The ultrastructure of the epiphyseal plate

A method of fixation has been developed for the cartilage cells of the epiphyseal plate. Improved preservation of the flattened chondrocytes reveals small vesicles that seem to originate in the rough endoplasmic reticulum and are found in large amounts in the Golgi area. Different types of vacuoles can be distinguished in the Golgi complex, e.g. intermediate vacuoles and large vacuoles, the latter usually containing inclusions. It seems likely that the vesicles and vacuoles each play a specific role in the transport and production of sulfated protein polysaccharides.

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Zusammenfassung Es wurde eine Methode zur Fixation der Knorpelzellen aus der Epiphysenplatte entwickelt. die besser erhaltenen abgeflachten Chondrocyten zeigen kleine Bläschen, welche aus dem groben endoplasmatischen Reticulum zu stammen scheinen und in großen Mengen im Golgi-Bereich vorliegen. Verschiedene Arten von Vacuolen können im Golgi-Apparat unterschieden werden, z.B. intermediate vacuoles und large vacuoles, wobei die letztgenannten gewöhnlich Einschlüsse enthalten. Es ist wahrscheinlich, daß die Bläschen sowie die Vacuolen eine spezifische Rolle beim Transport und der Bildung von sulfatierten Proteinpolysacchariden spielen.

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Résumé Une méthode de fixation des cellules cartilagineuses de la métaphyse est mise au point. Une meilleure préservation des chondrocytes applatis montre de petites vésicules qui semblent naître dans l'ergastoplasme et se trouvent en grande quantité au niveau de l'appareil de Golgi. Différents types de vacuoles sont visibles dans cet appareil, à savoir des vacuoles intermédiaires et de larges vacuoles contenant des inclusions. Il parait probable que les vésicules et vacuoles jouent un rôle spécifique dans le transport et la production de polysaccharides de protéines sulfatées.

     

牵拉骺分离关节镜下切除骨桥治疗骺板部分早闭

目的 :探讨治疗儿童骺板部分早闭的手术及评价其疗效。方法 :对 8例骺板部分早闭患者采用牵拉骺分离、关节镜下切除骨桥、自体骺软骨填充、早期纠正成角及短缩畸形。结果 :随访 1～ 4年 ,1例患者骺板已生理闭合 ,7例患者骺板无早闭现象 ,无成角畸形 ,其中 2例患者有肢体缩短 ,1例 0 6cm ,1例 1cm。结论 :采用牵拉骺分离、关节镜下切除骨桥、填充自体骺软骨 ,可以防止骨桥形成。     

骺板损伤的诊断与治疗进展

骺板损伤可导致骨骺与干骺端之间形成骨桥，骺板提前闭合，造成肢体短缩和(或)成角畸形，影响儿童生长发育。早期诊断较困难，X线、CT、MRI等影像学检查及“骨桥地图法”可协助诊断。传统治疗有骨桥切除后以脂肪、骨水泥等填塞，但效果不一。近年来，随着显微外科及组织工程等新技术的开展，用培养的骺软骨细胞、间充质干细胞等移植代替无活力的填充物植入，它能不断增殖并抑制骨桥形成，将为骺板损伤治疗提供更好的解决方案。本文结合国内外最新研究成果对骺板损伤的现状进行回顾，并对其前景作一展望。     

Molybdenum-induced changes in the epiphyseal growth plate

Summary Molybdenum (Mo), at high concentrations, induces changes in the epiphyseal growth plate through its effects on copper (Cu) metabolism but it is unclear whether or not Mo can induce changes independent of its effects on copper status. To this end, the effect of Mo on longitudinal bone growth was examined in rats. Dietary Mo was given either as ammonium heptamolybdate or as ammonium tetrathiomolybdate, the latter producing a marked Cu deficiency. There was a significant reduction in longitudinal bone growth in both groups; however, growth plate width was increased only in the Cu-deficient animals due to an increase in the width of the zone of transitional/hypertrophic chondrocytes. Both glucose 6-phosphate dehydrogenase activity and cell proliferation (assessed by bromodeoxyuridine incorporation) were markedly decreased in the proliferating zone of the growth plate in both Mo-treated groups. These changes were not apparently related to changes in circulating vitamin D metabolites or insulin-like growth factor-1. The results indicate that excess Mo impairs cell proliferation within the growth plate, whereas the effects of copper deficiency are more related to chondrocyte differentiation. Thus, Mo can induce changes in longitudinal bone growth which are distinct from those resulting from Cu deficiency.     

