Objective: To demonstrate the anatomy of the deep and superficial infrapatellar bursae using magnetic resonance (MR) imaging and anatomic correlation in cadavers.
Design: MR imaging of the infrapatellar bursae of nine cadaveric knees was performed after ultrasound-guided bursography. The images were compared with those seen on anatomic sectioning. Histologic analysis was obtained in two specimens.
Results: The deep infrapatellar bursa (DIB) was visualized in all specimens (n=9) and the superficial infrapatellar bursa (SIB) in five specimens (55%). The mean dimensions of the DIB in the craniocaudal, mediolateral, and anteroposterior planes were respectively 25, 28.7, and 6 mm, and for SIB 19.5, 21.2 and 2.2 mm. A fat apron dividing the DIB was depicted in eight knees (89%). Lateral extension of the DIB beyond the patellar tendon was observed in 100% of cases. Cadaveric analysis depicted a thin septum in the SIB in four of five cases (80%).
Conclusions: The DIB is generally present and extends beyond the lateral margin of the patellar tendon. A fat apron partially separating this structure is usual. The SIB is not an unusual finding and may have a septum separating its compartments.