Posts Categorized: Knee

Why has this golfer been bothered for nine weeks?

This 26-year-old male has anterior knee pain since a golf injury nine weeks ago and his knee gives out with steps but there is no locking. Q1 – What do you think has happened? Q2 – Why did this happen? Q3 – You are shown one blue horizontal arrow. What do you think it indicates?… Read more »

What is causing this teenager’s pain after a car accident?

This 16-year-old female presents with lateral knee pain following a motor vehicle accident. No internal derangement, no meniscal tear. No bone bruising. What other features can be associated with lateral knee pain? What is indicated by the arrows on the images?   Strict attention to the lateral mensicus (LM) demonstrates normal superior meniscal fascicle attachment… Read more »

Is this a meniscus tear? If not, what is it?

This 22-year-old has medial pain from a fall. You are shown three sagittal images (images 1-3): a T1, a simple 2D gradient-echo, and a proton density with fat suppression frequency selective. You are also shown a coronal proton density fat suppression image (image 4). Your first step is to establish if this is a meniscus… Read more »

Can you spot the odd abnormality in this case?

You are shown a sagittal T1 (image 1) and a sagittal proton density fat suppression water-weighted image (image 2) of the knee of a 61-year-old. What are the arrows indicating? What other abnormality is odd about the patella? The arrows point to an area of linear penetrating upper pole class 4 chondromalacia. What is odd… Read more »

This man fell at work. What’s the fallout?

This 53-year-old male has left knee pain since a fall at work. You are shown proton density (image 1) and proton density with fat-suppression (image 2) images with abnormality labeled (green arrow). Q1 – What is the most likely diagnosis? Q2 – What is the typical mechanism of injury? Q3 – What is the treatment… Read more »

How to incur the wrath of your orthopaedic surgeon

This 29-year-old presents with knee pain, and you are shown one sagittal water-weighted fat-suppressed image of a high signal intensity mass (green arrow). You have three choices for the diagnosis. Capsulosynovial cyst Ganglion pseudocyst Parameniscal pseudocyst of meniscal origin Which one do you choose?   Start by eliminating meniscal cyst of meniscal origin or pseudocyst… Read more »

What to do when “Baker’s Cyst” isn’t enough

This 53-year-old female presents with a posteromedial knee mass. You diagnose it as a Baker’s cyst with partial dehiscence. Are you out of the woods and ready to move on to the next case? Not quite yet. A Baker’s cyst is a posterior fluid-filled containing structure with heterogeneous etiologies. In other words, there are innumerable… Read more »

Which type of cyst is found in this patient’s knee?

This is a 57-year-old male presents with medial right knee pain. The pain has persisted for eight months. Do you favor capsulosynovial cyst, ganglion pseudocyst or parameniscal pseudocyst of meniscal origin? What sign clinches the diagnosis? How many different characteristics can you name that differentiate the natural history of lateral meniscus cyst / pseudocyst of… Read more »

How serious is this patient’s post-replacement knee pain?

This 69-year-old presents with knee pain post knee replacement. There is bone loss. Is it aggressive or non-aggressive? No, this is not aggressive. Posterior zone of transition is too sharp and a little sclerotic (green arrows). There is osteolysis from metal prosthesis with dense material (orange arrow) in the suprapatellar pouch, e.g. particulate disease, metallosis… Read more »

Guess the sport for this 30-year-old with knee pain

This 30-year-old male presents with knee pain after a motor vehicle accident. But his imaging should have you immediately thinking about his athletic background. Which two sports stand out as his likely hobbies? Bonus points if you know a position in one of the sports that seems to see this injury even more frequently.  … Read more »