Incidence and type of meniscal tears in multilligament injured knees

Meniscal injuries occurring during multi-ligament knee injuries (MLKI) are underreported. The purpose of this study was to compare the incidence and type of meniscal tears seen at the time of multi-ligament reconstruction surgery compared to those occurring during isolated anterior cruciate ligament (ACL) surgery.

Patients undergoing surgical treatment for MLKI and ACL-only injuries between 2010 and 2020 were reviewed. Two-hundred and thirty-five patients were included in the MLKI group. There were 131 chronic injuries and 104 acute injuries. Two-hundred and twenty-two ACL-only chronic injuries were used as a control group for comparison with the chronic MLKI group. Demographic data, type of meniscal tears, ligament injury patterns (Schenck classification) and time from injury to surgery were recorded. A delayed procedure was defined by a 4-week interval after the knee injury.

A meniscus was torn in 69 knees (29.4%): 36 knees (15.3%) with an isolated medial meniscus tear, 33 knees (17.9%) with an isolated lateral meniscus tear,.Nine knees (3.8%) had both menisci torn. MLKI with medial or lateral-sided bicruciate ligament injuries (KDIIIM-KDIIIL) were significantly associated with a lower rate of meniscal tears than knee injuries involving the ACL-only and medial/lateral-sided ligament injuries (KDI) (medial-sided injuries p = 0.025; lateral-sided injuries p = 0.049). Lateral-sided injuries had significantly less meniscal damage than medial-sided injuries: 22/124 (17.7%) vs. 41/100 (41%); (p < 0.001). No significant differences were found for frequency, type and distribution of meniscal tears between acute and chronic MLKI surgery. ACL-only chronic injuries were associated with a higher rate of meniscal tears: 123/222 knees (55.4%) vs. 35/131 (26.9%) chronic MLKI; (p < 0.001), mainly involving the medial meniscus: 102/222 (46%) vs. 18/131 (13.7%); (p < 0.001).

Meniscal tears were less common in the MLKI group than in the isolated ACL injury group. The degree of ligament injury patterns and the side of the injured collateral ligament influenced the type and incidence of meniscal damage. Contrary to isolated ACL injuries, a delayed procedure was not associated with a higher rate of meniscal lesions but did influence the type of treatment. Understanding of meniscal tears patterns in MLKI helps to improve the treatment management of these complex injuries.