Hip Dislocation Management in the ED 

Updated: Jan 07, 2022
Author: Stephen R McMillan, MD; Chief Editor: Barry E Brenner, MD, PhD, FACEP 

Overview

Practice Essentials

Traumatic dislocations of the hip are an orthopedic emergency. Although the diagnosis of common posterior hip dislocation is often straightforward, emergent diagnosis and reduction of the dislocation, especially in light of the multiply injured trauma patient, can be challenging. High-energy blunt force trauma is the most common cause, although prosthetic hip joints may dislocate with much less force. Multiple studies have shown that timely reduction plays a significant role in reducing later complications and associated comorbidity. As a result, routine screening for this injury has been adopted as part of the evaluation of trauma patients.[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Congenital dislocation of the hip also occurs and is termed developmental dysplasia of the hip (DDH). The annual incidence of DDH is approximately 2-4 cases per 1000 births; approximately 80-85% of affected individuals are girls. Routine screening for DDH includes the Barlow and Ortolani tests, with additional testing such as ultrasound for cases prompting concern.

The American College of Radiology published the following guidelines for DDH[11] :

  • Imaging is not recommended for the initial imaging of children younger than 4 wk with an equivocal physical examination or risk factors shown for DDH.
  • Ultrasonography (US) of the hips is usually appropriate for the initial imaging of children between the ages of 4 wk and 4 mo with an equivocal physical examination or risk factors shown for DDH.
  • US of the hips is usually appropriate for the initial imaging of children younger than 4 mo with physical findings of DDH at initial imaging.
  • Radiograph of the pelvis is usually appropriate for the initial imaging of children 4-6 mo of age with a concern for DDH at initial imaging.
  • Radiograph of the pelvis is usually appropriate for the initial imaging of children older than 6 mo with a concern for DDH.
  • US of the hips is usually appropriate for children younger than 6 mo with a known diagnosis of DDH during nonoperative surveillance imaging in harness.

A high index of suspicion for hip dislocation must be present whenever a patient who is involved in a major trauma such as a motor vehicle accident, a significant fall, or a sports-related injury is assessed.

Patients with a hip dislocation will be in severe pain. They may describe pain in the lower extremities, back pain, or pain in pelvic areas. Patients have difficulty moving the lower extremity on the affected side and may report numbness or paresthesias. Frequently, patients are victims of multiple trauma and may not pinpoint hip pain as a result of altered mental status or distracting injuries. Patients with a total hip replacement may present differently.

A proper neurovascular examination should be performed. If a neurovascular deficit exists, the need to reduce the dislocation is more urgent. Appropriate analgesia should be provided. If hemodynamic status permits, intravenous narcotics are usually indicated. Radiographs to detect hip pathology should be obtained. Computed tomography (CT) is an accurate test for diagnosing hip injuries except in patients with prosthetic hips; streak artifact obscures the image in these cases. Information obtained by CT can be used for emergency treatment and for long-term prognosis and management. 

Usually, 1 person applies traction and 1 or 2 people supply countertraction. A nurse or another physician provides sedation. More than 3 attempts at closed reduction in the emergency department (ED) is not recommended. 

Hip dislocation has been noted to be one of the most common complications of total hip arthroplasty.[7]

Pathophysiology

The hip is a modified ball-and-socket joint. The femoral head is situated deep within the acetabular socket, which is further enhanced by a cartilaginous labrum. The hip is bolstered by a fibrous joint capsule, the ischiofemoral ligament, and many strong muscles of the upper thigh and gluteal region. Because of this anatomic configuration, the hip is stable, as shown in the image below.

A normal anteroposterior (AP) pelvis radiograph. A normal anteroposterior (AP) pelvis radiograph.

Subsequently, a large force is required to dislocate the joint. Because a high-force mechanism is required, other life-threatening injuries and fractures are common.

Motor vehicle crashes account for two thirds of traumatic hip dislocations, but falls from a height are also a significant cause, whereas sports injuries are a less common cause.

