This document provides a classification of abnormalities that can occur in the infrapatellar fat pad, including benign tumors, cysts, ganglia, recesses, bursae, and overuse/impingement syndromes. Specific conditions mentioned include para-articular chondroma, localized villonodular synovitis, synovial hemangioma, parameniscal cysts, Hoffa's recesses, Hoffa's ganglion, infrapatellar bursitis, Hoffa's fat pad impingement, and cyclops lesions. The document also provides brief descriptions and imaging characteristics of some of these conditions.

1. INFRAPATELLAR FAT PAD
ABNORMALITIES

2. CLASSIFICATION
Para-articular chondroma, localized PVNS,
Synovial Hemangioma.
Benign tumors
and tumor like
lesions
• …..
Para-meniscal cyst, infrapatellar clefts,
ganglia,
Infrapatellar bursitis.
Cysts, ganglia,
recesses, bursae
• …..
Hoffa’s fat pad impingement,
cyclops lesion
Overuse/impingement
syndromes
• …..

3. Intracapsular chondroma

4. LOCALIZED VILLONODULAR SYNOVITIS
also been referred to as giant cell tumor of the tendon sheath

5. SYNOVIAL HAEMANGIOMA (RARE)

6. PARAMENISCAL CYST
Adjacent to meniscal tear

7. HOFFA’S RECESSES
located superiorly, close to the inferior border
of the patella, and oriented vertically.
located anterior to the anterior horns of the
menisci and has a horizontal direction, linear
in shape.
Depiction and characteristics of these recesses may depend on the concomitant amount of joint effusion and
synovitis

8. HOFFA’S GANGLION
May result from degeneration
of the transverse ligament
(arrows) .

9. INFRAPATELLAR BURSITIS.

10. HOFFA’S FAT PAD IMPINGEMENT
Edema at the superolateral aspect of the Hoffa fat pad

11. CYCLOPS LESION
Post operative localized anterior arthrofibrosis.
Nodular mass of hypointense T1 and T2 signal.