Factors associated with medial meniscal subluxation in knees with medial meniscus tears: a cross-sectional study

Abstract

Background Previous studies have indicated that medial meniscal subluxation (MMS) is associated with special types of medial meniscus tears (MMT) and chondral lesions. However, most of these studies lacked arthroscopic findings and did not adjust for possible confounders. The purpose of this study was to explore factors associated with MMS in patients with MMT using multivariate logistic regression analysis. Methods A retrospective analysis of 115 patients who underwent arthroscopic surgery for MMT was conducted. The medial meniscal extrusion (MME) distance was measured on a single mid-coronal magnetic resonance (MR) image, and the MMS group included patients with MME distance ≥3 mm (55 patients with 55 knees). Other patients were included as the control group (60 patients with 60 knees). Demographic and clinical data were collected as variates. A multivariate logistic regression analysis was performed to identify factors associated with MMS. Results In a univariate analysis, the Outerbridge classification (P=0.002) and the type of MMT (P<0.001) were significantly different between the MMS group and the control group. According to unadjusted and age- and body mass index (BMI)-adjusted multivariate logistic regression analysis, the type of MMT was an independent factor associated with MMS. Compared with horizontal tears, radial tears, posterior medial meniscus root tears (PMMRT) and complex tears had approximately 6-fold (adjusted OR 6.468, 95% CI 1.509–27.718, P=0.012), 10-fold (adjusted OR 10.324, 95% CI 1.719–61.989, P=0.011) and 4-fold (adjusted OR 4.458, 95% CI 1.602–12.408, P=0.004) higher associations with MMS, respectively. Conclusion The type of MMT was an independent factor associated with MMS in knees with MMT. Radial tears, PMMRT and complex tears were more likely than horizontal tears to result in MMS. The results suggest that MMT combined with MMS should be noted when managing MMT, especially radial tears, PMMRT and complex tears. Moreover, the results indicate that we must not only preserve the meniscus as much as possible but also restore its position to as close to normal as possible.

Medial Meniscal Extrusion in Patients With Medial Meniscus Root Tears: A Systematic Review and Meta-analysis

“…The pooled number of knees with major MME from 8 studies 5,10,18,33,35 –37,51 (n = 1381) was 275 for the MMRT group (n = 349) and 533 for the NRT group (n = 1032). Calculating the pooled odds ratio of knees that had major MME from these studies resulted in a pooled estimate of 3.45 (95% CI, 2.20-5.43; P < .001; I 2 = 41%) (Figure 4).…”