Development and validation of new model for microvascular transplantation of epiphyseal plate allografts with minimal adjoining epiphyseal and metaphyseal bone

A model for the free allograft microvascular transplantation of rabbit proximal tibial epiphyseal plate allografts was developed, validated, and tested in an in vivo animal model. Transplants contained the minimum amount of adjacent epiphyseal and metaphyseal bone compatible with preservation of the epiphyseal-plate vascular supply, as determined by corrosion casting. Perfusion to this graft was evaluated quantitatively using radioactive microspheres, and qualitatively using India-ink injection. Female New Zealand White rabbits at 12 weeks of age were utilized. Vascularized transplantation of epiphyseal plate allografts was performed either into a defect of matched size in the iliac crest or into a soft-tissue pocket without bone contact. Cyclosporine A immunosuppression (CSA) was administered daily for 6 weeks. Two control groups underwent identical surgical procedures, but had no postoperative immunosuppression. Epiphyseal plates both with and without bone contact, in rabbits immunosuppressed postoperatively with CSA, demonstrated longitudinal growth and preserved viability as determined by positive bromodeoxyuridine uptake. Control epiphyseal plates transferred without postoperative immunosuppression were uniformly nonviable. This new model has value as a basis for further studies into the clinical applicability of isolated epiphyseal-plate transplants.     

Fractures involving the distal epiphyseal plate of the femur

Summary Forty-two fractures involving the distal femoral epiphyseal plate in 41 patients were reviewed. The average age at injury was 11.2 years. The follow up period ranged from one year to 20.3 years, with an average of 6.3 years. The Salter-Harris classification of epiphyseal plate injuries proved to be a good indicator of the mechanism of injury and prognosis. Using stringent criteria to classify the end results, 2 out of 3 of the total group and 3 out of 4 of 29 Salter-Harris Type 1 and Type II injuries had good or excellent results. Type V crushing injuries of the growth plate, open injuries, fractures caused by high velocity motor vehicle accidents with severe displacement or multiple associated fractures, and incompletely reduced epiphyseal injuries gave only poor or fair results. Major problems responsible for poor or fair results were varus or valgus angulation, loss of joint motion and shortening due to premature epiphyseal closure. Orthoradiographs revealed the presence of some degree of shortening in 20 of 29 Salter-Harris Type I and Type II injuries which averaged 1.0 cm, but was of no clinical significance in most patients. These injuries must be reduced accurately. In the Type II epiphyseal separations unsatisfactory results were due to inadequate reduction or to associated injuries.

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Résumé Quarante-deux fractures, chez 41 malades, atteignant le cartilage épiphysaire de l'extrémité inférieure du fémur ont été colligées. L'âge moyen était de 11,2 ans. La période de surveillance a varié de 1 à 20,3 ans, avec une moyenne de 6,3 ans. La classification de Salter et Harris des lésions traumatiques du cartilage de conjugaison s'est avérée un bon indicateur du mécanisme et du pronostic. En utilisant, pour définir les résultats finaux, des critères rigoureux, on a trouvé que 2 patients sur 3 dans l'ensemble, et 3 sur 4 dans les 29 lésions des types I et II, avaient de bons ou d'excellents résultats. Le type V: écrasement du cartilage de conjugaison, les traumatismes ouverts, les fractures liées à des accidents de véhicules à grande vitesse, avec des déplacements importants ou chez les polytraumatisés, et les lésions épiphysaires incomplètement réduites, ont seuls donné des résultats médiocres ou mauvais. Les éléments principaux, facteurs de ces mauvais résultats, sont les désaxations en varus ou en valgus, la perte de la mobilité articulaire et le raccourcissement dû à une épiphysiodèse prématurée. Les orthoradiographies ont montré l'existence d'un certain degré de raccourcissement dans 20 des 29 types I et II, de l'ordre d'un cm, mais sans traduction clinique dans la majorité des cas. Ces lésions doivent être réduites avec précision. Dans le type II, les résultats insuffisants sont dus à une réduction incomplète ou à l'existence de traumatismes associés.

