Femoral trochlear dysplasia with tibial eminence fracture and chronic ACL tear
Presentation
Pain at knee joint, aggravated on walking
Patient Data
Axial images reveal that the trochlear surface of femoral condyle appears dyplastic with short sulcal depth, decreased medial facet length, lateralized patella, edematous medial retinaculum, scarring at medial patellofemoral ligament and articular cartilaginous edema & subchondral cyst at lateral undersurface of patella : findings consistent with femoral trochlear dysplasia with chronic lateral patellar instability
Coronal images show cortical breech at tibial eminence suggesting a depressed fracture extending in a posteromedial to anterolateral plane. Surprisingly no marrow edema is seen indicating a chronic pathology.
The ACL is mildly thickened and anteriorly bowed relative to the expected normal taut, Blumensaats parallel morphology, hence suggstive of lowgrade partial thickness tear involving predominantly the posterolateral fibers.
The quadriceps and infrapatellar tendon show fibrillar morphology with insertional edema. Some interstitial edema is seen at the meniscofemoral deep attachment of MCL with minimal fluid in the lateral recess of the suprapatellar pouch.
Case Discussion
This case reveals a medley of findings
- femoral trochlear dysplasia
- chronic lateral patellar instability
- partial low grade ACL tear
- insertional tendinosis at quadriceps and infrapatellar tendon
- fracture of tibial eminence