[Pain in the internal knee compartment].
The anatomical classification of the traumatic or non traumatic lesion gives a mnemotechnical list which assists in the etiological search for pain of the inner aspect of the knee: skin, sub cutaneous tissue, medial lateral ligament, meniscus, cartilage, sub chondral bone, cruciate ligaments. Each mean of imaging detect specific lesions according to its technical capabilities: standard X Ray film, arthrography, CT scanner, MRI, bone scintigraphy, and echography. In practice, strategy is adapted to the clinical presentation, traumatic or non traumatic. In emergency situations, one is looking for bone, ligamentous, and meniscus lesions. Without acute traumatism, one can discover ligamentous tear sequellae (Pelligrini Stieda's ossifications), transient osteoporosis (algodystrophy), degenerative lesions (arthrosis) of the inner compartment. Always remember "close to the knee", it is necessary to check for more serious infectious or tumoral pathology. If standard plain films remain the first means of examination, and are still useful, MRI is becoming increasingly necessary for a complete anatomical evaluation.