Wk 5, Case 5 - Review

Patient History
General left knee after physical activity for two weeks. Suspect medial meniscus tear or MCL sprain. Prior arthroscopy 15-20 years ago.
Findings
Menisci:

Medial Meniscus: Chronic undersurface body to posterior horn conversion signal related to previous meniscectomy/chronic horizontal cleavage tear of the rim. Mild associated extrusion of the undersurface indicating rim or meniscal fragment instabilty.

Lateral Meniscus: Chronic horizontal cleavage type intrameniscal signal.

Ligaments:

Anterior Cruciate Ligament: Intact but demonstrates diffuse myxoid degeneration. Diffuse notch synovitis is incidentally noted due to notch stenosis with impingement.

Posterior Cruciate Ligament: Intact.

Medial Collateral Ligament: Thickened intact proximal to mid tibial collateral ligament with extensive diffuse periligamentous edema, consistent with an intermediate grade (grade 2) MCL sprain. Meniscotibial and meniscofemoral ligaments remain intact but swollen.

Lateral Collateral Ligament: Intact.

Posterolateral Corner Structures: Intact.

Posteromedial Corner Structures: Intact.

Extensor Mechanism:

Patellar Tendon: Intact.

Distal Quadriceps Tendon: Intact.

Medial Patellofemoral Ligament: Markedly attenuated and edematous at its femoral origin, anterior to the proximal tibial collateral ligament and adjacent to the adductor tubercle, consistent with at least a grade 2-3 (intermediate to high-grade) sprain/tear.
Medial and Lateral Patellar Retinacula: Lax edematous medial patellar retinaculum. Intact lateral retinaculum.

Hoffa’s Fat Pad: Curvilinear scar within the right inferomedial patellar fat pad, consistent with previous arthroscopy.

Articulations:

Patellofemoral Compartment: Penetrating grade 4 chondromalacia with penetrating osteochondral erosions involving the mid to upper patella apex. Diffuse grade 2-3 chondromalacia involving the lateral patellar facet and trochlear sulcus.

Medial Compartment: Diffuse grade 2-3 medial tibiofemoral chondromalacia with a more focal area of high-grade penetrating chondromalacia (grade 4) on the posterior aspect of the medial femoral condyle.

Lateral Compartment: Diffuse grade 2-3 lateral tibiofemoral chondromalacia. No penetrating high-grade chondromalacia.

General:

Bones: Incidental notch dysplasia with notch stenosis and impingement.

Effusion: Moderate-sized suprapatellar effusion.

Baker’s Cyst: None.

Loose Bodies: None.

Soft tissue and Neurovascular: Unremarkable.

Conclusion

1. Intermediate (grade 2) MCL sprain.
2. Suspect intermediate to high-grade (grade 2-3) MPFL injury at its femoral origin.
3. Early medial compartment failure with meniscal and chondral insufficiency (diffuse grade 2-3 chondromalacia), with chronic undersurface medial meniscus conversion signal/horizontal cleavage tear and partial extrusion.
4. Grade 4 penetrating chondromalacia middle to upper patellar ridge and grade 2-3 chondromalacia trochlear sulcus lateral trochlear facet.
5. ACL myxoid degeneration and notch synovitis.