Linking meniscal pathology to Baker’s cyst formation: the role of tear type, location and chondral damage

BACKGROUND: Although Baker's cysts are commonly associated with meniscal tears, the role of specific tear morphologies and anatomic locations in cyst presence remains unclear. This study aimed to evaluate the associations between meniscal tear patterns, tear locations, and Baker's cysts and to explore whether these tear characteristics were also associated with concomitant chondral lesions. METHODS: In this retrospective cohort study, patients who underwent knee arthroscopy at a single institution were evaluated and categorized according to the presence or absence of a Baker's cyst on MRI. Arthroscopic video recordings were reviewed to identify meniscal tear morphology and tear location based on the Cooper classification, as well as the presence of chondral lesions. Separate multivariate logistic regression models were constructed for tear morphology and tear location to account for collinearity among meniscal variables. RESULTS: Of 353 patients (mean age 35.5 ± 13.4 years), 77 (21.8%) had a Baker's cyst. In the multivariate tear morphology model, horizontal, radial, and complex medial meniscal tears were significantly associated with Baker's cysts (OR: 7.321, 95% CI: 2.921-18.349, p < 0.001; OR: 3.380, 95% CI: 1.136-10.056, p = 0.039; and OR: 4.000, 95% CI: 1.907-8.394, p < 0.001, respectively). In the multivariate location model, tears involving Cooper zones A2, A3, and B3 were also significantly associated with Baker's cysts (OR: 2.956, 95% CI: 1.133-7.713, p = 0.027; OR: 3.978, 95% CI: 1.838-8.606, p < 0.001; and OR: 7.070, 95% CI: 2.878-17.371, p < 0.001, respectively). Chondral lesions remained independently associated with Baker's cysts in both models. In univariate analyses, these tear types and locations were also associated with chondral lesions, although these associations were not maintained after multivariate adjustment. CONCLUSION: In this retrospective cohort, horizontal, radial, and complex medial meniscal tears, particularly those involving Cooper zones A2, A3, and B3, were associated with the presence of Baker's cysts. These findings expand the current literature by providing a more detailed description of the relationship between meniscal tear morphology, tear location, and Baker's cysts, and may serve as a basis for future studies investigating the underlying mechanisms.