment and timely reduction matic dislocations are also seen after falls from height, can minimize pain and complications, but there are and in athletes involved in contact sports.3 many circumstances when emergent orthopedic Traumatic hip dislocations may be classified as ei- consultation is needed and surgical referral required. ther simple or complex. Simple dislocations are isolated This issue of Emergency Medicine Practice discusses dislocations without an associated fracture, whereas the mechanism of injury, diagnostic approach, treat- complex dislocations have an associated fracture of ment plans, and potential complications of disloca- the femoral head, femoral neck, or acetabulum.4 Ap- tions of the hip, knee, and ankle. proximately 90% of all native hip dislocations have an associated fracture.5 Acetabular fractures are the most Critical Appraisal of the Literature common and are seen in 70% of cases.6 The more the hip is flexed at the time of dislocation, the lower the 7 A literature search was performed in PubMed, EM- risk for associated fracture. Base, Medline®, Allied and Complementary Medi- Hip dislocations are further classified based

Copyright © 2017 EB Medicine. All rights reserved. 2 Reprints: www.ebmedicine.net/empissues on the direction of dislocation of the femoral head frequent mechanism of injury resulting in knee dis- relative to the acetabulum, either posterior or ante- location is MVCs, accounting for over 50% of cases, rior. Posterior dislocations are the most common, but high-impact sports, such as football, also place comprising 90% of all traumatic hip dislocations. patients at risk.10 These dislocations are the result of axial loading on There are 2 joints within the knee, the tibio- the femur, with the hip flexed and adducted. This femoral joint and patellofemoral joint. Knee disloca- is also known as the classic “dashboard injury.”4 tion refers to a dislocation of the tibiofemoral joint, Anterior dislocations make up 10% of traumatic whereas a patellar dislocation refers to dislocation of hip dislocations, and are subdivided into superior the patellofemoral joint. For more information on (10%) and inferior types (90%). The superior type patellar dislocation, see the "Special Circumstances" of dislocation occurs when the hip is abducted, section, page 18. externally rotated, and extended, often resulting in The tibiofemoral joint consists of the medial and a fractured femoral head. The inferior type of dislo- lateral femoral condyles articulating with the medial cation occurs when the hip is abducted, externally and lateral condyles of the tibia. (See Figure 2.) The rotated, and flexed. The obturator can indent the medial and lateral meniscus provide cushioning femoral head, resulting in an indentation fracture.3 between these articular surfaces. Four strong liga- These typically occur secondary to MVCs where ments provide stability to this joint: The anterior cru- the victim’s leg is abducted, from falls from height, ciate ligament (ACL) and posterior cruciate ligament or a blow to the back while squatted.8 (PCL) prevent anterior and posterior displacement Understanding the anatomy surrounding the of the tibia relative to the femur, respectively. The hip joint is important with regard to assessing for medial collateral ligament (MCL) prevents valgus associated injuries and the potential for long-term (apex medial) deviation. Finally, the lateral collateral complications. The primary blood supply to the ligament prevents varus (apex lateral) deviation. femoral head is from an extracapsular arterial ring There are 5 types of knee dislocation: anterior, at the base of the femoral neck. (See Figure 1.) The posterior, lateral, medial, and rotational. There can sciatic nerve lies posteriorly to the hip joint; and be overlap between them, based on the mechanism the femoral nerve, artery, and vein are superior and of injury. Each type of knee dislocation is named medial to the hip joint.4 While loss of blood supply after the displacement of the tibia relative to the to the femoral head is a concern in all cases of hip femur. Anterior dislocations are the most common, dislocation, other neurovascular injuries are depen- followed by posterior dislocations. dent on the direction of dislocation. Anterior knee dislocations are usually the result of extreme knee hyperextension mechanisms, usu- Knee Dislocation ally greater than 30°. As the knee moves past 30° of Knee dislocation is a rare injury.9 Spontaneously re- hyperextension, the posterior capsule tears. Typical- duced dislocations may be unrecognized, but carry ly, the ACL and then the PCL are torn, yielding the significant risk to adjacent structures.10,11 The most instability necessary for the tibia to move anteriorly; however, it is possible for the PCL to remain intact. If the knee continues to hyperextend past 50°, the Figure 1. Blood Supply of the Femoral Head popliteal artery is at risk for injury.12 Posterior knee dislocations are usually the result

Ligamentum Figure 2. Anatomy of the Knee teres

Medial femoral Lateral femoral circumflex artery circumflex artery

Profunda femoris artery

December 2017 • www.ebmedicine.net 3 Copyright © 2017 EB Medicine. All rights reserved. of an axial load on the proximal tibia with the knee The major nerves running through the popliteal in flexion. This pattern of injury is commonly seen region are the tibial nerve and the common peroneal in the setting of an MVC. In these cases, the patient’s nerve. (See Figure 4.) When the knee dislocates, the momentum supplies a sufficient axial load when classically injured nerve is the common peroneal the flexed knee strikes the dashboard. As the tibia is nerve, which innervates the muscles of dorsiflexion forced posteriorly, the PCL tears, followed usually and provides sensory innervation to the dorsum by the ACL. Approximately half of posterior disloca- of the foot and over the proximal anterior/lateral tions have some form of popliteal artery injury, often aspect of the fibula. with complete transection of the artery. Injury to the peroneal nerve is most likely to oc- Lateral and medial knee dislocations are less cur in the setting of lateral knee dislocations.12 This common, and each can be caused by varus or valgus is due to the anatomic course of the peroneal nerve, stress, depending on whether the strike occurred which wraps laterally around the head of the fibula. above or below the plane of the tibiofemoral joint. Traction on the peroneal nerve can lead to injury Typically, both the MCL and LCL are disrupted, ranging from neuropraxia to complete transection. along with at least 1 cruciate ligament, resulting in Apart from traction injury, peroneal nerve dysfunc- multidirectional instability.12 tion can result from laceration, compression, or focal Lateral dislocations occur when the medial ischemia following knee dislocation.14 The incidence femoral condyle buttonholes through the medial of peroneal nerve injury following knee dislocation capsule of the joint. These dislocations are poten- is as high as 50%.15 Tibial nerve injury is much less tially impossible to reduce with closed reduction. likely, with only sporadic reports in the literature.16 When this occurs, a dimple can be seen in the skin/ soft tissue of the knee medially, and should alert the Ankle Dislocation clinician that open reduction may be needed.13 (See Ankle dislocations are dislocations of the tibiota- Figure 3.) lar joint. They rarely occur in isolation, although The major artery traversing the knee joint is multiple case reports suggest that ankle dislocations the popliteal artery, which is anchored at both ends without fracture do occur.17-26 Wroble et al described of the popliteal fossa, proximally at the adductor 8 cases of ankle dislocation without associated hiatus, and distally at the soleus. Any significant fractures at their institution, but these were accumu- change in the length between these anchor points lated over a 28-year period.26 The majority of ankle due to dislocation in any direction can cause a trac- dislocations involve an associated fracture pattern, tion injury to the popliteal artery. Popliteal artery and up to half of all dislocations are open.26 This is injuries—either from traction as the joint dislocates or by direct trauma—occur in all types of knee dislo- Figure 4. Major Nerves of the Knee cation. Injury to the popliteal artery has been found to be present in 39% of anterior dislocations, 44% of Semitendinosus posterior dislocations, 25% in medial dislocations, 12 Biceps and 6% in lateral dislocations. femoris

Figure 3. An Irreducible Lateral Knee Dislocation That Demonstrates Dimpling Popliteal artery Tibial nerve Popliteal vein Common peroneal nerve

Gastrocnemius

Basem B Morcos, Sameh Hashem, Firas Al-Ahmad. Popliteal lymph node dissection for metastatic squamous cell carcinoma: a case report of an uncommon procedure for an uncommon Skeletal Radiology, Volume 38, Issue 11. 2009, pages 111-1114. Ali presentation. World Journal of Surgical Oncology. DOI: https://doi. Harb, Denis Lincoln, Jefferey Michaelson. © Springer. Reprinted with org/10.1186/1477-7819-9-130. Published under Creative Commons permission of Springer. Attribution License 2.0.

Copyright © 2017 EB Medicine. All rights reserved. 4 Reprints: www.ebmedicine.net/empissues due to the unique anatomy of the ankle joint mortise of multiple ankle sprains or prior fractures.30,31 and the strong ligaments that provide ankle stability. Patients with peroneal muscle weakness and liga- The ankle joint is comprised of the dome- mentous laxity from connective tissue disorders shaped talus that articulates with the tibia superi- are also at greater risk. One review of the combined orly and medially, and the fibula laterally, and it is case reports in the literature (total of only 8 patients) bound by multiple strong ligaments. This structure showed that > 80% of ankle dislocations occurred helps the ankle provide both the flexibility and from falls from height, MVCs, or sports activities.26 stability that are required for ambulation. The talus Ankle dislocations are described by the direction does not have any muscular insertions or origins, the talus moves in relation to the tibia: medial, pos- and 60% of its surface is covered by hyaline carti- terior, posteromedial, anterior, superior, and lateral. lage. The dorsalis pedis artery, posterior tibial ar- Medial dislocations are considered to be the most tery, and peroneal artery provide the blood supply common, though this is controversial and depends to the talus.27,28 on the case series and literature reviewed.26,32 The ankle ligamentous attachments include 3 Posterior dislocations occur when the foot is plan- lateral malleoli ligaments: the anterior talofibular tar-flexed and the talus is forced posterior to the tibia, ligament, the posterior talofibular ligament, and widening the ankle joint, disrupting the tibiofibular the calcaneofibular ligament.(See Figure 5.) The syndesmosis, and frequently causing a fracture of the medial malleolar ligaments include the superficial lateral malleolus. Anterior ankle dislocations occur deltoid ligament, which connects the medial tibia typically when the foot is forcibly dorsiflexed or a to the talus, calcaneus, and navicular bones; and significant posteriorly directed force is applied to the the deep deltoid ligament, which joins the tibia to tibia while the foot is in a fixed position. the talus and is the primary stabilizer of the ankle Lateral dislocations invariably have an associ- joint. The syndesmosis is the third ligamentous ated fracture of one or both malleoli and are the structure of the ankle joint and is the primary result of forced inversion, eversion, or rotation of the support of the ankle. It is comprised of 4 parts, all ankle. of which connect the tibia and fibula in different Superior dislocations are uncommon, but are ways: (1) the interosseous ligament, (2) the ante- severe injuries, resulting in separation at the tibiofib- rior inferior tibiofibular ligament, (3) the posterior ular syndesmosis when the talus is pushed superi- inferior tibiofibular ligament, and (3) the inferior orly between the lateral malleolus and tibia, causing transverse ligament.29 a diastasis. Significant axial loading force, such as Patients most at risk for ankle dislocations a fall from height, is the most commonly reported include young adult men and those with a history cause of superior dislocations, and these are associ-

Figure 5. Ankle Joint Ligaments

Interosseous (syndesmotic) ligament Posterior tibiofibular Anterior inferior Posterior tibiotalar ligament Anterior tibiotalar part tibiofibular ligament part

Anterior talofibular Calcaneofibular Tibiocalcaneal Tibionavicular part ligament ligament part

Lateral talocalcaneal A ligament B

View A: Anatomy of the lateral collateral and the syndesmotic ligaments of the ankle. View B: Anatomy of the medial collateral (deltoid) ligaments of the ankle. Copyright © 1995 From The Lower Extremity and Spine in Sports Medicine, 2nd ed. by James A. Nicholas and Elliott B. Hershman, eds. Reproduced by permission of Taylor and Francis Group, LLC, a division of Informa plc.

