Imaging Studies and Other Tests
Imaging studies
Before reduction of the injury, obtain anteroposterior and lateral radiographs of the elbow (see the image below). If clinicians feel comfortable trying a reduction in the field, they may do so before obtaining radiographs; however, postreduction films should be obtained and the affected limb's neurovascular status should be documented pre- and postreduction.
Posterior and lateral dislocation of the left elbow in a soccer goalie. A small avulsion fracture of the olecranon is present.
Postreduction films are also necessary to ensure adequate reduction and to evaluate for fractures. The recreation of a normal radiocapitellar line (the line drawn through the shaft of the radius through the center of the capitellum) should be evident on all radiographic views.
Ultrasound is also used to diagnose elbow pathology by presenting real-time, high-resolution imaging of tendons, ligaments, and nerves. [13]
CT scanning may be useful in the evaluation for the full extent and location of fractures that may occur with a complex elbow dislocation.
MRI has little use in an acute elbow dislocation.
Associated soft-tissue injuries may be visualized by means of MRI. [14] A study that retrospectively analyzed and described patterns of ligamentous, tendinous, and muscular injuries in patients with acute elbow dislocation and subsequent MRI evaluation reported that injuries to the ulnar collateral ligament and the common flexor tendon were most common. Ligamentous injuries are often associated with elbow dislocation; however, large studies of MRI findings have proved difficult because of the costs of MRI. [15]
Other tests
A role may exist for angiography in the evaluation of a suspected associated arterial injury; however, if angiography would significantly delay vascular repair, the operating room may be a more appropriate setting for its use.
Procedures
Several methods for reducing a posterior elbow dislocation have been suggested. [1, 2, 3, 4, 16, 17, 18, 19, 20] Before reduction, adequate patient analgesia and sedation are necessary not only for patient comfort but also for the reduction. Radial head subluxations in children (ie, nursemaid's elbow) can generally be reduced without the need for sedation or analgesia. The 2 most commonly used techniques for the posterior dislocation are as follows:
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The author's preferred method is to place the patient in a prone position with the affected elbow flexed at 90° and the humerus supported by the table (see the image below). The hand of the affected arm should be pointing toward the ground. Apply downward traction to the forearm, which is held in slight pronation, while using the other hand to grasp the humerus, and apply pressure to the olecranon in a downward motion to facilitate reduction.
The preferred method for posterior elbow dislocation reduction is to lay the patient prone with the humerus supported by the exam table. Place one hand around the wrist of the affected arm and apply downward traction, while the other hand stabilizes the humerus and the thumb is placed over the olecranon, with gentle pressure applied to facilitate reduction.
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A second method involves the patient lying supine with the affected arm extended to the side in slight flexion. An assistant applies traction to the humerus toward the patient's body, while a second individual applies in-line traction to the forearm, the latter of which is held slightly flexed and supinated to facilitate reduction.
Perform anterior elbow dislocation reductions by grasping the humerus with 2 hands to apply countertraction, while an assistant provides in-line traction to the forearm. Orthopedic assistance may be beneficial given the infrequency of anterior dislocations.
Treat radial head subluxations in children by supporting the child's affected arm with your nondominant hand, with moderate pressure placed on the radial head. With your dominant hand on the child's wrist, apply gentle traction to the arm, and in 1 motion, supinate and fully flex the affected elbow. You can palpate for a click over the radial head with your nondominant hand.
Some studies have suggested that hyperpronation may be a more effective way to reduce the subluxation. [21] The hyperpronation method also may be attempted if a subluxation cannot be reduced by the more commonly used supination and flexion method.
Postreduction
Place the elbow through gentle ROM testing. ( NOTE: Extending the elbow beyond 20° from full extension may cause the elbow to redislocate and is not recommended.) Inability to move the elbow smoothly through ROM following reduction should raise the suspicion of a trapped medial epicondyle fracture. Reexamination for neurovascular integrity should take place postreduction, followed by follow-up elbow radiographs. The elbow joint is expected to be unstable following a dislocation. ( NOTE: Assessment for stability following reduction is likely to be painful for the patient and does not provide further information for the management of this condition.)
If near-full ROM is present in the affected elbow without associated fractures, the elbow may be splinted using a posterior splint, with the forearm in slight pronation and the elbow flexed at 90°.
If there are any concerns regarding potential neurovascular compromise or excessive swelling, or the risk of compartment syndrome exists, it would be beneficial to admit the patient to a hospital for a 24-hour period of observation following the injury.
For on-site reductions, such as at a game or in a training room where radiographs may not be readily available, a physician who feels comfortable reducing an elbow may do so, provided the physician performs and documents a complete neurovascular examination before and after the reduction. [4] Because of the high association of fractures with elbow dislocations, the patient should be advised to obtain radiographs of the elbow soon after the reduction.
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Posterior and lateral dislocation of the left elbow in a soccer goalie. A small avulsion fracture of the olecranon is present.
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The preferred method for posterior elbow dislocation reduction is to lay the patient prone with the humerus supported by the exam table. Place one hand around the wrist of the affected arm and apply downward traction, while the other hand stabilizes the humerus and the thumb is placed over the olecranon, with gentle pressure applied to facilitate reduction.
