An unusual presentation of synovial chondromatosis of the knee in a 10-year-old girl

Abstract

Synovial chondromatosis commonly occurs in the anterior compartment of the knee joint, predominantly in middle-aged men. It is relatively unusual in female children and is rarely encountered in the synovium beneath the meniscus. The present report describes a rare case of synovial chondromatosis that developed in the synovium just inferior to both menisci of the right knee in a 10-year-old girl. At this unusual age and location, there is a greater probability of missed diagnosis, due to the lack of definite informative incidence, and difficulty in finding the lesions during arthroscopic examinations. In the present case, multiple loose bodies were hidden by the meniscus, and thus, there were no structural abnormalities in the initial arthroscopic views before probing the meniscus. After careful inspection, we found numerous cartilaginous loose bodies and removed them as much as possible with arthroscopy.

Synovial osteochondromatosis mimicking juvenile idiopathic arthritis in an adolescent: a case-based review

“…Approximately 30% of patients reported increased pain upon physical activity or exercise [ 9 ]. In pediatric patients, the most commonly affected joint was the knee [ 2 , 10 – 16 ] followed by the hip [ 6 , 17 – 21 ]. Destructive patterns of arthritis and involvement of more than one joint are uncommon findings but have been reported by Emad [ 3 ].…”

“…2018 [ 21 ] 7 M Right hip Pain and limping for 1 month Plain radiographCT scanMRI Large number of chondrocytes Arthrotomy with loose body removal Cho H.J. 2018 [ 16 ] 10 F Right knee Tender over medial and lateral joint line with locking sensation, flexion deformity, and limping for 6 months Plain radiographMRI Loose bodies composed of hyaline cartilage which was located beneath the thin synovial layer, filled interiorly with clusters of chondrocytes Arthroscopy with loose bodies removal and synovectomy Sathe P. 2020 [ 25 ] 8 M Right ankle Pain and swelling of right ankle for 7 months Plain radiographMRI Circumscribed nodules of central cartilaginous areas with endochondral ossification and fibrotic synovial membrane at the periphery without increased cellularity or mitosis Surgery for loose body removal with synovectomy Botaya E.G. 2020 [ 26 ] 10 F Left patella Pain and deformity of left patella precipitated by trauma for 6 months Plain radiographCT scanMRI Cartilaginous metaplastic, uniform chondrocytes with moderate pleomorphism without cellular atypicality Arthrotomy with loose body removal Pirimoglu B.…”