Age Differences in the Prevalence of Isolated Medial and Lateral Meniscal Tears in Surgically Treated Patients.

PURPOSE: To compare the prevalence of isolated lateral and medial meniscal tears in different aged populations.

METHODS: A five-year retrospective review for meniscal procedures performed on a total of 782 patients. Each chart was reviewed to document the prevalence of medial or lateral meniscal injuries. Inclusion criteria were patients found to have documented evidence of meniscal tear, either lateral or medial, without any concomitant injuries and/or any other procedures performed. Patients excluded from the study were those with concomitant pathologies, such as chondromalacia, malalignment or ligamentous injuries. Patients were classified by age into three groups: < 20 years, 20-30 years and > 30 years old.

RESULTS: 68.7% of patients had medial meniscal tears, (average age 37.6 years), 17.1% of these were isolated medial meniscus injuries (average 31.9 years). 31.3% had lateral meniscal injuries (average 27.7 years). Of these, 18.8 % had isolated lateral meniscal injuries (average 22.8 years). All remaining patients had additional diagnoses/procedures. Isolated medial meniscal injuries were more common in older patients as 48 of the 92 isolated medial tears (52.2%) were found in patients > 30 years of age (p <0.001). Isolated lateral meniscal injuries, on the other hand, were more common in younger patients. 29 of the 46 isolated lateral tears (63%) occurred in patients under 20 years (p = 0.002). Only seven (15.2%) isolated lateral tears were shown in patients older than 30 years.

CONCLUSION: Isolated lateral meniscal tears are more common in patients < 20 years, and decrease with age, while the prevalence of medial meniscal tears increase with age.