December 2017 • www.ebmedicine.net 5 Copyright © 2017 EB Medicine. All rights reserved. ated with other fractures of the long bones of the rare dislocations, comprising only 2% of major joint lower extremity as well as spinal column injuries.26 dislocations, but attempted reduction before imaging may actually lead to worsening of the subtalar Differential Diagnosis dislocation.33,34

Hip Dislocation Prehospital Care Hip dislocations are often caused by high-energy mechanisms and should be considered in the trauma Prehospital care of the injured lower extremity is patient presenting with hip pain or inability to am- directed at stabilizing the extremity and pain control. bulate. Since most patients with hip dislocations will The initial evaluation determines whether the patient appear to have a shortened leg with either internal has sustained any other more-significant injuries that or external rotation, they are often suspected prior to could lead to death or permanent disability. Since radiologic confirmation. Hip mobility and stability dislocations or fractures are considered distracting should be tested in trauma patients because of the injuries, emergency medical services (EMS) provid- possibility of more severe distracting injuries or if ers are often advised to immobilize the cervical spine the patient is altered or unresponsive. Additionally, if there is any potential for an unstable injury. Pre- this diagnosis should be considered in all elderly hospital evaluation of neurovascular status should patients presenting with hip pain or inability to am- be performed for any suspected dislocation and, if bulate after a ground-level fall. Due to the stability there is evidence of neurovascular compromise (cold, of the hip joint, hip dislocation is unlikely to be the pulselessness, loss of sensation, or discoloration), an cause of atraumatic hip pain, except in patients who attempt at immediate reduction should be consid- have undergone recent total hip arthroplasty. (See ered, particularly for the knee or the ankle.35 Table 1.) If a hip dislocation is suspected, the patient should be immobilized. Splinting is typically unnec- Knee Dislocation essary, unless the patient has an obvious deformity In addition to the 5 types of knee dislocations, the of the mid to distal femur, in which case a traction differential includes ligamentous injuries (usually splint can be placed to improve alignment and al- multidirectional instability), fractures, and neuro- leviate pain. Caution is advised in placing traction vascular injury (eg, peroneal nerve and popliteal splints, however, due to transport delays as well as artery). the risk of injury to the pelvis, knee, patella, or tibia/ fibula.36 Since 25% of hip dislocations have associ- Ankle Dislocation ated knee injuries, the knee and lower leg should be assessed for an associated fracture or dislocation and The differential diagnosis of ankle injury involves 37 fracture, fracture dislocation patterns, and isolated splinted in the best anatomical alignment possible. dislocations. These can involve any of the various at- Prehospital evaluation of knee dislocations tachments involving the ankle joint. The differential involves considering a potential popliteal artery diagnoses that are most important to consider prior injury by assessing for the presence of the pedal to reduction are total talar dislocation and subtalar pulse. Although presence of the pedal pulse does not dislocation. (See Table 2.) sufficiently rule out vascular injury, the absence of On outward appearance, subtalar dislocations a pulse should prompt immediate consideration for may appear similar to ankle dislocations. These are relocation of the knee in the field; this is best done under medical control and taking transport time into consideration.38 Basic testing for peroneal nerve Table 1. Differential Diagnosis for Traumatic function can be achieved in the field by evaluating Hip Pain for weakness in dorsiflexion and objective numb- ness of the dorsum of the foot. The most basic step in prehospital care of a knee dislocation is immobi- • Hip dislocation • Femoral head fracture • Femoral neck fracture • Trochanteric fracture (greater and lesser) Table 2. Differential Diagnosis of Ankle • Intertrochanteric fracture Dislocation • Subtrochanteric fracture • Acetabular fracture • Subtalar dislocation • Pubic ramus fracture • Total talus dislocation • Ipsilateral knee dislocation • Tibia fracture • Ligamentous injury to the ipsilateral knee • Fibula fracture • Sciatic nerve injury • Talus fracture • Injury to the femoral neurovascular bundle • Calcaneus fracture • Hemarthrosis • Ankle sprain

Copyright © 2017 EB Medicine. All rights reserved. 6 Reprints: www.ebmedicine.net/empissues lization and splinting with prehospital techniques, ated injury such as a femoral neck or shaft fracture depending on available equipment. Usually, the or ipsilateral knee dislocation is likely.8 Additionally, knee is immobilized in the field “as is,” meaning in the ipsilateral knee needs to be examined closely due the position found, without attempt at reduction or to the high incidence of associated knee injuries. realignment.39 Many cases of knee dislocations may Orthopedic surgery should be consulted emer- spontaneously reduce, which may cloud the picture gently for all native hip dislocations. In the setting when EMS communicates to the receiving ED. of a simple prosthetic hip dislocation, orthopedic consultation may be delayed, as avascular necrosis is Emergency Department Evaluation no longer a concern.

Hip Dislocation Knee Dislocation Because 95% of traumatic hip dislocations will have Evaluation of the patient with a suspected knee dis- significant associated injuries, patients with a hip location focuses on the mechanism of injury, includ- dislocation after an MVC should be evaluated ac- ing the direction of force on the knee. Although most cording to Advanced Trauma Life Support (ATLS) knee dislocations are due to high-energy mecha- guidelines or by a specialist trained in trauma nisms, knee dislocations from low-velocity mecha- evaluation.3,6 (See Table 3.) Important historical data nisms have been described. Specifically, there have include the mechanism of injury, associated injuries, been case reports of knee dislocations in morbidly the time of the incident, the presence of weakness or obese patients resulting from falls from standing or 40 paresthesia, a history of prior dislocation or arthro- from a single step. plasty, and comorbidities. As soon as a knee dislocation is suspected, Without radiography, traumatic hip dislocations consultation with both orthopedic and vascular may be difficult to distinguish from hip fractures, surgeons should be arranged while the patient is in but some physical examination findings can assist the ED. Further information should be obtained to the emergency clinician in suspecting these injuries. include prior knee injuries, changes in distal neuro- Patients presenting with a posterior dislocation have vascular symptoms, and any associated traumatic a shortened, adducted, and internally rotated leg injuries. It is easy to anchor on an obviously de- on the injured side.4 Up to 10% to 14% of posterior formed and dislocated knee, ignoring other subtle— dislocations result in sciatic nerve injury, which will but potentially more serious—injuries. present with loss of sensation to the posterior leg, in- When evaluating undifferentiated knee pain fol- ability to dorsiflex, and diminished deep tendon re- lowing trauma, examination of the knee must include flexes at the ankle.7 Anterior dislocation will appear evaluation for ligamentous stability. Instability in any as a slightly shortened, abducted, and externally ro- direction may be the only finding to suggest that a tated leg. In superior-anterior dislocations, the femo- knee dislocation is present, whether spontaneously ral head is often palpable in the area of the anterior reduced or not. Deformity of the knee can help iden- superior iliac spine, whereas in inferior-anterior dis- tify the direction of dislocation; however, extensive locations, the femoral head may be palpated in the swelling or obesity may complicate the physical ex- 11 buttock region.3 Superior dislocations should also amination. Once a knee dislocation is suspected, the raise concern for injury to the femoral artery, vein, or evaluation should assess for popliteal artery injury. nerve. A large hematoma may suggest a significant The simplest method for evaluating the popliteal ar- vascular injury. Femoral nerve injury results in loss tery is a pulse examination of the posterior tibial and of sensation over the thigh, weakness of the quad- dorsalis pedis pulses; however, the presence of these riceps, and loss of deep tendon reflexes at the knee. pulses may not sufficiently rule out an important If the hip is dislocated without obvious internal or injury. A 2002 meta-analysis showed that abnormal external rotation on physical examination, an associ- pedal pulses were only 79% sensitive for a popliteal artery injury requiring surgical intervention.38 Since the pulse examination is not definitive, it Table 3. Injuries Associated With Traumatic is recommended that all patients suspected of hav- Hip Dislocation3 ing a knee dislocation have an ankle-brachial index (ABI) test performed. The ABI is the measurement Injury Co-occurrence Rate of arterial insufficiency based on the ratio of ankle Acetabular fracture 70% systolic pressure to brachial systolic pressure (the Ipsilateral knee injury 25% ankle systolic pressure divided by the arm systolic Closed head injury 24% pressure). Multiple studies have validated the use of Upper-extremity fracture 21% the ABI in the setting of a traumatic knee dislocation. Thoracic injury 21% An ABI of < 0.9 is 95% to 100% sensitive and 80% to Abdominal injury 15% 100% specific for arterial injuries requiring operative 41 Sciatic nerve injury 10% management. A prospective study of 38 patients

December 2017 • www.ebmedicine.net 7 Copyright © 2017 EB Medicine. All rights reserved. with knee dislocations found that an ABI > 0.9 has artery, and a lack of pulse warrants emergent reduc- a negative predictive value of 100% for surgical tion to be able to fully assess arterial flow. Motor and popliteal artery injuries, with zero missed surgical sensory neurologic evaluation should follow, as ap- popliteal injuries.42 Traditionally, the assessment for propriate, both before and after reduction attempts popliteal artery injury has been done with computed are made. tomographic (CT) angiography or angiogram, although duplex ultrasound may see a growing role in Diagnostic Studies the near future. Following the assessment of arterial injury, the Hip Dislocation patient should be evaluated for peroneal nerve in- Initial diagnostic testing for hip dislocations involves jury. Motor dysfunction can be evaluated by testing x-ray imaging. Trauma patients may be difficult to for loss of strength in ankle dorsiflexion, foot ever- transport or transfer to an x-ray table for imaging. sion, and toe extension. Peroneal nerve-associated An initial bedside anteroposterior (AP) pelvis x-ray motor dysfunction can be differentiated from a is appropriate in most cases and will reveal most hip more proximal source (eg, L4-L5 radiculopathy) by dislocations. (See Figure 6.) Shenton’s line, created testing quadriceps, hip adduction, and hip abduc- 15 by the inferior borders of the superior pubic ramus tion strength. Sensory innervation of the dorsum and neck of the femur, will be abnormal, suggesting of the foot to the first web space should be tested dislocation or fracture. If the femoral head is supe- as well. Confirmatory testing for neurologic injury rior to the acetabulum and smaller when compared occurs well after the ED evaluation, consisting of to the contralateral side, this is likely a posterior dis- electromyography, nerve conduction velocity, and location. Alternatively, if the femoral head is inferior magnetic resonance imaging (MRI). to the acetabulum and larger in appearance than the Lastly, serial evaluation for the development contralateral side, this is likely an anterior disloca- of compartment syndrome must be performed in tion. The lesser trochanter will also be more appar- any suspected case of knee dislocation. This com- ent in anterior dislocations, due to external rotation.4 plication can be easily misdiagnosed as the more If the AP film is indeterminate, a lateral film common vascular and neurologic injuries discussed may confirm the type of dislocation. Judet (internal previously. Also, the impressive edema from a knee and external oblique) views will help to evaluate for dislocation can mimic a compartment syndrome. associated acetabular fracture, and are particularly A loss of pulses on examination must be assumed useful in posterior dislocations, as 70% have an as- to be from popliteal artery injury rather than com- sociated fracture of the posterior acetabulum.6,8 If partment syndrome until proven otherwise, and the Judet view shows a posterior acetabular fracture, capillary perfusion will be compromised at a pres- a CT scan should be performed prior to reduction, sure much lower than that required to lose pulses. Sensory deficits in compartment syndrome are more likely to appear progressively and circumferentially rather than in a dermatomal distribution. Compart- Figure 6. Posterior Hip Dislocation With mental pressure readings may help to differentiate Fracture of Acetabular Wall compartment syndrome from other complications of knee dislocation.43

Ankle Dislocation The initial evaluation of the patient with an ankle injury should include details of the mechanism of injury such as determining whether the injury is due to a fall from height, MVC, or from sports-related activity. Ascertaining the mechanism is important to predict the expected injury pattern as well as to help determine the type of force that will be required for reduction, as an opposite force from the injury will likely be needed to reduce the joint. Evaluation of the ankle should include a detailed assessment of the location of greatest pain, deformity, skin-tenting, and whether or not the joint is open. Vascular evaluation should be performed before and after reduction to assess for the presence and strength From James F. Fiechtl, Michael A. Gibbs. An evidence-based approach of posterior tibial and dorsalis pedis pulses as well to managing injuries of the pelvis and hip in the emergency as the quality of the distal capillary refill. Anterior department. Emergency Medicine Practice. 2010;12(12):1-24. © EB ankle dislocations can impinge the dorsalis pedis Medicine. Used with permission.

Copyright © 2017 EB Medicine. All rights reserved. 8 Reprints: www.ebmedicine.net/empissues since a posterior acetabular fracture comprising osseous anatomy. Historically, conventional angi- more than 40% of the rim is considered unstable and ography was the standard, and it remains an alter- requires open reduction and internal fixation. If < native to CT angiogram. In fact, it is still the most 20% of the posterior acetabular rim is fractured, the frequently used modality of evaluation for popliteal hip is considered stable, and emergent closed reduc- injury following knee dislocation.46 Conventional tion by orthopedic surgery is indicated, followed angiography, however, is being left out of more re- by stability testing with fluoroscopy under general cent diagnostic and treatment algorithms in favor of anesthesia.4 CT angiography, as trauma literature has shown its If the hip can be emergently reduced in the ED, superiority.41,46 postreduction radiographs are then obtained to A 2004 retrospective study of 55 patients dem- confirm concentric reduction. Postreduction CT scan onstrated that routine CT angiography on every should be performed on all traumatic hip dislocations patient with suspected knee dislocation is unneces- to assess for associated femoral head fractures, loose sary. This study showed that, in patients with a nor- bodies, and acetabular fractures.44 mal vascular examination along with a normal ABI When reduction in the ED fails, a prompt CT scan (using an ABI > 0.9 as normal), performing serial should be obtained to evaluate for occult fractures or vascular examinations was an acceptable strategy, loose bodies that were not appreciated on the initial and no popliteal artery injuries in need of surgi- plain films. In a complex fracture-dislocation, CT scan cal intervention were missed.47 Other studies have should also be considered prior to open reduction replicated this finding.48 The 3 criteria for 24 hours and internal fixation to assess the fracture pattern.3 of vascular check in lieu of vascular imaging include MRI has a limited role in the initial workup the following:47 and management of acute hip dislocation and can 1. Normal distal pulses be performed at a later date to assess for avascular 2. Well-perfused limb necrosis, labrum tears, or other ligamentous and 3. Ankle-brachial index > 0.9 soft-tissue injury.45 In the case of an abnormal pulse examination, Knee Dislocation even if it normalizes following initial closed reduc- In acute knee trauma, the primary imaging modality tion, this selective algorithm does not apply, and CT is AP and lateral radiographs of the knee. (See Fig- angiography should be performed. Conversely, if ure 7.) Plain films should not delay closed reduction patients have hard signs of ischemia such as pulse- if there is vascular compromise, but if the vascular lessness, pulsatile hemorrhage, expanding hema- examination is normal and imaging can be obtained toma, or palpable thrill/audible bruit following a at once, AP/lateral x-rays are recommended, as they knee dislocation, immediate surgical exploration may reveal osseous fractures or instability that may and repair are indicated. prevent stable reduction.43 Repeat x-rays should be Magnetic resonance angiography (MRA) is an- performed post reduction. other imaging option for evaluation of the popliteal To evaluate for arterial injury, the initial test of artery, with the added benefit of excellent visualiza- choice is CT angiography, as it can reveal intimal tion of the osseous and ligamentous structures of injuries and has the added benefit of detailing the the knee. MRA has practical limitations, however,

Figure 7. X-Ray Images of Knee Dislocations

From Skeletal Radiology. Multiligamentous injuries and knee dislocations. Volume 22, Issue 11. 2015, page 1559. Lana H. Gimber, Luke R. Scalcione, Andrew Rowan, et al. © Springer. Reprinted with permission of Springer.

