Chapter 79. Basic Principles of Fracture and Joint Reductions

Orthopedic injuries are some of the most common presenting complaints facing the Emergency Physician (EP). Forces that cause injury can be large enough to result in fractures, displaced fractures, and joint dislocations. While each injury is different, some general principles can be applied to all displaced fractures and joint dislocations. For specific instructions on the techniques to reduce common fractures and dislocations, please refer to Chapters 80 through 91.

The most common reason for a fracture to be displaced or a joint to be dislocated in a particular direction is the mechanism of injury. In the upper extremity, for example, a fall forward on an outstretched arm is the most common mechanism. Therefore, elbow dislocations occur most frequently in a posterior direction, distal radius fractures are most often Colles fractures, and supracondylar fractures are extension type fractures in 95% of cases.1

The deforming forces of muscles and ligaments also play an important role in the appearance of a fracture. Injury results in the muscles surrounding a fracture to contract or spasm. This leads to further deformity such as shortening, angulation, and rotation of the bone fragments distal and proximal to the fracture. For example, depending on the location of a humeral shaft fracture, the bone fragments will displace in different directions (Figure 79-1). Fractures that occur between the insertions of the pectoralis major and deltoid muscles will result in a proximal humerus that is adducted from contraction of the pectoralis major muscle and a distal humerus that is abducted from contraction of the deltoid muscle (Figure 79-1A). Conversely, if the fracture occurs distal to the deltoid insertion, the proximal humerus will be abducted from contraction of the deltoid muscle and the distal humerus will be adducted from contraction of the biceps and triceps muscles (Figure 79-1B).

The reduction of fractures and joint dislocations in the Emergency Department (ED) is more frequently indicated than it is not. Reduction is more readily achieved if it occurs soon after an injury. No fracture benefits from a prolonged period of angulation or displacement because the reduction becomes more difficult the longer the fracture has been present. No joint benefits from a prolonged dislocation as damage to articular cartilage increases with time.

Reduction should occur on an emergent basis when perfusion to the extremity is absent. A nonperfused extremity has a finite period of time before nerve and muscle death occur. For this reason, reduction should occur as soon as possible. The earlier perfusion is restored, the better the chance of avoiding tissue necrosis.

Vascular injury can occur after any displaced fracture or dislocation. The EP should note the presence of an expanding hematoma, absent distal pulses, or delayed capillary refill. Some examples of orthopedic injuries more commonly associated with vascular injury include knee dislocations, posterior sternoclavicular joint dislocations, and supracondylar fractures. The importance of early reduction and repair of vascular injuries is emphasized in the case of a knee dislocation. If surgery is delayed more than 8 hours, up to 86% of patients will require an amputation.2

Not all displaced fractures and dislocations suspected of causing vascular injury should be reduced by the EP. When vascular injury is suspected in a patient with a posterior sternoclavicular joint dislocation, for example, reduction is best performed in the operating room with a cardiothoracic surgeon available because the distal clavicle may be tamponading a lacerated subclavian vessel.3 In a similar manner, supracondylar fractures require immediate reduction only when the extremity is pulseless and perfusion is absent.4

Urgent reduction of displaced fractures and joint dislocations is also indicated to reduce the incidence of other potential complications. The incidence of compartment syndrome of the forearm is reduced by early reduction of displaced supracondylar fractures.5 Likewise, a posterior hip dislocation should be reduced in a timely manner. The likelihood of avascular necrosis rises exponentially from a rate of 5% with less than 6 hours of being dislocated to 50% with greater than 6 hours of being dislocated.6

Neurologic injury results from the original injury, traction on a nerve, or compression of a nerve. Patients may experience altered sensation, decreased sensation, and/or paresthesias. These injuries require urgent reduction to decrease potential long-term complications.

Despite the potential advantages of early reduction of fractures and dislocations in the ED, the EP should be aware of potential relative and absolute contraindications. Chronic or previously unrecognized dislocations are difficult to reduce in a closed manner and overly forceful attempts increase the chances of causing a fracture. An example is a surgical neck of the humerus fracture in a patient when attempting to reduce a chronic shoulder dislocation. Reduction in the ED is contraindicated when the patient requires immediate operative treatment. An open fracture in a perfused extremity should be reduced in the operating room where an appropriate surgical washout can occur.

Reduction is unnecessary when the potential for remodeling is such that the fracture angulation will correct without the need of a painful reduction or the risk of procedural sedation. For example, distal radius fractures in children have been shown to heal well even when they are 15° to 20° angulated.7–10 Other fractures where some degree of displacement or angulation may be acceptable and frequently do not require reduction include the clavicle, humeral shaft, and neck of the fifth metacarpal.1,11–17

Reduction may be contraindicated in the ED for numerous other reasons. Adequate analgesia may not be possible due to the patient's medical condition or the inability to appropriately monitor the patient. These cases may require general anesthesia in the operating room. It is prudent to consult and wait for an Orthopedic Surgeon when the potential complications of a reduction attempt are high or the EP is uncomfortable performing the technique. A busy EP in a chaotic ED with single coverage may not have the time or resources to adequately sedate a patient and reduce the fracture or dislocation. This situation may require calling in an additional EP or an Orthopedic Surgeon to assist.

