Clinical criteria for using radiography for children with acute knee injuries

Number of positive radiographic findings in pediatric trauma patients

PURPOSE

Conventional radiography is frequently performed in pediatric patients in whom fractures and dislocations are suspected. However, until now, the rate of positive findings of the most commonly performed radiographic examinations in pediatric patients is unknown. The aim of this study was to evaluate the number of positive findings in the 20 most frequently requested standard radiographic examinations in pediatric patients in a level 1 trauma center systematically.

METHODS

A transversal cohort study was conducted at a level 1 trauma center in Germany (2008-2014). In a statistical pre hoc analysis, a sample size of 200 images of each standard radiograph was determined. The picture archiving and communication system (PACS) was searched for radiographic examinations in patients under 18 years.

RESULTS

The following fracture rates for the investigated 20 most common examinations were found: 70.5% clavicle, 54.5% forearm, 53% wrist, 41.5% elbow, 30.5% lower leg, 20% hand, 18.5% finger, 12.5% toe, 12% forefoot, 11.5% ankle, 9% shoulder, 6.5% patella, 5.5% foot, 4% knee, 2% conventional rib series, 1.5% lumbar spine, 1% Towne view, 0.5% skull, 0% cervical spine, and 0% odontoid. Differences in the mean age of analyzed pediatric trauma patients in correlation to different standard radiographs were found.

CONCLUSIONS

In our study, a relevant amount of different standard radiographs revealed a low fracture rate. Therefore, indications for X-ray should be checked properly and alternative procedures should be discussed with the patient and the parents. Clinical decision rules should be developed and pathways have to be implemented to minimize radiation exposure, waiting time, and costs.

Performance of a decision rule for radiographs of pediatric knee injuries

Although decision rules for radiographs of pediatric knee injuries have been suggested from retrospective studies, prospective evaluations of such rules have been limited. We sought to prospectively assess the performance of a rule in children presenting with acute knee injuries. Eligible participants were children aged 3-18 years with an acute knee injury. The settings for the study were a tertiary pediatric emergency department (ED), a community hospital ED, and a pediatric urgent care center. All of the participants received standard knee radiographs. Before radiography, each patient was assessed by a pediatrician or pediatric emergency physician for presence of the following: 1) inability to bear weight, 2) inability to flex the knee to 90( degrees ), 3) presence of bony tenderness. The radiographs were interpreted by a radiologist blinded to the study; those with findings reported as consistent with acute fracture were considered positive. A total of 146 patients were enrolled (65% male, mean age 11.6 years). Of these, 15 (10.3%) had a fracture on their radiograph, 6 of which were related to trampoline use. Seventy-seven (53%) were negative for criterion 1 (i.e., able to bear weight immediately after the accident and in the ED), none (0%) of whom had fractures. The negative predictive value of this criterion was 1.0 (95% CI 0.94-1.0). The positive predictive value was 0.22 (95% CI 0.13-0.34). The sensitivity was 1.0 (95% CI 0.82-1.0). The specificity was 0.59 (95% CI 0.50-0.67). Three patients negative for criterion 3 were found to have fractures. The proximal tibia was the most common fracture site (47%). In conclusion, assessment of the ability to bear weight would have decreased the use of radiography by 53% without missing any fractures in our study population. No additional value to the rule was found by adding assessment of the ability to flex the knee or bony tenderness.

The Ottawa knee rule: avoiding unnecessary radiographs in sports

Physicians are often called upon to evaluate acute knee injuries. Radiographs are frequently ordered, but they may not be helpful for making the diagnosis and guiding treatment of soft-tissue injuries. A set of clinical criteria, called the Ottawa knee rule, has been established to predict when radiographs are truly necessary. The sensitivity and negative predictive value of the rule were both validated at 100% for fractures of the knee in adults. By using the Ottawa knee rule, at least 25% of unnecessary films can be avoided without risking patient safety. The rule has not specifically been studied among sports participants, but indications are that it can be useful in this population.

Validation of the Ottawa Knee Rule in children: a multicenter study

STUDY OBJECTIVE

The main objective of this study was to determine the sensitivity and specificity of the Ottawa Knee Rules when they were applied to children. The secondary objective was to determine post hoc whether use of the rules would reduce the number of knee radiographs ordered.

METHODS

This prospective, multicenter validation study included children aged 2 to 16 years who presented to the emergency department with a knee injury sustained in the preceding 7 days. Children were assessed for the variables comprising the Ottawa Knee Rules, and physicians ordered radiographs at their discretion. A positive outcome was defined as any fracture. A negative outcome was defined as children who did not have a fracture on radiograph or, if no radiograph was obtained, were asymptomatic after 14 days.

RESULTS

A total of 750 children were enrolled. The mean age was 11.8+/-3.1 years, and 443 (58.7%) were male patients. Seventy children had fractures. Radiography was performed for 670 children, whereas 80 children had only a structured telephone interview. The Ottawa Knee Rules were 100% sensitive (95% confidence interval [CI] 94.9% to 100%), with a specificity of 42.8% (95% CI 39.1% to 46.5%). Only 460 children would have required a radiograph if radiographs had been performed according to the Ottawa Knee Rules, which would have resulted in an absolute reduction of 209 (31.2%) radiographs.

CONCLUSION

The Ottawa Knee Rules are valid in children and have the potential to decrease the use of radiography in children with knee injuries.

Rate of abnormal osteoarticular radiographic findings in pediatric patients

OBJECTIVE

The objective of our study was to assess the rate of abnormal radiographic findings in the most frequent osteoarticular locations of traumatic injury in a pediatric population.

SUBJECTS AND METHODS

During two periods of 12 weeks each, all patients admitted to the pediatric emergency department for osteoarticular trauma who underwent radiography were prospectively included in this study. A connection was drawn between the rate of abnormal radiographic findings for the seven most frequently radiographed locations and the clinical findings.

RESULTS

Of 3128 locations of trauma in 2470 children, only 22% of the radiographic examinations were considered to reveal abnormal findings. In decreasing order, the hand and fingers, the ankle, the wrist, the knee, the elbow, the foot and toes, and the forearm were the most frequently examined locations. The rate of abnormal findings was 25.7% for the hand and fingers, 9.0% for the ankle, 42.5% for the wrist, 9.5% for the knee, 33.3% for the elbow, 18.3% for the foot, and 43.2% for the forearm. When only the direct sign of fracture was taken into account, these rates decreased for the ankle and knee to 2.6% and 1.9%, respectively. There was always a significant link between the degree of clinical suspicion and the rate of abnormal radiographic findings. However, fewer than 50% of the cases with high clinical suspicion of fracture were radiographically confirmed.

CONCLUSION

It appears necessary, especially in cases of lower limb trauma, to evaluate clinical tests, including the implementation of the Ottawa ankle rules, to reduce the number of unnecessary radiographic examinations. This reduction will improve some parameters of children's quality of life and will significantly decrease the cost of emergency care.