December 2017 • www.ebmedicine.net 9 Copyright © 2017 EB Medicine. All rights reserved. Clinical Pathway for Emergency Department Management of Clinical Pathway For Emergency Department Management Of Multiple Shocks Suspected Hip Dislocation

Patient presents with suspected traumatic hip dislocation

Obtain 2-view x-rays +/- Judet views or CT of abdomen/pelvis

Native hip Prosthetic hip

• Perform closed reduction Dislocation with associated fracture? • No time limit unless neurovascular deficit is present

YES

No fracture Successful reduction on x-ray?

YES No reduction or Emergent orthopedic Attempt closed reduction nonconcentric reduction consultation (Class I) in the ED (Class I)

Obtain orthopedic consultation (Class II) • Obtain emergent CT scan (Class III) Successful reduction? orthopedic consultation (Class I) • Operating room/ Pain controlled and YES admission (Class I) No reduction or able to ambulate? Operating room nonconcentric reduction YES NO

X-ray confirmation of reduction Discharge home with Obtain orthopedic motion precautions consultation and admit (Class II) (Class I) • Abduction splint (Class I) • Knee immobilizer (Class I) Obtain emergent • Non–weight-bearing (Class I) orthopedic consultation (Class I)

Obtain orthopedic consultation and admit (Class I)

Appropriate Advanced Trauma Life Support trauma workup and adequate pain control should be initiated Abbreviations: AP, anteroposterior; CT, computed tomography; ED, emergency department. For Class of Evidence definitions, see page 12.

Copyright © 2017 EB Medicine. All rights reserved. 10 Reprints: www.ebmedicine.net/empissues Clinical Pathway for Emergency Department Management of Clinical Pathway For Emergency Department Management Of Multiple Shocks Suspected Knee Dislocation

Patient presents with suspected knee dislocation

Open dislocation? YES Operating room (Class II)

Perform closed reduction (Class II)

Pulse present? NO Operating room (Class II)

YES

Perform ankle-brachial index testing*

• No computed tomographic angiography required Ankle-brachial index* ≥ 0.9? YES • Admit for serial examinations and orthopedic evaluation (Class II) NO

Is injury more than 6 hours old? YES Operating room (Class II)

Perform computed tomographic angiography

Is vascular injury present? YES Operating room (Class II)

Disposition in consultation with vascular and orthopedic surgery

*Ankle-brachial index is calculated thus: brachial systolic pressure divided by ankle systolic pressure. Appropriate Advanced Trauma Life Support trauma workup and adequate pain control should be initiated. For Class of Evidence definitions, see page 12.

December 2017 • www.ebmedicine.net 11 Copyright © 2017 EB Medicine. All rights reserved. Clinical Pathway for Emergency Department Management of Clinical Pathway For Emergency Department Management Of Multiple Shocks Suspected Ankle Dislocation

Patient presents with suspected ankle dislocation

If evidence of ischemia is present, reduce the ankle joint (Class III)

Prepare for open reduction Prepare for closed reduction

X-ray imaging – AP, lateral, and mortise views (Class III) X-ray imaging – AP, lateral, and mortise views (Class III)

Emergent orthopedic consultation (Class III) Reduction of dislocation in the ED (Class III)

Open reduction and washout (Class III) Postreduction imaging (x-rays, possible CT) (Class III)

Bulky Jones splint and orthopedic consultation (Class III)

Disposition in conjunction with orthopedic consultation

Appropriate Advanced Trauma Life Support trauma workup and adequate pain control should be initiated. Abbreviations: AP, anteroposterior; CT, computed tomography; ED, emergency department.

Class Of Evidence Definitions

Each action in the clinical pathways section of Emergency Medicine Practice receives a score based on the following definitions.

Class I Class II Class III Indeterminate • Always acceptable, safe • Safe, acceptable • May be acceptable • Continuing area of research • Definitely useful • Probably useful • Possibly useful • No recommendations until further • Proven in both efficacy and effectiveness • Considered optional or alternative treat- research Level of Evidence: ments Level of Evidence: • Generally higher levels of evidence Level of Evidence: • One or more large prospective studies • Nonrandomized or retrospective studies: Level of Evidence: • Evidence not available are present (with rare exceptions) historic, cohort, or case control studies • Generally lower or intermediate levels of • Higher studies in progress • High-quality meta-analyses • Less robust randomized controlled trials evidence • Results inconsistent, contradictory • Study results consistently positive and • Results consistently positive • Case series, animal studies, • Results not compelling compelling consensus panels • Occasionally positive results

This clinical pathway is intended to supplement, rather than substitute for, professional judgment and may be changed depending upon a patient’s individual needs. Failure to comply with this pathway does not represent a breach of the standard of care. Copyright © 2017 EB Medicine. 1-800-249-5770. No part of this publication may be reproduced in any format without written consent of EB Medicine.

Copyright © 2017 EB Medicine. All rights reserved. 12 Reprints: www.ebmedicine.net/empissues as it is expensive and takes much longer to perform. evidence of femur or acetabular fracture on plain The risk of the long scanning time for an MRA may films, prompt reduction should be attempted in the outweigh the benefit of the test if it causes a delay in ED. If the decision is made to emergently reduce a surgical management, and therefore increased likeli- native traumatic hip dislocation, it should be per- hood of amputation.41 formed within 6 hours of the time of injury to decrease the risk of avascular necrosis.49 No more than Ankle Dislocation 3 attempts should be made in the ED, as this can also Prereduction radiographic imaging of the injured increase the risk of avascular necrosis and damage ankle begins with AP, lateral, and mortise or the articular cartilage.4 oblique x-rays. Further imaging of the lower leg If the patient needs to be transferred to a trauma and foot is likely to be appropriate as well, depend- center, the emergency clinician should consider ing on the extent of injury. (See Figure 8.) Postre- reducing the hip dislocation prior to transfer, not duction imaging should also be obtained following only because of the increased risk of avascular ne- reduction.27 CT imaging of the dislocated ankle is crosis, but to reduce the risk of sciatic nerve injury. A reasonable following reduction to evaluate for frac- retrospective study of 106 patients showed that there tures that are often present. CT imaging helps de- was a much higher risk of severe sciatic nerve injury fine the extent of these fractures and allows better in patients who were not reduced prior to transfer operative planning by the orthopedic surgeon.27,28 (16%) versus those patients who were reduced prior to transfer (4%).50 Treatment Reduction of Hip Dislocation Hip Dislocation Prior to definitive reduction of a hip dislocation, pain control and muscle relaxation should be ad- The primary decision in hip dislocation management dressed. Ultrasound-guided fascia iliaca com- is whether or not to reduce the hip in the ED versus partment block can be performed by the emer- obtaining emergent orthopedic surgery consultation gency clinician to achieve pain relief and may for reduction in the operating room. All complex hip reduce the need for systemic analgesia.51 Proce- dislocations (ie, those with an associated fracture) dural sedation prior to reduction should aim for require emergent orthopedic surgery consultation. adequate analgesia and muscle relaxation. In one Other indications for surgical management include study, sedation was safely performed by a single- irreducible dislocation, nonconcentric reduction, provider/single-nurse model, with low risk of neurovascular deficit after closed reduction, and as- adverse outcome and 96% success rate; however, sociated proximal femur or acetabular fracture caus- each institution has sedation/analgesia policies ing hip instability. Surgical management ranges from that should be followed.52 open arthrotomy to minimally invasive hip arthros- Successful reduction of a dislocated hip must copy, which is popular for treating intra-articular hip overcome the acetabular rim as well as the gluteal pathology such as loose bodies, chondral defects, muscles.53 There are multiple techniques that have and labral tears.4 been developed for closed hip reduction; the most For a simple hip dislocation that does not show well-known are the Allis and Bigelow methods,

Figure 8. Ankle Dislocations

Posterior Lateral Anterior Superior

December 2017 • www.ebmedicine.net 13 Copyright © 2017 EB Medicine. All rights reserved. first described in the late 1800s.(See Figures 9 and Knee Dislocation 10.) Both of these techniques usually require that Any confirmed or suspected knee dislocation neces- the clinician stand on the gurney to provide the sitates emergent orthopedic and/or vascular surgery appropriate traction. This is not only precarious, consultation, and they should be able to assist in the but can predispose the clinician to lumbar strain. decision-making process. Progression through the More recently, several methods, such as the Captain treatment algorithm for knee dislocation must be Morgan technique, the Rocket Launcher technique, achieved quickly and efficiently, with the key points and the East Baltimore Lift, have been designed to being early reduction and identifying and treating be ergonomically safer and have also shown promis- surgical neurovascular injuries. Previous studies ing success rates in case studies. (See Figures 11 and have shown that popliteal artery injuries in knee 12, page 15.) No studies definitively recommend one dislocation result in an 11% amputation rate if vas- technique over another. A clinician should consider cular repair is achieved < 8 hours postinjury, but the his or her physical limitations, support staffing, and amputation rate is 86% if vascular repair is achieved comfort level with each technique to decide which is > 8 hours post injury.43 right for the patient. If evidence of vascular compromise is seen on initial examination, immediate closed reduction should be attempted. Following reduction, repeat Figure 9. The Allis Method vascular examination and postreduction films should be performed. If a pulse examination on initial

Figure 10. The Bigelow Method

As an assistant applies downward pressure on each anterior superior iliac spine, the provider exerts upward inline traction on the femur B and flexes it to 90°, adducting and internally/externally rotating the In view A, the provider applies upward traction on the femur while an femur until it reduces.54 View B shows the maneuver with a second assistant stabilizes the pelvis. In view B, the hip is externally rotated assistant applying lateral traction to the thigh. and extended while the femur is distracted. Source: Eric F. Reichman: Emergency Medicine Procedures, Second Source: Eric F. Reichman: Emergency Medicine Procedures, Second Edition: www.accessemergencymedicine.com. Copyright © The Edition: www.accessemergencymedicine.com. Copyright © The McGraw-Hill Companies, Inc. Used with permission. McGraw-Hill Companies, Inc. Used with permission.

Copyright © 2017 EB Medicine. All rights reserved. 14 Reprints: www.ebmedicine.net/empissues assessment is normal, prereduction films and ABI This can also be accomplished with 2 clinicians: one should be obtained, which will lead to the next deci- providing inline traction on the distal femur and the sion point: Does the patient require imaging for arte- other applying the traction to the tibia while apply- rial injury? Using the selective angiography criteria ing force in the opposite direction of the dislocation. discussed previously, if the patient has normal distal Having appropriate traction and counter-traction pulses, a well-perfused limb, and an ABI > 0.9, a pa- will help to minimize the lateral and medial force tient may be considered for a 24-hour admission for necessary to perform these reductions.58 serial vascular examinations. If criteria are not met or Once closed reduction has been achieved, the admission is not feasible, vascular imaging is recom- knee should be immobilized in approximately 20° of mended. Although time to intervention is important flexion, pending definitive management, in order to to decrease the risk of amputation, it is reasonable prevent posterior subluxation of the tibia.59 Following to obtain angiography if the time from injury is < 6 closed reduction in the ED, multiligamentous injuries hours and if the delay to the surgical intervention is may be managed surgically or nonoperatively. A 2015 negligible.46 meta-analysis demonstrated that surgical treatment appeared to be associated with improved outcomes, Reduction of Knee Dislocation defined as average range of motion, flexion contrac- Reduction techniques for the knee are relatively sim- ture, and a subjective symptom scale (the Lysholm ple compared to other joint reductions, with slight score). However, surgical intervention resulted in no differences based upon the direction of dislocation.58 difference from the patients' preinjury employment Reductions are ideally performed by a clinician with or athletic ability compared to nonoperative man- 2 assistants. While one assistant applies steady, inline agement, and the potential for significant disability traction on the tibia distally, the other assistant will remained whichever route was chosen.60 When man- apply inline counter-traction on the distal femur. The clinician should hold the proximal tibia with both hands, applying force in the opposite direction of the Figure 12. The Rocket Launcher Technique dislocation until the knee reduces, being careful not to hyperextend the knee or overshoot the reduction.

Figure 11. The Captain Morgan Technique

As an assistant applies downward pressure on each anterior superior iliac spine, the provider stands on the side of the affected leg, facing the patient’s feet, and flexes the affected hip to 90°. The provider places the patient’s knee over his shoulder, with the inside hand As an assistant applies downward pressure on each anterior superior on the patient’s knee and the outside hand on the ankle. Assume iliac spine, the provider flexes the patient’s hip to 90°. The provider a squat position, and lean toward the patient, while pulling the places one foot on the stretcher, with his knee behind the patient’s ankle laterally, to adduct and internally rotate the femur. Stand from knee. Downward force is applied to the patient’s ankle. With the other a squatted position to provide upward traction. Once reduced to hand under the patient’s knee, the provider simultaneously lifts with his length, externally rotate and abduct the affected hip to reduce the hand and knee to create upward traction. Gently rock the patient’s hip, deformity.57 (T = traction, AD = adduction, IR = internal rotation.) creating internal/external rotation to assist with reduction.56 Michael Dan, Alfred Phillips, Marcus Simonian, Scott Flanagan. Rocket Reprinted from Annals of Emergency Medicine. Volume 58, Issue 6. launcher: a novel reduction technique for posterior hip dislocations Gregory W. Hendey, Arturo Avila. The Captain Morgan technique for and review of current literature. Emergency Medicine Australasia. the reduction of the dislocated hip. Pages 536-540. Copyright 2011, 2015. Volume 27, Issue 3. Pages 193-195. Reprinted with permission with permission from Elsevier. of John Wiley and Sons.