     

Soluble and resistant proteoglycans in epiphyseal plate cartilage

The proteoglycans of cartilage occur in a form which is readily extracted (soluble) and in form which is relatively difficult to extract (resistant). Following the extraction of the soluble proteoglycans from slices of epiphyses from young rats, the distribution of the resistant proteoglycans are visualized by staining with toluidine blue. Daily quantitative recoveries of uronic acid over 7 days are used as an index of the rate and completeness of extraction. In contrast to other cartilages (nasal, costal, ear, articular) in which the resistant proteoglycans are restricted to perilacunar localizations, the resistant proteoglycans in epiphyseal plate extend across the plate as a continuous stratum and occupy extraterritorial regions. This stratum of resistant proteoglycans is difficult to identify with a specific zone in the plates of young individuals, because of primitive columniation. In more highly organized, older human and porcine epiphyseal plates, however, the stratum is clearly seen at the junction of the zones of resting and proliferating chondrocytes. It dips down a short distance between the columns, disappears and then reappears again at the level of the zone of provisional calcification. These observations are discussed in the context of endochondral growth.

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Zusammenfassung Die Knorpelproteoglycane kommen in einer leicht extrahierbaren (löslichen) und in einer relativ schwer extrahierbaren (resistenten) Form vor. Nach der Extraktion der löslichen Proteoglycane aus Epiphysenschnitten junger Ratten wird die Verteilung der resistenten Proteoglycane durch Toluidinblau-Färbung aufgezeigt. Als Index für die Geschwindigkeit und Vollständigkeit der Extraktion wird die tägliche quantitative Ausbeute von Uronsäure während 7 Tagen verwendet. Im Gegensatz zu anderen Knorpelarten (Nasen-, Rippen-, Ohren- und Gelenkknorpel), bei welchen die resistenten Proteoglycane nur perilacunär vorkommen, gehen die resistenten Proteoglycane der Epiphysenplatte über die Platte als zusammenhängende Schicht hinaus und treten in extraterritorialen Bereichen auf. Diese Schicht resistenter Proteoglycane kann in den Platten junger Individuen wegen der ursprünglichen Säulenbildung nur schwierig als eine bestimmte Zone identifiziert werden. In höher organisierten, älteren Epiphysenplatten des Menschen und des Schweines ist die Schicht jedoch deutlich an der Berührungsstelle der Zonen ruhender und proliferierender Chondrocyten ersichtlich. Sie setzt sich eine kurze Strecke zwischen den Säulen fort, verschwindet dann aber und erscheint wieder auf der Höhe der vorläufigen Verkalkungszone. Diese Beobachtungen werden mit dem endochondralen Wachstum in Zusammenhang gebracht.

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Résumé Les protéoglycanes du cartilage se présentent sous une forme que l'on peut extraire facilement (soluble) et sous une formule difficile à extraire (résistante). Après extraction de protéoglycanes de coupes d'épiphyses de jeunes rats, le répartition des protéoglycanes résistantes est visualisée par coloration au bleu de toluidine. La détermination quantitative quotidienne d' acide uronique pendant 7 jours est utilisée comme indice de la vitesse et de l'efficacité de l'extraction. Contrairement à d'autres cartilages (nasal, costal, oreille, articulaire) où les protéoglycanes résistantes sont limitées à des régions périlacunaires, les protéoglycanes résistantes de la métaphyse s'étendent au-delà sous forme d'une couche continue et occupent des régions extra-territoriales. Cette couche de protéoglycanes résistantes est difficile d'identifier avec une zone spécifique dans la métaphyse de jeunes individus, par suite d'un alignement primitif. Cependant au niveau de métaphyses humaines ou de porcs plus âgés, cette couche est nettement visible à la jonction des zones de chondrocytes au repos et en division. Elle s'étend sur une courte distance entre les cellules sériées, disparait et réapparait à nouveau au niveau de la zone de calcification temporaire. Ces résultats sont discutés en fonction de la croissance enchondrale.

