Treatment of Symptomatic Discoid Lateral Meniscus
For symptomatic discoid lateral meniscus, arthroscopic partial meniscectomy (saucerization) with meniscal repair of any peripheral detachment is the treatment of choice to preserve meniscal function and prevent long-term osteoarthritis. 1, 2, 3, 4
Surgical Approach
The primary goal is meniscal preservation rather than complete removal, as total or subtotal meniscectomy significantly increases the risk of degenerative arthritis 5, 4. The surgical strategy follows this algorithm:
Step 1: Saucerization (Partial Meniscectomy)
- Reshape the abnormally thick discoid meniscus to approximate normal meniscal anatomy
- Use the midbody of the medial meniscus as a reference for appropriate thickness 4
- Preserve as much functional meniscal tissue as possible to mitigate osteoarthritis risk 6
- Visualize the popliteal hiatus, which is often thickened and enlarged in discoid meniscus 3
Step 2: Assess for Tears and Instability
After saucerization, thoroughly evaluate for:
- Meniscal tears (horizontal patterns in children, complex patterns in adults) 3
- Peripheral detachment causing instability (anterior, posterior, or both) 3, 4
- Wrisberg variant (complete posterior peripheral detachment) 4
Step 3: Repair When Indicated
- Repair all peripheral detachments to stabilize the meniscus 4
- Consider marrow stimulation or biologic augmentation (platelet-rich plasma) to optimize healing 6, 3
- Multiple repair techniques should be available (inside-out, all-inside, outside-in) 3
Technical Considerations
Portal placement is critical: Create a more proximal and medial anteromedial portal directed over the tibial spines into the lateral compartment for optimal working trajectory 3. Switch portals frequently for complete assessment. Small joint and 70° scopes may facilitate visualization in select cases 3.
Expected Outcomes
Surgical management demonstrates excellent results:
- Lysholm scores improve from 57.8 to 88.6 postoperatively 1
- IKDC scores improve from 59.6 to 87.3 1
- Return to sports and daily activities typically within 3 months 2
- Significant symptom relief with restoration of knee function 2
Important Caveats
Retear rates range from 0-23.7% and reoperation rates from 0-36.7% in the literature 1. This underscores the importance of:
- Adequate saucerization without over-resection
- Secure repair of peripheral detachment
- Structured postoperative rehabilitation
Avoid total or subtotal meniscectomy as this historical approach leads to increased degenerative arthritis risk 5, 4. If total meniscectomy has already been performed, meniscal allograft transplantation shows satisfactory long-term functional outcomes 5.
Asymptomatic Cases
Asymptomatic discoid meniscus requires close follow-up without surgical intervention 4. Surgery is reserved for patients with mechanical symptoms (locking, clicking, snapping), pain, swelling, or loss of terminal knee extension 3, 4.