December 2017 • www.ebmedicine.net 15 Copyright © 2017 EB Medicine. All rights reserved. aged surgically, there is often delay to surgical liga- for operative debridement/intervention. Operative mentous repair to allow for a vascular observation pe- reduction after washout and debridement is recom- riod, among other orthopedic advantages;61 however, mended if there is not vascular compromise in an the timing of intervention is still a matter of debate. In open dislocation.63 Although rare, severe skin tent- 2015, a 12-study review was performed that showed ing can open during reduction attempts, and even if no significant difference in clinical results when mul- the joint is successfully reduced and the laceration is tiligamentous injury was repaired acutely (< 3 weeks small, operative management should be considered.63 after injury) versus delayed (> 3 weeks after injury).62 Once the reduction has been completed, a neuro- This debate, of course, refers only to orthopedic repair vascular examination should be repeated to ensure of the multiligamentous injury, not vascular or neuro- good perfusion. The patient should be placed in a logic repair. long-leg posterior splint with a sugar-tong splint in No specific treatment of complicating peroneal addition, for maximal stability and immobilization, nerve injuries is undertaken in the ED. Treatments with the ankle held in a 90° flexed position (“bulky after the ED setting are focused on the management Jones” splint).63 Significant swelling can be present of drop foot, aiming to restore normal heel-toe gait.14 and worsen after reduction, and the splint should allow for this. Postreduction films should be obtained Ankle Dislocation to include AP, lateral, and mortise views. Orthopedic Control of pain should be instituted immediately consultation should be obtained in the ED because for all ankle dislocations. In order to achieve good of the unstable nature of these dislocations and the long-term outcomes, the goals of treatment for ankle risk of associated fractures and neurovascular injury, dislocations are joint reduction with reimplantation often requiring surgical intervention.64,65 of the talus and reversal of any neurovascular compromise.22,31 Prompt reduction prior to imaging is Disposition warranted when there is concern for neurovascular compromise, but in most cases, prereduction imag- Hip Dislocation ing should be obtained. After any reduction attempts in the ED, the patient’s neurovascular status should be re-evaluated. The af- Reduction of Ankle Dislocation fected leg is then immobilized in extension, external In the majority of patients, significant pain control rotation, and slight abduction. An abduction pillow or procedural sedation should be initiated prior or another object can be placed between the knees in to reduction attempts. Reduction of the dislocated order to avoid flexion, internal rotation, and adduc- ankle will require an assistant for counter-traction. tion of the hip. The patient may also be placed in a The procedure involves having 1 person hold the pa- knee immobilizer to prevent inadvertent flexion at tient’s knee at 90° of flexion, which will help reduce the hip.4 Radiographs should be repeated to confirm the tension of the Achilles tendon. If only 1 provider reduction, followed by a postreduction CT scan if is available, putting the patient’s knee, bent to 90°, at concern exists for an incomplete reduction, occult the edge of the bed can provide counter-traction. fracture, or intra-articular loose bodies. A noncon- The clinician should hold the patient’s foot in a centric reduction is a surgical emergency due to plantar-flexed position. One hand grasps the distal the pressure on the articular cartilage, even though foot and the other hand grasps at the heel. Axial blood supply may have been restored to the femoral traction is applied, and the talus is moved into an head. The affected hip may require traction and/or anatomic position, dependent upon the direction of open reduction.4 Orthopedic surgery consultation 29,63 the dislocation. Often, there is a palpable “clunk” in the ED should be considered in most cases of hip when the talus falls into the correct location inferior dislocation. The patient may be admitted for pain to the tibia. Prior to attempts at moving the talus, control, and should remain non–weight-bearing axial traction should be applied to the foot to help until orthopedic consultation. Early passive range of fatigue the musculature. motion and rehabilitation is recommended.8 If reduction is unsuccessful after 2 or 3 attempts, open reduction may be required in the operating Knee Dislocation room. Fractures, foreign bodies, and tendon rup- All patients who present with a knee dislocation or tures may be in the joint capsule, making reduction with a presentation suspicious for a spontaneously impossible. Repeated attempts at closed reduction reduced dislocation should be considered for serial may cause significant damage to the talar cartilage, vascular checks and compartment syndrome evalu- as there may be an obstruction and may also cause ation. Patients with a lower suspicion for dislocation greater soft-tissue injury and swelling. and with vascular imaging showing no evidence of Open dislocations still warrant reduction in arterial injury can be considered for discharge. This the ED if vascular compromise is present, but these decision should be made with input from specialist should have emergency orthopedic consultation consultation.

Copyright © 2017 EB Medicine. All rights reserved. 16 Reprints: www.ebmedicine.net/empissues Ankle Dislocation consequences, including amputation, resulting from Orthopedic consultation should be obtained in the these injuries. A 2005 study performed in Australia ED for all ankle dislocations, either after reduction demonstrated an amputation rate of 26% follow- or if the ankle is unable to be reduced. Because of ing popliteal artery injury, with prolonged ischemia the high rate of concomitant tibial, fibular, and talar time from delayed diagnosis increasing the need for 68 fractures, which are often unstable injuries, many of amputation. these patients will require surgery. Delayed surgical intervention is, however, appropriate in certain Ankle Dislocation cases. If the patient is stable, neurovascularly intact, Vascular compromise and neurologic injury are the and does not require open reduction or operative primary severe complications one should address intervention, they may have the joint immobilized with prompt reduction for ankle dislocations. Lack and be considered for discharge home. The patient of blood flow to the talus can lead to avascular ne- should be kept strictly non–weight-bearing pending crosis, and skin tenting and vascular compromise to close orthopedic follow-up. the skin and soft tissues can lead to ischemic or soft- tissue necrosis and, potentially, gangrene. Rarely, Complications amputations are required due to complications from ischemia. In open dislocations, the risk of infection is Hip Dislocation also a well-described complication and, in general, open dislocations have a higher rate of vascular in- Overall prognosis following a hip dislocation is jury. Long-term osteoarthritis is common after both dependent on a number of factors. Simple hip open and closed dislocations.26,29 (See Table 4.) dislocations can range from a normal, functional hip to a severely painful, arthritic hip or permanent neurovascular injury.3 Factors that lead to worse Special Circumstances prognosis include increased time to reduction, posterior dislocation, cartilaginous injury to the femoral Hip Dislocation Following Total Hip head, associated acetabular fracture, the presence Arthroplasty of polytrauma, and pre-existing comorbidities.3,66 Special consideration is necessary for patients pre- These risk factors increase the patient’s risk of de- senting with dislocation of a prior total hip arthro- veloping long-term complications such as avascular plasty (THA). Approximately 2% of individuals who necrosis, posttraumatic arthritis, sciatic nerve palsy, have undergone THA will present with hip disloca- and heterotopic ossification.3 tion, which typically results from minimal traumatic Time to reduction of the femoral head within the force.69 These are usually due to activities such as acetabulum, and therefore restored blood supply, is bending over to pick something up off the floor, put- one of the most important factors affecting develop- ting on shoes and socks, and getting into and out of ment of these complications, specifically avascular bed.70 Approximately 60% of dislocations following necrosis and posttraumatic arthritis. The accepted THA occur within the first 3 months, and 77% occur time to reduction is controversial. In 2016, Kellam within the first year.71 and Ostrum published a comprehensive review of Reduction techniques are similar to those de- the existing literature on this topic and found that, scribed in the "Reduction of Hip Dislocation" section for certain anterior dislocations and posterior hip on page 13; however, the urgency of reduction is dislocations, the severity of injury correlates with an not as pressing, since there is no risk of avascular increase in the development of avascular necrosis necrosis, since the femoral head has been replaced. and posttraumatic arthritis. Posterior dislocations Prompt reduction is still encouraged however, due were more likely to develop avascular necrosis and to patient discomfort as well as the risk of sciatic posttraumatic arthritis, with posttraumatic arthritis nerve injury. Of note, forceful reduction of a dislocat- being more common. The risk of avascular necrosis ed hip prosthesis may dislodge the acetabular cup, in hip dislocations reduced after 12 hours was sig- fracture underlying osteoporotic bone, or loosen the nificantly increased, up to 5.6 times more likely than those reduced in < 6 hours.66 The incidence of posttraumatic arthritis is much lower in simple disloca- Table 4. Complications of Ankle Dislocation tions than in fracture-dislocations, 70% of which will develop posttraumatic arthritis.67 • Fractures and risk of malunion or nonunion • Osteoarthritis Knee Dislocation • Avascular necrosis of the talus • Entrapment of the tibialis posterior tendon Neurovascular injury is the primary complica- • Entrapment of fracture fragment tion that can be minimized with appropriate and • Cartilaginous injury timely intervention. Specifically, popliteal artery • Talar dome osteochondral fractures injury must be assessed, due to the devastating • Arterial injury/amputation

December 2017 • www.ebmedicine.net 17 Copyright © 2017 EB Medicine. All rights reserved. prosthesis. If reduction is unsuccessful after multiple tion without other injury, there are seldom complica- attempts, orthopedic surgery should be consulted tions, and the reduction can be performed without for reduction in the operating room. analgesia or sedation. Anxiolysis can be considered Following successful reduction, plain films for the anxious patient. should be obtained to confirm concentric reduction. The reduction technique involves mild flexion Abduction bracing following closed reduction of at the hip to shorten the quadriceps, then slowly a hip prosthesis is ineffective in preventing recur- extending the knee. This usually reduces the dislo- rent dislocation, and is therefore unnecessary.72 The cation. If still dislocated, apply gentle pressure to patient may attempt to walk after sedation has worn the patella toward the patellar groove. All uncom- off. Unlike native hip dislocations, patients with mon types of patellar dislocations (intra-articular, prosthetic hip dislocations often will not require horizontal, and superior) can be difficult to reduce hospital admission and may be discharged after by closed manipulations and may require operative discussion with the consulting orthopedic surgeon. reduction. Orthopedic consultation is recommended These patients should be given precautions to avoid for these cases, and in cases where there is an associ- recurrent dislocation, such as avoiding sitting with ated fracture.77,78 the hips below the level of the knees, bending over Perform postreduction radiographs to include to pick things up, or crossing the legs. They should patellar views to confirm the reduction and evaluate sleep with a pillow between the legs. Follow-up with for osteochondral fracture. Following the reduction, the patient's orthopedic surgeon within 2 weeks is immobilize the patient in extension, with a knee recommended.45 immobilizer or long leg splint. The patient should be discharged with crutches, a 1-week follow-up with Knee Dislocation Following Knee orthopedics, and instructions to remain non–weight- Replacement bearing. The patient will likely stay non–weight- Unlike hip prostheses, knee replacements rarely dis- bearing or partially weight-bearing for 2 to 4 weeks. locate.73 The majority of the literature involves case Longer periods of immobilization are associated reports and small case series. Prosthetic dislocations are more commonly posterior and can also have 74 associated neurovascular injury. Often, reduction Figure 13. Patellar Dislocations may be difficult because prostheses often contain a vertical post which must be overcome. Due to their less familiar nature, expert consultation may be considered for assistance.

Patellar Dislocation Patellar dislocations are simple to manage in most cases. These injuries are usually related to trauma, but they can result from a minor force. Risk factors include female gender, adolescence, vastus media- lis atrophy, obesity, genu valgus, flat intercondylar groove, and a large quadriceps angle ("Q angle").75,76 Most patellar dislocations are lateral, due to the upward and lateral pull of the quadriceps muscle; however, it can also dislocate medially, superiorly, horizontally, and intra-articularly. (See Figure 13.) The laterally dislocated patella is easy to identify, as the affected knee will be held in partial flexion, with a bulging deformity over the lateral aspect. Many of these dislocations will reduce spontaneously prior to ED evaluation. Palpate over the patellar tendon from the origin at the inferior patella to the insertion on the tibial tuberosity. Identifying a continuous, firm band ensures that the tendon has not completely ruptured; consider ultrasound to aid in confirming the continuity of the tendon.77 Obtain initial knee radiographs to look for patellar fractures or other bony injury. If the patient is not tolerating the dislocation, reduction before imaging Source: Eric F. Reichman: Emergency Medicine Procedures, Second may be appropriate. For a lateral or medial disloca- Edition: www.accessemergencymedicine.com. Copyright © The McGraw-Hill Companies, Inc. Used with permission.

