Double-layered Lateral Meniscus Research Articles

Double-Layered Lateral Meniscus

We report a case of double-layered lateral meniscus, where an accessory proximal hemimeniscus was overlying the body and posterior horn of the lateral meniscus. The double-layered meniscus arises proximal and parallel to the normal lateral meniscus with its periphery dissociated from the capsule and was significantly thinner and more mobile than its underlying true lateral meniscus. The accessory hemimeniscus was resected arthroscopically. Key words: Double-layered; Lateral meniscus

Displaced Double-Layered Lateral Meniscus That Mimicked the Bucket-Handle Tear: a Case Report

Various different types of meniscal abnormalities have been reported in the literature. Among them, the occurrence of a double-layered lateral meniscus is extremely rare. The double-layered lateral meniscus includes both the upper additional and the lower normal meniscus (1) (Fig. 1). As the upper additional meniscus is mobile, although very rare, it can be displaced and flipped over the intercondylar eminence of tibia, mimicking the bucket-handle tear. In the English literature, there is only one previously published report of a displaced double-layered lateral meniscus that mimicked the bucket-handle tear (2). Here, we describe a rare case of displaced double-layered lateral meniscus mimicking the bucket-handle tear, where a displaced upper additional meniscus was observed in the intercondylar notch of the knee. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Received: August 11, 2016 Revised: September 11, 2016 Accepted: September 12, 2016

Double-Layered Lateral Meniscus in an 8-Year-Old Child: Report of a Rare Case.

Reports of congenital abnormalities of the lateral meniscus include discoid meniscus, accessory meniscus, double-layered meniscus, and ring-shaped meniscus. Particularly, only a few cases of double-layered meniscus have been reported. We report a case of double-layered lateral meniscus, in which an additional semicircular meniscus was observed under the normal lateral meniscus. The accessory hemimeniscus was resected by means of arthroscopic surgery. This case demonstrates an interesting and extremely rare anatomical abnormality of the lateral meniscus.

Double-Layered Lateral Meniscus Accompanied by Meniscocapsular Separation.

We report an extremely rare case of double-layered lateral meniscus accompanied by meniscocapsular separation. The upper accessory meniscus was connected with the posterior horn and middle segment of the lower normal meniscus and was more mobile than the lower normal meniscus. A meniscocapsular separation was evident at the overlapping middle segment. Clinical symptoms were significantly improved by the resection of the upper accessory meniscus and the repair of the meniscocapsular separation. Careful arthroscopic analysis of other associated pathologies together with this rare abnormality was needed to achieve clinical improvement.

Dislocated Double-layered Lateral Meniscus Mimicking the Bucket-handle Tear

Various shapes of congenital abnormalities of the meniscus have been reported. Among them, the double-layered meniscus is rare. This article describes a 22-year-old man with a double-layered lateral meniscus who reported right knee pain with no history of trauma. The double-layered lateral meniscus included both the upper and lower meniscus. The anterior and posterior edge of the upper meniscus was attached to the lower lateral meniscus, and its periphery was not connected to the capsule and the lower meniscus. In addition, the upper meniscus was dislocated into the intercondylar notch, mimicking a bucket-handle tear. However, the lower meniscus was normal in appearance, so a bucket-handle or horizontal tear of the meniscus was ruled out of the differential diagnosis. Although this is a rare case, clinicians should be aware of this anomaly due to the potential for a double-layered meniscus to contribute to a bucket-handle or horizontal tear of the lower meniscus. Therefore, early diagnosis and proper treatment of a double-layered meniscus are needed before an additional injury occurs to a normal meniscus.

Double-layered lateral meniscus

A case of double-layered lateral meniscus in which an accessory proximal hemimeniscus was overlying the body and posterior horn of the lateral meniscus is here reported. The accessory hemimeniscus lays marginal and parallel to the normal lateral meniscus with its periphery dissociated from the capsule and was significantly thinner and more mobile than its underlying counterpart. It was resected arthroscopically, and the patient's symptoms were significantly improved. This case demonstrates an interesting and extremely rare anatomical abnormality of the lateral meniscus.

An 11-Year-Old Girl Presenting with Chronic Knee Pain: A Case Report with Diagnostic Dilemma

Discoid meniscus is the commonest anatomical aberration of the knee joint, among rare cases such as bilateral separated lateral meniscus, accessory lateral meniscus, partial deficiency of the lateral meniscus and double-layered lateral meniscus. An 11-year-old girl presented with history of chronic pain in her right knee for the last 6 months. The problem disturbed her involvement in the sport activities at school. Clinical examination revealed a clicking sensation on knee extension with lateral joint line tenderness. Magnetic resonance imaging (MRI) of her right knee showed torn posterior horn of lateral meniscus. Arthroscopy examination revealed a discoid meniscus with absence posterior horn. Posterior horn deficient discoid meniscus is a rare form of a congenital meniscus anomaly. We as clinicians believe that the abnormal shaped meniscus may pose a diagnostic challenge clinically and radiologically. Presentation of this case may be beneficial for orthopaedicians in their daily clinical practice.

Bilateral double-layered lateral meniscus: a report of two cases

Only a few cases of double-layered meniscus have been described in the English literature. We report two cases of bilateral double-layered lateral meniscus, where an additional semicircular meniscus was observed over the normal lateral meniscus. One of the patients exhibited a bucket-handle tear with a double-layered meniscus. To our knowledge, this abnormality is extremely rare and the incidence of double layered meniscus with bucket-handle tear has not been previously reported.

A case report of double-layered lateral meniscus with bilateral knee joints

A case report of double-layered lateral meniscus with bilateral knee joints

Double-layered lateral meniscus. A rare anatomical aberration

We report a case of double-layered lateral meniscus, where an accessory proximal hemimeniscus was overlying the body and posterior horn of the lateral meniscus. It lay 1–2 mm proximal and parallel to the normal lateral meniscus with its periphery attached to the capsule and was significantly thinner and more mobile than its underlying counterpart. The accessory hemimeniscus was resected arthroscopically. This case demonstrates an interesting and extremely rare anatomical abnormality of the lateral meniscus and is the first one described outside a Japanese population.

Double-layered lateral meniscus: A newly found anomaly

We report two cases of a double lateral meniscus, with one meniscus overlying another. It was characteristic that the upper accessory meniscus was connected at the posterior horn and middle segments of the lower meniscus. Symptoms in both cases disappeared after resecting the upper meniscus arthroscopically. There was no evidence of tear or other pathologic finding in the meniscus, which showed no disturbance of the fiber arrangement.