Hip dislocations can be divided into simple and complex, with the latter having associated fractures. One study suggests that complex dislocations are associated with poorer functional and radiologic outcomes than simple dislocations. Researchers found a strong association between intra-articular fragments and osteoarthritis, so surgical fragment removal could be considered in these cases.[12]

The relationship of the femoral head to the acetabulum is used to classify the dislocation. The 3 main patterns are posterior, anterior, and central.

Posterior dislocation

Posterior dislocations constitute approximately 80-90% of hip dislocations caused by motor vehicle accidents. The femoral head is situated posterior to the acetabulum. During a motor vehicle crash, force is transmitted to the flexed hip in 1 of 2 ways. During rapid deceleration, the knees strike the dashboard and transmit force through the femur to the hip. If the leg is extended and the knee is locked, force can be transmitted from the floorboard though the entire lower and upper leg to the hip joint.

In evaluating posterior hip (femur) dislocation, the first question an examiner should ask is whether the patient has a native hip or a prosthetic hip joint, as the clinical approach varies significantly. Additionally, it is paramount to evaluate for associated injuries such as fractures, as this will also drastically alter management.[13]

(A posterior dislocation is shown in the image below.)

Right posterior hip dislocation in a young woman f Right posterior hip dislocation in a young woman following a high-speed motor vehicle collision (MVC).

Anterior dislocation

The femoral head is situated anterior to the acetabulum. An anterior dislocation is most commonly caused by a hyperextension force against an abducted leg that levers the femoral head out of the acetabulum. Less commonly, an anterior force against the posterior femoral neck or head can produce this dislocation pattern.

Anterior hip dislocations have been reported to account for approximately 5-10% of all hip dislocations. Of all anterior hip dislocations, inferior or obturator dislocations are more common, constituting approximately 70% of all anterior dislocations. Risk factors for closed reduction of anterior hip dislocation include preexisting osteopenia on plain films, age greater than 65 years, and radiographic femoral head impingement on the surrounding bony pelvis. In one study, the need for closed reduction of both anterior and posterior hip dislocations was noted to be urgent; this procedure should occur within 6 hours after the time of dislocation.[7]

Central dislocation

A central dislocation is always a fracture-dislocation. As shown in the image below, the femoral head lies medial to a fractured acetabulum. This is caused by a lateral force against an adducted femur, as is commonly seen in side-impact motor vehicle collisions.

(A central fracture-dislocation is shown in the image below.)

Fracture-dislocation of the right hip. The bony fr Fracture-dislocation of the right hip. The bony fragments are likely part of the acetabulum.

Epidemiology

Posterior hip dislocations are more common than anterior ones and account for almost 90% of hip dislocations. Their frequency has decreased with increased use of seat belts and air bags. Anterior dislocations and central fracture-dislocations account for less than 10% of hip dislocations.

Most studies have found that the incidence of dislocation after total hip arthroplasty (THA) is approximately 2-5%, with almost three quarters of these dislocations occurring in the first 6 weeks after surgery.[14]

Claims data for a large sample from a comprehensive health database in Taiwan illustrate several points regarding the epidemiology of hip dislocation[15] :

  • The hip was the most commonly dislocated joint of the lower extremity, with an incidence of 5.2%.

  • Closed reduction was achieved for more than 74% of the dislocations.

  • The incidence of recurrent dislocation was greater than 12%.

Another report indicates that the incidence of traumatic hip dislocation may be increasing due to larger numbers of high-speed motor vehicle accidents[16] —a phenomenon that may be repeated globally as larger populations gain access to motor vehicles.

Hip dislocation is more common among young males than among others because this injury is associated with risk-taking behavior.

In a study of sports-related hip injuries based on the sex and age of patients, the main diagnoses for males were labral tear (23.1%), avulsion fracture (11.5%), slipped capital femoral epiphysis (11.5%), dislocation (7.7%), and tendinitis (7.7%); and the main diagnoses for females were labral tear (59.0%), tendinitis (14.8%), snapping hip syndrome (6.6%), strain (4.9%), and bursitis (4.9%). The increase in hip injuries with advancing age was significantly greater among female than male athletes.[17]

Hip dislocation resulting from traumatic injuries (especially motor vehicle accidents) is more common in those younger than 35 years than in older people, whereas hip dislocation from a fall is more common in those older than 65 years.