1. “I didn't consider injuries other than hip dislo- 6. “I didn't think I needed to consult orthopedics cation.” to see the patient before discharging him from Hip dislocation may be a distracting injury; 95% the ED.” of patients have other associated injuries. Be Even if reduction is successful, patients can still sure to perform a thorough trauma evaluation, have complications from their injuries. If the and maintain a low threshold for ordering patient's neurovascular status is abnormal, or imaging on any suspected injury. there is a nonconcentric reduction, they may still require emergent orthopedic consultation and 2. “The patient had a head injury, so she couldn’t open reduction and internal fixation. tell us that her hip was hurting.” Hip dislocations may be missed due to other 7. “Did you realize the distal pulses were dimin- distracting injuries, especially in high-speed ished on arrival?” MVCs, due to altered mental status, etc. Strongly An immediate neurovascular examination is consider pelvic imaging for any patient with a crucial, and may prompt timely evaluation with dangerous mechanism with distracting injury. advanced imaging. Performing an ABI test can evaluate vascular status more objectively. 3. “I couldn’t get the patient comfortable enough to perform the reduction.” 8. “I was waiting for the CT read before perform- Adequate sedation and muscle relaxation is ing the reduction.” key to successful ED reduction. Sedatives such Radiographs are typically sufficient for as benzodiazepines and propofol provide both prosthetic hip dislocation, knee dislocations, and sedation and muscle relaxation. ankle dislocations. CT scans may ultimately be required, but they are not usually required prior 4. “Did the patient have intact sensation and to reduction. pulses after the reduction was completed?” Check neurovascular status before and after 9. “The reduction went smoothly, and the pain reduction; sciatic nerve injury occurs in 10% was much relieved, so I didn’t pursue further to 20% of hip dislocations, popliteal artery imaging.” injury is a risk with knee dislocations, and the Because of the risk of other, associated fractures, vascular supply of the talus is at risk with ankle CT should be obtained following all native dislocations. hip reductions to assess for loose fragments and femoral neck, femoral head, or acetabular 5. “The patient still had a fair amount of pain fracture. CT should also be obtained for many even after reduction.” ankle dislocations. Pain should improve following reduction and immobilization, but pain medication may 10. “I tried to reduce the joint multiple times, but I still be needed. If there is still a great deal of was unsuccessful.” pain after reduction, examine the patient for Repeated unsuccessful attempts at reduction or neuromuscular compromise and assess the associated fractures should prompt orthopedic postreduction film to verify adequate reduction consultation. and to ensure that there are no fractures.

December 2017 • www.ebmedicine.net 19 Copyright © 2017 EB Medicine. All rights reserved. with decreased range of motion, but lower rates of and abduction. The initial physical examination and recurrence. The ultimate decision for surgical man- AP pelvic radiograph is usually sufficient to make agement versus physical therapy alone is decided the diagnosis; however, additional views, such as on a case-by-case basis by the patient’s orthopedic Judet views, may be needed to evaluate for associ- surgeon.78,79 ated fractures. Traumatic dislocations of the native hip should be reduced within 6 hours to reduce the Knee Dislocation in Children risk of long-term complications such as avascular A knee dislocation in the pediatric population also necrosis and posttraumatic arthritis. Due to the high carries a similar risk of neurovascular injury and incidence of associated injuries, a thorough trauma compartment syndrome. The management of a knee evaluation is necessary. There are multiple reduction dislocation in a child does not vary significantly techniques described; however, none have proven from that of an adult.80 significantly superior. Some methods are designed to be ergonomically safer for the practitioner, such Controversies and Cutting Edge as the Captain Morgan and Rocket Launcher techniques. All fracture-dislocations should be deferred There is literature that challenges the accepted time to orthopedic surgery and should be promptly re- to reduction of the dislocated hip and how much duced in the operating room under general anesthe- time truly increases the risk of avascular necro- sia. Most native hip dislocations should be admitted sis. Brav reviewed 262 patients and found that in to the hospital; however, uncomplicated reductions patients reduced in < 12 hours, 22% developed of prosthetic hips may be considered for discharge avascular necrosis versus 52% in those reduced after home. 12 hours.81 Hougaard and Thompsen reviewed 100 Knee dislocations, although uncommon, re- cases after 5-year follow-up and found that 4% of quire timely reduction and assessment for a limb- patients reduced in < 6 hours developed avascular threatening neurovascular injury. Complicating the necrosis, versus 58% reduced > 6 hours.82 Dreinhofer emergency clinician’s evaluation, many knee dislo- et al evaluated 50 patients and reported that there cations spontaneously reduce, so maintaining a low was no difference in reduction < 1 hour as opposed threshold of suspicion for this injury is paramount, to < 6 hours, all of which had a 12% risk of avascu- as missing an associated arterial injury can be lar necrosis.5 As previously discussed, Kellam and catastrophic. With early consultation of orthopedic Ostrum recently performed a meta-analysis of the surgery and vascular surgery in all cases of obvious existing literature, and found that reducing a hip in or suspected knee dislocation, as well as application < 6 hours significantly reduces the risk of avascular of a selective approach to CT angiography, the risk necrosis, which confirms the current practice of most of missing a clinically significant arterial injury is emergency clinicians and orthopedic practitioners.66 minimized. Two providers using a traction/counter- It is likely that time to reduction represents a con- traction technique can perform successful reduction tinuum of increasing risk, and for that reason, it is of the dislocated knee. advisable to attempt reduction as soon as feasible. Primary ankle dislocation in any direction without associated fractures are rare. They can be Ultrasound-Guided Procedural Sedation associated with significant neurovascular, skin, and soft-tissue complications, and they require immedi- In recent years, sonography has become an increas- ate recognition and prompt reduction in the ED. If ingly useful tool in the ED and its use is highly the dislocation is open, complicated, or unable to incorporated into the training of emergency clini- be reduced, emergent orthopedic consultation is cians. Multiple case reports suggest that an ultra- required. A bulky Jones splint and strict non–weight- sound-guided fascia iliaca compartment block by bearing should be maintained until evaluated by the emergency clinician improves patient comfort orthopedics. and increases the likelihood of successful reduction in the ED. This can reduce the complications of procedural sedation or general anesthesia, especially Case Conclusions in the elderly population. The success of regional anesthetic techniques for hip fractures suggests that The 25-year-old man with traumatic native hip injury this technique may also be effective for joint reduc- after MVC underwent trauma surgery consultation, tion, but further study is warranted.51 including a primary and secondary survey. The patient did not have any associated injuries. On the portable AP Summary pelvis radiograph, the right femoral head was higher and smaller appearing than the left, suggesting posterior hip dislocation. A CT scan of the abdomen/pelvis confirmed Ninety percent of hip dislocations are posterior and this diagnosis and revealed a 40% acetabular rim fracture; present with internal rotation and adduction, while therefore, orthopedic surgery was emergently consulted 10% are anterior and present with external rotation

Copyright © 2017 EB Medicine. All rights reserved. 20 Reprints: www.ebmedicine.net/empissues and the patient underwent open reduction and internal Key Points fixation in the OR. The elderly woman with history of right hip pros- • Native hip dislocations may require admission thesis who presented after a fall had right hip and pelvis to the hospital after reduction, but most patients radiographs with Judet views, revealing a posterior dislo- with prosthetic hip dislocations can be safely cation of her right THA, without any associated fractures. discharged home with abduction restrictions fol- After a successful closed reduction in the ED, repeat lowing ED reduction. radiographs showed a concentric reduced hip joint. The • Complete hip radiographs are usually sufficient patient was neurovascularly intact following reduction prior to reducing both native and prosthetic and could ambulate without pain. Orthopedic surgery hip dislocations, and reduction should not be was consulted and recommended discharge home with delayed for CT. Postreduction radiographs are close follow-up. sufficient following successful prosthetic hip re- The 19-year-old man was suspected to have suffered ductions; however, CT scan should be obtained hyperextension resulting in an anterior knee dislocation in the setting of a native hip reduction. that had spontaneously reduced. Initial distal vascular • Immediately reduce knee dislocations that have and neurologic examination was unremarkable; however, distal pulse deficits. Do not delay immediate ABI was found to be 0.7. The knee was immobilized in closed reduction to obtain ABI or x-rays, as this 20° of flexion as orthopedic and vascular surgery were will not alter management yet, and it can be consulted. A CT angiogram was performed and identified performed after reduction. Knee dislocations for a popliteal artery disruption. The patient was taken for longer than 8 hours have a much higher inci- surgical repair by vascular surgery, with the aid of ortho- dence of amputation. pedic surgery. • Following reduction of a dislocated knee, a The 27-year-old man who jumped out of a tree was vascular examination alone is insufficient to de- found on x-ray to have a posterior ankle dislocation termine the presence of a popliteal artery injury without an associated ankle fracture. He required seda- that will require surgical intervention. Admis- tion for reduction, but was successfully reduced on the sion for 24 hours of serial vascular examinations first attempt and had an intact neurovascular exam after or vascular imaging is recommended. Admis- reduction. A bulky Jones splint was applied, and ortho- sion will also allow for monitoring for compart- pedics was consulted for further care. CT scan revealed ment syndrome, which can present as a delayed small osteochondral fractures to the talar dome, but he did complication after a knee dislocation. not require surgery and recovered after a prolonged period • Many dislocated ankles still require surgical of remaining non–weight-bearing. intervention, even after closed reduction. Emer- gent orthopedic consultation and postreduction Time- And Cost-Effective Strategies CT are necessary after reduction of a dislocated ankle. • Reducing a native hip in < 6 hours reduces risk for avascular necrosis and posttraumatic arthri- References tis, ultimately reducing future medical expenses. • Though less emergent due to the lack of risk for Evidence-based medicine requires a critical ap- avascular necrosis, decreased time to reduction praisal of the literature based upon study methodol- of prosthetic hips reduces risk of sciatic nerve ogy and number of subjects. Not all references are injury and pain, and may help prevent hospital equally robust. The findings of a large, prospective, admission. randomized, and blinded trial should carry more • An ultrasound-guided fascia iliaca compart- weight than a case report. ment block may decrease the amount of sedation To help the reader judge the strength of each necessary and increase likelihood of success- reference, pertinent information about the study is ful reduction of both native and prosthetic hip included in bold type following the reference, where dislocations in the ED, thereby reducing time to available. In addition, the most informative referenc- reduction, preventing need for operative inter- es cited in this paper, as determined by the authors, vention, and reducing length of stay. are noted by an asterisk (*) next to the number of the • Reduction of knee or ankle dislocations, either reference. closed in the ED or open in the operating room, should be achieved in < 8 hours in order to mini- 1. Epstein HC, Wiss DA. Traumatic anterior dislocation of the mize the risk for significant limb ischemia and hip. Orthopedics. 1985;8(1):130, 132-134. (Review) subsequent amputation. Not only is this a limb- 2. Pietrafesa CA, Hoffman JR. Traumatic dislocation of the hip. saving measure, but it will significantly reduce JAMA. 1983;249(24):3342-3346. (Retrospective study) 3.* Clegg TE, Roberts CS, Greene JW, et al. Hip dislocations-- both the short-term and long-term costs of care. epidemiology, treatment, and outcomes. Injury. 2010;41(4):329-334. (Review)

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Injury. 2011;42(11):1198-1204. patients) (Review) 80. Mayer S, Albright JC, Stoneback JW. Pediatric knee disloca- 60. Dedmond BT, Almekinders LC. Operative versus nonopera- tions and physeal fractures about the knee. J Am Acad Orthop tive treatment of knee dislocations: a meta-analysis. Am J Surg. 2015;23(9):571-580. (Review) Knee Surg. 2001;14(1):33-38. (Meta-analysis; 206 patients) 81. Brav EA. Traumatic dislocation of the hip. J Bone Joint Surg 61. Cole BJ, Harner CD. The multiple ligament injured knee. Am. 1962;44(6):1115-1134. (Retrospective review; 3 patients) Clin Sports Med. 1999;18(1):241-262. (Review) 82. Hougaard K, Thomsen PB. Traumatic posterior dislocation 62. Jiang W, Yao J, He Y, et al. The timing of surgical treatment of of the hip--prognostic factors influencing the incidence of knee dislocations: a systematic review. Knee Surg Sports Trau- avascular necrosis of the femoral head. Arch Orthop Trauma matol Arthrosc. 2015;23(10):3108-3113. (Systematic review; Surg. 1986;106(1):32-35. (Retrospective review; 98 patients) 150 patients) 63. Horn A, Ufberg J. Management of Common Dislocations. In: Roberts JR, ed. Roberts and Hedges’ Clinical Procedures in Emer- gency Medicine. 6th ed. Philadelphia, PA: Elsevier; 2014:954-998. (Textbook chapter) 64. Thangarajah T, Giotakis N, Matovu E. Bilateral ankle dislocation without malleolar fracture. J Foot Ankle Surg. 2008;47(5):441-446. (Case report; 1 patient) 65. Grotz MR, Alpantaki K, Kagda FH, et al. Open tibiotalar dislocation without associated fracture in a 7-year-old girl. Am J Orthop (Belle Mead NJ). 2008;37(6):E116-E118. (Case report; 1 patient) 66. Kellam P, Ostrum RF. Systematic review and meta-analysis of avascular necrosis and posttraumatic arthritis after traumatic hip dislocation. J Orthop Trauma. 2016;30(1):10-16. (Systematic review and meta-analysis; 1707 patients) 67. Stewart MJ, Milford LW. Fracture-dislocation of the hip; an end-result study. J Bone Joint Surg Am. 1954;36(A:2):315-342. (Retrospective study) 68. Yahya MM, Mwipatayi BP, Abbas M, et al. Popliteal artery injury: Royal Perth experience and literature review. ANZ J Surg. 2005;75(10):882-886. (Review) 69. Meek RM, Allan DB, McPhillips G, et al. Epidemiology of dislocation after total hip arthroplasty. Clin Orthop Relat Res. 2006;447:9-18. (Meta-analysis; 14,314 patients)

