Presentation
History of recurrent patellar dislocation
Patient Data
Age: 35 years
Gender: Male
Note: This case has been tagged as "legacy" as it no longer meets image preparation and/or other case publication guidelines.
From the case:
Femoral trochlear dysplasia - measurements (MRI)
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Trochlear dysplasia as described below:
- ventral trochlear prominence seen in 69% of knees with dysplastic trochlea
- the distance between anterior femoral cortex and most ventral part of trochlear floor was >6.9 mm in all cases with dysplastic trochlea
- the trochlea at 3 cm above joint line has a "flattened" appearance
- average trochlear depth calculated as - (6.08+5.84/2)- 5.68= 2.7m using a cutoff of <3 mm the sensitivity using this cutoff was 100% and a specificity was 96%
- patellar lateralization was measured using a cutoff of >6 mm the sensitivity was 75% and specificity was 83%
- facet asymmetry is expressed as a percentage of medial to lateral facet ratio - in this case, it was 32%, taking a cutoff of <40% sensitivity was 100% and specificity was 96%
Case Discussion
The above images represent most of the findings of femoral trochlear dysplasia and how the measurements should be taken.