Long-term Evaluation of Posterior Lateral Meniscus Root Tears Left In Situ at the Time of Anterior Cruciate Ligament Reconstruction

Background: The long-term radiographic and subjective results of patients with posterior lateral meniscus root tears left in situ at the time of anterior cruciate ligament reconstruction has not been reported. Hypothesis: The authors hypothesized that patients who had posterior lateral meniscus root tears left in situ would have statistically significantly lower subjective scores and greater joint-space narrowing as compared with a control group. Study Design: Cohort study; Level of evidence, 3. Methods: Thirty-three patients who had isolated posterior lateral meniscus root tear and >5 years objective and subjective follow-up were evaluated and compared with a matched control group without meniscal tears based on sex, chronicity of tear, age, and follow-up time. Patients were evaluated subjectively and objectively using the International Knee Documentation Committee criteria. Results: The mean objective follow-up time was 10.6 ± 4.5 years. The mean subjective total score was 84.6 ± 14 in the study group versus 90.5 ± 13 in the control group (P = .09). Radiographs showed lateral joint-space narrowing rated as normal in 19, mild in 10, moderate in 3, and severe in 1 versus the control group, which was normal in 28 and mild in 5 patients. The measured amount of lateral joint-space narrowing compared with the other knee was 1.0 ± 1.6 mm in the study group versus 0 ± 1.1 mm in the controls on 45° flexed posteroanterior radiographs (P < .006). Conclusion: At a mean of 10 years’ follow-up of posterior lateral meniscus root tears left in situ, mild lateral joint-space narrowing was measured without significant differences in subjective or objective scores compared with controls. This study provides a baseline that can be used to compare the results of procedures used to treat these tears in other manners.