MR imaging of the medial collateral ligament bursa: Findings in patients and anatomic data derived from cadavers

OBJECTIVE. The purpose of this work was to define the MR imaging findings o f fluid collections confined to the medial collateral ligament (MCL) bursa and to correlate these findings with anatomic features shown in cadaveric s pecimens. MATERIALS AND METHODS. The anatomic location of the MCL bursa was investiga ted by MR-anatomic correlation in seven cadaveric knees. The MR imaging stu dies and clinical charts of six patients with fluid collections confined to the MCL bursa were reviewed. RESULTS. On anatomic sections, the MCL bursa was located between the superf icial and deep portions of the MCL. Separate femoral and tibial compartment s were seen in most specimens. CONCLUSION. The anatomy of the MCL bursa is shown with MR. imaging in cadav eric specimens and patients. Understanding the compartmentlike distribution of fluid in the MCL bursa at MR imaging allows accurate diagnosis and diff erentiation from other conditions.