Alar ligament of the patella injury

Case contributed by Dr Domenico Nicoletti


Knee deformity after trauma.

Patient Data

Age: 14 years
Gender: Female

MRI knee

Medial alar ligament lesion with external patellar subluxation. Bone marrow edema is present in the medial surface of the patella and in the lateral femoral condyle. The femoral trochlea is flat. There is a knee joint effusion.

Normal cruciate ligaments, collateral ligaments, and menisci.

Case Discussion

The patella is maintained in place by two ligaments one internal and external and are called the alar ligaments.

After the first episode of dislocation, the possibility of recurrence is high.  This is especially the case if dislocation occurs at a young age or if there are predisposing congenital factors, such as a valgus knee, or flattened trochlea.

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Case information

rID: 56779
Published: 21st Nov 2017
Last edited: 16th Jul 2018
Inclusion in quiz mode: Included

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