Bilateral symptomatic ring-shaped meniscus: a case report

Discoid meniscus is the most common meniscal anatomical variant, affecting almost exclusively the lateral meniscus. Ring-shaped meniscus is an extremely rare meniscal variant in which there is an intermeniscal bridge between the anterior and posterior horns, forming a complete ring. Ring-shaped meniscus is generally asymptomatic and found incidentally. We present the case of a 16-year-old male who presented with bilateral mechanic knee pain associated with positive meniscal tests. Arthroscopic surgery was performed and ring-shaped lateral meniscus with complex tears were identified in both knees. Partial lateral meniscectomies were performed on both knees and hay-bale mattress sutures were used to preserve the remnant lateral meniscus of the left knee. After surgery, the patient obtained good outcomes with regards to pain and mechanical symptom relief. To our knowledge this is the first reported case of bilateral symptomatic ring-shaped meniscus. The reported case demonstrates that complex ring-shaped lateral meniscus tears can be successfully addressed with arthroscopic surgery.