When to Image for Sports-Related Complaints




Abstract


Injuries are a common occurrence in the athletic population. Radiographic imaging can be a useful tool in distinguishing between minor and severe injuries, those needing active rehabilitation and those needing immobilization and change in activity. Radiation is a real concern with imaging, especially with younger athletes. Deciding when it is appropriate and needed to order radiographic imaging will help limit radiation exposure, assist in determining diagnosis and best treatment, and help prevent further injury.




Keywords

Canadian Head Rules, cervical spine imaging, concussion imaging, elbow dislocation imaging, facial injury imaging, fracture, growth plate injuries, head trauma imaging, knee trauma imaging, Ottawa ankle rules, Ottawa knee rules, Pittsburgh knee rules, Segond fracture, shoulder dislocation imaging, x-ray imaging

 





In an acutely injured athlete, what should I look for to decide if x-ray imaging might be needed?


Focal swelling, point tenderness over bony prominences or growth plates, gross deformity, inability to move a joint, and traumatic mechanism of injury are all signs of potential fracture. Any concern for fracture would justify proceeding with radiographic imaging.





When ordering plain radiographs, how many views should be requested?


A good rule of thumb is two views for long bones and three views for joints.





Are there any special views I should consider for pediatric injuries given growth plates and ossification centers?


Contralateral imaging in addition to the area of concern for pediatric injuries will allow comparison of the injury to the patient’s “normal.” This can help in determining if the growth plates or ossification centers are asymmetric. Any asymmetry that correlates with injury and/or tenderness on exam justifies treatment and follow-up.





A middle-aged male sustains an injury to his ankle. He is unable to bear weight immediately after the event. Upon evaluation in the office he is able to walk four steps and has no tenderness on palpation of the foot or ankle. Is imaging indicated at this time?


Given the patient is able to ambulate and has no tenderness on exam, he does not require imaging at this time.





What guideline can be applied to help determine if imaging is indicated after a foot or ankle injury?


The Ottawa ankle rules ( Table 35.1 ) were created to encourage judicious use of radiography in acute midfoot and ankle injuries. These rules can be useful in ruling out fracture due to their high sensitivity.



Table 35.1

Ottawa Ankle Rules












Ankle series if any criteria below are met Foot series if any criteria below are met



  • Bony tenderness of the distal 6 cm of the posterior edge of the lateral malleolus



  • Bony tenderness of the distal 6 cm of the posterior edge of the medial malleolus




  • Bony tenderness of the base of the fifth metatarsal



  • Bony tenderness of the navicular bone

Inability to bear weight for four steps both immediately following the injury and upon presentation to the physician’s office or emergency room





In what scenarios do the Ottawa ankle rules not apply?


These rules should not be applied to patients less than 5 years old or ankle injury greater than 10 days old. The rules should also not be applied to patients with intoxication, skin injuries, head injury, or decreased sensation in the lower extremities.





A patient presents with an acute knee injury. Is there a decision rule that can be used to help rule out fracture in acute knee injury?


Both Ottawa knee rules and Pittsburgh knee rules can be used to rule out fracture in acute knee injury ( Table 35.2 ). Pittsburgh knee rules have been found to have a sensitivity of 99%–100% with a slightly better specificity than the Ottawa rules. While the Ottawa rules initially were validated in adults, the Pittsburgh criteria were described in patients of all ages.



Table 35.2

Comparison of Ottawa and Pittsburgh Criteria













Ottawa Knee Rules Pittsburgh Knee Rules
One or more of the following: Blunt trauma or fall plus either of the following:



  • Age >55 years



  • Tenderness of patella



  • Tenderness over fibular head



  • Limited knee flexion to 90 degrees



  • Inability to bear weight




  • Age <12 or >50 years



  • Inability to bear weight






Can the Ottawa knee rules be applied to children?


In a systematic review and meta-analysis in 2009, the Ottawa knee rules were found to have high sensitivity (99%) and adequate specificity (46%) for children over 5 years of age.





What exclusion criteria exist for the Ottawa and Pittsburgh knee rules?


Decision rules for imaging in knee injuries should not be applied to patients with skin injuries surrounding the knee, multiple injuries, injuries greater than 1 week old, altered consciousness or intoxication, head injury, decreased sensation in the lower extremities, or history of previous surgery or fracture on the affected knee.





What fractures seen on plain films of the knee are concerning for associated ligament and meniscal tears requiring further evaluation with MRI?