Mortality/Morbidity

Hip dislocation is a marker for a high-force mechanism. Most mortality is the result of associated injuries. Life-threatening injuries to the pelvis, abdomen, chest, and head should be specifically sought out.

Long-term disability after hip dislocation is a significant risk. Up to 50% of patients will have limited use or chronic pain as a result of hip dislocation. Prognosis becomes worse with delayed diagnosis and management. Complications include deep venous thrombosis (DVT), sciatic nerve injury, avascular necrosis (AVN), vascular injury, recurrent dislocation, arthritis, and chronic pain.

Local venous injury and prolonged immobilization associated with hip dislocation lead to a significant incidence of deep venous thrombosis and potentially lethal pulmonary embolus in affected patients. If no contraindications are known, patients should receive DVT prophylaxis as part of the hospital and rehabilitation treatment.

Sciatic nerve injury is common, reportedly occurring in up to 19% of patients. The femoral head or bony fragments can stretch or tear the nerve as it passes posteriorly. Neurapraxia is generally transient or minor. Full recovery or recovery with only minor neurologic effects can be expected for most patients. Performing and documenting a brief neurologic examination before and after relocation is imperative.

Avascular necrosis of the femoral head (AVN) occurs in 2-17% of patients. This can occur with pure dislocation but is more common with fracture-dislocation of the femoral head. Numerous studies suggest that risk of AVN rises in proportion to time to relocation. In other words, the longer it takes to relocate a hip, the higher is the risk of AVN. Early relocation of a hip can make the difference between a healthy joint and a chronically disabled joint.

Vascular compromise is rare. With anterior dislocation, the femoral artery is at risk. Pulses and perfusion should be checked and documented before and after reduction. If a patient has vascular compromise, reducing the hip should not be delayed. If a patient has a persistent or new-onset perfusion deficit, open reduction and consultation with a vascular surgeon may be indicated.

Recurrent hip dislocation is uncommon compared to recurrent shoulder dislocation. Risk factors for recurrent hip dislocation include large capsular defects, intra-articular fragments, or a prosthetic hip.

Posttraumatic arthritis is the most frequent long-term complication following hip dislocation. It occurs in up to 16% of affected individuals and is often associated with lifelong gait disturbances and chronic pain. If an associated acetabular fracture is present, the incidence of traumatic arthritis can be as high as 80%.

Traumatic dislocation is accompanied by a variety of intra-articular hip joint pathologies. Managing posterior acetabular rim fracture after traumatic posterior hip dislocation by using arthroscopic reduction and fixation with anchors is a safe and minimally invasive option and delays the progression of traumatic osteoarthritis.[18]

Prognosis

The prognosis of the patient with a hip dislocation varies with type of dislocation, associated fractures of the femoral head or acetabulum, and the presence of other injuries. Overall, 50-93% of patients have good to excellent results.

The principal determinants of a poor prognosis are as follows:

  • AVN occurs in 4-21.8% of patients in some reviews, and in 8-13% in others. The incidence is increased with delay in reduction beyond 6 hours and with open reduction. The severity of AVN is increased in patients who undergo early weight bearing. AVN is a serious complication that usually requires replacement with a prosthetic hip.

  • Severe osteoarthritis occurs in at least 10% of patients and is more common among older patients. This seems to be an increased incidence compared to populations of a similar age without hip dislocation; some authors have found the incidence to range from 30 to 71% after open reduction.

  • Injury to the femoral or sciatic nerve usually consists of neurapraxia; eventual recovery of function can be expected in these cases. Permanent injury to these nerves can result in disabling deficits. If the patient has a neurologic deficit, surgery usually is not indicated. Electromyography can be useful in determining prognosis.

  • Recurrent dislocation is a complication if supporting ligaments have been disrupted.

