MRI sequences at different degrees of flexion to investigate knee popping: an unusual way to diagnose an isolated pigmented villonodular synovitis lesion

• Published in: Skeletal radiology Vol. 53; no. 8; pp. 1633 - 1637
• Main Authors: Horteur, Clément, Beaudoin, Pierre, Gastaldi, Romain, Morin, Vincent, Gaulin, Benoit, Barth, Johannes
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.08.2024; Springer Nature B.V
• Subjects: Anterior cruciate ligament; Cartilage; Case Report; Case reports; Imaging; Investigations; Knee; Lesions; Ligaments; Magnetic resonance imaging; Medicine; Medicine & Public Health; Nuclear Medicine; Orthopedics; Pathology; Radiology; Range of motion; Signs and symptoms; Surgery; Synovitis; Knee; Villonodular synovitis; Arthroscopy; MRI
• ISSN: 0364-2348; 1432-2161; 1432-2161
• DOI: 10.1007/s00256-023-04538-7

Knee popping is a frequent symptom among knee disorders which requires further investigation in case of a recent evolution of the symptom or pathological associated ones. This article reports a rare presentation of pigmented villonodular synovitis (PVNS), identified as the cause of knee popping symptoms, by performing MRI sequences at various degrees of knee flexion for a patient complaining from a gradual onset of knee popping, occurring when bending the knee over 120° of flexion. MRI sequences were performed just before the popping occurs (flexion 90°) and right after it had occurred (flexion 120°). The latter confirmed the origin of the symptom as the lesion moved forward, passing brutally through the interstice between the PCL and the ACL at 120° of flexion, explaining the popping. Treatment decision was to perform an arthroscopic resection of the lesion. Diagnosis of isolated PVNS was confirmed after anatomopathological analysis.