Chapter 86. Hip Joint Dislocation Reduction

Hip dislocations are true orthopedic emergencies. The Emergency Physician (EP) must be capable of reducing a dislocated hip. Neurovascular damage to the hip and leg is a consequence of a hip dislocation. Avascular necrosis (AVN) may occur in up to 20% of patients with a hip dislocation. Other studies show that AVN following a hip dislocation is a time-dependent phenomenon. The longer a hip is dislocated, the higher the incidence of avascular necrosis. Dislocation of a hip for more than 6 hours almost universally results in this devastating complication.

The main etiologies of a hip dislocation are traumatic dislocations of a normal hip, mechanical dislocations of a prosthetic hip, spontaneous dislocations, and pathologic dislocations. Less impressive mechanisms may result in hip dislocations in the young and the elderly. A simple fall from standing may dislocate a geriatric hip. Dislocations may occur with minor force in children, as during athletic activities.

Many techniques have been described to reduce dislocated hips.1–7 The EP must be familiar with some of these methods and how to apply them appropriately to optimize patient management and outcome. Dislocations of both normal and prosthetic hips are seen in the Emergency Department. Dislocations of prosthetic hips are now more common than those of normal hips.8 While these are not associated with avascular necrosis, the pressure from the dislocated prosthetic head may result in other neurovascular complications.

Ball-and-socket joints are inherently stable. The strong muscles, ligaments, and fibrous joint capsule of the hip reinforce this innate stability. Consequently, in the average adult, a great deal of force must be transmitted to dislocate the hip. This is significant, as the patient with a hip dislocation may have other life-threatening injuries that take precedence over the management of the hip dislocation. The mortality associated with a hip dislocation results from associated injuries of the head, thorax, or pelvis.

Hip dislocations are classified into anterior, posterior, and central based upon the relationship of the dislocated femoral head to the acetabulum. Anterior hip dislocations occur with the leg in a neutral or abducted position. The femoral head is pushed anterior to the coronal plane of the acetabulum. These patients present in extreme pain with the hip and knee flexed 90°. The leg will be held in external rotation. A slight shortening of the leg may be noted, but this is difficult to detect with the knee in flexion. There are three subtypes of an anterior hip dislocation: anterior obturator, anterior iliac, and anterior pubic. The femoral head displaces medially and lies in the obturator canal in anterior obturator dislocations. The femoral head moves superiorly and lies over the iliac wing in anterior iliac dislocations. The femoral head moves inferiorly over the pubic ramus in anterior pubic dislocations.

Posterior hip dislocations are the most common type. They account for nearly 90% of all hip dislocations. This is because the posterolateral half of the femoral neck lies outside the joint capsule and the weaker posterior support of the hip. Posterior dislocations result from force transmitted along the femoral shaft with the leg adducted. The most common mechanism of injury is a motor vehicle collision where the knees strike the dashboard and the femoral head is pushed posterior to the coronal plane of the acetabulum. The presentation of a posterior dislocation is of a patient in extreme pain. The leg will be internally rotated with marked knee flexion and adduction of the thigh. The femoral head is rarely visible but may be palpable in the buttock region. Posterior hip dislocations are further categorized into posterior ischial and posterior iliac sub-types. The femoral head is displaced inferiorly and lies over the ischium in posterior ischial dislocations. The femoral head is displaced superiorly and lies over the iliac wing in posterior iliac dislocations.

Central hip dislocations are the rarest form. The femoral head remains on the same coronal plane as the acetabulum in central dislocations. However, it is displaced superiorly. Most central hip dislocations are associated with acetabular fractures.

All hip dislocations must be reduced. Emergent hip reduction by the EP is indicated when distal neurologic or vascular deficits are present or if the Orthopedic Surgeon is not immediately available. The incidence of avascular necrosis is time-dependent and necessitates reduction as soon as possible to limit this complication.

Any life-threatening conditions must be treated before the hip is reduced. Closed reduction is contraindicated if a surgical indication for repair exists. Surgical exploration is required for hip dislocations associated with femoral head fractures, femoral shaft fractures, or the finding of sciatic nerve dysfunction. Surgery is also indicated for an irreducible dislocation, persistent instability of the joint after closed reduction, and for any postreduction neurovascular deficits.

• Procedural sedation equipment and supplies (Chapter 129)
• Assistants
• Sheets

The patient must be appropriately stabilized with prioritization of the ABCs (airway, breathing, and circulation). Life-threatening associated injuries and comorbid conditions must be adequately addressed. Obtain plain radiographs to define the anatomic dislocation pattern, to rule out any associated fractures, and to guide relocation attempts.

Explain the risks, benefits, complications, and aftercare of the reduction procedure and obtain an informed consent from the patient and/or their representative. The patient must be sedated to achieve optimal muscle relaxation and pain control. Perform procedural sedation after obtaining a separate informed consent for this procedure.

