Intrameniscal degeneration and meniscotibial ligament loosening are associated factors with meniscal extrusion of symptomatic discoid lateral meniscus

Abstract

Purpose This study aimed to compare the amount of extrusion of the discoid lateral meniscus (DLM), which was symptomatic and required surgery, with normal meniscuses and asymptomatic DLMs and examine factors associated with the extrusion of symptomatic DLM. Methods Medical records of participants with DLM or normal lateral meniscus (LM) were retrospectively reviewed using magnetic resonance imaging (MRI). DLM cases were divided into symptomatic and asymptomatic groups. The midbody meniscal extrusion was measured using mid-coronal MRI. The association between meniscal extrusion and MRI indings, including the meniscofemoral ligament, meniscotibial ligament (MTL), intrameniscal signal intensity of the peripheral rim, meniscal shift, and skeletal maturity, was evaluated. Results Eighty-six knees with DLM (63 symptomatic) were included. The control group included 31 patients. The symptomatic group showed signiicantly greater meniscal extrusion (mean ± standard deviation symptomatic DLM: 1.0 ± 1.1 mm, asymptomatic DLM: 0.1 ± 0.4 mm, and normal LM: 0.3 ± 0.6 mm, P < 0.001) and had a signiicantly higher incidence of MTL loosening (P = 0.02) and intrameniscal signal (P < 0.001) than the other two groups. In the symptomatic group, multivariable linear regression analysis showed that MTL loosening [β = 1.45, 95% conidence interval (CI) 1.03-1.86, P < 0.001] and intrameniscal signal (β = 0.49, 95% CI 0.09-0.90, P = 0.002) were independent associated factors. Conclusions LM extrusion was signiicantly more common in patients with symptomatic DLM than in those with asymptomatic DLM or a normal LM. MTL loosening and intrameniscal high-signal intensity on MRI were independently associated with meniscal extrusion. These indings help explain the pathogenesis and diagnosis of symptomatic DLM. Level of evidence III.

Comparative analysis of discoid lateral meniscus size: a distinction between symptomatic and asymptomatic cases

“…Meniscal extrusion was slightly greater in the symptomatic than in the asymptomatic group. Previous studies have shown that meniscal extrusion is more frequent in symptomatic DLMs than in asymptomatic DLMs or normal menisci [11] and that the extent of extrusion progresses after saucerization with or without repair [12,21], which is consistent with the results of the present study.…”

“…The symptomatic group was further subdivided according to whether there was an intrameniscal high signal indicating a horizontal tear on MRI fat saturation scans. [11, 23]. The group without a horizontal tear was referred to as group “N” and the group with a horizontal tear was referred to as group “H”.…”

Menisco discoide, la importancia de un diagnóstico incidental. Revisión de la literatura y pictográfica

“…El menisco discoide es una variante morfológica, descrita por primera vez en 1889, que condiciona una alteración de la cinemática de la rodilla con un aumento de la incidencia de desgarros e inestabilidad del menisco a una temprana edad. A nivel mundial su prevalencia se calcula en 5.0-16.6%, siendo aparentemente más prevalente en la población asiática 1 ; sin embargo, al ser una entidad principalmente asintomática está prevalencia pudiera estar infraestimada. Si bien sus complicaciones son bien conocidas, su etiopatogenia, clasificación y tratamiento siguen siendo discutidos.…”

Effect of Injury to the Lateral Meniscotibial Ligament and Meniscofibular Ligament on Meniscal Extrusion: Biomechanical Evaluation of the Capsulodesis and Centralization Techniques in a Porcine Knee Model

“…17,27 Meniscal extrusion is associated with various pathologies (eg, early knee osteoarthrosis, meniscus posterior root tears, radial tears) after anterior cruciate ligament reconstruction 28 and after meniscectomy for symptomatic discoid lateral meniscus. 3,14,23 It is frequently accompanied by rapid progression of the degenerative process of the knee as well as by substantial morbidity and pain. 14 Restoring the lost function caused by meniscal extrusion can delay osteoarthrosis progression 25 and/or lead to improvement of articular cartilage after a meniscal allograft transplantation.…”