     

骨骺生长滑动钢板的设计及动物实验研究

目的：设计一种骨骺部可滑动延长钢板，通过动物实验了解该钢板在动物体内能否在有效固定骨折的同时，又能减轻对骨骼纵向生长的抑制，减少肢体畸形的发生。方法：根据儿童、青少年股骨髁部的解剖特点设计出适用于儿童、青少年股骨髁部骨折的内固定滑动钢板。实验动物选30只1．5月龄健康山羊，12只为正常对照组，余18只为钢板内固定组，其中右后肢采用普通钢板固定，左后肢采用滑动钢板固定。术后不同时相点对所有山羊双侧股骨进行X线摄片检查和使用组织化学、电镜观察评估骨骺细胞的生长情况。结果：X线摄片检查钢板内固定组在术后1d双侧股骨长度差异无统计学意义，在术后1、2、4、6个月双侧股骨长度差异有统计学意义，可滑动延长钢板侧股骨长度明显长于普通钢板侧，股骨长度术后l、2、4、6个月分别与术后1d增长的数值进行比较分析，普通钢板侧和正常对照组右侧股骨长度差异有统计学意义，可滑动延长钢板侧和正常对照组左侧股骨长度差异无统计学意义（尸〉0．05）；光镜观察示滑动组骨骺板总厚度及肥大细胞计数均明显大于普通钢板固定组（尸〈0．01）；Safranine0组织化学观察示滑动组于术后3、6个月SafranineO组织化学染色明显深于普通组；电镜观察示滑动组于术后3、6个月软骨增殖区软骨细胞分裂及生长活跃。结论：动物实验证实可滑动钢板在动物体内随骨骺的生长可自动延长，对骺板无加压抑制作用，能明显减少继发骺板损伤，不会产生骨骺生长抑制、骨骺早闭，符合发育期骨骺生长的生理特点。     

Shear strength of the human femoral capital epiphyseal plate.

After the determination of the shear strength and modes of failure of the capital femoral epiphyseal plates in twenty-five pairs of hips obtained post mortem from children five days to fifteen years and ten months old, with the plate intact on one side and with the perichondrial fibrocartilaginous complex removed on the other, the gross and microscopic morphology was studied. The shear strength of the human epiphyseal plate varied with age and was greatly dependent on the surrounding perichondrial complex in infancy and early childhood, but less so in adolescence. When this complex was excised, the strength of the epiphyseal plate was diminished, especially in specimens from younger children. The forces necessary to cause slipping were found to be within the physiological range of the force that would be generated in overweight children, suggesting that purely mechanical factors may play a major role in the etiology of slipped capital femoral epiphysis.     

Histological and biological changes in the epiphyseal plate during fracture healing

The alterations that the epiphyseal plate undergoes during fracture healing are well documented microscopically, yet there are no reports in the literature which discuss the cellular and molecular changes that accompany this process. We studied fracture healing in 49 Wistar rats (5 weeks old) in which we inflicted a fracture to the distal third of the femur of the right hind leg (experimental side). The rats were killed 2 weeks later, and we dissected both hind legs from the hip joint to the knee joint, detaching all the surrounding soft tissues. We manually detached the distal epiphyses and the epiphyseal plates from both femurs. A piece of the epiphyseal plate was removed from the epiphyseal side of the femurs. In 25 animals, we analyzed the DNA content. In 8 animals, the specimen was studied under an electron microscope, and in the remaining 16 animals, the control and experimental sides were studied histologically. We found that healing was accompanied by an increase in DNA content, by a change in cellular activity, and by greatly accelerated apoptosis. Received: December 7, 2000 / Accepted: August 22, 2001     

Microscopic examination of a naturally occurring epiphyseal plate fracture

We had the opportunity to examine a naturally occurring Salter-Harris Type I fracture in the distal tibia of a 9-year-old boy. The injury was simultaneous with traumatic amputation of the extremity a few centimeters distal to the knee. The epiphyseal plate was examined microscopically, and the plane of cleavage was found not to be uniform, but to involve the zones of resting, proliferating, hypertrophying, and provisionally calcified cartilage cells. We hope by demonstrating the inconsistency of the cleavage plane in this case to assist in understanding the complexity of physeal fractures and the unpredictable results that occasionally occur.     

骺板损伤动物模型及制备方法

骨骺骨折并发骺板损伤临床多见,损伤分型与其临床诊断、治疗及预后密切相关。临床骺板损伤由内翻、外翻、剪切、压缩等不同组合的外力所致。目前常用的骺板损伤动物模型的制备方法克氏针钻孔法、磨钻法、直接刮除法、凿除法、手动成角法及重锤敲击法等,很难复制出与临床一致的骺板损伤类型。该文就骺板损伤动物模型制备方法及相关问题作一综述,并对统一制备骺板损伤模型的可能方法进行了设想。