 

Presentation

Physical

As with any victim of major trauma, assessment of airway, breathing, and circulation is of primary importance. During the secondary survey, examination of the pelvic girdle and hip is mandatory. Examination should consist of inspection, palpation, active/passive range of motion, and a neurovascular examination.

Inspection

Isolated anterior dislocation has a classic appearance, as does isolated posterior dislocation. In practice, appearances may be altered by the presence of fracture-dislocation or other bony abnormalities of the leg.

  • Posterior: The hip is flexed, internally rotated, and adducted.

  • Anterior: The hip is minimally flexed, externally rotated, and markedly abducted.

Palpation

Palpate the pelvis and the lower extremity for gross bony deformities or step-offs. With anterior hip dislocation, the femoral head occasionally can be palpated. A large hematoma may signify vascular injury.

Range of motion

Patients with hip dislocation have severely limited range of motion due to pain. Evaluate what the patient can do comfortably. Do not forcefully perform range of motion on a patient who cannot tolerate manipulation. Normal, painless range of motion virtually excludes hip dislocation.

Neurovascular examination

Signs of sciatic nerve injury include loss of sensation in the posterior leg and foot, loss of dorsiflexion (peroneal branch) or plantar flexion (tibial branch), and loss of deep tendon reflexes (DTRs) at the ankle.

Femoral nerve injury may be seen as loss of sensation over the thigh, weakness of the quadriceps, and loss of DTRs at the knee.

The patient with vascular injury may present with hematoma, loss of pulses, and pallor.

 

DDx

 

Workup

Imaging Studies

Identification and timely management of hip dislocation is highly dependent on imaging, both at presentation and after attempted reduction. It is imperative for the radiologist to understand imaging features that guide management of hip dislocation to ensure timely identification, characterization, and communication of clinically relevant results.[19]

Radiography

A portable anteroposterior (AP) radiograph of the pelvis is often ordered as part of an initial trauma workup and should include an image of the pelvis and hip. The presence of a hip dislocation can be subtle, but most should be detected upon careful inspection of the AP pelvis radiograph. Lateral views may be useful in further classifying the type of dislocation.

The position of the femoral head relative to the acetabulum should be symmetrical. The joint space should be examined for bony fragments, for widening, or for evidence of an effusion.

Both femoral heads should be roughly the same size. In a posterior dislocation, the femoral head may appear smaller than the contralateral side because it is farther away from the x-ray beam and is magnified less. The opposite is true of anterior dislocation.

The position of the trochanters in relation to the femoral shaft may reveal abnormal rotation.

Shenton’s line is a smooth curved line defined by the obturator foramen and the femoral metaphysis. If this line is disrupted, a hip fracture or dislocation or a femoral neck fracture should be suspected.

The film must be thoroughly inspected for associated fractures.

If the AP pelvis film is nondiagnostic and a high index of suspicion exists, a lateral hip film, dedicated hip films, Judet views, or computed tomography (CT) scan may be indicated.[5]

Radiography should be the initial imaging study in patients with suspected AVN.[20]

The image below is a routine AP pelvis film obtained from a patient who experienced a multiple rollover motor vehicle crash. It demonstrates that sometimes radiographic findings can be subtle.

Portable AP pelvis with subtle presentation of rig Portable AP pelvis with subtle presentation of right posterior hip dislocation. Abnormal rotation is present, and the right femoral head appears smaller, indicating that it is further away.

CT scan

Computed tomography (CT) is an accurate test for diagnosing hip injuries, except in patients with prosthetic hips, for whom streak artifact obscures the image. CT accurately delineates the type of dislocation as well as any accompanying fractures (as shown in the image below). CT scans of the pelvis are routinely obtained for patients with major trauma. Information obtained on CT can be used for emergency treatment and for long-term prognosis and management. If a CT scan is performed to evaluate the abdomen and pelvis, the hip should be examined for pathology. However, a dedicated hip CT scan should not delay reduction. After the hip is reduced, a CT scan of the hip will provide information to the orthopedist that is valuable for further surgical or conservative management.