December 2017 • www.ebmedicine.net 23 Copyright © 2017 EB Medicine. All rights reserved. CME Questions 5. Which of the following tests should not be used to assess for popliteal artery injury? a. X-ray series of the knee Take This Test Online! b. Duplex ultrasound c. CT angiogram Current subscribers receive CME credit absolutely d. Arteriogram free by completing the following test. Each issue in- TM cludes 4 AMA PRA Category 1 Credits , 4 ACEP Cat- 6. The common force that is applied in the reduc- egory I credits, 4 AAFP Prescribed credits, or 4 AOA Take This Test Online! tion of all types of knee dislocation is: Category 2A or 2B credits. Online testing is available a. Axial loading for current and archived issues. To receive your free b. Anterior force on the proximal tibia CME credits for this issue, scan the QR code below c. Posterior force on the proximal tibia with your smartphone or visit d. Traction/counter-traction www.ebmedicine.net/E1217. 7. When should a knee or ankle joint be reduced in the field by EMS before transport? a. Significant deformity b. Severe and unremitting pain c. Open dislocation d. Concern for ischemia distal to the injury

8. What type of knee dislocation is the most com- 1. What is the most common type of hip disloca- mon? tion? a. Medial a. Lateral b. Anterior b. Medial c. Posterior c. Anterior d. Lateral d. Posterior e. Rotational

2. Delaying a native hip reduction can result in 9. What other injury should be excluded before which of the following complications? attempting reduction of an ankle dislocation? a. Compartment syndrome a. Hip fracture b. Further blood loss b. Calcaneal fracture c. Avascular necrosis c. Subtalar dislocation d. Infection d. Tibial shaft fracture

3. Which of the following hip dislocations should 10. What potential complication from a dislocated not be reduced by an emergency clinician ankle is the primary reason for timely reduc- without an orthopedic surgeon present? tion of the talus? a. Dislocation with associated fracture a. Postoperative infection b. Dislocation with a prosthetic hip b. Avascular necrosis of the talus c. Dislocation without fracture c. Long-term osteoarthritis d. No dislocation should be reduced without d. Compartment syndrome orthopedic consultation

4. To avoid complications, what should be the goal time-to-reduction of a native hip disloca- Don't forget... tion? You can LISTEN to highlights and CME a. Less than 1 hour hints for this issue on b. Less than 6 hours c. Less than 24 hours d. Less than 72 hours

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Copyright © 2017 EB Medicine. All rights reserved. 24 Reprints: www.ebmedicine.net/empissues EB MEDICINE EB MEDICINE Get the Truth About Mobile Medical Apps: Get themHealth Truth Aboutin Emergency Mobile MedicineMedical Apps: mHealth in Emergency Medicine Thanks to today’s technology, you can access the best evidence- based decision support tools in the palm of your hand. Thanks to today’s technology, you can access the best evidence- Smartphonebased decision apps support for emergency tools in the medicine palm of yourclinicians hand. can help you make better clinical decisions, reference conversions and Smartphone apps for emergency medicine clinicians can help data, and aid you in physical examinations. mHealth in Emergency Medicine: you make better clinical decisions, reference conversions and Grab Your Smartphone But how can you know the apps you’re using are reliable, data, and aid you in physical examinations. TomHealth Get ina EmergencyGrip on App-DrivenMedicine: accurate, and evidence-based? ClinicalGrab Your Decision Smartphone Rules & Tools But how can you know the apps you’re using are reliable, AUTHOR With the proliferation of smartphones over the past several years, apps Nicholas Genes, MD, PhD now play a prominent role in many social and work contexts, including ToAssociate Professor,Get Department ofa Gripmedicine. This ison enough of aApp-Driven phenomenon to have inspired the abbreviation With the free mHealth in Emergency Medicine Emergency Medicine, Icahn School of “mHealth,” short for mobile health. The number of clinical app-driven Medicine at Mount Sinai, New York, NY calculators, checklists, and risk scores in common use in the emergency accurate, and evidence-based? department (ED) has significantly increased and shows no sign of slowing. ClinicalEB Medicine is pleased to bringDecision Rules & Tools you mHealth in Emergency Thanks to this digital development and innovation, clinical decision support special report, authored by emergency physician and Medicine, a Special Report is now just a finger tap away. developedAUTHOR in conjunction with With the proliferation of smartphones over the past several years, apps FREE ourNicholas strategic Genes, partner MD, MDCalc. PhD Asnow of play2016, a thereprominent were roleapproximately in many social 20,000 and appswork incontexts, the “Medical” including LookAssociate for Professor,the first Department edition of of our categorymedicine. of This Apple’s is enough app store. of a phenomenon1 There are at toleast have 300 inspired apps specifically the abbreviation With the free mHealth in Emergency Medicine jointlyEmergency published Medicine, Calculated Icahn School of targeted“mHealth,” to emergencyshort for mobile clinicians health.2 and, The given number the varietyof clinical of patientapp-driven informatics expert Dr. Nick Genes, you’ll learn how to DecisionsMedicine at supplement,Mount Sinai, New which York, NY presentations,calculators, checklists, general-purpose and risk scores apps and in common apps from use other in the specialties emergency likely Special follows this report. It features department (ED) has significantly increased and shows no sign of slowing. EB Medicine is pleased to bring merit usage in the ED. “Nick’s Picks,” content from 10 Thanks to this digital development and innovation, clinical decision support MDCalcyou mHealth calculators in Emergency Dr. Genes Despiteis now just the a abundance finger tap ofaway. apps and their potential to improve patient care, special report, authored by emergency physician and deemsMedicine as most, a Special essential Report to recognize the best apps for emergency clinicians. developed in conjunction with however, which apps to choose and use is largely a decision left to each Report!emergency medicine. Starting FREE now,our strategic Calculated partner Decisions MDCalc. will be clinician,As of 2016, with there little were guidance approximately on best practices 20,000 appsor potential in the “Medical” risks. The purpose 1 publishedLook for the on firsta regular edition basis of andour ofcategory this article of Apple’s is to educate app store. emergency There areclinicians at least about 300 appsmedical specifically apps that can availablejointly published free to subscribers Calculated of betargeted utilized to to emergency improve patient clinicians care2 and,during given a shift. the variety of patient informatics expert Dr. Nick Genes, you’ll learn how to Decisions supplement, which Emergency Medicine Practice and presentations, general-purpose apps and apps from other specialties likely Special follows this report. It features Pediatric Emergency Practice. merit usage in the ED. “Nick’s Picks,” content from 10 EB MEDICINE MDCalc calculators Dr. Genes Despite the abundance of apps and their potential to improve patient care, deems as most essential to recognize the best apps for emergency clinicians. however, which apps to choose and use is largely a decision left to each Report!emergency medicine. Starting now, Calculated Decisions will be clinician, with little guidance on best practices or potential risks. The purpose published on a regular basis and of this article is to educate emergency clinicians about medical apps that can available free to subscribers of be utilized to improve patient care during a shift. Emergency Medicine Practice and Pediatric Emergency Practice. EB MEDICINE Calculated Along with this special report, you’ll get the premier POWERED BY issue of Calculated Decisions. This collaborative project Decisions betweenAlong with MDCalc this special and EBreport, Medicine you’ll providesget the premier in-depth CalculatedClinical Decision Support for Emergency Medicine Practice Subscribers Emergency Department Assessment POWERED BY reviewsissue of ofCalculated key medical Decisions calculators. This to collaborative help you better project of Chest Pain Score (EDACS) Identifies chest Decisionspain patients with low risk of major adverse between MDCalc and EB Medicine provides in-depth cardiac event Clinical Decision Support for Emergency Medicine Practice Subscribers understand best practices for the risk scores and decision

Introduction procedure. TheEmergency Emergency Department Assessment Department of Chest Pain » AssessmentDeath from cardiovascular causes. Score (EDACS) identifies chest pain patients with low » Ventricular arrhythmia. toolsreviews you of use key every medical day. calculators to help you better riskof of majorChest adverse cardiac Pain event. It wasScore developed (EDACS)» Cardiac arrest. by Dr. Martin Than and colleagues in Christchurch, New » Cardiogenic shock. ZealandIdentifies and published chest in Emergency pain Medicine patients Austral- with» lowHigh atrioventricular risk of block.major adverse asiacardiac in 2014. event understand best practices for the risk scores and decision Management Why Use Introduction For low-riskprocedure. patients, consider other causes of Patients requiring serial blood testing (serial troponin chest pain due to aortic, esophageal, pulmonary, The Emergency Department Assessment of Chest Pain » Death from cardiovascular causes. markers typically at 0 and 6 hours to rule out myocar- cardiac, and abdominal, and musculoskeletal Score (EDACS) identifies chest pain patients with low » Ventricular arrhythmia. tools you use every day. dial infarction) and further risk stratification require an sources prior to discharge. risk of major adverse cardiac event. It was developed » Cardiac arrest. extended emergency department evaluation, or hos- For non-low-risk patients, physicians should by Dr. Martin Than and colleagues in Christchurch, New » Cardiogenic shock. pital admissions, leading to crowding, bed allocation use their best judgment to workup and treat as Zealand and published in Emergency Medicine Austral- » High atrioventricular block. problems, and exposure of patients to side effects of per usual chest pain protocols, including but not asia in 2014. increased testing. The authors of this study were able limited to consideration of aspirin, nitroglycerin, Powered by to find a low risk group of patients (~45%) that could andManagement serial EKGs and biomarkers. Why Use safely be discharged from the ED after two biomarkers For low-risk patients, consider otherPremier causes of issue justPatients two hours requiring apart, serial EKG, blood history testing and physical(serial troponin exam. Criticalchest pain Actions due to aortic, esophageal, pulmonary, markers typically at 0 and 6 hours to rule out myocar- Patientscardiac, deemedand abdominal, low risk andare safemusculoskeletal for discharge Whendial infarction) to Use and further risk stratification require an tosources early outpatientprior to discharge. follow-up investigation (or extended emergency department evaluation, or hos- For non-low-risk patients,with physicians shouldNick’s Picks - Use in patients with chest pain or other anginal symp- proceed to earlier inpatient testing). For patients pital admissions, leading to crowding, bed allocation use their best judgment to workup and treat as toms requiring evaluation for possible acute coronary who are NOT low risk, physicians should use problems, and exposure of patients to side effects of per usual chest pain protocols, including but not syndrome who may be potentially low risk and appropri- their best judgment, as this “Rule Out” calculator increased testing. The authors of this study were able limited to consideration of aspirin, nitroglycerin,reviewing 7 Powered by ate for early discharge from the emergency department. was not designed to “rule in” patients with ACS. to find a low risk group of patients (~45%) that could Physiciansand serial cannotEKGs and use biomarkers. EDACS to rule out ACS. Pearls/Pitfallssafely be discharged from the ED after two biomarkers Premier issue just two hours apart, EKG, history and physical exam. Critical Actions of the most • The EDACS-ADP (accelerated diagnostic protocol) CONTENTPatients CONTRIBUTOR deemed low risk are safe for discharge Whenstudy to included Use any symptoms lasting longer than to early outpatient follow-up investigation (or five minutes that the attending physician thought Graham Walker, MD with Nick’s Picks - Use in patients with chest pain or other anginal symp- Departmentproceed to of earlier Emergency inpatient Medicineimportant testing). For patients medical were worth working up for possible acute coronary toms requiring evaluation for possible acute coronary Kaiserwho Permanenteare NOT low San risk, Francisco physicians should use syndrome (ACS). This is a broader definition than syndrome who may be potentially low risk and appropri- their best judgment, as this “Rule Out” calculator other studies like the Vancouver Chest Pain Score, reviewing 7 ate for early discharge from the emergency department. Josephwas not Habboushe, designed to MD, “rule MBA in” patientscalculators with ACS. which only included chest pain patients specifically. DepartmentPhysicians of cannot Emergency use EDACS Medicine to rule out ACS. Similar to other chest pain evaluation studies, the Pearls/Pitfalls NYU Langone / Bellevue Medical Center primary outcome was MACE (major adverse cardiac of the most • The EDACS-ADP (accelerated diagnostic protocol) events), as defined by any of the following: CONTENT CONTRIBUTOR »study ST-elevation included any or non-ST-symptoms elevation lasting MI.longer than five minutes that the attending physician thought Graham Walker, MD » Requiring an emergency revascularization Department of Emergency Medicineimportant medical were worth working up for possible acute coronary Kaiser Permanente San Francisco Volumesyndrome 1 | Issue (ACS). 1 • Emergency This is a broaderMedicine definition Practice than 1 Copyright © 2017 EB Medicine. All rights reserved. other studies like the Vancouver Chest Pain Score, Joseph Habboushe, MD, MBA calculators which only included chest pain patients specifically. Department of Emergency Medicine Similar to other chest pain evaluation studies, the NYU Langone / Bellevue Medical Center primary outcome was MACE (major adverse cardiac events), as defined by any of the following: » ST-elevation or non-ST- elevation MI. » Requiring an emergency revascularization

1 Copyright © 2017 EB Medicine. All rights reserved. Volume 1 | Issue 1 • Emergency GoMedicine Practice to www.ebmedicine.net/calculators to get your free report from EB Medicine and MDCalc! Go to www.ebmedicine.net/calculators to get your free report from EB Medicine and MDCalc!

