Orthopedic Department, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy; Transalpine Center of Pediatric Sports Medicine and Surgery, University of Milano-Bicocca - Hospital Couple Enfant, Monza (Italy), Grenoble, France; School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy; Department of Paediatric Orthopaedic Surgery, Hospital Couple Enfant, Grenoble Alpes University, Grenoble, France.
School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.
Knee. 2021 Jun;30:205-213. doi: 10.1016/j.knee.2021.04.006. Epub 2021 May 1.
Discoid meniscus (DM) is a rare variant of regular knee anatomy. Compared to standard meniscus it is thicker and abnormal in shape; these characteristics make it more prone to tear. It is a congenital defect whose correct etiology is still debated and far from being clarified. The purpose of this systematic review is to evaluate evidences of DM in human fetuses in order to assess whether embryological development may have a role.
A systematic review was performed on PubMed, Scopus, and Embase with different combinations of the keywords "discoid meniscus", "embryology", "fetus", "neonatal". Search yielded 1013 studies, on which we performed a primary evaluation.
Seven studies were considered including a total of 1378 fetal menisci specimens, from 396 different fetuses. Discoid shape was not found represented as a normal stage of prenatal development. From 782 lateral menisci analyzed, only 86 (10.86%) were discoid (13 complete, 73 incomplete type). None of medial menisci was found to be discoid. Lateral meniscus was observed to cover a larger surface of tibial plateau than medial one until 28th gestational week.
Lateral meniscus seems to be more prone to discoid shape for its natural tendency of covering a larger surface of the tibial plateau during fetal stages. However the fact that a discoid shape was not found in the majority of fetuses suggests that it is not a normal stage of fetal development. To support a single etiological factor it will be appropriate to have further morphological and morphometric studies.
盘状半月板（DM）是一种罕见的膝关节正常解剖变异。与标准半月板相比，它更厚，形状异常；这些特征使其更容易撕裂。它是一种先天性缺陷，其正确病因仍存在争议，远未得到阐明。本系统评价的目的是评估人类胎儿中 DM 的证据，以评估胚胎发育是否可能起作用。
在 PubMed、Scopus 和 Embase 上进行了系统评价，使用了不同的关键词组合，如“盘状半月板”、“胚胎学”、“胎儿”、“新生儿”。搜索共产生了 1013 项研究，我们对这些研究进行了初步评估。
共纳入了 7 项研究，共包括 396 个不同胎儿的 1378 个胎儿半月板标本。盘状形态并未被发现是产前发育的正常阶段。在分析的 782 个外侧半月板中，只有 86 个（10.86%）为盘状（13 个完全型，73 个不完全型）。未发现内侧半月板为盘状。直到 28 孕周，外侧半月板覆盖的胫骨平台面积大于内侧半月板。
外侧半月板在胎儿期覆盖胫骨平台的面积较大，因此更容易出现盘状形态。然而，大多数胎儿中未发现盘状形态表明它不是胎儿发育的正常阶段。为了支持单一的病因学说，进行进一步的形态学和形态计量学研究是合适的。