In a series of adolescents after posterior hip dislocation, CT identified all bone injuries but underestimated the involvement of posterior wall fractures. Posterior wall size and fracture displacement could be assessed with magnetic resonance imaging (MRI). All soft tissue injuries that were confirmed at surgery, including avulsion of the posterior labrum, were identified preoperatively on MRI.[6]

Posterior dislocation of right hip with acetabular Posterior dislocation of right hip with acetabular fracture.

MRI

Magnetic resonance imaging (MRI) has a limited role in acute diagnosis and delineation of hip dislocation. Patients with multiple trauma are often unstable and cannot undergo MRI, which is time consuming and is often unavailable. Once the patient's condition has stabilized and the hip has been reduced, MRI can provide valuable information about long-term management and prognosis.[6]  MRI 2-3 months after reduction can verify proper location and can be used to screen for complications, such as avascular necrosis (AVN), osteoarthritis, and heterotopic calcification, at an early stage.

Intra-articular injuries and loose bodies are common among adolescent and young adult patients undergoing arthroscopy after traumatic hip dislocation. In a study of 12 hips in 12 patients (8 males, 4 females; mean age, 16.3 yr; range, 11-25 yr), loose bodies were identified in 6 of 12 patients (50%) on preoperative imaging and in 8 of 12 patients (67%) at arthroscopy. The 2 patients with unidentified loose bodies on imaging did not undergo preoperative MRI. CT was performed in 11 patients and MRI in 4, and in 3 patients both CT and MRI were conducted.[5]

Radionuclide scanning is a sensitive method for depicting AVN, although MRI has greater sensitivity and specificity.[20]

ACR guidelines for DDH

The American College of Radiology (ACR) published the following imaging guidelines for DDH[11] ​:

  • Imaging is not recommended for the initial imaging of children younger than 4 wk with an equivocal physical examination or risk factors shown for DDH.
  • Ultrasonography (US) of the hips is usually appropriate for the initial imaging of children between the ages of 4 wk and 4 mo with an equivocal physical examination or risk factors shown for DDH.
  • US of the hips is usually appropriate for the initial imaging of children younger than 4 mo with physical findings of DDH at initial imaging.
  • Radiograph of the pelvis is usually appropriate for the initial imaging of children 4-6 mo of age with a concern for DDH at initial imaging.
  • Radiograph of the pelvis is usually appropriate for the initial imaging of children older than 6 mo with a concern for DDH.
  • US of the hips is usually appropriate for children younger than 6 mo with a known diagnosis of DDH during nonoperative surveillance imaging in harness.

Procedures

Although data comparing specific techniques are limited, the individual success rates of most maneuvers range from 60-90%. Each technique has distinct advantages and limitations associated with its use. It is important for emergency physicians to be familiar with several different reduction techniques in case the initial reduction attempt is unsuccessful, or patient characteristics limit the use of certain maneuvers.[21]

Particular attention should be taken when reducing hip dislocation in the adolescent population, who may be predisposed to epiphysiolysis (separation of the epiphysis from the bone shaft caused by excessive strain on the proximal humeral growth plate). Preservation of periosteal soft tissue attachments and the use of small-diameter drill holes to promote femoral head blood flow may contribute to optimal patient outcomes.[22]

Reduction techniques for posterior dislocation

Allis method 

With the Allis method, the patient is supine and is under procedural sedation. The combined weight of the patient and the physician may exceed the weight limit of the stretcher. It is generally unsafe for the physician to be standing on a stretcher. For these reasons, placing the patient on the floor rather than on the stretcher is most useful.[1, 23]

An assistant should stabilize the pelvis. At first, the physician should be facing toward the patient’s feet, providing in-line traction. The physician then should gently flex the hip 60-90º while maintaining in-line traction. At this point, the physician is standing directly above the patient’s hip, providing traction in-line with the deformity.

Gently adducting the hip can force the head of the femur laterally and can help it clear the acetabular rim. Alternatively, gentle lateral traction can be applied to the proximal femur.

Reduction can be confirmed by a click that is felt and may be heard as well. The patient should assume a normal anatomic position.

