Pericruciate fat pad of the knee: anatomy and pericruciate fat pad inflammation: cadaveric and clinical study emphasizing MR imaging.
OBJECTIVE
The pericruciate fat pad is located in the intercondylar fossa, intimate with the cruciate ligaments. With MR imaging, signal abnormality of the pericruciate fat pad has been observed in patients with posterior knee pain. The purpose of this study was to describe the anatomy of the pericruciate fat pad in cadaveric specimens and to document the clinical spectrum of pericruciate fat pad inflammation.


METHODS
Twelve cadaveric knees underwent MR imaging with T1 and T2 multiplanar images. Cadaveric sections were then prepared for macroscopic evaluation, with additional histologic analysis performed in four cases. MR images in seventeen patients (ten males, seven females; average age, 31.5 years; age range, 19-57 years) involved in intensive sporting activity and with posterior knee pain were reviewed.


RESULTS
MR images in cadaveric specimens showed a fat pad that was located above and between the cruciate ligaments, near their attachment sites in the inner portion of the femoral condyles, within the intercondylar fossa. Fatty tissue covered by a thin layer of synovial membrane was confirmed at histology. Seventeen patients with posterior knee pain and without gross cartilage, meniscal, or ligamentous abnormalities all revealed an increased signal in this fat pad in fluid-sensitive fat-suppressed images, mainly in the sagittal and axial planes. In eight cases, enhancement of this fat pad was demonstrated following intravenous gadolinium administration.


CONCLUSIONS
The pericruciate fat pad is a structure located in the intercondylar fossa, intimate with both the anterior and posterior cruciate ligaments. Inflammatory changes in this fat pad may be found in patients, especially athletes with posterior knee pain.
Department of Radiology, Hospital do Coração, Rua Desembargador Eliseu Guilherme, 147, São Paulo, SP, Brazil. abskaf@gmail.com
Abdalla Youssef
AY
Skaf
Guinel
G
Hernandez Filho
Berna
B
Dirim
Mani
M
Wangwinyuvirat
Debra
D
Trudell
Parviz
P
Haghighi
Parvitz
P
Haghigi
Donald
D
Resnick
D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000473:pathology*; D002102:Cadaver; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015434:Panniculitis / Q000473:pathology*