:With the knee in 20° flexed, this angle should normally open laterally.<ref name="SagginSaggin2012"/>
*The '''patellofemoral index''' is the ratio between the thickness of the medial joint space and the lateral joint space (L). With the knee 20° flexed, it should measure 1.6 or less.<ref name="SagginSaggin2012"/>
<gallery mode=packed>
File:Lateral patellofemoral angle.jpg
File:Lateral and medial joint space of patella.jpg
</gallery>
Also, look for any resultant fractures of the patella.
{{Bottom}}