Abstract
BACKGROUND: Meniscal cysts are a relatively uncommon form of meniscus pathology and often coexist with meniscus tears or degeneration. They are typically diagnosed as intra-meniscal cysts or para-meniscal cysts. The majority of para-meniscal cysts protrude towards the joint capsule side of the meniscus, and to date, no cases have been documented at the free edge of the meniscus. The present case of free-edge medial meniscal cysts will contribute to a deeper understanding of meniscal cysts. CASE SUMMARY: A 30-year-old male presented with intermittent right knee pain six months ago. Diagnostic arthroscopic examination revealed a medial meniscus tear accompanied by a meniscal cyst. The patient's clinical findings, imaging results, surgical procedures, relevant images and outcomes are described. The unique aspect of this case is the occurrence of the meniscal cyst at the free-edge of the meniscus, providing valuable insights for the classification and further study of meniscal cysts. CONCLUSION: This first case of meniscal free-edge cyst exemplifies the expansion of the spectrum of morphological types of meniscal cysts.