Meniscal injuries to the knee

1. How do medial and lateral meniscus injuries usually occur?
2. What are the symptoms of acute and degenerative meniscus injury?
3. What is seen on physical exam?
4. What is the imaging gold standard for meniscus injury diagnosis?
5. What is the treatment?

Answers:
1. Medial meniscus: injured with tibial rotation while knee partially flexed (football, soccer). Lateral meniscus: injured during squatting in full flexion with rotation (wrestling).
2. An acute tear is associated with a pop with true locking, effusion, and knee stiffness. Degenerative tears involve minimal trauma in >40 yrs.
3. Decreased ROM, flexion limited by effusion, tenderness at jt line, positive Apley and McMurray tests.
4. MRI.
5. Injury to inner 2/3 of meniscus needs surgery due to poor vascularization. NWB for 4-6 wks after surgery if meniscus repaired, WBAT in 1-2 days if meniscus is removed.