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Open Access Research article

Prevalence of MRI-detected mediopatellar plica in subjects with knee pain and the association with MRI-detected patellofemoral cartilage damage and bone marrow lesions: data from the Joints On Glucosamine study

Daichi Hayashi12*, Li Xu13, Ali Guermazi1, C Kent Kwoh45, Michael J Hannon4, Mohamed Jarraya1, Stephanie M Green4, John M Jakicic6, Carolyn E Moore7 and Frank W Roemer18

Author Affiliations

1 Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, FGH Building 3rd Floor, 820 Harrison Avenue, Boston, MA 02118, USA

2 Department of Radiology, Bridgeport Hospital, Yale University School of Medicine, Bridgeport, CT 06610, USA

3 Department of Radiology, Beijing Jishuitan Hospital, Beijing 100035, China

4 Division of Rheumatology and Clinical Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA

5 Pittsburgh VA Healthcare System, Pittsburgh, PA 15240, USA

6 Department of Health and Physical Activity, University of Pittsburgh, Pittsburgh, PA 15260, USA

7 Department of Nutrition and Food Science, Texas Woman’s University, Houston, TX 77030, USA

8 Department of Radiology, University of Erlangen, Erlangen, Germany

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BMC Musculoskeletal Disorders 2013, 14:292  doi:10.1186/1471-2474-14-292

Published: 12 October 2013



The mediopatellar plica is a synovial fold representing an embryonic remnant from the developmental process of the synovial cavity formation in the knee. We aimed to examine the frequency of MRI-detected mediopatellar plica and its cross-sectional association with MRI-detected cartilage damage and bone marrow lesions (BMLs) in the patellofemoral joint (PFJ) in a cohort of subjects with knee pain.


342 knees with chronic frequent knee pain were evaluated for MRI-detected mediopatellar plica (type A, B or C according to the modified Sakakibara classification). Cartilage damage (scored 0 to 6) and BMLs (scored 0 to 3) were semiquantitatively assessed in four subregions of the PFJ on MRI. Hoffa-synovitis and effusion-synovitis were graded 0 to 3. Patellar length ratio (PLR), lateral patellar tilt angle (LPTA), bisect offset (BO), and sulcus angle (SA) were measured on MRI. The presence of mediopatellar plica and its association with cartilage damage and BMLs in the PFJ was assessed using logistic regression after adjusting for age, gender, body mass index, PLR, LPTA, BO, SA, and Hoffa- and effusion-synovitis.


163 (47.7%) knees exhibited mediopatellar plica (76 (22.2%) type A, 69 (20.2%) type B, and 18 (5.3%) type C) on MRI. Significant cross-sectional associations of MRI-detected mediopatellar plica and cartilage damage were observed for the medial patella (adjusted odds ratio (aOR) 2.12, 95% CI 1.23-3.64 for all types combined, and aOR 4.20, 95% CI 1.92-9.19 for type B lesion), but not for the anterior medial femur or the lateral PFJ. No associations were found between the presence of MRI-detected mediopatellar plica and BMLs in any patellofemoral subregion.


On MRI, types A and B mediopatellar plicae were commonly observed in this cohort of subjects with knee pain. MRI-detected mediopatellar plica was cross-sectionally associated with higher likelihood of the presence of MRI-detected medial patellar cartilage damage after adjustment for confounders.

Mediopatellar plica; Cartilage; Bone marrow lesion; Knee; MRI