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.
• Meniscal tears can lead to knee pain and disability and, ultimately, are a risk factor for the development of knee osteoarthritis (OA).

Pediatric Considerations

• Meniscal injuries are rare in children <10. In this population, they are often due to a discoid meniscus and not trauma (1).
• MRI is still the study of choice but is less sensitive and specific for diagnosing meniscal tears in children <12.
• Meniscal repair is an effective treatment option with good clinical outcomes in the pediatric/adolescent population.

Epidemiology

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

Incidence
Medial meniscus more commonly injured

Prevalence
One of the most common musculoskeletal injuries, affecting 0.6 to 8 per 1000 patients each year (2)

Etiology and Pathophysiology

• Traumatic tears are acute. They generally occur due to a twisting motion of the knee with foot planted.
• Degenerative tears are chronic. They generally occur with overuse and minimal trauma.

Genetics
No specific gene locus has been identified.

Risk Factors

• Traumatic tear:
  • High degree of physical activity (especially cutting sports)
  • Younger patients
  • Anterior cruciate ligament (ACL) insufficiency
  • Underlying meniscal degeneration—can still increase risk of meniscal tear even in traumatic event (2)
• 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
• Weight management

Commonly Associated Conditions

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