Wk 3, Case 2, Knee MR - Review

Patient History

Other tear of medial meniscus, current injury, right knee, initial encounter. Sprain of anterior cruciate ligament of right knee, initial encounter. Stepped the wrong way and fell down December 30, 2018, heard a pop when getting up. Pain.

Findings

Cruciate ligaments: The ACL is torn. PCL is moderately strained at its insertion on the posterior intercondylar notch.

Bones: Passive anterior displacement of the tibia. Nondisplaced fracture of the fibular styloid.

Mildly depressed, shouldered contusion osteochondral fracture of the middle aspect of the lateral femoral condyle weight-bearing surface at the terminal sulcus.

Contusion mildly depressed nonshouldered osteochondral fractures involving the posterolateral and posteromedial aspects of the tibial plateaus.

Menisci: Complex vertical tears of the posterior horns and bodies of the menisci with anterior flipping of the posterior horns which displace the anterior horns given the “double delta sign” appearance; the inner edges are also displaced into the intercondylar notch. Truncation and small appearance of the meniscal body. These are consistent with bucket-handle tears.

Lateral Compartment: High-grade sprain without avulsion of the proximal fibular collateral ligament. High-grade sprain with focal avulsion of the popliteofibular and fabellofibular ligaments. The arcuate ligament is deranged. The biceps femoris is intact.

The medial meniscocapuslar reflection or junction is torn with low grade sprain of the semimembranosus insertion.

Medial Compartment: Intact medial collateral ligament.

Anterior Compartment: No patellofemoral dysplasia. The medial patellofemoral ligament and lateral patellar retinaculum are intact.

Extensor Compartment: Normal.

Flexor Compartment: Mild fluid distention of the gastrocnemius/semimembranosus bursa without dehiscence. The rest of the flexor mechanism and neurovascular bundle are intact.

General: Moderate joint effusion/hemarthrosis without internal debris or free bodies. Periarticular soft tissue swelling.

Edema throughout the Hoffa's fat pad.

Impressions

1. Right knee pivot shift injury with ACL tear and anterior passive tibial translation.

2. Moderate-grade sprain of the PCL at its insertion on the posterior intercondylar notch.

3. Complex anteriorly flipped medial and lateral menisci bucket-handle tears with displacement into the intercondylar notches.

4. Posterolateral corner injury with a nondisplaced avulsion fracture of the fibular styloid associated with high-grade sprain of the proximal fibular collateral ligament and high-grade sprain with focal avulsion of the popliteofibular and fabellofibular ligaments. Complete tear of the arcuate ligament. The biceps femoris remains intact.

5. Ramp 1 lesion with injured medial meniscocapsular reflection and low grade sprain of the semimembranosus insertion at the posteromedial corner. Findings raise suspicion for knee dislocation.

6. Mildly depressed, shouldered osteochondral fracture of the lateral femoral condyle at the terminal sulcus.

7. Mildly depressed nonshouldered osteochondral fractures of the posterolateral and posteromedial aspects of the tibial plateaus.

8. Moderate joint effusion/hemarthrosis without internal debris or free bodies.