Marco Turati1, Filippo Maria Anghilieri2, Franck Accadbled3, Massimiliano Piatti4, Paolo Di Benedetto5, Francesca Moltrasio6, Giovanni Zatti7, Nicolò Zanchi8, Marco Bigoni9. 1. 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. Electronic address: turati.mrc@gmail.com. 2. School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy. 3. Department of Orthopedics, Children's Hospital, Toulouse University Hospital, France. 4. 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. 5. Medical Departement (DAME) - University of Udine, Italy; Clinic of Orthopaedics, Friuli Centrale Healthcare and University Trust (ASUFC), Udine, Italy. 6. Pathology O.U., San Gerardo Hospital, Monza, Italy. 7. Orthopedic Department, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy; School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy. 8. 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. 9. 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.
Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.