caa a22 4500 477095135 CHVBK 20180405111525.0 cr unu---uuuuu 170330e19960101xx s 000 0 eng 10.1007/BF00186833 doi (NATIONALLICENCE)springer-10.1007/BF00186833 The postnatal development of the insertions of the medial collateral ligament in the rat knee [Elektronische Daten] [Xiaochun Wei, Karola Messner] Bone soft tissue remodelling at the femoral and tibial insertions of the medial collateral ligament (MCL) of the rat knee was monitored at regular intervals from birth to 120 days of age in 40 Sprague Dawley rats. At birth the femoral insertion originated from the perichondrium of the epiphysis. By day 8 the perichondrium within the insertion had turned into fibrocartilage. Secondary ossification of the femoral epiphysis had progressed in the region near to the insertion site by day 15. The epiphyseal cartilage was entirely replaced by bone by day 40 except for the fibrocartilage within the insertion. After that stage, no qualitative change in zonal insertion characteristics was observed, but only increase in size and decrease in cellularity. At birth, the tibial ligament inserted onto the thin cortical bone of the metaphysis via periosteum. At day 8, osteoclasts started to resorb the thin cortical bone at the ligament insertion, thus forming a metaphyseal depression between days 10 and 20. From days 20 to 120, the insertion remained qualitatively unchanged, showing three zones, the ligament, periosteum, and metaphyseal trabecular bone. The deep periosteal layer showed osteoclastic activity in the proximal part and osteoblastic activity in the distal part. The migration mechanism of the ligament insertion during growth seems to be caused by this growth-related osteoclastic resorption of the proximal metaphyseal bone and by simultaneous osteogenic activity, which successively cements the distal part of the ligament to bone. The persistence of the periosteal layer and the metaphyseal depression for up to 120 days may be regarded as a sign of continuing growth in this animal model. This is the first investigation showing that the formation of the metaphyseal depression is a purely postnatal event, and suggests that this process might be initiated by the change in mode of growth and joint biomechanics after birth, enabling ligament development and migration in a growing and increasingly loaded weight-bearing joint. The mainly resorptive process, which takes place during development of the tibial MCL insertion, may account for the tensile failure of this ligament that commonly occurs at this site during growth. The pronounced morphological differences between the chondral femoral and the periosteal tibial attachment of the adult MCL are apparently caused by the different postnatal developmental processes at epiphyses and metaphyses. Springer-Verlag, 1996 Ligament nationallicence Bone nationallicence Enthesis nationallicence Remodelling nationallicence Morphogenesis nationallicence Wei Xiaochun Department of Sports Medicine, Faculty of Health Sciences, University Linköping, S-58185, Linköping, Sweden aut Messner Karola Department of Sports Medicine, Faculty of Health Sciences, University Linköping, S-58185, Linköping, Sweden aut Anatomy and Embryology Springer-Verlag 193/1(1996-01-01), 53-59 0340-2061 193:1<53 1996 193 429 https://doi.org/10.1007/BF00186833 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00186833 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wei Xiaochun Department of Sports Medicine, Faculty of Health Sciences, University Linköping, S-58185, Linköping, Sweden aut NATIONALLICENCE 700 1- Messner Karola Department of Sports Medicine, Faculty of Health Sciences, University Linköping, S-58185, Linköping, Sweden aut NATIONALLICENCE 773 0- Anatomy and Embryology Springer-Verlag 193/1(1996-01-01), 53-59 0340-2061 193:1<53 1996 193 429 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer