MRI of traumatic patellar dislocation in children.
BACKGROUND
Traumatic patellar dislocations (TPD) are common injuries in children, and MRI is useful in evaluation of pediatric musculoskeletal injuries. However, no pediatric studies on the MR features of TPD have been reported.


OBJECTIVE
To review the injuries after TPD in children.


METHODS
Patients with clinical or radiological recognition of TPD and those with suggestive MR findings were selected. Bone, cartilage and soft-tissue injuries and patellofemoral relationships were assessed.


RESULTS
A total of 26 patients (age range 10-18 years) were identified. The following injuries were seen: bone bruising of the inferomedial patella (81% of patients) and the lateral femoral condyle (81% of patients), cartilage injuries of the inferomedial patella (38% of patients) and the lateral femoral condyle (38% of patients), osteochondral fragments (42% of patients) and injuries of the medial patellar restraints (81% of patients).


CONCLUSIONS
Pediatric manifestations of TPD seen on MRI are similar to those in adults. TPD is often occult in children. Early recognition of bone bruising of the patella and lateral femoral condyle, associated osteochondral injuries, and medial patellar stabilizer injury is important for timely diagnosis.
Zaidi
Ali
A
Diagnostic Imaging, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada. a.zaidi@utoronto.ca
Babyn
Paul
P
Astori
Ivan
I
White
Lawrence
L
Doria
Andrea
A
Cole
William
W
D000293:Adolescent; D002648:Child; D005260:Female; D005269:Femur / Q000473:pathology; D006801:Humans; D007718:Knee Injuries / Q000145:classification; D007719:Knee Joint / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D031222:Patellar Dislocation / Q000175:diagnosis* / Q000503:physiopathology; D012189:Retrospective Studies