Summary
During artrhoscopic exploration, if you find only an isolated ACL lesion, you've probably missed something.
Abstract
Background
Medial meniscus ramp lesion (MMRL), lateral meniscus root tear (LMRT) and anterolateral ligament (ALL) tear are individual injuries that have been described in patients who have an anterior cruciate ligament (ACL) tear. But the prevalence of these lesions and their combination has not been defined.
Study design: Prospective case series; level of evidence, 2
Purpose
The objective of this study was to define the individual and combined prevalence of MMRL, LMRT and ALL tears in a case series of patients undergoing ACL reconstruction and to identify the risk factors for combined injuries.
Methods
Patients older than 15 years undergoing primary ACL reconstruction between January 2019 and June 2021 were enrolled in the study. A preoperative ultrasound scan was done to look for an ALL tear. The presence of MMRL and LMRT was determined during a standardized arthroscopy exploration. A multivariate logistic regression model was used to determine the individual effect of demographic variables on the risk of associated single, dual, triad or tetrad (i.e., MMRL-LMRT-ALL-ACL) injuries represented by an adjusted odds ratio (aOR)).
Results
The case series consisted of 602 patients who underwent primary ACL reconstruction. An isolated ACL injury was present in 147 patients (24%). A dual injury was detected in 34 patients (6%) who had ACL/MMRL, 16 (2,5%) who had ACL/LMRT and 265 patients (44%) who had ACL/ALL. A triad injury was detected in 80 patients (13,5%) who had ACL/ALL/MMRL, 36 patients (6%) who had ACL/ALL/LMRT and 3 patients (0.5%) who had ACL/MMRL/LMRT. A tetrad injury pattern was detected in 21 patients (3,5%). Multivariate analysis showed that the occurrence of tetrad injury was significantly lower in older patients (aOR by year = 0.93 (95%CI 0.88; 0.99), p = 0.028). Identifying LMRT increased by 2.11 times (95%CI 1.09; 3.12; p = 0.031) the likelihood of also finding MMRL+ALL injuries.
Conclusion
Isolated ACL tear is less common than combined injuries, which are quite frequent. Younger age is a risk factor for combined injuries. The search for damaged secondary stabilizers of the knee must be meticulous and systematic, especially when one injured structure has already been diagnosed.
What is known about the subject: The isolated prevalence of injuries to each of the secondary stabilizers of the knee has been featured in multiple published studies. However, there is no information on the prevalence of combined injuries or the risk factors for these combined injuries.
What this study adds to existing knowledge: Our study measured the prevalence of combined injuries. It reported the contribution of each injury to combined injury patterns and identified age and sex as risk factors for combined injuries.