Anatomy Module 1 - Bones and Cartilage

We've designed this series of cases for people at all stages of training. The cases are designed to be taken as unknowns. Claripacs is a fully functioning cloud-based PACS, which allows you to view the entire study, as they would at work. After reviewing the images open the "case discussion" tab to review the pertinent findings; we've also included an "expert commentary" tab for a more in depth review written by a Stanford Musculoskeletal Radiologist.

We will begin each block of cases with a review of the relevant anatomy, starting with the bones and cartilage:

The knee is the largest and most complex joint in the body. In all positions the femur is in contact with the tibia and the patella is in contact with the femoral trochlea. The stability of the joint is maintained by the ligaments, tendons, capsule and menisci, which will be discussed subsequently.
To help orient you on coronal or axial images when the fibula is not visible, note that the lateral femoral condyle appears wider.
To help orient you on sagittal images when the fibula is not visible, note that the medial tibial plateau has the shape of a golf tee, while the lateral tibial plateau has the shape of a golf club or the butt of a rifle.
The lateral femoral condyle has a subtle indentation in its anterior weight-bearing surface, termed the lateral femoral condylar notch or sulcus terminalis. The cartilage over this indentation is normally thinner. This is an important landmark, not only in that it helps you to distinguish the medial and lateral femoral condyles on sagittal images, but because deepening of this notch or a double contour can indicate a contusion pattern associated with ACL injury.
The cartilage is normally thicker over the posterior condyles, which articulate with the tibia in the flexed position. The anterior weight-bearing surface has thinner overlying cartilage.
It is important to note that the proton density sequences best evaluate the cartilage; T2-weighted sequences underestimate cartilage thickness due to the similar signal of cortex and cartilage.
The patella is a large triangular sesamoid. The lateral facet is long and shallow, while the medial facet is short and more strongly angulated. Some patellas, such as this one, may contain a third facet more laterally, termed the odd facet. Occasionally, a patella may appear bipartite or multipartite; this always occurs in the upper outer quadrant.

Keeping all of that in mind, please proceed through cases 1 through 10. If at any time you'd like to review the anatomy please refer to the anatomy atlas, titled "MSK Anatomy - Knee MRI," included in the case list.

Accession: CL0009

Study description: MR Knee Left