The prepatellar bursa: cadaveric investigation of regional anatomy with MRI after sonographically guided bursography.

OBJECTIVE: The purpose of this study was to use MRI and anatomic correlation in cadavers to show the macroscopic anatomic configuration of the prepatellar bursa.

MATERIALS AND METHODS: MRI of the prepatellar bursa of nine cadaveric knees was performed after sonographically guided bursography. The images were compared with those seen on anatomic sectioning. Histologic analysis was obtained in two specimens.

RESULTS: Mean dimensions of the prepatellar bursa in the craniocaudal, lateromedial, and anteroposterior planes were 39.7, 40.5, and 3.2 mm, respectively. A trilaminar aspect of the bursa was shown in seven of the nine knees (78%) and a bilaminar appearance in two of the nine knees (22%). Lateral extension of the bursa over the patella was observed in three knees (33%) and medial extension in one knee (11%). On histopathologic analysis, three potential bursal spaces were found.

CONCLUSION: The prepatellar bursa is most commonly a trilaminar structure, and variation in its relation to the patella can occur.