Correlation between time from injury to surgery and the prevalence of ramp and hidden lesions during anterior cruciate ligament reconstruction. A new diagnostic algorithm.

Background Anterior cruciate ligament tears (ACL) are associated with meniscal lesions, that could involve the posterior horn of the medial meniscus (PHMM). A variety of techniques has been proposed to better visualise the postero-medial (PM) compartment. The aim of the study is to evaluate the prevalence of longitudinal tears of peripheral attachment of the PHMM during arthroscopic ACL reconstruction, and to describe a diagnostic algorithm. Methods 115 patients who underwent arthroscopic ACL reconstruction were enrolled for the study. An anterior and an intercondylar notch visualisation were ordinarily performed. A postero-medial (PM) portal was performed when the instability of the posterior horn was detected. Statistical significance was assessed by a Chi-squared or Fisher's Exact Test for categorical variables, and by a Mann-Whitney U test for continuous variables. Results We recorded a 9.6% prevalence of lesions of the peripheral attachment of PHMM. Nine ramp lesions and two hidden lesions were diagnosed. Patients treated within 6 months from injury, revealed a statistically significant correlation with a higher prevalence of these lesions. Conclusion Ramp and hidden lesions are very common ACL rupture associated injuries. Our diagnostic algorithm is a valid and safe option to diagnose these kinds of lesions. A correlation between a longer time from injury than 6 months and a reduced prevalence of these lesions was recorded in our population. Level of evidence IV.