Cor T2W FS MR image of the left knee in a teenager who suffe | Figure 1

CincyKidsRad

Cincinnati Children's Radiology

Cor T2W FS MR image of the left knee in a teenager who suffered a knee dislocation shows injury of numerous supporting structures. There is a high grade tear of the proximal lateral/fibular collateral ligament (blue), and the popliteus tendon has been completely avulsed (orange). The femoromeniscal component of the deep MCL (yellow) is also torn. Only a few ACL fibers (pink) can be identified. The PCL was also torn (not shown).

Coronal MIP image from a 2D TOF MRA in the same patient shows narrowing of the popliteal artery (yellow) at the left knee. Patients with true tibiofemoral dislocations tear at least 3 of the 4 major supporting structures (ACL, PCL, MCL, and LCL/FCL) and have a high likelihood of injury of the popliteus tendon, popliteal artery, and/or peroneal nerve. A Doppler ultrasound showed that the popliteal artery was actually normal in this case. Some advocate vascular imaging only if distal pulses are diminished after reduction, though normal pulses do not exclude vessel injuries. #MSKMonday

More about this case

Resolved

Why you should join Figure 1

Similar cases



2 back to back patients. Image 1 shows intact ACL (orange arrow). Image 2 shows disarray of ACL with essentially full thickness tear.



37 year old roller derby player presented after hyperflexion injury to left knee. Posterior sag sign (hips and knees flexed to 90 degrees) easily demonstrated as well as posterior drawer (unable to post video). Both findings consistent with #PCL tear



A1 - Image 7 demonstrates an acute ACL tear (blue arrow). In addition, osseous contusions are identified in the posterior aspect of the lateral compartment in both the lateral femoral condyle (red arrow) and lateral tibial plateau (yellow arrow). Image 8 (arrow) also demonstrates an osseous contusion in the anterior medial tibial plateau (anterior medial tibial rim sign). Radiologists are most familiar with pivot-shift contusions in the lateral compartment. However, medial compartment osseous contusions also occur, and are associated with higher-energy injuries. The most commonly reported mechanism with an anterior medial tibial rim sign is axial loading. Axial loading occurred in this 52-year-old male following a fall from a ladder. An anterior medial rim sign is identified in approximately 30% of individuals with acute ACL tears.
A2 - The rim sign is associated with a significant increased risk of contusions and fractures as well as posterolateral corner injuries and tears of the posterior horn lateral meniscus. Image 9 (arrow) indicates a torn popliteofibular ligament. Images 10 and 11 (arrows) indicate a complex tear of the posterior horn / root attachment of the lateral meniscus. Image 12 (arrows) demonstrates an impaction fracture of the posterolateral tibial plateau.



This 17-year-old male reports with knee pain following a football injury. Be sure to size up the case by looking at the first two images without arrows before looking at the same images with arrows to indicate key findings.
What are the anatomical structures indicated by the arrows? (Note: Arrows will be provided with the follow-up) Hint: While this patient's anterior cruciate ligament (ACL) is intact, these structures are very important in the setting of acute ACL tear. #KneeMRI #MRI #Radiology #RadRes

Trending now



A 52-year-old man presented with a 20-minute history of chest pain radiating to the left shoulder and neck, associated with dyspnea and diaphoresis.
He had a history of hypertension, long-term smoking, and a sedentary lifestyle.
On physical examination, bibasilar crackles were noted on lung auscultation. An electrocardiogram (ECG) was performed in the primary care setting, and the patient was promptly referred to the emergency department.



A 28-year-old woman presented with a 3-day history of intense pruritus over the lower back. She reported no recent travel or exposure to new environments. She cares for a small kennel with approximately eight dogs rescued from the streets.
Physical examination revealed multiple small vesicles, some clustered and others scattered, predominantly involving the lumbar region and the left gluteal area.



A 4-month-old male infant presented with skin lesions localized to the chin for the past 3 days. Physical examination revealed multiple small pustules with surrounding inflammatory signs on the chin, along with a few scattered papules on the chest.



patient in late teens presenting after a collapse, no chest pain, no previous cardiac history, no history of sudden death in family, are there any features in this ekg that would warrant further work-up or is this just a pediatric ekg?