• Procedural sedation equipment and supplies (Chapter 129), if applicable
• Hematoma block supplies (Chapter 125), if applicable
• Regional nerve block supplies (Chapter 126), if applicable
• Stretcher
• Weights for distraction
• Bed sheets for traction–countertraction techniques
• Splinting/casting material or commercially made splints (e.g., knee immobilizer)
• Finger traps for upper extremity reductions
• Fluoroscopy, if available, to assist with the reduction and postreduction radiographs
• Assistants depending on the reduction technique

Reduction techniques require a well-informed patient and a signed consent if possible. Explain the risks, benefits, and alternatives to the patient and/or their representative. Tell the patient what to expect. This knowledge may actually assist in the successful performance of the procedure. Anterior shoulder dislocation reduction, for example, can be performed with minimal or no sedation if the patient is able and willing to relax their musculature while the EP slowly manipulates the humeral head back into position.18 The patient should also be consented for the anesthesia technique as this is a second procedure with potential complications much different from the reduction.

The physical preparation of a patient for the reduction of a fracture or dislocation is dependent on the type of injury and the clinical setting. In general, the patient should be resting as comfortably as possible on a gurney. The patient should be supine whenever possible. Fully expose the involved extremity. Remove any constricting pieces of clothing or jewelry both proximal and distal to the injury. If fluoroscopy is judged to be useful and it is available it should be moved into position. Frequently splint material is measured and set up prior to the start of the procedure so that it may be immediately applied to the extremity in the setting of an unstable fracture or dislocation.

The basic principles to reduce a displaced fracture or a joint dislocation are similar. The procedure can be divided into four steps.19 These are distraction, disengagement, reapposition, and release. The four steps can be used to reduce most, but not all, displaced fractures or joint dislocations.

The first step is distraction. It involves creating a longitudinal force to pull the fracture fragments or bones involved with a dislocated joint apart. This step should be performed gradually and sometimes requires time to be most effective in overcoming muscle spasm. Distraction is important when the fractured ends of the bone are overriding. It can be applied manually with the help of an assistant or by using weights.

To reduce a distal radius fracture, for example, one common technique to distract the injury uses finger traps to hold the hand in place while weights are wrapped around the arm (Figure 79-2). Saline bags placed in stockinette are equally effective and comfortable for the patient when weights are not available (Figure 79-3). Each liter bag of saline is equivalent to 1 kg or 2.2 pounds.

Disengagement is the second step to reduction. It allows for further disimpaction of the fracture fragments than distraction alone. Disengagement can be achieved by rotation of the distal fragment or more classically by “recreating the fracture deformity.” It relieves tension on the surrounding soft tissues to allow the interlocking fracture fragments to reposition (Figure 79-4).

Disengagement is also important for dislocation reduction. It is most frequently achieved by rotation of the bone distal to the joint. An example is the external rotation technique to reduce an anterior shoulder dislocation.

The third step is reapposition. This is achieved by reversing the forces that caused the injury to bring the bony fragments back into alignment (Figure 79-5). While this step seems simple conceptually, it may not be as easy in clinical practice. One important pitfall to avoid is ignoring a rotational deformity that might create functional problems if the bone healed with a rotational deformity. This is especially important when treating fractures of the hand where a 5° rotational deformity of a proximal metacarpal fracture can translate into a distal fingertip that is 1.5 cm out of position20 (Figure 79-6).

Release refers to the removal of the initial distracting force with the intent that alignment will be maintained. It is at this point that forces such as muscle contraction and gravity return and the fracture fragments are at risk for becoming malaligned again. A properly applied splint or cast can protect from loss of fracture alignment. It is advisable to have the splint measured and ready to apply before manual reduction is initiated.

There are frequently alternative techniques or variations of the four steps outlined above that are available to the EP depending upon the circumstance or the success of previous attempts. If the initial technique is unsuccessful, then the next maneuver is attempted and so on. The author uses the following sequence of maneuvers to reduce an anterior shoulder dislocation: scapular manipulation with downward arm traction (disengagement and distraction), then external rotation (disengagement), followed by the Milch technique (disengagement), and finally traction–countertraction (distraction).18,21–24 The astute EP should also be aware of the limitations of the closed reduction technique. If soft tissue is interposed in an interphalangeal finger dislocation, for example, no amount of distraction or an alternative technique will reduce the dislocation without taking the patient to the operating room.

The neurovascular status of the extremity must be assessed to ensure that pulses are present, the extremity is perfusing, and that nerve function has not been compromised before and after any reduction attempt. It should also be assessed after any casting or splinting to the extremity. Postreduction radiographs are taken to assess the success of the reduction, look for any fractures that may have been missed on the prereduction radiographs, and assess any complications from the reduction.

Immobilize the extremity as required for the specific fracture or dislocation. A record of the procedure should be placed in the chart including any complications and the method of reduction. The patient should undergo repeat plain radiography in most cases to document the success of the reduction. Patients with reduced fractures and dislocations should be referred to an Orthopedic Surgeon. Occasionally, a fracture that is properly reduced and immobilized will be unstable and become displaced again, frequently necessitating operative fixation.

When performed properly, complications of fracture and dislocation reduction are uncommon. However, even with proper techniques, complications can occur. These include converting a closed fracture to an open fracture, soft tissue trauma that produces a compartment syndrome, a reduction attempt that causes injury to the soft tissues making the fracture more unstable, producing a fracture during the dislocation reduction attempt by using excessive force, or neurovascular injury/compromise due to bony laceration, or compression of a nerve or blood vessel.

Displaced fractures and joint dislocations requiring reduction are commonly seen in the ED. As the EP approaches these injuries, the initial step in assessment should be determining the neurovascular status of the extremity. When vascular compromise is present, emergent reduction is the rule with few exceptions. While all dislocations require reduction, not all displaced fractures necessitate reduction. The EP should be familiar with which displaced fractures benefit from reduction. When fracture reduction is indicated, the basic elements of the procedure are distraction, disengagement, reapposition, and release.