Localized pigmented villonodular synovitis in the knee associated with locking symptoms

Area of Science:

• Orthopedic Surgery
• Musculoskeletal Pathology

Background:

• Pigmented villonodular synovitis (PVNS) is a rare joint disorder.
• Localized PVNS is less common than the diffuse form, often affecting the knee.
• Meniscal tears can cause knee locking, necessitating accurate diagnosis.

Observation:

• A patient presented with knee locking symptoms attributed to a lateral meniscus injury.
• Initial treatment for the meniscus tear did not resolve the locking.
• MRI revealed a neoplastic lesion in the intercondylar space alongside the meniscus tear.

Findings:

• Arthroscopic resection of the intercondylar lesion was performed.
• Histological examination confirmed the lesion as localized pigmented villonodular synovitis (PVNS).
• The patient remained symptom-free with no recurrence of PVNS two years post-surgery.

Implications:

• Localized PVNS can present as a cause of knee locking, potentially complicating diagnosis in the presence of meniscal pathology.
• This case highlights the importance of considering PVNS in the differential diagnosis of persistent knee locking.
• Early and accurate diagnosis and treatment of PVNS are crucial for symptom resolution and preventing recurrence.