So Young Park, Presenter: Nothing to Disclose

Wook Jin, Abstract Co-Author: Nothing to Disclose

Ji Seon Park MD, PhD, Abstract Co-Author: Nothing to Disclose

Kyung Nam Ryu MD, PhD, Abstract Co-Author: Nothing to Disclose

Dal Mo Yang, Abstract Co-Author: Nothing to Disclose

Hyun Cheol Kim, Abstract Co-Author: Nothing to Disclose

This study was designed to assess retrospectively the relationship between the medial patellar plica (MPP) and the low signal band on the posterosuperior portion of the infrapatellar fat pad (LSBIFP) as depicted on MR imaging and to investigate the possibility of a thick LSBIFP as a landmark for a thickened, medially invaginated MPP.

The institutional review board approved this retrospective study and the requirement for informed patient consent was waived. This study included a total of 75 patients underwent MR imaging of the knee. The MR imaging findings were analyzed by two musculoskeletal radiologists independently. MPP was classified into three types on following criteria: type 0, absent or indistinct MPP; type 1, MPP without extending into medial patellofemoral (PF) joint space (Sakakibara classification type A or B); type 2, MPP extending into medial PF joint space (Sakakibara classification type C or D). The thicknesses of the LSBIFP on sagittal image and MPP in the medial parapatellar bursa on axial image were measured. Calculating κ statistics, analysis of variance (ANOVA), calculating Pearson’s correlation coefficient and an independent samples t test were applied for statistical analysis.

For the classification of the three MPP types, agreement between the observers was good (κ = 0.742). The Bonfferoni multiple comparisons test showed significant differences in both the MPP thickness and LSBIFP thickness according to the MPP type (p < .01 for both observers). A significant Pearson’s correlation was found between the MPP thickness and the LSBIFP thickness (r = 0.761, observer 1; r = 0.809, observer 2) (p < .01 for both observers). There was no significant difference in the MMP types, MPP thickness and LSBIFP thickness according to sex, age and side of the knee (p > .01 for both observers).

A thick LSBIFP might be a useful landmark for the detection of a pathological MPP regardless of the presence of joint effusion or the use of fluid-sensitive axial MR sequences.

A thick LSBIFP might be a more helpful finding for the detection of a pathological MPP regardless of the presence of joint effusion or the use of fluid-sensitive axial MR sequences.

Park, S, Jin, W, Park, J, Ryu, K, Yang, D, Kim, H, Thick Low Signal Band of the Infrapatellar Fat Pad on Knee MR Imaging: A Landmark for the Detection of Thickened Medial Patellar Plica?.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8013402.html