"Fat Brook" in the Popliteal Fossa: Cadaveric and Clinical Investigation With Magnetic Resonance Imaging.
OBJECTIVE
This study aimed to describe the "fat brook" (FB) in the popliteal fossa of a cadaver and to evaluate its clinical significance.


METHODS
Ten fresh cadaveric knees underwent magnetic resonance imaging and histologic analyses. In addition, magnetic resonance imaging images from 321 patients (108 men, 213 women; mean age, 49.8 years; age range, 5-92 years) were retrospectively reviewed. Two radiologists independently determined the presence/absence of the FB and internal derangement of the knee.


RESULTS
The FB was present in all cadaveric specimens without synovial lining or joint communication. In the clinical study, the prevalence of FB was 97.8% (314/321). The FB was associated with effusion (P = 0.001) and tear of the medial meniscus (P = 0.022). There was no significant association between prevalence of FB and age or other structures. Determining FB and internal derangement of the knee had excellent interobserver agreement (concordance correlation coefficient = 0.966, 0.834-1.000).


CONCLUSIONS
The FB might be a part of the superficial layer of superficial fascia and not be mistaken for a fat fracture or Morel-Lavallée lesion.
From the *Department of Radiology, Hanyang University Hospital; †Department of Anatomy and Cell Biology, College of Medicine, Hanyang University; and ‡Department of Pathology, National Police Hospital, Seoul, Korea.
Yoonah
Y
Song
Seunghun
S
Lee
Doo-Jin
DJ
Paik
Jiyoon
J
Bae
D000273:Adipose Tissue / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult