Description

• The menisci are fibrocartilaginous structures between the femoral condyles and tibial plateaus.
• The menisci help stabilize the knee and distribute forces across the joint.
• There are acute/traumatic and chronic/degenerative meniscal tears.

Pediatric Considerations

• Meniscal injuries are rare in children <10 years of age and are often due to a discoid meniscus.
• MRI is less sensitive and specific for diagnosing meniscal tears in children <12 years of age.
• Meniscal repair is an effective treatment option with good clinical outcomes in the pediatric/adolescent population (1,2).

Epidemiology

Bimodal age distribution—young athletes (traumatic) and older patients >40 years (degenerative)

Incidence
Medial meniscus more commonly injured

Prevalence
One of the most common musculoskeletal injuries

Etiology and Pathophysiology

• Acute/traumatic tears occur due to a twisting motion of the knee with foot planted.
• Chronic/degenerative tears occur with minimal trauma or overuse.

Genetics
Presence of a discoid meniscus increases the risk for a meniscal tear. No specific gene locus has been identified.

Risk Factors

• Acute/traumatic tear:
  • High degree of physical activity (especially cutting sports)
  • Younger patients
  • Anterior cruciate ligament (ACL) insufficiency
• Chronic/degenerative tear:
  • Increased age (>60 years)
  • Obesity
  • Work-related kneeling/squatting/climbing stairs

General Prevention

• Treatment and rehabilitation of previous knee injuries, particularly ACL injuries
• Strengthening and increased flexibility of quadriceps and hamstring muscles

Commonly Associated Conditions

• Acute/traumatic tear
  • ACL is concomitantly torn in 1/3 of cases.
• Degenerative tear:
  • Baker cyst—association with medial meniscal tears
  • Osteoarthritis (OA)