MRI of the knee in diffuse pigmented villonodular synovitis

Area of Science:

• Orthopedics
• Radiology
• Oncology

Background:

• Pigmented villonodular synovitis (PVNS) is a rare joint disorder.
• Accurate diagnosis and mapping of PVNS are crucial for effective treatment.
• Distinguishing PVNS from other intra-articular pathologies can be challenging.

Purpose of the Study:

• To evaluate the utility of Magnetic Resonance Imaging (MRI) in diagnosing and characterizing knee PVNS.
• To delineate the distribution patterns of PVNS within the knee joint.
• To establish MRI-based differential diagnostic criteria for PVNS versus other knee pathologies.

Main Methods:

• Retrospective analysis of MRI scans from 11 patients with surgically confirmed knee PVNS.
• Detailed assessment of MRI features including hemosiderin deposition, joint effusion, and synovial hypertrophy.
• Inclusion of 9 additional cases with joint hemorrhage, hemophilia, desmoplastic tumors, and synovial chondromatosis for comparative analysis.

Main Results:

• MRI accurately identified key features of PVNS, including hemosiderin, joint effusion, and hyperplastic synovium.
• The study mapped the intra-articular distribution of PVNS, noting frequent involvement behind cruciate ligaments and in the popliteal fossa.
• MRI demonstrated utility in preoperative planning and postoperative surveillance for residual or recurrent PVNS.

Conclusions:

• MRI is a valuable tool for diagnosing knee PVNS, providing detailed anatomical information.
• MRI findings aid in distinguishing PVNS from other intra-articular conditions, improving diagnostic accuracy.
• The detailed imaging provided by MRI supports effective surgical planning and monitoring of PVNS patients.