Mimi Kim MD, Presenter: Nothing to Disclose

Seunghun Lee MD, Abstract Co-Author: Nothing to Disclose

Bong Gun Lee, Abstract Co-Author: Nothing to Disclose

Doo Jin Paik MD, Abstract Co-Author: Nothing to Disclose

Jiyoon Bae, Abstract Co-Author: Nothing to Disclose

The purposes of our study were to illustrate the MRI and cadaveric findings of medial synovial fold of posterior cruciate ligament (PCL) and to classify the types according to anatomic position.

MRI studies of 22 cadaveric knees were performed. Two musculoskeletal radiologists prospectively reviewed MR images to classify medial synovial folding type of PCL in consensus. MRI types were categorized into three groups, a) invisible type, b) inferior and short type, c) inferior and long type. First, Invisible types didn’t show definitive medial fold of PCL on MRI. And, inferior and short types showed visible medial fold without impingement. Finally, inferior and long types had long synovial fold, enough for impingement in the medial femorotibial joint. Correlations were made between findings derived from MRI studies and cadaveric dissections. Histologic analyses were also performed.  

Most common type of medial synovial folding of PCL was inferior and short type, 76.4% (n=13), followed by inferior and long type, 11.8% (n=2), and invisible type, 11.8% (n=2). At the gross inspection, medial folds of both inferior short and long types were projected into the medial femorotibial joint. Moreover, invisible type on MRI had also protruding medial synovial folding at the superior aspect of PCL. Histologic examinations showed collagenous tissues which were surrounded by single layer of synovial cells.

Medial synovial folding of PCL is thought to be a normal variant and may be shown in the high frequency of populations according to MRI and cadeveric studies

The point is that medial synovial fold of PCL from MRI images is normal variant, it is possible to reduce unnecessary examination.  

Kim, M, Lee, S, Lee, B, Paik, D, Bae, J, Medial Synovial Fold of Posterior Cruciate Ligament: Cadaveric Investigation with MRI and Histologic Correlation.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13021630.html