Meniscus - Discoid

synonyms: "Popping knee syndrome," discoid meniscus

Discoid Meniscus ICD-9

• 717.5 (derangement of meniscus, not elsewhere classified)

Discoid Meniscus Etiology / Epidemiology / Natural History

Discoid Meniscus Anatomy

Discoid Meniscus Clinical Evaluation

• C/O knee pain with mechnical symptoms.
• Meniscal symptoms in a child <10y/o.
• Classic complaint is popping with the knee in extension.

Discoid Meniscus Xray / Diagnositc Tests

• Lateral and weight bearing A/P knee films, may show joint space widening, squaring of the lateral condlye, cupping of the lateral tibia plateau or a hypoplastic lateral intercondylar spine.
• MRI: generally clearly shows abnormal meniscal morphology.

Discoid Meniscus Classification / Treatment

• Incomplete (Type II):
• Complete (Type I):
• Wrisberg's variant Type III): discoid meniscus is only attached to the medial femoral condyle via the meniscofemoral (Wrisberg) ligament. Can displace into the notch with knee extension.
• Incidental discoid meniscus found during knee arthroscopy do not require treatment
• Tears in discoid menisci are treated with excision of the torn portion and saucerization. Repair is indicated for peripheral detachments.

Discoid Meniscus Associated Injuries / Differential Diagnosis

• Meniscal Tear

Discoid Meniscus Complications

Discoid Meniscus Follow-up Care

• 71% excellent, 24% good, 5% fair for arthroscopic lateral menisectomy in patients with symptomatic discoid lateral meniscus. (Aglietti P, Am J Knee Surg 1999;12:83).

Discoid Meniscus Review References

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