Hip reduction techniques have been described with the patient in every imaginable position.1–9 The relative success rates for each technique have not been reliably reported.8 Therefore EPs typically use the technique(s) that was demonstrated to them during their residency training. The editor recommends using the Allis maneuver as the treatment of choice for the reduction of posterior hip dislocations. The other techniques are described in the text primarily for historical information, to give the reader full information regarding procedures that have been used and described for the reduction of this common problem, and as alternative techniques if the Allis maneuver is not successful in reducing the hip.

Allis Maneuver

This is the most common hip reduction method (Figure 86-1A). It was described by Allis in 1893.1 The technique has been improved by the addition of procedural sedation. Place the patient supine and perform procedural sedation. Instruct an assistant to stabilize the patients pelvis to the gurney by pressing down on the anterior superior iliac spines. It may be necessary for the assistant to use both hands on the side of the pelvis associated with the hip dislocation to stabilize the pelvis. Flex the affected knee and hip 90°. Grasp the affected knee with both hands. Apply axial traction to the thigh with incrementally increasing force. Simultaneously rotate the femur laterally and medially until the hip relocates.

If relocation is not easily accomplished, instruct a second assistant to apply lateral traction to the inner thigh of the affected proximal femur (Figure 86-1B). Repeat the entire procedure with the addition of lateral traction to reduce the dislocation.

Modified Allis Maneuver

This technique incorporates all of the maneuvers described above. Additionally, place the hip in maximum adduction. Apply longitudinal traction to the femur while an assistant presses down on the pelvis with one hand and pushes the head of the affected femur toward the acetabulum with the other hand.

Gravity Method of Stimson

Place the patient prone on the gurney. Perform procedural sedation. Monitoring may be more difficult due to the prone positioning. Extra attention must be paid to the patient's airway and breathing when placed prone. Associated injuries may preclude prone positioning of the patient.

Place the affected leg hanging over the side of the gurney with the knee and hip each flexed 90°. Alternatively, hang both legs off the distal edge of the gurney with the knees and hips flexed 90° (Figure 86-2A). Instruct an assistant to hold the patient down on the gurney by applying downward pressure on the posterior pelvis at the posterior superior iliac spines.

Grasp the ankle in one hand to support the limb and to be able to apply internal and external rotation to the extremity (Figure 86-2A). Place the other hand on the proximal posterior calf. Exert gradual longitudinal traction on the femur by placing pressure on the affected calf until the hip is felt to pop into place. A subtle internal and external rotary motion may help to move the femoral head over the acetabular rim. Care must be taken not to compress the structures in the popliteal fossa with excessive pressure behind the knee.

A much greater degree of force can be applied to the hip if the EP, instead of generating traction with their arm, places a knee in the affected popliteal fossa (Figure 86-2B). Pull the affected ankle upward while simultaneously exerting downward force on the calf to reduce the dislocation.

Whistler/Rochester/Tulsa Technique

This technique was described at three separate sites (Figure 86-3). Whistler Healthcare Center in Vancouver, Canada, described it in 1997.10 The Orthopedic Associates of Rochester described it in 1999. Vosburgh described it in 1995 as the “Tulsa method.”11 It is reported as being easier to implement than the other techniques and appropriate for use in the Emergency Department.10,11 Another advantage is that it can be performed without the aid of an assistant. Pelvic stabilization is provided by a counterforce on the uninjured knee. The force and counterforce occur through the same fulcrum and are therefore exactly equivalent.9

Place the patient supine. Perform procedural sedation. Stand to the side of the affected hip. Flex the unaffected knee 130°. Place your elbow under the affected knee, allowing the leg to dangle over your forearm. Reach to grasp the flexed unaffected knee with the palm. Grasp the affected ankle with your other hand in order to flex the knee and rotate the hip. The hold is now established (Figure 86-3).

Elevate the affected knee by raising your shoulder and using your arm as a lever (Figure 86-3(1)). Simultaneously apply a longitudinal force by progressively flexing the patient's knee over your arm (Figure 86-3(2)). This applies traction to the femoral head, moving it anteriorly and around the acetabular rim. Once the acetabular rim is cleared, externally rotate the leg to allow the femoral head to reduce (Figure 86-3(3)). External rotation is achieved by swinging the ankle laterally. A pop should be felt as the femoral head falls into the acetabulum. Reduction can be verified by internal and external rotation of the hip. An assistant may occasionally be required to stabilize the pelvis.

Fulcrum Technique

Lefkowitz described this technique in 1993 and Bergman described it in 1994.6 The advantage of this technique is that leverage allows greater reduction forces to be applied to the hip with less strength and effort on the part of the EP (Figure 86-4). A steady and constant force can easily be applied that reduces the risk of fractures and nerve injuries. This constant traction is superior to the sudden jerks that are inevitable in some of the other reduction techniques.6

Place the patient supine and perform procedural sedation. Secure the patient to the gurney with a sheet or use an assistant to stabilize the patient's pelvis. Lower the bed, preferably to within 2 to 3 feet of the floor. Stand on the side of the affected hip. Place one foot on the edge of the bed at the level of the patient's hip. A platform or footstool may be used to gain a mechanical advantage if the level of the bed is too high or you are too short.

