2023 ISAKOS Biennial Congress ePoster
No Dynamic Extrusion of the Medial Meniscus in Ultrasound Examination in Patients with Confirmed Root Tear Lesion
Katrin Karpinski, MD, Berlin GERMANY
Theresa Diermeier, MD, Berlin GERMANY
Lukas Willinger, MD, Munich GERMANY
Andreas B. Imhoff, MD, Prof. Emeritus, Sauerlach / Munich, Bavaria GERMANY
Andrea E. Achtnich, Assoc. Prof., Munich GERMANY
Wolf Petersen, MD, Prof, Berlin GERMANY
Martin Luther Hospital, Berlin, GERMANY
FDA Status Not Applicable
Summary
Dynamic ultrasound examination of the medial meniscus shows significantly decreased dynamic medial displacement for medial root tears compared to healthy meniscus.
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Abstract
Purpose
Extrusion of the medial meniscus evaluated on magnetic resonance imaging (MRI) has been described as indirect radiological sign for meniscus root tears. However, ultrasound detectable dynamic extrusion is observed in normal physiological settings. The aim of the present study was to analyze the dynamic meniscal extrusion using ultrasound (US) examination in patients with MRI confirmed meniscal root tears. The hypothesis was that dynamic meniscus extrusion is reduced in patients with medial root tear but not in the healthy meniscus.
Methods
Twenty-five patients with a medial root lesion of the meniscus (group I) and 25 healthy controls (group II) were enrolled in this study. The medial meniscus extrusion (MME) of the index knee was determined using ultrasound (US) in supine position and under full weight bearing. Standard knee MRI was used for determining whether the patients were eligible for this study according to the inclusion and exclusion criteria, respectively.
Results
In group I, the mean MME was 3.6 mm (± 1.0 mm) in supine position and 3.7 mm (± 0.9 mm) under full weight bearing according to US measurements. The mean ?-extrusion was 0.1 mm (± 0.2 mm) and the ratio was 1.0 (± 0.1). Mean medial meniscus extrusion on MRI was 3.9 mm (± 0.9 mm). In group II, mean MME was 1.3 mm (± 0.3 mm) in supine position (US) and 2.3 mm (± 0.4 mm) under full weight bearing (US). The mean ?-extrusion was 1.0 mm (± 0.4 mm) and the extrusion ratio was 1.8 (± 0.4). In this group mean extrusion in MRI was 1.4 mm (± 0.7 mm). The difference in mean ultrasound ?-extrusion, ratio and MRI extrusion between both groups was statistically significant (p<0.001).
Conclusions
Based on the results of dynamic ultrasound examination of the medial meniscus, medial root tear leads to significantly decreased dynamic medial displacement of the meniscus compared to healthy meniscus status. Absence of dynamic meniscus extrusion may be an indicator for medial meniscus root injury and could be detected using ultrasound ("dead meniscus sign").
Key words: dynamic meniscal extrusion, root tear, ultrasound, meniscal extrusion, dynamic extrusion, magnetic resonance imaging
Level of Evidence: III