Patient History
16-year-old with posterior knee pain after a collision injury playing soccer.
Findings
Menisci:
Medial Meniscus: Intact.
Lateral Meniscus: Delicate intrasubstance signal posterior horn. No communicating tear.
Ligaments:
Anterior Cruciate Ligament: Intact.
Posterior Cruciate Ligament: Intact.
Medial Collateral Ligament: Intact.
Lateral Collateral Ligament: Intact. Unremarkable.
Posterolateral Corner Structures: Diffusely swollen lax popliteal fibular ligament with periligamentous edema and increased intraligamentous signal. Increased intraligamentous signal with fiber discontinuity within the distal attachment at the styloid process, consistent with intermediate to high-grade partial-thickness tear. The remainder of the posterolateral corner structures including the arcuate ligament, fibular collateral ligament, popliteus tendon and myotendinous unit, posterior popliteal meniscal fascicles, distal biceps tendon and iliotibial band are unremarkable
Posteromedial Corner Structures: Intact.
Extensor Mechanism:
Patellar Tendon: Intact.
Distal Quadriceps Tendon: Intact.
Medial Patellofemoral Ligament: Intact.
Medial and Lateral Patellar Retinacula: Intact.
Hoffa’s Fat Pad: Unremarkable.
Articulations:
Patellofemoral Compartment: Unremarkable.
Medial Compartment: Unremarkable.
Lateral Compartment: Unremarkable.
General:
Bones: Microtrabecular contusion involving the posterior tibial spine at the distal PCL attachment.
Effusion: Sliver of suprapatellar recess fluid.
Baker’s Cyst: None. Small Baker’s cyst without evidence for dehiscence or rupture. No popliteal neurovascular involvement.
Loose Bodies: None.
Soft tissue and Neurovascular: Small (1.0 x 0.5 cm) capsulosynovial or ganglion cyst adjacent to the proximal tibiofibular joint.
Conclusion
1.Isolated posterolateral corner injury involving the popliteofibular ligament only, with intermediate to high-grade partial thickness tear of the distal attachment adjacent to the fibular styloid. Otherwise unremarkable posterolateral corner structures.
2.Microtrabecular contusion posterior tibial plateau at the distal PCL attachment. PCL intact.