Flex the affected knee 90° over your knee (Figure 86-4). Grasp and hold the affected ankle. Apply steady, gentle downward traction on the ankle to flex the knee while simultaneously plantarflexing your foot on the gurney. This will cause the knee to exert an upward force on the patient's knee, raising the femoral head around the edge of the acetabulum and reducing the hip. It may be necessary to gently rotate the affected foot internally and externally if the hip does not reduce easily.

Simple Longitudinal Traction

This technique is similar to the reduction of a shoulder dislocation (Figure 86-5). Place the patient supine and perform procedural sedation. Extend the affected lower extremity at the hip and knee. Wrap a sheet around the affected proximal thigh. Grasp the patient's ankle with both hands. Do not grasp the foot, as this can result in secondary injury. Instruct an assistant to apply lateral traction to the sheet and proximal thigh to move the femoral head over the acetabular rim while simultaneously exerting longitudinal traction to the leg by pulling on the patient's ankle to reduce the hip (Figure 86-5).

The editor prefers to use a padded leather restraint around the affected ankle. Wrap the two ties of the restraint around your hips and secure them with a knot. You can then slowly lean backward to allow your body weight to reduce the hip. This method is especially useful if you are small in stature or do not have significant upper body strength. Do not wrap the ties around your waist, as this can cause low back strain.

Bigelow Maneuver

Bigelow described this technique in the literature in 1870 (Figure 86-6). It was the first documented hip reduction technique. Perform procedural sedation. Place the patient supine with the affected hip and knee flexed 90°. Hold the affected knee in the crook of your flexed elbow with the patient's foot in the opposite hand (Figure 86-6A). Instruct an assistant to stabilize the pelvis by applying downward pressure to the anterior superior iliac spines. Lift your shoulder and arm supporting the patient's knee to apply distal traction to the femur (Figure 86-6A). Externally rotate and extend the hip while distracting the femur to reduce the hip (Figure 86-6B).

This is considered the “classic” reduction technique. Its disadvantages are that it requires great strength on the part of the EP to reduce the hip. The force applied is often jerking and inconsistent. The aid of a strong assistant is required to stabilize the pelvis.

Lateral Reduction Technique

This technique was described in 1986 by Skoff.8,12 It gives a mechanical advantage to the EP, as most of the force exerted is by the EPs own body weight (Figure 86-7). It also capitalizes on the principle of recreating the position of injury in order to exactly reverse the forces of the injury to produce the reduction.

Place the patient in the lateral decubitus position lying on the unaffected extremity. Perform procedural sedation. Flex the affected hip 100° and allow it to gravitate to adduction. This position recreates the typical position of the hip during the dislocation. Internally rotate the patients hip 45° while maintaining 45° of adduction to exaggerate the hip dislocation. Place a looped sheet around the patient's hips and an assistant's hips. Place a second looped sheet around the patient's knee and your own hips. The use of sheets allows optimal leverage by using body weight as the reduction force. Grasp the affected ankle to maintain the patient's knee flexed 90°. Apply distal traction to the femur by slowly leaning backward while the assistant simultaneously applies posteriorly directed countertraction to the femoral head. The assistant can use their hands to apply a distally directed force to the femoral head to assist in the reduction.

The appropriate evaluation of any dislocation requires a thorough pre- and postreduction neurologic and vascular examination of the distal extremity. Any neurologic or vascular deficits require immediate evaluation by an Orthopedic Surgeon. Obtain a postreduction radiograph to confirm the reduction and rule out any fractures missed on the initial radiographs or as a result of the reduction procedure. Monitor the patient until they recover from the procedural sedation. A computed tomography scan may help identify any acetabular or osteochondral fractures.

All patients with a hip dislocation require an evaluation by an Orthopedic Surgeon. All native hip dislocations and most prosthetic hip dislocations require hospitalization and traction after reduction.13

The complications of a hip dislocation itself are fractures, avascular necrosis of the femoral head, injury to the sciatic and femoral nerve, and injury to the femoral artery. Posttraumatic arthritis, recurrent dislocation, and myositis ossificans can also occur.13 Complications may occur despite the most expedient treatment, and prosthetic hip replacement may become necessary.

The complication of avascular necrosis is time-dependent. Reductions delayed over 6 hours are at an extreme risk for avascular necrosis. The risk of avascular necrosis increases as the time of the dislocation increases. Reductions that apply steady, non-jerking force to the limb have a lower incidence of associated fractures as well as fewer neurovascular complications. Multiple attempts at reduction are also associated with an increase risk of avascular necrosis. More than three attempts at closed reduction are associated with an increase risk of avascular necrosis and should prompt the EP to seek orthopedic consultation.14

Neurologic injury is one of the most common complications of hip dislocations, even when successful closed reduction is achieved. Sciatic neurapraxia, from peroneal branch damage, occurs in up to 15% of adult traumatic dislocations though symptoms resolve in 60% to 70% of cases.15 Sciatic dysfunction may lead to an equinus deformity and will need immediate consultation with an Orthopedic Surgeon.15

Multiple techniques exist to reduce hip dislocations. The EP should master one or two methods in order to provide essential care to these patients, limit complications, and enhance outcomes. The sooner a dislocated hip is reduced, the fewer the potential complications.