Zusammenfassung
Wegen ihres ausgezeichneten Weichteilkontrasts ist die MRT die Methode der Wahl, um Gelenke und die sie umgebenden Strukturen zu beurteilen. Eine gute Diagnostik setzt dabei mindestens voraus, Anatomie, Pathologie, pathophysiologische Mechanismen und häufige Verletzungsmuster zu kennen. Aber auch die in diesem Beitrag vorgestellten weniger augenscheinlichen Diagnosen sind essenzieller Bestandteil der Diagnostik.
Abstract
Magnetic resonance imaging (MRI) is the most powerful imaging technique to diagnose rare diseases of the knee and the surrounding soft tissues. The knowledge of the normal anatomy is essential to understand signs and differential diagnoses of these pathologies. Three of these rare illnesses are part of this article.
Intraneural ganglia are most frequently seen within the peroneal nerve. The pathogenesis is not clarified yet. The most promising theory is the “Unifying Articular (Synovial) Theory” i.e. a direct connection of the synovia via capsule innervating roots allowing synovial fluid collected in the epineurium. On MRI, specific signs are present that one should not miss.
A chronic tear of the anterior cruciate ligament (ACL) is hard to diagnose, if scar tissue is in anatomic position. It is an important diagnosis in case of instability to avoid early osteoarthritis. Some hints on MR images are helpful in making the right diagnosis.
Meniscocapsular separation is a rarely perceived disease. The specifity on MRI is minor and therefore besides clinical aspects a careful analysis of the meniscotibial and meniscalfemoral ligaments as well as of the joint capsule is mandatory.
Schlüsselwörter
Kniegelenk - intraneurales Gangion - alte VKB-Ruptur - meniskokapsuläre Separation - MRT
Key words
knee joint - intraneural ganglion - old ACL tear - meniscocapsular separation - MR imaging
