Various pathologies involve the knee joint. The most common, arthrosis, affects older patients and is an chronic degenerative disease affecting the capsule, ligaments and cartilage and brings about a gradual wearing down of the joint.
Pathologies of the knee may also diagnosed in younger patients, such as meniscal lesions or ruptures of the anterior cruciate ligament caused by traumas or repeated stress, as occurring in sport for example. Pain may also be felt in the knee due to overload pathologies or post-trauma pathologies such as bursitis or tendinitis.
The simplest radiological test for completing the diagnosis is radiography.
Radiography of the knee shows the bone parts (pale, ie. radiopaque), making it possible to see the shape of the femur, tibia and patella and any pathological phenomena such as calcification or lytic lesions (consumption of bone). It also makes it possible to assess the extent of articular space, ie. the thickness of the femoral and tibial cartilages, which being radiotransparent (dark) can be identified in the “empty space” between the femoral condyles and the tibial plateau.
CAT (or CT) is useful when closer examination of bones, menisci or ligaments is necessary.
Magnetic Resonance Imaging (MRI) is used to ascertain bone deficiency (eg. of the tibial plateau or femoral condyles in the initial stage when not visible with radiography), lesions to the lateral or medial meniscus, lesions to the cruciate or collateral ligaments or problems in the surrounding soft tissues (eg. bursitis and cystitis).
Echography is rarely prescribed because it very often adds little to what is already apparent from the clinical picture and radiography, and sometimes provides less information than MRI.