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Spectrum of injuries associated with paediatric ACL tears: an MRI pictorial review.

Jaremko JL, Guenther ZD, Jans LB, Macmahon PJ - Insights Imaging (2013)

Bottom Line: ACL injury usually occurs with axial rotation in the valgus near full extension.Paediatric-specific issues of note include tibial spine avulsion, normal difficulty visualising a thin ACL and posterolateral corner structures, and differentiation between incompletely closed physis and impaction fracture.Awareness of the spectrum of secondary findings illustrated here and the features distinguishing them from normal variation can aid in accurate assessment of ACL tears and related injuries, enabling effective treatment planning and assessment of prognosis. • The ACL in children normally appears thin or attenuated, while thickening and oedema suggest tear. • Displaced medial meniscal tears are significantly more common later post-injury than immediately. • The meniscofemoral ligaments merge with the posterior lateral meniscus, complicating tear assessment. • Tibial plateau impaction fractures can be difficult to distinguish from a partially closed physis. • Axial MR sequences are more sensitive/specific than coronal for diagnosis of medial collateral ligament (MCL) injury.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology and Diagnostic Imaging, 2A2.42 Walter Mackenzie Health Sciences Centre, University of Alberta, Edmonton, Alberta, Canada, T6G 2B7, jjaremko@ualberta.ca.

ABSTRACT

Objective: Magnetic resonance imaging (MRI) findings in anterior cruciate ligament (ACL) injury are well known, but most published reviews show obvious examples of associated injuries and give little focus to paediatric patients. Here, we demonstrate the spectrum of MRI appearances at common sites of associated injury in adolescents with ACL tears, emphasising age-specific issues.

Methods: Pictorial review using images from children with surgically confirmed ACL tears after athletic injury.

Results: ACL injury usually occurs with axial rotation in the valgus near full extension. The MRI findings can be obvious and important to management (ACL rupture), subtle but clinically important (lateral meniscus posterior attachment avulsion), obvious and unimportant to management (femoral condyle impaction injury), or subtle and possibly important (medial meniscocapsular junction tear). Paediatric-specific issues of note include tibial spine avulsion, normal difficulty visualising a thin ACL and posterolateral corner structures, and differentiation between incompletely closed physis and impaction fracture.

Conclusion: ACL tear is only the most obvious sign of a complex injury involving multiple structures. Awareness of the spectrum of secondary findings illustrated here and the features distinguishing them from normal variation can aid in accurate assessment of ACL tears and related injuries, enabling effective treatment planning and assessment of prognosis.

Teaching points: • The ACL in children normally appears thin or attenuated, while thickening and oedema suggest tear. • Displaced medial meniscal tears are significantly more common later post-injury than immediately. • The meniscofemoral ligaments merge with the posterior lateral meniscus, complicating tear assessment. • Tibial plateau impaction fractures can be difficult to distinguish from a partially closed physis. • Axial MR sequences are more sensitive/specific than coronal for diagnosis of medial collateral ligament (MCL) injury.

No MeSH data available.


Related in: MedlinePlus

Lateral tibial plateau partial fusion versus fracture. Sagittal and coronal PD images in three teens. a Normal partial closure of proximal tibial physis: similar to the distal tibial physis at the ankle, the lateral margin is last to fuse completely (arrow). Note the intact ACL. b Lateral tibial plateau fracture. On close inspection, the transverse low-signal band representing fracture (arrow) is slightly above the physis. Note also the corresponding femoral condylar impaction fracture (arrowhead). c Pseudo-fracture. On the coronal image, a transverse line just above the physis (arrow) resembles a fracture. On sagittal image, this corresponds to a point (circled), representing a vascular channel. Note the lack of visible ACL fibres, and the lateral femoral condyle impaction fracture (arrowhead)
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Fig11: Lateral tibial plateau partial fusion versus fracture. Sagittal and coronal PD images in three teens. a Normal partial closure of proximal tibial physis: similar to the distal tibial physis at the ankle, the lateral margin is last to fuse completely (arrow). Note the intact ACL. b Lateral tibial plateau fracture. On close inspection, the transverse low-signal band representing fracture (arrow) is slightly above the physis. Note also the corresponding femoral condylar impaction fracture (arrowhead). c Pseudo-fracture. On the coronal image, a transverse line just above the physis (arrow) resembles a fracture. On sagittal image, this corresponds to a point (circled), representing a vascular channel. Note the lack of visible ACL fibres, and the lateral femoral condyle impaction fracture (arrowhead)

Mentions: There is often either contusion or an undisplaced fracture in subchondral bone at the lateral tibial plateau; less frequently, also at the medial tibial plateau. In teenagers this can be difficult to distinguish from a partially closed physis, especially since the site of the last portion of the physis to close is very near the most common fracture site (Fig. 11). A fracture is likely if the physis is separately visible and/or there is associated oedema. Like the femoral condyle impaction fracture, this fracture is not treated clinically, but suggests a high force impact mechanism.Fig. 11


Spectrum of injuries associated with paediatric ACL tears: an MRI pictorial review.

