Evaluation of Ligamentum Mucosum in Anterior Cruciate Ligament Injuries

Objective: Over the past few years, histopathological studies have demonstrated that the ligamentum mucosum (LM) contains neural and vascular structures. These findings suggest that LM can be used for proprioception and revascularization in the repair of anterior cruciate ligament (ACL). The aim of this study was to evaluate the LM structure in knees with ACL injuries. Methods: The data of patients who underwent knee arthroscopy at our clinic between 2017 and 2022 were retrospectively analyzed. Three groups were included in the study; acute ACL tears (n=89), chronic ACL tears (n=111) and intact ACLs (n=101). The arthroscopic video records of all patients were evaluated retrospectively. LM was defined in three different forms: (1) Intact, (2) ruptured, and (3) non-presence. Results: The non-presence of the LM was significantly more common in chronic ACL tears compared to the other groups (p=0.021), while the presence of the LM (either intact or ruptured) was similar between acute ACL tears and intact ACLs. In acute tears, the number of intact LM was significantly lower than that of intact ACLs (p<0.001). However, it was significantly greater than that of chronic tears (p=0.001). Conclusion: According to the present study, the likelihood of intact LM in chronic ACL tears is quite low. In this regard, we suggest that performing surgery in the acute phase of ACL injury will increase the chances of using the LM as a neurovascular source. In addition, because of the possible effect of the LM on proprioception, we recommend preserving the structure during knee arthroscopy procedures if a healthy LM is present.