injuries poisoning
Overview of Dislocations
Evaluation of Dislocations
Evaluation for serious injuries History and physical examination X-rays Sometimes MRI or CT Sometimes a dislocation is clinically obvious, but in other cases (eg, a shoulder deformity in an adolescent), dislocations must be distinguished from fractures and other injuries. In the emergency department, if the mechanism of injury suggests potentially severe or multiple injuries (as in a high-speed motor vehicle crash or fall from a height), patients are first evaluated from head to toe for serious injuries to all organ systems and, if needed, are resuscitated (see Approach to the Trauma Patient ). Patients, especially if a hip dislocation is suspected, are evaluated for Patients should be checked for fractures and other musculoskeletal injuries as well as dislocations; sometimes parts of this evaluation are deferred until fracture is excluded. The joint above and below the dislocated joint should also be examined. Some dislocations can be diagnosed clinically, but x-rays are usually still taken. The mechanism (eg, the direction and magnitude of force) may suggest the type of injury. However, many patients do not remember or cannot describe the exact mechanism. If a patient reports a deformity that has resolved before the patient is medically evaluated, the deformity should be assumed to be a true deformity that spontaneously reduced. Examination includes Vascular and neurologic assessment Inspection for open wounds, deformity, swelling, ecchymoses, and decreased or abnormal motion Palpation for tenderness, crepitation, and gross defects in bone or tendon Examination of the joints above and below the injured area Sometimes for subluxations, stress testing of the affected joints for instability If muscle spasm and pain limit physical examination (particularly for stress testing), examination is sometimes easier after the patient is given a systemic analgesic or local anesthetic. Or the injury can be immobilized until muscle spasm subsides, usually for a few days, and then the patient can be reexamined. Certain findings may indicate a dislocation or another musculoskeletal injury. If awoundis near a dislocation, the dislocation is assumed to be open. Deformitymay indicate dislocation or subluxation (partial separation of bones in a joint), but it may also indicate fracture. Swellingcommonly indicates a significant musculoskeletal injury but may require several hours to develop. Tendernessaccompanies nearly all musculoskeletal injuries, and for many patients, palpation anywhere around the injured area causes discomfort. Gross joint instabilitysuggests dislocation or severe ligamentous disruption. Stress testing None If muscle spasm is severe despite use of analgesia or anesthetic injection, the examination should be repeated a few days later, when the spasm has subsided. Attention to certain areas during examination can help detect commonly missed injuries (see table Examination for Some Commonly Missed Dislocations and Upper-Extremity Musculoskeletal Injuries ). If physical examination is normal in a joint that patients identify as painful, the cause may be referred pain. For example, patients with a slipped capital femoral epiphysis (or less often hip fracture) may feel pain in their knee. Not all limb injuries require imaging. If imaging is needed, x-rays are usually done first. Plain x-raysshow primarily bone and thus are useful for diagnosing dislocations. They should include at least 2 views taken in different planes (usually anteroposterior and lateral views). Additional views (eg, oblique) may be done when The evaluation suggests fracture and 2 projections are negative. They are routine for certain joints (eg, a mortise view for evaluating an ankle, an oblique view for evaluating a foot). Certain abnormalities are suspected (eg, Y view of the shoulder when posterior dislocation is suspected). For lateral views of digits, the digit of interest should be separated from the others. MRIorCTmay be done to check for subtle fractures, which may accompany a dislocation. Other tests are done to check for related injuries: Arteriography or CT angiography to check for suspected arterial injuries (eg, possible popliteal artery injury in patients with a knee dislocation) Electromyography and/or nerve conduction studies to check for suspected nerve damage (usually done as an outpatient procedure and not done in the acute setting) 