Description
Purpose
The aim of this study is to evaluate the prevalence of meniscus tears associated to anterior cruciate ligament (ACL) rupture and their influence on antero-posterior and rotatory knee stability.
Methods
This prospective study involved 213 patients who underwent an arthroscopic ACL reconstruction in a time lapse of 36 months. Based on the arthroscopic findings and the type of the performed treatment, patients were classified into the following 4 groups: 1) isolated ACL injury, 2) ACL injury plus medial meniscus tears, 3) ACL injury plus lateral meniscus tears, 4) ACL injury plus combined medial and lateral meniscus tears. Demographic features (age, BMI, gender), sport activity, time between injury and treatment, prevalence of Lachman test grade ≥ 2, prevalence of pivot shift ≥ 2 and arthrometric value with KT1000 were preoperatively collected and compared using the student T test or the Chi square test, where appropriate. A p <0.05 was defined as statistically significant.
Results
Associated meniscal tears were found in 143 out of 213 cases (67.1%), with 64 cases of associated medial meniscus lesions, 47 cases of concomitant lateral meniscus lesions and 32 cases of combined medial plus lateral meniscus lesions. Patients with associated medial meniscus tears presented significantly higher age, BMI, time from injury when compared with patients who sustained an isolated ACL tear. Conversely, patients with concomitant lateral meniscus tears had significant higher BMI when compared to patients with isolated ACL tears, but no significantly increased age and time from injury. Patients with concomitant medial meniscus tears had greater rates of Lachman test grade ≥ 2 and greater KT1000 values (5,49 ± 1,47) when compared to isolated tears (5 ± 0,85, p=0.0190), but comparable rates of pivot shift grade ≥ 2. Patients with concomitant lateral meniscus tears presented higher rates of pivot shift grade ≥ 2 (p =0.0264), but not statistically significant differences in terms of KT1000 values. Patients with combined medial plus lateral meniscus tears had significantly higher KT1000 values (6,55 ± 1,76) compared not only to isolated ACL tears (P<0.0001), but also to concomitant medial meniscus tears (p=0.0025) and concomitant lateral meniscus tears (p=0.0029).
Conclusion
The findings of this study underline the importance of meniscal structures in the biomechanics of the knee. In patients with severe instability, particular attention is recommended in order to identify and promptly treat such injuries, with the aim to restore joint kinematics as close as possible to native status.