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Table 7. Exclusion Criteria for Noninvasive Positive-Pressure Ventilation and Indications for Intubation First Responders • Inability to tolerate a tightly sealed face mask l Discomfort What changes do you anticipate making in your l Craniofacial abnormalities (eg, trauma, burns, etc) practice as a result of this activity? l Significant air leak POINTS & PEARLS • Inability to protect airway or coordinate breathing with ventilator Maintain a broad differential diagnosis when l A Quick-Read Review Of Key Points & Clinical Pearls, October 2017 Depressed mentation “ suspecting acute COPD exacerbation. l Hemodynamic instability l Vomiting or Inability to clear secretions

l Maintain O Apnea or respiratory arrest “ 2 saturation 88% to 92%. Diagnosis and Management of Acute Exacerbation • Recent gastrointestinal surgery (due to risk of aerophagia) Earlier use of NIPPV and decrease in antibiotic of Chronic Obstructive PulmonaryPearls Disease “ use in outpatients. Maintain lower tidal volume, lower acceptable Points All patients concerning for a COPD exacerbation require a chest x-ray. For more-severe “ saturation. • More than 1.7 million patients per year present to exacerbations, consider blood tests and an the emergency department requiring treatment for electrocardiogram. Use lower-dose steroids. chronic obstructive pulmonary disease (COPD), “ with about 20% requiring inpatient hospitalization. Treatment includes supplemental oxygen Give a shorter course of steroids and lower dose This costs the United States, directly and indirectly, titrated to maintain an oxygen saturation of Access the issue by scanning “ for outpatients. between $35 and $50 billion each year. 88% to 92%. the QR code with a smart- • The GOLD guidelines, updated in 2016, contain phone or tablet. a consensus definition for acute exacerbation of NIPPV is associated with better outcomes. Re- COPD, risk assessment, and evidence-based man- member to use a long expiratory time to avoid Clinical Pathway for MDCalc Score Calculators agement strategies. breath-stacking. Management of Acute Global Initiative for Obstructive Lung Disease (GOLD) Exacerbation of COPD Criteria for COPD: https://www.mdcalc.com/global- • In patients with purulent sputum, a short course Questions, comments, suggestions? To write a letter of antibiotics is warranted. Community-acquired Bronchodilators, either beta-2 agonists, anti- initiative-obstructive-lung-disease-gold-criteria-copd to the editor, email: [email protected]. mMRC (Modified Medical Research Council) Dyspnea pathogens include Haemophilus influenzae, Strep- cholinergics, or both, should be given simulta- Scale: https://www.mdcalc.com/mmrc-modified-medical-research- tococcus pneumoniae, and Moraxella catarrhalis. In neously. Most Important References council-dyspnea-scale critically ill patients, Pseudomonas and methicillin- A short course of corticosteroids should be DECAF Score for Acute Exacerbation of Chronic Obstructive Pul- resistant Staphylococcus aureus (MRSA) are more monary Disease (COPD): prescribed. Typically, a 5-day course of 40 mg 3. Celli BR, MacNee W, Agusti A, et al. Standards for the diag- common, and antibiotic regimens should be tailored exacerbation-copd https://www.mdcalc.com/decaf-score-acute- prednisone is sufficient, per the REDUCE trial. nosis and treatment of patients with COPD: a summary of to cover those pathogens as well. the ATS/ERS position paper. Eur Respir J. 2004;23(6):932-946. • Although you should always defer to your local anti- (Systematic review; consensus guidelines) biogram, outpatient management typically includes with or without inhaled corticosteroids with their DOI: https://dx.doi.org/10.1183/09031936.04.00014304 of chronic obstructive pulmonary disease: the REDUCE random- either cefdinir, doxycycline, or azithromycin. Inpatient primary care doctor. 4. Global Strategy for the Diagnosis, Management and Preven- ized clinical trial. JAMA. 2013;309(21):2223-2231. (Randomized controlled trial; 314 patients) management often includes amoxicillin/clavulanate, • Consider a patient’s social situation and ability to tion of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2016. Available at: http://goldcopd.org/. DOI: http://dx.doi.org/10.1001/jama.2013.5023 levofloxacin, or moxifloxacin. Consider vancomycin follow up when determining a disposition. (Systematic review; consensus guidelines) 89. Vollenweider DJ, Jarrett H, Steurer-Stey CA, et al. Antibiotics for or linezolid if there is concern for MRSA. 68. Vestbo J, Hurd SS, Agusti AG, et al. Global strategy for the exacerbations of chronic obstructive pulmonary disease. Cochrane diagnosis, management, and prevention of chronic obstructive Database Syst Rev. 2012;12:CD010257. (Systematic review and • Early use of noninvasive positive-pressure ventila- Issue Authors tion (NIPPV) has been shown to decrease the need pulmonary disease: GOLD executive summary. Am J Respir meta-analysis; 16 trials, 2068 patients) Van Holden, MD Crit Care Med. 2013;187(4):347-365. (Consensus statement; DOI: https://dx.doi.org/10.1002/14651858.CD010257 for intubation, reduce length of hospital stay, and Pulmonary and Critical Care Fellow, Division of Pulmonary and Critical Care guidelines) 93. Ram FS, Picot J, Lightowler J, et al. Non-invasive positive pressure DOI: https://doi.org/10.1164/rccm.201204-0596PP decrease mortality. Medicine, University of Maryland Medical Center, Baltimore, MD 85. Leuppi JD, Schuetz P, Bingisser R, et al. Short-term vs ventilation for treatment of respiratory failure due to exacerbations of chronic obstructive pulmonary disease. Cochrane Database • CPAP or BiPAP (continuous positive airway pres- Donald Slack, III, MD conventional glucocorticoid therapy in acute exacerbations sure/bilevel positive airway pressure) can be used. Pulmonary and Critical Care Medicine, Greater Baltimore Medical Center, Syst Rev. 2004;(3)(3):CD004104. (Systematic review and meta- Baltimore, MD analysis; 14 studies) With BiPAP, initial settings should2O include greater anthan in -the Michael T. McCurdy, MD, FCCM, FCCP, FAAEM spiratory pressure that is 5 cm H Associate Professor, Department of Emergency Medicine and Department expiratory pressure. The pressures can be titrated of Medicine, Division of Pulmonary and Critical Care; Director, Critical Care EB MEDICIN Medicine Fellowship Program, University of Maryland School of Medicine, Emergency Medicine Practice subscribers: AreE you getting the every few minutes over the first hour to patient Baltimore, MD Contact EB Medicine: response and relief of symptoms. full value from your subscription? Visit your free online account at Phone: 1-800-249-5770 or 678-366-7933 Nirav G. Shah, MD, FCCP www.ebmedicine.net to search archives, browse clinical resources, Patients not improving on NIPPV typically require Associate Professor of Medicine, Division of Pulmonary and Critical Care Fax: 770-500-1316 • 2 to intubation. Use a short inspiratory time and long Medicine; Director, Pulmonary and Critical Care Medicine Fellowship take free CME tests to earn credit, and more. Address: 5550 Triangle Parkway, Program, University of Maryland School of Medicine, Baltimore, MD expiratory time. Remember to titrate the FiO Emergency Medicine Practice Suite 150, 150, Norcross, GA 30092). Opinions expressed are not necessarily those of this publication. Mention of products or services does not constitute endorsement. This publication is (ISSN Print: 1524-1971, ISSN Online: 1559-3908, ACID-FREE) is published monthly (12 timesNorcross, per year) by GAEB Medicine30092 (5550 Triangle Parkway, Suite achieve a saturation of 88% to 92%. Points & Pearls Contributors intended as a general guide and is intended to supplement, rather than substitute, professional judgment. It covers a highly technical and complex subject and should not be used for making specific medical decisions. The materials contained herein are not intended to establish policy, procedure, or standard of care. Copyright © 2017 EB Medicine. All rights Preventative measures are critically important. In reserved. No part of this publication may be reproduced in any format without written consent of EB Medicine. This publication is intended for the use of the individual subscriber only • Nachi Gupta, MD & Jeffrey Nusbaum, MD current smokers, encourage smoking cessation. The Department of Emergency Medicine, Icahn School of Medicine at Mount and may not be copied in whole or part or redistributed in any way without the publisher’s prior written permission. Sinai, New York, NY Copyright influenza and pneumococcal vaccines should be of- © 2017 EB Medicine. All rights reserved. fered or at least encouraged. Patients should also be 2017 EB Medicine. All rights reserved. Copyright © encouraged to discuss long-acting bronchodilators 1 2 www.ebmedicine.net October 2017 • Emergency Medicine Practice

