Abstract
Background: A discoid lateral meniscus is a relatively common anatomic variant in Korean and Japanese subjects that presents with snapping knee syndrome.
Purpose: To evaluate the relationship between the location of the Wrisberg ligament and the frequency of lateral meniscus tear in patients with complete discoid lateral meniscus.
Material and Methods: A total of 109 consecutive patients with arthroscopically proven complete discoid lateral menisci and another 100 patients with non-discoid lateral menisci were evaluated retrospectively. We reviewed the MR images to determine the attachment level of the Wrisberg ligament on the medial femoral condyle, the thickness of the Wrisberg ligament, and the presence and type of lateral meniscus tear. The relationship between the frequency of lateral meniscus tear according to the attachment level on the medial femoral condyle and the thickness of the Wrisberg ligament on both groups was analyzed.
Results: Among them, 153 patients had Wrisberg ligament, 76 patients had complete lateral discoid menisci, and 77 patients had non-discoid lateral menisci. Lateral meniscus tears were found in 115 patients; 83 tears were in the Wrisberg ligament group (n=153) and 32 tears were in the non-Wrisberg ligament group (n =56). The presence of Wrisberg ligament alone was not significantly related to lateral meniscus tear (P=0.755). Among 83 lateral meniscus tears in the Wrisberg ligament group, 58 were identified in complete discoid lateral meniscus with high-riding Wrisberg ligament. The frequency of a lateral meniscus tear was lower in patients with low-riding Wrisberg ligament on complete discoid lateral meniscus (P = 0.020).
Conclusion: In patients with complete discoid lateral meniscus, lateral meniscus tear is seen less often with low- than high-riding Wrisberg ligament.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.