Jaremko JL, Guenther ZD, Jans LB, Macmahon PJ - Insights Imaging (2013)

Lateral tibial plateau partial fusion versus fracture. Sagittal and coronal PD images in three teens. a Normal partial closure of proximal tibial physis: similar to the distal tibial physis at the ankle, the lateral margin is last to fuse completely (arrow). Note the intact ACL. b Lateral tibial plateau fracture. On close inspection, the transverse low-signal band representing fracture (arrow) is slightly above the physis. Note also the corresponding femoral condylar impaction fracture (arrowhead). c Pseudo-fracture. On the coronal image, a transverse line just above the physis (arrow) resembles a fracture. On sagittal image, this corresponds to a point (circled), representing a vascular channel. Note the lack of visible ACL fibres, and the lateral femoral condyle impaction fracture (arrowhead)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3675256&req=5

Fig11: Lateral tibial plateau partial fusion versus fracture. Sagittal and coronal PD images in three teens. a Normal partial closure of proximal tibial physis: similar to the distal tibial physis at the ankle, the lateral margin is last to fuse completely (arrow). Note the intact ACL. b Lateral tibial plateau fracture. On close inspection, the transverse low-signal band representing fracture (arrow) is slightly above the physis. Note also the corresponding femoral condylar impaction fracture (arrowhead). c Pseudo-fracture. On the coronal image, a transverse line just above the physis (arrow) resembles a fracture. On sagittal image, this corresponds to a point (circled), representing a vascular channel. Note the lack of visible ACL fibres, and the lateral femoral condyle impaction fracture (arrowhead)
Mentions: There is often either contusion or an undisplaced fracture in subchondral bone at the lateral tibial plateau; less frequently, also at the medial tibial plateau. In teenagers this can be difficult to distinguish from a partially closed physis, especially since the site of the last portion of the physis to close is very near the most common fracture site (Fig. 11). A fracture is likely if the physis is separately visible and/or there is associated oedema. Like the femoral condyle impaction fracture, this fracture is not treated clinically, but suggests a high force impact mechanism.Fig. 11

Bottom Line: ACL injury usually occurs with axial rotation in the valgus near full extension.Paediatric-specific issues of note include tibial spine avulsion, normal difficulty visualising a thin ACL and posterolateral corner structures, and differentiation between incompletely closed physis and impaction fracture.Awareness of the spectrum of secondary findings illustrated here and the features distinguishing them from normal variation can aid in accurate assessment of ACL tears and related injuries, enabling effective treatment planning and assessment of prognosis. • The ACL in children normally appears thin or attenuated, while thickening and oedema suggest tear. • Displaced medial meniscal tears are significantly more common later post-injury than immediately. • The meniscofemoral ligaments merge with the posterior lateral meniscus, complicating tear assessment. • Tibial plateau impaction fractures can be difficult to distinguish from a partially closed physis. • Axial MR sequences are more sensitive/specific than coronal for diagnosis of medial collateral ligament (MCL) injury.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology and Diagnostic Imaging, 2A2.42 Walter Mackenzie Health Sciences Centre, University of Alberta, Edmonton, Alberta, Canada, T6G 2B7, jjaremko@ualberta.ca.

ABSTRACT

Objective: Magnetic resonance imaging (MRI) findings in anterior cruciate ligament (ACL) injury are well known, but most published reviews show obvious examples of associated injuries and give little focus to paediatric patients. Here, we demonstrate the spectrum of MRI appearances at common sites of associated injury in adolescents with ACL tears, emphasising age-specific issues.

Methods: Pictorial review using images from children with surgically confirmed ACL tears after athletic injury.

Results: ACL injury usually occurs with axial rotation in the valgus near full extension. The MRI findings can be obvious and important to management (ACL rupture), subtle but clinically important (lateral meniscus posterior attachment avulsion), obvious and unimportant to management (femoral condyle impaction injury), or subtle and possibly important (medial meniscocapsular junction tear). Paediatric-specific issues of note include tibial spine avulsion, normal difficulty visualising a thin ACL and posterolateral corner structures, and differentiation between incompletely closed physis and impaction fracture.

Conclusion: ACL tear is only the most obvious sign of a complex injury involving multiple structures. Awareness of the spectrum of secondary findings illustrated here and the features distinguishing them from normal variation can aid in accurate assessment of ACL tears and related injuries, enabling effective treatment planning and assessment of prognosis.

Teaching points: • The ACL in children normally appears thin or attenuated, while thickening and oedema suggest tear. • Displaced medial meniscal tears are significantly more common later post-injury than immediately. • The meniscofemoral ligaments merge with the posterior lateral meniscus, complicating tear assessment. • Tibial plateau impaction fractures can be difficult to distinguish from a partially closed physis. • Axial MR sequences are more sensitive/specific than coronal for diagnosis of medial collateral ligament (MCL) injury.

No MeSH data available.


Related in: MedlinePlus