Association between ACL tear chronicity and ramp lesion subtypes: double longitudinal ramp lesions are predominant in chronic ACL tears

Background: Few studies have investigated the relationship between the chronicity of anterior cruciate ligament (ACL) tears and the incidence of ramp lesion subtypes. The purpose of this study was to evaluate the relationship between the chronicity of ACL tears and the new subtypes of ramp lesions for treatment selection. Methods: Between May 2015 and April 2023, 367 patients who underwent primary ACL reconstruction were evaluated. Meniscal repair was performed in cases where a ramp lesion was identified. According to the exclusion criteria, 96 patients who underwent repair of ramp lesion were divided into three groups (PR type: pure ramp lesion, RR type: red–red ramp lesion, and DL type: double longitudinal ramp lesion), and the groups were compared for chronicity of ACL tears and time from injury (TFI). Results: Of the 30 patients classified as having PR type lesions, 11 (36.7%) had chronic ACL tears. Likewise, of the 37 patients classified as having RR type lesions, 14 (37.8%) had chronic ACL tears. In contrast, among the 29 patients classified as having DL type lesions, 20 (69.0%) had chronic ACL tears, indicating a statistically significant difference (p < 0.05). This distinction was significant up to 12 months after injury. Conclusions: Pure ramp lesions accounted for only 31% of all ramp lesions in ACL tears. In addition, chronic ACL tears are more frequently accompanied by double longitudinal tears than by red–red zone longitudinal tears or pure ramp lesions of the meniscus posterior horn. Study Design: case series, level of evidence IV.