Definition of the MRI findings assessed
| MRI finding | Definition |
| Meniscal degeneration | Significant hyperintense signal change within the meniscus without contact to the surface. |
| Meniscal tear | Significant linear hyperintense signal change within the meniscus with contact to the surface. |
| Cartilage lesion | Focal substance loss of the cartilage ICRS first to ICRS fourth degree. |
| ACL and PCL abnormalities | Tears, partial tears and significant signal alterations of the ACL or the PCL as well as the presence of a graft after ligament reconstruction. |
| Abnormalities of the patellar tendon or the quadriceps tendon (overall and subclassified with respect to location) | Morphological changes of the insertion or the tendon itself (hyperintense signal change, tendon thickening, oedema and ossicles). |
| Trochlear dysplasia | Flattened trochlear groove (Dejour type A–D). |
| Bone marrow oedema of the femoral condyles | Significant hyperintense signal change within the bone of the medial or lateral femoral condyle close to the articular surface. |
| Distal femoral cortical irregularities | Circumscript area of signal hyperintensity with a dark rim at the periphery at the insertion sites of the medial or lateral head of the gastrocnemius or the adductor magnus at the distal femur. |
| FOPE zones | Focal bone marrow oedema (significant hyperintense signal change) adjacent to areas of physeal fusion. |
| Joint effusion | Presence of increased intra-articular fluid. |
| Baker’s cyst | Popliteal fluid collection between medial head of the M. gastrocnemius and M. semimembranosus. |
| Hoffa’s fat pad oedema | Significant hyperintense signal change in the Hoffa’s fat pad. |
ACL, anterior cruciate ligament; FOPE, focal periphyseal oedema; ICRS, International Cartilage Repair Society; PCL, posterior cruciate ligament.