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December 2017 • www.ebmedicine.net 27 Copyright © 2017 EB Medicine. All rights reserved. Physician CME Information Date of Original Release: December 1, 2017. Date of most recent review: November 10, 2017. Termination date: December 1, 2020. Accreditation: EB Medicine is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians. This activity October 2016 Volume 18, Number 10 has been planned and implemented in accordance with the accreditation requirements and Author policies of the ACCME. Julianna Jung, MD, FACEP Optimizing Survival Outcomes Associate Professor and Director of Undergraduate Medical Education, Department of Emergency Medicine, Johns Hopkins University School of For Adult Patients With Medicine, Baltimore, MD Credit Designation: EB Medicine designates this enduring material for a maximum of 4 AMA PRA Peer Reviewers Nontraumatic Cardiac Arrest William J. Brady, MD Professor of Emergency Medicine and Medicine; Chair, Medical Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of Emergency Response Committee; Medical Director, Emergency Abstract Management, University of Virginia Medical Center, Charlottesville, VA Faheem Guirgis, MD, FACEP Assistant Professor of Emergency Medicine, University of Florida Health their participation in the activity. Patient survival after cardiac arrest can be improved significantly- Jacksonville, Department of Emergency Medicine, Division of Research, with prompt and effective resuscitative care. This systematic Jacksonville, FL CME Objectives review analyzes the basic life support factors that improve survival- outcome, including chest compression technique and rapid defi Upon completion of this article, you should be able to: ACEP Accreditation: Emergency Medicine Practice is approved by the American College of brillation of shockable rhythms. For patients who are successfully 1. Describe the elements of high-quality basic life support. resuscitated, comprehensive postresuscitation care is essential. Tar 2. Discuss the evidentiary basis and current guidelines for advanced life support interventions. Emergency Physicians for 48 hours of ACEP Category I credit per annual subscription. geted temperature management is recommended for all patients 3. Describe essential considerations in postresuscitation care following who remain comatose, in addition to careful monitoring of oxygen- restoration of spontaneous circulation. ation, hemodynamics, and cardiac rhythm. Management of cardiac 4. List modifications to standard resuscitation protocols that may be considered in special resuscitation situations. arrest in circumstances such as pregnancy, pulmonary embolism, AAFP Accreditation: This Enduring Material activity, Emergency Medicine Practice, has been opioid overdose and other toxicologic causes, hypothermia, and Prior to beginning this activity,on the back see “Physicianpage. CME Information” coronary ischemia are also reviewed. International Editors reviewed and is acceptable for credit by the American Academy of Family Physicians. Term Robert Schiller, MD Peter Cameron, MD Chair, Department of Family Medicine, Academic Director, The Alfred Eric Legome, MD Beth Israel Medical Center; Senior Emergency and Trauma Centre, Chief of Emergency Medicine, Faculty, Family Medicine and Monash University, Melbourne, Daniel J. Egan, MD of approval begins 07/01/2017. Term of approval is for one year from this date. Physicians King’s County Hospital; Professor of Community Health, Icahn School of Australia Associate Professor, Department Clinical Emergency Medicine, SUNY Medicine at Mount Sinai, New York, NY Editor-In-Chief of Emergency Medicine, Program Downstate College of Medicine, Giorgio Carbone, MD Andy Jagoda, MD, FACEP Director, Emergency Medicine Brooklyn, NY Scott Silvers, MD, FACEP Chief, Department of Emergency Professor and Chair, Department of Residency, Mount Sinai St. Luke's Chair, Department of Emergency Medicine Ospedale Gradenigo, Keith A. Marill, MD should claim only the credit commensurate with the extent of their participation in the activity. Emergency Medicine, Icahn School Roosevelt, New York, NY Medicine, Mayo Clinic, Jacksonville, FL Torino, Italy Research Faculty, Department of of Medicine at Mount Sinai, Medical Nicholas Genes, MD, PhD Emergency Medicine, University Corey M. Slovis, MD, FACP, FACEP Suzanne Y.G. Peeters, MD Director, Mount Sinai Hospital, New Emergency Medicine Residency Assistant Professor, Department of of Pittsburgh Medical Center, Professor and Chair, Department York, NY Director, Haga Teaching Hospital, Emergency Medicine, Icahn School Pittsburgh, PA of Emergency Medicine, Vanderbilt The Hague, The Netherlands Approved for 4 AAFP Prescribed credits. University Medical Center, Nashville, TN Associate Editor-In-Chief of Medicine at Mount Sinai, New Charles V. Pollack Jr., MA, MD, York, NY FACEP Ron M. Walls, MD Hugo Peralta, MD Kaushal Shah, MD, FACEP Chair of Emergency Services, Hospital Associate Professor, Department of Michael A. Gibbs, MD,Evidence-Based FACEP Professor and Senior Advisor for ManagementProfessor and Chair, Department of Italiano, Buenos Aires, Argentina Emergency Medicine, Icahn School Professor and Chair, Department Interdisciplinary Research and Emergency Medicine, Brigham and November 2016 of Medicine at Mount Sinai, New of Emergency Medicine, Carolinas Clinical Trials, Department of Women's Hospital, Harvard Medical Dhanadol Rojanasarntikul, MD York, NY Medical Center, University of North Emergency Medicine, Sidney Kimmel School, Boston, MA Attending Physician, Emergency Volume 18, Number 11 AOA Accreditation: Emergency Medicine Practice is eligible for up to 48 American Carolina School ofOf Medicine, Potassium Chapel Medical College of Thomas Disorders Jefferson In TheMedicine, Authors King Chulalongkorn Editorial Board Hill, NC University, Philadelphia, PA Critical Care Editors Memorial Hospital, Thai Red Cross, Thailand; Faculty of Medicine, Saadia Akhtar, MD Michael S. Radeos, MD, MPH William A. Knight IV, MD, FACEP John Ashurst, DO, MSc Steven A. Godwin, MD, FACEP Chulalongkorn University, Thailand Associate Professor, Department of Professor and Chair,Emergency Department Assistant Professor Department of Emergency Associate Professor of Emergency Director of Emergency Medicine Residency Research, Duke Lifepoint Osteopathic Association Category 2-A or 2-B credit hours per year. Emergency Medicine, Associate Dean of Emergency Medicine, Assistant Medicine, Weill Medical College Medicine and Neurosurgery, Medical StephenConemaugh H. Thomas, MD,Memorial MPH Medical Center, Johnstown, PA for Graduate Medical Education, Dean, Simulation Education, of Cornell University, New York; Director, EM Midlevel Provider Professor & Chair, Emergency Program Director, Emergency University of Florida COM- Research Director, Department of Program, Associate Medical Director, Medicine,Shane Hamad R. Sergent,Medical Corp., DO Medicine Residency, Mount Sinai Jacksonville, Jacksonville, Abstract FL Emergency Medicine, New York Neuroscience ICU, University of WeillDepartment Cornell Medical of EmergencyCollege, Qatar; Medicine, Conemaugh Memorial Hospital, Beth Israel, New York, NY Hospital Queens, Flushing, NY Cincinnati, Cincinnati, OH Emergency Physician-in-Chief, Gregory L. Henry, MD, FACEP Johnstown, PA Ali S. Raja, MD, MBA, MPH Scott D. Weingart, MD, FCCM Hamad General Hospital, Doha, Qatar The need for this educational activity was determined by a survey William J. Brady, MD Needs Assessment: Clinical Professor, Department of Professor of Emergency Medicine Vice-Chair, Emergency Medicine, Associate Professor of Emergency Benjamin J. Wagner, DO Emergency Medicine,Hypokalemia University and hyperkalemia are the most common elec- Edin Zelihic, MD and Medicine; Chair, Medical Massachusetts General Hospital, Medicine, Director, Division of ED Department of Emergency Medicine, Conemaugh Memorial Hospital, of Michigan Medical School; CEO, Head, Department of Emergency trolyte disorders managed in the emergencyCritical department. Care, Icahn School ofThe Medicine Emergency Response Committee; Medical Practice Risk Assessment, Boston, MA Medicine,Johnstown, Leopoldina PA Hospital, Medical Director, Emergency at Mount Sinai, New York, NY Inc., Ann Arbor,diagnosis MI of theseRobert potentially L. Rogers, MD, life-threatening FACEP, disorders is chal Schweinfurt, Germany of medical staff, including the editorial board of this publication; review of morbidity and Management, University of Virginia FAAEM, FACP Peer Reviewers Medical Center, Charlottesville, VA John M. Howell, MD, FACEP lenging due to the Assistantoften Professorvague of symptomatology Emergency Senior Research a patient Editors may- Clinical Professor of Emergency Camiron L. Pfennig, MD, MHPE Calvin A. Brown III, MD Medicine,express, George Washington and treatmentMedicine, options The University may of be basedJames upon Damilini, very PharmD, little BCPS Director of Physician Compliance, University, Washington, DC; Director Maryland School of Medicine, Clinical Pharmacist, Emergency Associate Professor of Emergency Medicine, University of South Carolina Baltimore, MD mortality data from the CDC, AHA, NCHS, and ACEP; and evaluation of prior activities for Credentialing and Urgent Care of Academicdata Affairs, due Best to Practices, the time it may take for laboratoryRoom, values St. Joseph’s to Hospital return. and School of Medicine; Emergency Medicine Residency Program Director, Medical Center, Phoenix, AZ Services, Department of Emergency Inc, Inova Fairfax Hospital, Falls Alfred Sacchetti, MD, FACEP Greenville Health System, Greenville, SC Church, ThisVA review examines the most current evidence with regard to Medicine, Brigham and Women's Assistant Clinical Professor, Joseph D. Toscano, MD Hospital, Boston, MA Corey M. Slovis, MD, FACP, FACEP Shkelzenthe Hoxhaj, pathophysiology, MD, MPH, MBA Department diagnosis, of Emergency and Medicine, management Chairman, ofDepartment potassium of Emergency Chief of Emergency Medicine, Baylor Thomas Jefferson University, Medicine, San Ramon Regional Professor and Chair, Department of Emergency Medicine, Vanderbilt emergency physicians. Peter DeBlieux, MD disorders. In this review, classic paradigms, such as the use of Professor of Clinical Medicine, College of Medicine, Houston, TX Philadelphia, PA Medical Center, San Ramon, CA University Medical Center, Nashville, TN Interim Public Hospital Director sodium polystyrene and the routine measurement of serum CME Objectives of Emergency Medicine Services, Louisiana State University Health magnesium, are tested, and an algorithm for the treatment of Upon completion of this article, you should be able to: Science Center, New Orleans, LA potassium disorders is discussed. 1. Identify the etiology of the depletion of potassium in patients with Target Audience: This enduring material is designed for emergency medicine physicians, hypokalemia. 2. Identify and manage the etiology and underlying causes of hyperkalemia. 3. Describe the algorithmic management of hypokalemia and physician assistants, nurse practitioners, and residents. hyperkalemia. Prior to beginning this activity, see “Physician CME Information” Editor-In-Chief Daniel J. Egan, MD on the back page. Andy Jagoda, MD, FACEP Eric Legome, MD Associate Professor, Department Robert Schiller, MD Professor and Chair, Department of of Emergency Medicine, Program Chief of Emergency Medicine, International Editors Goals: Upon completion of this activity, you should be able to: (1) demonstrate medical Chair, Department of Family Medicine, Emergency Medicine, Icahn School Director, Emergency Medicine King’s County Hospital; Professor of Beth Israel Medical Center; Senior Peter Cameron, MD of Medicine at Mount Sinai, Medical Residency, Mount Sinai St. Luke's Clinical Emergency Medicine, SUNY Faculty, Family Medicine and Academic Director, The Alfred Director, Mount Sinai Hospital, New Roosevelt, New York, NY Downstate College of Medicine, York, NY Brooklyn, NY Community Health, Icahn School of Emergency and Trauma Centre, Nicholas Genes, MD, PhD Medicine at Mount Sinai, New York, NY Monash University, Melbourne, decision-making based on the strongest clinical evidence; (2) cost-effectively diagnose and Keith A. Marill, MD Associate Editor-In-Chief Australia Assistant Professor, Department of Research Faculty, Department of Scott Silvers, MD, FACEP

Kaushal Shah, MD, FACEP Emergency Medicine, Icahn School Emergency Medicine, University Chair, Department of Emergency Giorgio Carbone, MD Associate Professor, Department of of Medicine at Mount Sinai, New of Pittsburgh Medical Center, Medicine, Mayo Clinic, Jacksonville, FL Chief, Department of Emergency Emergency Medicine, Icahn School York, NY Pittsburgh, PA Corey M. Slovis, MD, FACP, FACEP Medicine Ospedale Gradenigo, treat the most critical presentations; and (3) describe the most common medicolegal pitfalls of Medicine at Mount Sinai, New Michael A. Gibbs, MD, FACEP Torino, Italy York, NY Charles V. Pollack Jr., MA, MD, Professor and Chair, Department Professor and Chair, Department FACEP of Emergency Medicine, Vanderbilt Suzanne Y.G. Peeters, MD of Emergency Medicine, Carolinas Professor and Senior Advisor for University Medical Center, Nashville, TN Emergency Medicine Residency Editorial Board Medical Center, University of North Saadia Akhtar, MD Interdisciplinary Research and Ron M. Walls, MD Director, Haga Teaching Hospital, for each topic covered. Carolina School of Medicine, Chapel Associate Professor, Department of Clinical Trials, Department of Professor and Chair, Department of The Hague, The Netherlands Hill, NC Emergency Medicine, Sidney Kimmel Emergency Medicine, Associate Dean Emergency Medicine, Brigham and Hugo Peralta, MD Medical College of Thomas Jefferson for Graduate Medical Education, Steven A. Godwin, MD, FACEP Women's Hospital, Harvard Medical Chair of Emergency Services, Hospital University, Philadelphia, PA Program Director, Emergency Professor and Chair, Department School, Boston, MA Italiano, Buenos Aires, Argentina Medicine Residency, Mount Sinai of Emergency Medicine, Assistant Michael S. Radeos, MD, MPH Dhanadol Rojanasarntikul, MD Beth Israel, New York, NY Dean, Simulation Education, Associate Professor of Emergency Critical Care Editors Objectives: Upon completion of this activity, you should be able to: (1) assess different Attending Physician, Emergency University of Florida COM- Medicine, Weill Medical College William J. Brady, MD William A. Knight IV, MD, FACEP Medicine, King Chulalongkorn Jacksonville, Jacksonville, FL of Cornell University, New York; Professor of Emergency Medicine Associate Professor of Emergency Memorial Hospital, Thai Red Cross, Gregory L. Henry, MD, FACEP Research Director, Department of and Medicine; Chair, Medical Medicine and Neurosurgery, Medical Thailand; Faculty of Medicine, Emergency Medicine, New York Emergency Response Committee; Clinical Professor, Department of Director, EM Midlevel Provider Chulalongkorn University, Thailand types of lower-extremity joint dislocations based on physical examination and radiographic Hospital Queens, Flushing, NY Medical Director, Emergency Emergency Medicine, University Program, Associate Medical Director, Stephen H. Thomas, MD, MPH Management, University of Virginia of Michigan Medical School; CEO, Ali S. Raja, MD, MBA, MPH Neuroscience ICU, University of Professor & Chair, Emergency Medical Center, Charlottesville, VA Medical Practice Risk Assessment, Vice-Chair, Emergency Medicine, Cincinnati, Cincinnati, OH Inc., Ann Arbor, MI Medicine, Hamad Medical Corp., Massachusetts General Hospital, Scott D. Weingart, MD, FCCM Calvin A. Brown III, MD Boston, MA Weill Cornell Medical College, Qatar; studies; (2) choose the most appropriate methods for reduction of dislocation, based on staff John M. Howell, MD, FACEP Associate Professor of Emergency Emergency Physician-in-Chief, Director of Physician Compliance, Clinical Professor of Emergency Robert L. Rogers, MD, FACEP, Medicine, Director, Division of ED Hamad General Hospital, Doha, Qatar Credentialing and Urgent Care Medicine, George Washington Services, Department of Emergency FAAEM, FACP Critical Care, Icahn School of Medicine University, Washington, DC; Director Edin Zelihic, MD Medicine, Brigham and Women's Assistant Professor of Emergency at Mount Sinai, New York, NY of Academic Affairs, Best Practices, Medicine, The University of Head, Department of Emergency resources and patient needs; and (3) describe the circumstances when it is necessary to Hospital, Boston, MA Inc, Inova Fairfax Hospital, Falls Maryland School of Medicine, Senior Research Editors Medicine, Leopoldina Hospital, Peter DeBlieux, MD Church, VA Baltimore, MD Schweinfurt, Germany James Damilini, PharmD, BCPS Professor of Clinical Medicine, Shkelzen Hoxhaj, MD, MPH, MBA Alfred Sacchetti, MD, FACEP Clinical Pharmacist, Emergency Interim Public Hospital Director Chief of Emergency Medicine, Baylor Assistant Clinical Professor, Room, St. Joseph’s Hospital and obtain specialist consultation for a lower-extremity dislocation. of Emergency Medicine Services, College of Medicine, Houston, TX Department of Emergency Medicine, Medical Center, Phoenix, AZ Louisiana State University Health Thomas Jefferson University, Science Center, New Orleans, LA Joseph D. Toscano, MD Philadelphia, PA Chairman, Department of Emergency Medicine, San Ramon Regional Medical Center, San Ramon, CA Discussion of Investigational Information: As part of the journal, faculty may be presenting investigational information about pharmaceutical products that is outside Food and Drug Administration–approved labeling. Information presented as part of this activity is intended solely as continuing medical education and is not intended to promote off-label use of any In upcoming issues of pharmaceutical product. Faculty Disclosure: It is the policy of EB Medicine to ensure objectivity, balance, independence, Emergency Medicine Practice.... transparency, and scientific rigor in all CME-sponsored educational activities. All faculty participating in the planning or implementation of a sponsored activity are expected to disclose to the audience any relevant financial relationships and to assist in resolving any conflict • Oncologic Emergencies of interest that may arise from the relationship. In compliance with all ACCME Essentials, Standards, and Guidelines, all faculty for this CME activity were asked to complete a full disclosure statement. The information received is as follows: Dr. Arnold, Dr. Fayos, Dr. • Jaundice Bruner, Dr. Arnold, Dr. Leber, Dr. Tainter, Dr. Mishler, Dr. Toscano, and their related parties report no significant financial interest or other relationship with the manufacturer(s) of any • Thermal Burns commercial product(s) discussed in this educational presentation. Dr. Jagoda made the following disclosures: Consultant, Daiichi Sankyo Inc; Consultant, Pfizer Inc; Consultant, • Emerging Infectious Diseases Banyan Biomarkers Inc; Consulting fees, EB Medicine. 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