Captain Morgan technique 

Another reduction technique for posterior dislocation is Captain Morgan, which is a modification of the technique reported by Lefkowitz.[24] Its name is derived from the resemblance of this position to the pose of the captain on the logo of a popular commercially available rum.[25]

With this technique, the patient is placed supine (with the suggestion that the patient be on a backboard with the pelvic strap retained) with the injured side knee flexed to 90º. The physician stands on the ipsilateral side facing across the stretcher and places a foot upon the stretcher (or backboard) with the knee under the ipsilateral knee of the patient. The physician then places 1 hand behind the knee and stabilizes the other by holding the ipsilateral ankle. Traction force is generated when the physician lifts with the hand behind the knee and plantar flexes the foot that is under the knee. Rotational and abduction/adduction forces can be applied to facilitate the maneuver if necessary.

When this technique is used, care must be taken to prevent use of the knee as a fulcrum because ligamentous disruption of the knee can occur.[26]

East Baltimore lift 

With the East Baltimore lift,[27]  the patient is placed supine, with the physician on the ipsilateral side of injury and an assistant facing the physician across the table. The physician gently flexes the leg so the hip and the knee are in approximately 90º of flexion; then the physician faces the assistant and places 1 hand on the ankle, while crossing the other arm under the proximal calf to place the hand on the assistant’s shoulder, cradling the flexed knee at the elbow. The assistant or a second assistant then braces the pelvis, while the physician and the first assistant squat slightly, bending at the knees; upon rising, they apply gentle, controlled traction to the femur, while the physician manipulates the ankle, allowing rotational control of the hip to facilitate reduction.

Stimson method 

The Stimson method is mechanically the same as the Allis method, but positioning is done in the opposite way.[1, 23] Although some physicians prefer this method because of its technical ease and high success rate, it is associated with some important disadvantages. This method requires the patient to be in a prone position, which may not be possible for the patient with multiple trauma. Also, monitoring the patient during procedural sedation may be difficult.

The prone patient is placed so the pelvis on the affected side hangs over the end or over the side of the stretcher. The hip and the knee are flexed to 90º. Downward pressure is applied to the popliteal fossa, providing traction in-line with the deformity. An assistant stabilizes the pelvis and the trunk, which prevents the patient from being pulled off the stretcher.

Whistler technique 

With the Whistler technique, the patient is placed supine with the ipsilateral knee flexed to 120º. The physician stands on the affected side and places an arm under the ipsilateral knee, while resting the hand on the contralateral knee. The pelvis and the ankle are stabilized by an assistant or by the physician’s free hand. Upon raising his or her arm, the physician applies an anterior force to the knee and subsequently to the affected hip.[1]

Reduction technique for anterior dislocation

Modified Allis technique

With this technique, the patient is placed supine. The physician stands at the foot of the stretcher and applies traction to a neutral hip, while an assistant stabilizes the pelvis. Gentle lateral traction applied to the proximal femur forces the femoral head laterally, clearing the acetabular rim.[1]

 

Treatment

Emergency Department Care

When hip dislocation occurs, patients often have life-threatening injuries that take precedence. Once life-threatening injuries have been stabilized or ruled out, the hip dislocation can be addressed. A proper neurovascular examination should be performed. If a neurovascular deficit exists, there is even more urgency to reduce the dislocation.

Appropriate analgesia should be provided. If hemodynamic status permits, intravenous narcotics are usually indicated.

Radiographs should be obtained to detect hip pathology.

Reduction is greatly facilitated by the use of procedural sedation. Unless sufficient sedation and muscle relaxation are achieved, attempts at relocation are futile. A variety of medications may be used for this purpose, depending on physician preference and hospital protocol. A combination of agents with muscle relaxant and analgesic properties is optimal. The patient should be appropriately monitored during procedural sedation according to institutional protocol.

Simple hip dislocation without associated fracture is within the practice scope of most emergency physicians. Consider orthopedic consultation if this will not delay relocation beyond a reasonable length of time—usually within 6 hours.

