[Osteochondritis dissecans - an easy classification in MRI].
OBJECTIVE
For the diagnosis of osteochondritis dissecans (OD) MRI is used besides X-ray. However, there is no consensus about the necessity of MRI or the interpretation of MRI. The aim of this prospective study was to find a diagnostic concept for OD which is simple and practicale for daily routine.


METHODS
In 90 patients with OD of the knee or ankle MRI (T1- and T2-w SE) was carried out before arthroscopy. According to the interface between the osteochondral fragment and the parent bone, MRI was classified in 2 stages ("stable" or "unstable") and compared with the arthroscopic findings.


RESULTS
With the 2-stage classification of MRI, a prediction of the stability of the osteochondral fragment was possible in 92 %. Out of the 90 patients 7 (8 %) differed regarding preoperative stability in MRI compared to stability in arthroscopy. Incorrect diagnosis in MRI was only found among the patients with unstable fragments.


CONCLUSIONS
The chosen 2-stage classification in MRI is well suitable for the planning of stage-related therapy.
Jürgensen
I
I
Orthopädische Klinik und Poliklinik der Justus-Liebig-Universität Giessen, Germany.
Bachmam
G
G
Schleicher
I
I
Haas
H
H
D000293:Adolescent; D000328:Adult; D000843:Ankle Joint / Q000473:pathology; D002358:Cartilage, Articular / Q000473:pathology; D002648:Child; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007719:Knee Joint / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010008:Osteochondritis Dissecans / Q000145:classification* / Q000175:diagnosis; D012680:Sensitivity and Specificity