From the Guidelines
A bone bruise is often misdiagnosed as a Salter-Harris type I fracture on MRI because both conditions can present with similar imaging findings, particularly bone marrow edema, and radiologists may not always accurately distinguish between them, whereas pediatric orthopedic surgeons are more likely to correctly identify a bone bruise due to their specialized training and experience. The key difference lies in the interpretation of these findings, with a bone bruise appearing as an area of increased signal intensity on T2-weighted or STIR sequences, representing microtrabecular fractures and edema within the bone marrow, as noted in the context of acute trauma to the ankle 1. A Salter-Harris type I fracture, on the other hand, involves the growth plate (physis) with separation but no displacement, which can look similar to the edema pattern of a bone bruise.
Some key points to consider in differentiating between bone bruises and Salter-Harris type I fractures include:
- The presence of bone marrow edema, which can be associated with both conditions
- The location and extent of the edema, which may help distinguish between a bone bruise and a fracture
- The clinical examination and mechanism of injury, which can provide important context for interpreting imaging findings
- The importance of subspecialty expertise in pediatric musculoskeletal imaging interpretation, as highlighted by the ability of pediatric orthopedic surgeons to correctly identify bone bruises on MRI 1.
The distinction between bone bruises and Salter-Harris type I fractures is crucial because treatment approaches differ significantly - bone bruises typically require conservative management with rest and pain control, while Salter-Harris fractures might need immobilization or even surgical intervention to prevent growth disturbances, as implied by the importance of accurate diagnosis in treatment planning 1.
From the Research
Misdiagnosis of Bone Bruises as Salter-Harris Fractures
- A bone bruise is often misdiagnosed as a Salter-Harris type I fracture by radiologists on MRI, as seen in a study where the clinical diagnosis of Salter-Harris type I fracture was incorrect in 100% of cases 2.
- In almost 90% of these patients, MRI identified ligamentous sprains and/or bony contusions, rather than a Salter-Harris type I fracture 2.
- The misdiagnosis may be due to the fact that bone bruises or contusions are characterized by a diffuse or localized pattern of low signal intensity on T1-weighted images without a defined fracture, which can be mistaken for a Salter-Harris type I fracture 3.
Characteristics of Bone Bruises
- Bone bruises are defined as a type of injury that occurs when the bone is subjected to a traumatic force, causing damage to the bone marrow and surrounding tissue 4.
- They can be classified into different types, including diffuse and localized patterns, and can be associated with other injuries such as ligamentous sprains and osteochondral fractures 3.
- The significance of bone bruises lies in their potential to cause pain and disability, and their ability to mimic other conditions such as meniscal tears 3.
Diagnostic Challenges
- The diagnosis of Salter-Harris type I fractures can be challenging, and ultrasound may not be sufficient to eliminate the diagnosis 5.
- MRI is a more sensitive tool for detecting bone bruises and other injuries, but even MRI can be misinterpreted, leading to misdiagnosis 2.
- A thorough evaluation of the patient's symptoms and imaging studies is necessary to make an accurate diagnosis and develop an effective treatment plan 2, 6.