Osteochondral defect (unstable)

Clinical History:
This is a 14-year-old female with right knee pain for several months. She first started noticing the pain while running track, which she has stopped due to the degree of pain. She obtained radiographs (not shown) which showed an osteochondral defect. An MRI was then obtained to determine stability of the lesion.

Diagnosis:
IOsteochondral defect (unstable).

MR Technique:
3.0 T Scanner (Siemens Verio) using a 15-channel knee coil. Image 1: coronal T2 scan (TR/TE 3500/70 ms, scan time 4 min 42 sec, slice thickness 4 mm); Image 2: coronal STIR scan (TR/TE 4700/34 ms, scan time 3 min 10 sec, slice thickness 4 mm); Image 3: sagittal Proton Density scan (TR/TE 3150/37 ms, scan time 3 min 55 sec, slice thickness 4 mm).

Imaging Findings:
An undisplaced osteochondral defect is seen in the medial femoral condyle (Image 1). The osteochondral fragment shows bone edema with pockets of fluid around an undetached and undisplaced osteochondral fragment (Image 2). On the sagittal Proton Density images (Image 3), it can be seen that the overlying cartilage is intact. Given the degree of edema surrounding the undisplaced defect, the lesion is characterized as being unstable.