Once procedural sedation has been achieved, the hip may be reduced by one of the preceding methods. Reducing a hip usually requires significant space and resources. Usually, 1 person applies traction and 1 or 2 people supply countertraction. A nurse or another physician can provide sedation. More than 3 attempts at closed reduction in the ED is not recommended. The incidence of AVN is increased with multiple attempts. If the dislocation cannot be reduced, an emergent CT scan is indicated to visualize any bony or soft tissue fragments that may hinder reduction. Closed reduction may be attempted in the operating room with the patient under general anesthesia. However, a majority of these patients will require open reduction.

Fracture-dislocation or concomitant fracture of the femoral neck usually requires the expertise of an orthopedic specialist. Practice styles vary widely. Some orthopedists make an attempt at closed reduction, whereas others immediately perform an open reduction if a fracture-dislocation exists.

After closed reduction, placement should be confirmed with a repeat radiograph. A repeat neurovascular examination should be performed and documented as well. CT scan or MRI of the hip can provide valuable information about further treatment and prognosis.

If relocation of the hip is successful, immobilize the legs in slight abduction by using a pad between the legs to prevent adduction until skeletal traction can be instituted.

After reduction, patients with hip dislocation should be admitted to the hospital. Patients will be nonambulatory and will require a great deal of supportive care. Pain will be significant, even after reduction, and patients may require parenteral narcotics.

The duration of traction and of non–weight-bearing immobilization is controversial. Evidence suggests that early weight bearing (eg, 2 weeks after relocation) may increase the severity of aseptic necrosis when it occurs. However, early weight bearing decreases the incidence of other complications (eg, venous thromboembolism, decubiti), and some studies have found equivalent outcomes with early and delayed weight bearing.

Once stabilized, a patient with multiple trauma may be transferred. A patient with an isolated hip dislocation may be transferred if no neurovascular deficit is suspected, and if transfer time does not extend dislocation time by longer than 6 hours. In general, hip dislocations are reduced at the receiving facility and, if necessary, the patient is transferred for ongoing inpatient care with appropriate immobilization en route.

Indications for open reduction

Indications for open reduction include the following:

  • Irreducible dislocation (approximately 10% of all dislocations).

  • Persistent instability of the joint following reduction (eg, fracture-dislocation of the posterior acetabulum).

  • Fracture of the femoral head or shaft.

  • Neurovascular deficits that occur after closed reduction.

An orthopedic surgeon and/or a trauma surgeon should be consulted.

Follow-up

Various techniques can be used to accomplish open reduction, acetabular repair, and fixation of associated fractures.

After the hip dislocation is reduced, obtain repeat AP and lateral radiographs of the hip to verify proper reduction.

After open or closed reduction of a hip dislocation, the patient is instructed to remain on bed rest with legs abducted and with skeletal traction designed to keep the hip from displacing posteriorly.

The duration of traction is approximately 2 weeks, but the recommended period with no weight bearing is controversial and varies from 9 days to 3 months.

Complications

AVN of the hip

Avascular necrosis (AVN) is common, occurring in 8-13% of patients.

Early diagnosis and treatment of dislocation decreases the incidence of AVN.

The effect of early weight bearing on the occurrence of AVN is controversial. Most studies have shown that early weight bearing after reduction is associated with more severe AVN but does not appear to increase the incidence.

The incidence of AVN is increased with delayed reduction, repeated attempts at reduction, and open reduction (40% vs 15.5% with closed reduction). This finding may be due to operative trauma or to the fact that dislocations requiring surgery are inherently more severe.

AVN may not become apparent on plain radiographs for several months. Early diagnosis can be made with MRI or nuclear scanning; these modalities should be considered for a patient who develops late and persistent pain after a dislocation.

Sciatic nerve injury (posterior dislocation)

Injury to the sciatic nerve during the initial trauma or during relocation occurs in 10-14% of patients with posterior dislocation.

Function of the sciatic nerve should be verified before and after relocation to detect this complication. The finding of sciatic nerve dysfunction mandates surgical exploration to release or repair the nerve.

Femoral nerve injury

Anterior dislocation is occasionally associated with injury to the femoral artery or nerve.

