From the case:
Illustration for lateral patellar dislocation
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Figure 1: normal orientation of patellofemoral components in extension.
Figure 2: impaction of medial aspect of patella against lateral femoral condyle following injury.
Figure 3: recoiling of patella.
Case Discussion
Sites for retinacular injury are as follows:
- at patellar insertion,
- at midsubstance, or
- within vastus medialis obliquus muscle.