Segond fracture, tibial spine fracture, fibular head avulsion fracture, and posterior tibial plateau fracture.





A patient presents after a traumatic event with inability to move the left arm and severe pain. On exam, his arm is held in adduction and internal rotation. You suspect anterior shoulder dislocation. What imaging test do you obtain to confirm the diagnosis?


Plain radiograph is used to verify the diagnosis and rule out fracture. Anteroposterior (AP), axillary, and lateral scapular views should be obtained. These images are also important to rule out associated humeral and glenoid fractures.





After verifying the anterior dislocation by radiograph, you reduce the shoulder. What image can be used to confirm reduction of anterior dislocation?


Axillary plain radiograph can be used to confirm reduction in anterior dislocations.





What additional radiographs can be obtained to identify common associated bony injuries with recurrent dislocations and instability?


The West Point axillary view may be used to identify a fracture of the anterior glenoid rim, also known as a bony Bankart lesion. Additionally, a Stryker notch view may be used to identify a Hill-Sachs lesion in the posterosuperior portion of the humeral head, caused by recurrent contact of the humeral head with the glenoid rim.





Is there an indication for plain radiographs in the diagnosis of elbow dislocation?


In order to facilitate timely reduction of elbow dislocations, diagnosis is often based on evidence of obvious deformity with the elbow held in varus position and the forearm supinated on physical exam. If diagnosis is unclear, confirmation with anteroposterior and lateral plain radiographs is appropriate.





Should imaging studies be completed after reduction of an elbow dislocation?


Postreduction anteroposterior and lateral radiographs should be obtained to verify reduction and identify any associated fractures, such as a coronoid process avulsion.





Can head imaging be a useful tool in diagnosing concussion?


Concussion is a clinical diagnosis. Structural neuroimaging should be normal in patients with concussion and is not necessary for diagnosis. Imaging may be indicated to evaluate for more serious traumatic brain injury in patients with certain symptoms.





What imaging guidelines could be applied to determine the need for computed tomography (CT) after minor head injury?


Canadian Head Computed Tomography Rules can be applied to patients with minor head injury who present with a Glasgow Coma Scale (GCS) of 13–15 after witnessed loss of consciousness, amnesia, or confusion.





How are the Canadian Head Computed Tomography Rules used to determine need for imaging?


Computed tomography of the head is recommended if any of the risk factors are met ( Table 35.3 ). In a study completed in 2001, high-risk factors had 100% sensitivity for predicting neurologic intervention and medium-risk factors had 98.4% sensitivity and 49.6% specificity for predicting clinically important brain injury.



Table 35.3

Canadian Head Computed Tomography Rules: Risk Factors






















High-Risk Factors Medium-Risk Factors
Glasgow Coma Scale Score <15 at 2 hours after injury Amnesia before impact >30 minutes
Any sign of basilar skull fracture:


  • Hemotympanum



  • Raccoon eyes



  • Cerebrospinal fluid otorrhea or rhinorrhea



  • Battle sign

Dangerous mechanism:


  • Pedestrian struck by motor vehicle



  • Occupant ejected from motor vehicle



  • Fall from 3 or more feet or down five stairs

Suspected open or depressed skull fracture
Two or more episodes of vomiting
Age 65 or older





What exclusion criteria exist for the Canadian Head Computed Tomography Rules?


Canadian Head Computed Tomography Rules should not be used for patients with GCS score less than 13, age less than 16 years, obvious open skull fracture, seizure after injury, bleeding disorder, or use of anticoagulation.





What guideline can be applied to help determine if imaging is indicated after a foot or ankle injury?


The Ottawa ankle rules ( Table 35.1 ) were created to encourage judicious use of radiography in acute midfoot and ankle injuries. These rules can be useful in ruling out fracture due to their high sensitivity.



Table 35.1

Ottawa Ankle Rules












Ankle series if any criteria below are met Foot series if any criteria below are met



  • Bony tenderness of the distal 6 cm of the posterior edge of the lateral malleolus



  • Bony tenderness of the distal 6 cm of the posterior edge of the medial malleolus




  • Bony tenderness of the base of the fifth metatarsal



  • Bony tenderness of the navicular bone

Inability to bear weight for four steps both immediately following the injury and upon presentation to the physician’s office or emergency room

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Sep 15, 2018 | Posted by in EMERGENCY MEDICINE | Comments Off on When to Image for Sports-Related Complaints

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