A Useful MRI Classification for Symptomatic Discoid Lateral Meniscus

Abstract

Purpose The purpose of this study is to classify the discoid lateral meniscus (DLM) according to the signal and shape in magnetic resonance imaging (MRI), and to provide information not only in diagnosis but also in treatment. Materials and Methods We reviewed 162 cases who diagnosed with DLM by MRI and underwent arthroscopic procedures from April 2010 to March 2018. Three observers reviewed MRI findings of all cases and predicted arthroscopic tear using three MRI criteria (criterion 1,2 and 3). Among three criteria, the criterion that most accurately predicts arthroscopic tear was selected. Using this criterion, the cases of predicted tear were named group 1. In addition, group 1 was divided into three subgroups (group 1a, 1b and 1c) by deformation or displacement on MRI and arthroscopic type of tear and procedures were analyzed according to these subgroups. Results The intra-meniscal signal change itself (criterion 3) on MRI showed the highest agreement with the arthroscopic tear. No meniscal deformation and displacement on MRI (group 1a) showed no specific type of tear and more cases of meniscal saucerization. The meniscal deformation on MRI (group 1b) showed more simple horizontal tears and more cases of meniscal saucerization. The meniscal displacement on MRI (group 1c) showed more peripheral tears and more cases of meniscal repair and subtotal meniscectomy. Comparing arthroscopic type of tear and type of arthroscopic procedure between three subgroups, there were significant differences in three groups (P < .05). Conclusions Intra-meniscal signal change itself on MRI is the most accurate finding to predict arthroscopic tear in symptomatic DLM. In addition, subgroup analysis by deformation or displacement on MRI is helpful to predict the type of arthroscopic tear and procedures.

Chinese Experts Consensus and Practice Guideline on Discoid Lateral Meniscus

“…The sensitivity and specificity of this criterion are 95% and 97%, respectively 100,101 . In addition, MRI has a certain diagnostic value in classification, tear type and location, and peripheral rim stability of DLM 48,95,102–107 . The diagnostic specificity and sensitivity of MRI in adult DLM tears are 100% and 97.8%, 108 but in children's DLM and its lesions are still controversial 47,109,110 …”

“…1,98 As the preferred imaging method, the specificity and sensitivity of MRI in diagnosing DLM and its lesions is higher, but in diagnosing the classification and peripheral rim stability of DLM, important to surgical plan and prognosis prediction, is difficult. 102,104,108,179 The accuracy of ultrasonography in diagnosing meniscus lesions is comparable to that of MRI, but the diagnosis of DLM and its classification and lesions is potential and still in the preliminary exploration stage. The real-time dynamic observation, the unique advantages of ultrasound, may enable it to become a reliable new method for diagnosing DLM and its classification and lesions.…”

“…The history and clinical manifestations of symptomatic DLM are not specific, and the diagnosis is mainly based on imaging examination 1,98 . As the preferred imaging method, the specificity and sensitivity of MRI in diagnosing DLM and its lesions is higher, but in diagnosing the classification and peripheral rim stability of DLM, important to surgical plan and prognosis prediction, is difficult 102,104,108,179 . The accuracy of ultrasonography in diagnosing meniscus lesions is comparable to that of MRI, but the diagnosis of DLM and its classification and lesions is potential and still in the preliminary exploration stage.…”

“…100,101 In addition, MRI has a certain diagnostic value in classification, tear type and location, and peripheral rim stability of DLM. 48,95,[102][103][104][105][106][107] The diagnostic specificity and sensitivity of MRI in adult DLM tears are 100% and 97.8%, 108 but in children's DLM and its lesions are still controversial. 47,109,110 In patients with unilateral symptomatic DLM, the probability of DLM in the contralateral knee is about 73%-97%, 6 and of the same type in both is 88%.…”

Nonextruded Grafts Result in Better Cartilage Quality After Lateral Meniscal Allograft Transplantation: Quantitative 3-T MRI T2 Mapping

“…After the bone bridge of the meniscal allograft was secured in an optimal position, arthroscopic repair was performed using the inside-out technique from the posterior horn to the midbody and the outside-in technique for the anterior portions, with PDS 2-0 (Ethicon, Somerville, NJ, USA) and Ethibond 2-0 (Ethicon, Somerville, NJ, USA) sutures. 10 Appropriate peripheral suture tension was determined using arthroscopy.…”