Dislocation in children can occur with relatively minor trauma (eg, sports activities); reduction must be gentle to avoid iatrogenic injury to the femoral epiphysis (eg, slipped capital femoral epiphysis).

Other complications

Other complications of hip dislocation include the following:

  • Osteoarthritis.

  • Heterotopic calcification.

  • Recurrent dislocation.

  • Ligamentous injury of the knee, other fractures.

  • Complications of immobilization (DVT, pulmonary embolus, decubiti, pneumonia).

  • Femoral artery injury (in anterior dislocation).

 

Guidelines

Clinical Practice Guidelines

The American College of Radiology published the following guidelines for DDH[11] :

  • Imaging is not recommended for the initial imaging of children younger than 4 wk with an equivocal physical examination or risk factors shown for DDH.
  • Ultrasonography (US) of the hips is usually appropriate for the initial imaging of children between the ages of 4 wk and 4 mo with an equivocal physical examination or risk factors shown for DDH.
  • US of the hips is usually appropriate for the initial imaging of children younger than 4 mo with physical findings of DDH at initial imaging.
  • Radiograph of the pelvis is usually appropriate for the initial imaging of children 4-6 mo of age with a concern for DDH at initial imaging.
  • Radiograph of the pelvis is usually appropriate for the initial imaging of children older than 6 mo with a concern for DDH.
  • US of the hips is usually appropriate for children younger than 6 mo with a known diagnosis of DDH during nonoperative surveillance imaging in harness.
 

Medication

Medication Summary

Administer adequate parenteral analgesia. The emergency physician, the consultant, and the patient must decide on the most appropriate type and place for reduction: open versus closed and emergency department versus operating room.

If closed reduction is attempted in the ED, procedural sedation is required. Procedural sedation policies should be established to define who can administer medication, who must monitor the patient, which classes and doses of procedural sedation medications should be used, and what resources should be kept on hand for resuscitation.

In addition to airway protection and rescue, procedural sedation goals must include pain relief, muscle relaxation, and procedure amnesia.

General anesthesia in the operating room may be required for patients with dislocations that are irreducible by closed means and for those with significant associated fractures, central dislocation, or associated neurovascular injury.

Analgesics

Class Summary

Pain control is essential for good-quality patient care. It ensures patient comfort, promotes pulmonary toilet, and aids physical therapy regimens. The analgesic must have rapid onset and predictable action and must be easily titratable.

Morphine sulfate (Duramorph, MS Contin, MSIR)

Drug of choice (DOC) for analgesia because of reliable and predictable effects, good safety profile, and ease of reversibility with naloxone.

Various IV doses are used; commonly titrated until desired effect is obtained.

Fentanyl citrate (Duragesic, Sublimaze)

More potent narcotic analgesic with shorter half-life than morphine sulfate. Suitable for procedural sedation analgesia. Excellent choice for pain management and sedation; short duration (30-60 min) and easy to titrate. Easily and quickly reversed by naloxone.

Meperidine (Demerol)

Narcotic analgesic with multiple actions similar to those of morphine. May produce less constipation, smooth muscle spasm, and depression of cough reflex than similar analgesic doses of morphine.

Sedative hypnotics

Class Summary

These agents should be used for procedural sedation with rapid onset and short duration.

Propofol (Diprivan)

Phenolic compound; sedative-hypnotic agent used for induction and maintenance of anesthesia or sedation; anticonvulsant properties.

Anxiolytics

Class Summary

Patients with painful injuries usually experience significant anxiety. Anxiolytics allow the clinician to administer a decreased dose of an analgesic while achieving the same effect.

Diazepam (Valium)

Increasing the activity of GABA, a major inhibitory neurotransmitter, depresses all levels of CNS, including limbic and reticular formation. Dose should be individualized and increased cautiously to avoid adverse effects.

Lorazepam (Ativan)

Sedative-hypnotic in benzodiazepine class that has a short onset of effect and a relatively long half-life. Increasing the activity of GABA, a major inhibitory neurotransmitter, may depress all levels of CNS, including limbic and reticular formation. Excellent medication when patient needs to be sedated longer than 24 hours.