From the Guidelines
When there's a disagreement between a radiologist and a pediatric orthopedic surgeon about an ankle MRI interpretation, with one diagnosing a Salter-Harris type I fracture and the other seeing only a bone bruise, you should defer to the pediatric orthopedic specialist's assessment. The orthopedic surgeon has specialized training in pediatric bone injuries and integrates the clinical examination findings with imaging results. Salter-Harris type I fractures can be subtle on imaging and sometimes difficult to distinguish from bone bruises. The orthopedic surgeon's physical examination of the child's ankle, including assessment of pain, swelling, range of motion, and growth plate tenderness, provides crucial context that complements the MRI findings. Some key points to consider in this scenario include:
- The importance of clinical correlation in diagnosing ankle injuries, as emphasized by the American College of Radiology's appropriateness criteria for acute trauma to the ankle 1.
- The potential for MRI to identify ligamentous injuries and other soft tissue abnormalities, as discussed in the context of chronic ankle pain 1.
- The need for careful consideration of the potential consequences of misdiagnosis, including delayed or inappropriate treatment, and the importance of prioritizing the pediatric orthopedic surgeon's assessment in this regard. Treatment approaches differ significantly - a fracture might require immobilization with a cast or boot for 3-4 weeks, while a bone bruise typically needs only rest, ice, compression, and elevation (RICE therapy) with gradual return to activities as tolerated. For definitive management, follow the orthopedic surgeon's recommendations since they will be responsible for the child's ongoing care and monitoring of proper bone healing and growth.
From the Research
Discrepancies in Ankle MRI Interpretation
- When a radiologist and a pediatric orthopedics surgeon interpret an ankle MRI differently, it can lead to varying diagnoses, such as a Salter-Harris I growth plate fracture versus a bone bruise.
- A study published in 2010 2 found that in skeletally immature children, isolated lateral ankle injuries without radiograph-visible fractures are often misdiagnosed as Salter-Harris I fractures of the distal fibula.
- The study revealed that none of the 18 patients had evidence of fibular growth plate injury on MR imaging, and instead, most had ligamentous sprains and/or bony contusions.
Diagnostic Challenges
- Another study from 2017 3 described two unique cases of adolescents with completely displaced Salter-Harris Type I distal fibula fractures, highlighting the complexity of diagnosing these injuries.
- A prospective MRI study published in 2016 4 found that out of 31 patients with a clinical suspicion of Salter-Harris Type I epiphyseal fracture of the distal fibula, none had evidence of this fracture on MRI.
- The study concluded that most children had ligamentous lesions, bone contusion, or joint effusion, rather than a Salter-Harris Type I fracture.
Comparison of Radiographic Interpretation
- A study from 2021 5 compared the radiographic interpretation between orthopaedists and radiologists at a Level I Trauma Center, finding that orthopaedic providers were significantly faster and more accurate in their interpretations.
- The study also found that orthopaedic providers made fewer mistakes affecting patient care, with a frequency of changes in clinical management after inaccurate interpretation of 0%, compared to 7.6% for radiology providers.
- However, it is essential to note that pitfalls in pediatric radiology can occur, as highlighted in a 2015 study 6, which emphasized the importance of being aware of potential diagnostic errors in pediatric imaging.