Clinical and arthroscopic features of meniscal tears and a search for the role of infection in histologically confirmed meniscal mucoid degeneration

Abstract

Mucoid degeneration (MD) of the meniscus has received little attention. The pathology deserves special interest as it may lead to loss of the meniscus even in very young individuals. The cause of MD and the clinical features of meniscal tears due to that pathology have not been understood. This study analyzed the age profile and the role of trauma in patients with torn menisci with MD, examined meniscal tear patterns and clinical features, and investigated the role of bacterial infection in causing MD. Meniscal samples obtained from 27 consecutive patients during arthroscopic resection of torn menisci considered to be due to MD (typical yellow color) underwent pathological investigation. The samples were scored according to the light microscopic criteria of Copenhaver; 24 menisci (23 patients) with stage 2-3 MD comprised the study group. Magnetic resonance imaging obtained in 11 patients typically revealed increased intrasubstance signal intensity that extended to at least one of the meniscal surfaces. Pieces of resected meniscal tissue were also subject to PCR investigation to search for presence of bacteria. Of the 24 knees 21 (87%) had no history of trauma. Mean Tegner activity level was 4 (1 and 7). Mean duration of symptoms was 11.6 months (1-36). Pain was the most frequent symptom ( n=22). Joint line tenderness and McMurray's test (pain and/or clicking) were present in 22 and 16 knees, respectively. Medial meniscus was affected in 16 and lateral meniscus in 8. Meniscal cyst and incomplete discoid meniscus was present in 5 and 2 of the lateral menisci. All of the torn menisci were degenerated and yellow in color. The most common tear patterns were radial and/or flap, and longitudinal-horizontal tears. PCR study revealed no bacteria. Mucoid degeneration of the meniscus does not seem to be related to the aging process. Clinical findings of torn such menisci are insidious compared to traumatic tears. Lack of history of trauma may delay the diagnosis. Bacterial infection has no role in the cause.

NITEGE-Expression in Meniscal Matrix. A New, Immunohistochemical Marker of Meniscal-Tissue Degeneration

“…The panel of histochemically stained paraffin sections (HE) was evaluated by two pathologists who used the criteria for meniscus degeneration according to Krenn et al [16]. This scoring system which is partly based on the criteria of Copenhaver (Boya et al [5]) focuses on the cellularity and matrix alterations of bradytrophic tissues leading to grades of low, moderate and severe degeneration ( Figure 1). GRADE 0: normal histological morphology: the matrix of an intact fibrocartilaginous meniscus consists of chondrocytes distributed homogenously in a homogenouseosinophilic-stained, ground substance (see Figure 1(a)).…”

Histopathologischer Degenerations-Score des Faserknorpels

“…Trotz der Tatsache, dass die ersten Beschreibungen charakteristischer histopathologischer Veränderungen bei der MD aus den 1930er Jahren stammen [16], gibt es nur sehr wenige aussagekräf-tige Daten hinsichtlich der Pathogenese. Grundlage für das Verständnis dieser ist grundsätzlich die diagnostische Bildgebung [5] und die konventionelle HE-(Hämatoxylin-Eosin-), Alzianblau-oder EvG-(Elastika-van-Giesson-) Färbung. In einer aktuellen immunhistochemischen Studie wurde nachgewiesen, dass Komplementfaktoren (C4d) und CD68-positive Makrophagen in der Nähe der Stelle der Gewebedesintegration zu finden sind, was auf eine komplementbedingte Rolle bei der MD [9] hinweist.…”

“…Dieses z. T. auf den Kriterien von Boya et al [5] basierende Bewertungssystem konzentriert sich auf die Zellularität und Matrixveränderungen von bradytrophen Geweben und definiert den Grad leichter, mäßiger und schwerer Degeneration (. Tab.…”

“…8 Gegenüberstellung der Zellgröße in der Nähe eines Risses und an einer von dieser abgelegenen Stelle, wobei in der Nähe eines Risses die Zellengröße zunimmt Abb 5. 8 Extrazelluläre NITEGE-Ablagerungen in stark degeneriertem Meniskusgewebe (Grad 3) zeigen ein feingranuläres extrazelluläres, teilweise konfluierendes Muster dere in schwergradig degenerativ verändertem Meniskusgewebe nachgewiesen werden.…”

Case report: intra-tendinous ganglion of the anterior cruciate ligament in a young footballer

“…The prevalence of ganglia associated with the ACL is reported to be 0.12–0.44% on MRI [ 2 , 3 ]. Mucoid degeneration is characterized by an increase in the mucoid ground substance in the connective tissue containing glycoprotein and mucoprotein [ 4 ]. The prevalence of mucoid degeneration of the ACL has been reported to be 0.43% [ 5 ].…”