2015 ISAKOS Biennial Congress ePoster #1369

The Patterns of Meniscal Tiers in Stable and Unstable Knee with the Anterior Cruciate Ligament (ACL) Injury

Vytautas Tutkus, MD, PhD, Vilnius LITHUANIA
Janina Tutkuviene, MD, PhD, Prof., Vilnius LITHUANIA
Faculty of Medicine, Vilnius University, Vilnius, LITHUANIA

FDA Status Cleared

Summary: The purpose of present study was to analyze tear patterns in patients with stable and unstable knee. The patterns of meniscal tears were evaluated by ISAKOS classification. Data of 780 patients with stable and 793 patients with ACL rupture were analyzed. Radial, horizontal and complex tiers were more often detected in the stable knee. Longitudinal tears were observed more often in unstable knee.

Abstract:

Purpose. The type of meniscal injury is believed to be related to patient’s prognosis. However, there is a lack of studies on tear types in stable und unstable knee, and there is variation between study results. The purpose of present study was to analyze tear types in patients with stable and unstable knee with ACL rupture.
Methods. The present retrospective study was based on the analysis of 1573 patients who underwent arthroscopic knee surgery for menisci ruptures and ACL injuries. The patterns of meniscal tears were evaluated by ISAKOS classification (Anderson 2010). All patients were consulted and operated by one surgeon. Descriptive statistics and multivariate cluster analysis of tear types in relation to the other knee pathology in stable and unstable knee were performed. Data were calculated using the standard statistical package SPSS 20.0.
Results. Patients with the stable knee (n=780) four times more often had medial than lateral meniscus tears (77% versus 19%; both menisci were injured in 4% of patients). The majority of tear patterns in the stable knee was distributed rather similar in medial and lateral meniscus with the exception of radial and horizontal tears: longitudinal type – 44.4%/44.9%, flap – 29.6%/19.6%, complex – 19.6%/16.7%, radial – 5.1%/13%, horizontal – 1.3%/5.8% (in medial/lateral meniscus respectively). Patients with ACL rupture (n=793) only two times more frequently had injured medial than lateral meniscus (58% versus 25%; tears of both menisci – in 17% of patients). The majority of tear patterns in the knee with ACL rupture was also distributed rather similar in medial and lateral meniscus. However, in the unstable knee with ACL rupture longitudinal tears (66.7%/57.0% – in medial/lateral meniscus respectively) were detected more often while complex tears – more seldom (6.5%/7.6% – in medial/lateral meniscus respectively) than in the stable knee. Women were more likely than men to suffer from radial (p<0.001) and complex tear patterns (p<0.05) – that’s usually characteristic for degenerative damage. The cluster analysis showed that longitudinal tear patterns in both (medial and lateral) menisci were more strongly related (on the level of r=0.6) to the location at red-white zone and posterior horn of meniscus (on the level of r=0.53), while the other tear patterns formed slightly weaker cluster (on the level of r=0.35) with the location in white zone and middle part of meniscus (there was no difference between both genders).
Conclusions. 1. Radial, horizontal and complex tiers (characteristic for degenerative pathology) were more often detected in stable knee. 2. Longitudinal tears were observed more often in unstable knee. 3. Longitudinal tear patterns were more frequent in the red-white zone and posterior horn, while the other tear types prevailed in the white zone and middle part of lateral or medial meniscus.