Presentation
Recent trauma during sports.
Patient Data
Bone contusion of the lateral femoral condyle and medial aspect of the patella with an osteochondral defect of the medial patellar facet. The detached osteochondral fragment is displaced and well-visualised in the anteromedial aspect of the knee joint. Joint effusion is noted. The medial patellar retinaculum is thickened with intrinsic high signal but no rupture is seen.
Normal chondral thickness of the trochlear facets as well as the femoral condyles.
The cruciate and collateral ligaments as well as the menisci and quadriceps and patellar tendons are intact.
Annotated images showing the different measurements in this case:
lateral trochlear inclination (LTI) = 10.8° (an angle <11° indicates trochlear dysplasia)
trochlear depth (TD) = 2.2 mm (a trochlear depth <3 mm indicates trochlear dysplasia)
facet asymmetry (FA) = 33 % (a ratio of <40%, in this case, indicates trochlear dysplasia)
Case Discussion
MRI features of a transient lateral dislocation of the patella complicated by an osteochondral fracture of the medial patellar facet on the background of trochlear dysplasia.
Unable to process the form. Check for errors and try again.