Tears of the posterior meniscal root significantly compromise the ability of the meniscus to convert axial loads into circumferential hoop stresses. This results in loss of meniscal function and increased joint contact pressures, rendering the biomechanical consequences comparable to those of a total meniscectomy
Sagittal MRI – Ghost sign
Fig. 1 - The ‘ghost sign,’ defined as the absence of a clearly visualized posterior medial meniscus root on sagittal T2-weighted MRI, is a highly suggestive imaging marker of a complete posterior root tear.
Axial MRI
Fig 2 - Absence of a clearly visualized posterior medial meniscus root on axial T2-weighted MRI, is a highly suggestive imaging marker of a complete posterior root tear.
Coronal MRI
Fig 3 - The cleft sign, characterized by a linear hyperintense signal line at the posterior horn of the medial meniscus on sagittal MRI, is a suggestive finding in posterior medial meniscus root tears, reflecting a radial separation near the root attachment site.
Fig. 4 - Medial meniscal extrusion, defined as displacement of the meniscus beyond the tibial plateau by more than 3 mm on coronal MRI, is a characteristic finding in posterior medial meniscus root tears. This extrusion reflects the loss of meniscal hoop tension and contributes to increased tibiofemoral contact pressure and joint degeneration.
Arthroscopic view of a posterior medial meniscus root tear
The root is clearly detached from its tibial insertion
Treatment
Source:
Bump Sign After Anatomic Repair of Medial Meniscus Posterior Root Tear
Guilherme de Paiva Marques M.D., João Lopes, João Raposo M.D., Tânia Veigas M.D., João;Lobo, M.D., João Campos M.D.,Levi Reina Fernandes M.D.
Arthroscopy Techniques, Volume 14, Issue 5, 103416