| 摘要: |
| 目的：探讨不同直径可吸收聚消旋乳酸棒(poly-D,L-lactide acid,PDLLA)植入对幼兔股骨远端骺板生长的影响。方法：采用封闭群系5周龄新西兰大白兔75只，随机分为3组，每组25只。在幼兔右侧股骨远端跨骺板中心分别植入直径为1.5、2.2、3.2 mm的PDLLA棒;在左侧骺板造成同样大小的钻洞，不植入PDLLA棒，作为对照。术前计算骺板损伤面积，术后3、6、9、12、24周处死动物。通过测量双侧股骨长度、双侧膝关节外翻角、组织病理学和透射电镜等方法观察PDLLA棒对骺板生长的影响。结果：1.5、2.2、3.2 mm组钻洞所造成的骺板损伤分别占骺板面积的(1.86±0.10)%、(4.03±0.52)%、(7.52±1.02)%；术后24周实验侧和对照侧的股骨长度(单位：mm)分别为：90.60±0.55、90.27±0.84,87.53±0.67、87.06±0.78，85.30±1.39、84.91±1.40；双侧膝关节外翻角(单位：°)分别为：7.86±1.26、8.11±1.18,8.86±1.30、9.45±1.95，11.90±2.80、14.45±5.17。各组内实验侧和对照侧相比，双侧股骨长度、外翻畸形无明显差异(P>0.05)，但3.2 mm组较1.5 mm、2.2 mm组双侧股骨长度出现短缩。镜下各组实验侧和对照侧软骨细胞生长形态无异常，没有发现明显的炎症反应，仅可见轻微非特异的异物反应，部分巨噬细胞浸润。结论：PDLLA棒本身不会对骺板生长造成不良的影响。骺板生长是否出现阻滞，取决于骺板损伤面积的大小，超过骺板横截面积约7%，就可能导致骺板生长受到抑制。 |
| 关键词: 聚消旋乳酸 骺板 生长 |
| DOI：10.3724/SP.J.1008.2007.00978 |
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| 基金项目: |
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| Effect of absorbable poly-D,L-lactide acid rod on development of rabbit epiphyseal plate |
| YE Yan-ping,CHEN Ai-min* |
| (Department of Orthopaedics,Changzheng Hospital,Second Military Medical University,Shanghai 200003,China) |
| Abstract: |
| Objective：To assess the influence of absorbable poly-D,L-lactide acid (PDLLA) rods on the development of epiphyseal plate after implanted into the distal femoral epiphysis in skeletally immature New Zealand white rabbits.Methods: Seventy-five New Zealand white rabbits were evenly randomized into 3 groups according to the diameter of rods:1.5 mm PDLLA rod group,2.2 mm PDLLA rod group,and 3.2 mm PDLLA rod group.The absorbable PDLLA rods were placed into a drill hole of equal size in the intercondylar portion of the right femur,crossing the central portion of epiphyseal plate; empty drill holes of same size were made across the left femoral physis,which served as a control.The area of injured epiphyseal plates was calculated before operation.The animals were sacrificed at 3,6,9,12 and 24 weeks after operation.Measurement of femur bone length,radiographic measurement of both knee joint valgus angles,histology sections and transmission electron microscopic examination of the physis and adjacent bones were performed to evaluate the influence of implanted rods on epiphyseal plate.Results: The proportions of injured area caused by the drill holes in 1.5 mm group,2.2 mm group,and 3.2mm group were (1.86±0.10)%,(4.03±0.52)% and (7.52±1.02)%,respectively.At 24 weeks after operation,femur bone lengths (mm) of experimental and control sides were 90.60±0.55 and 90.27±0.84 in 1.5 mm group,87.53±0.67 and 87.06±0.78 in 2.2 mm group,and 85.30±1.39 and 84.91±1.40 in 3.2 mm groups, respectively; their knee joint valgus angles (°) were 7.863±1.26 and 8.110±1.18 in 1.5 mm group,8.858±1.30 and 9.453±1.95 in 2.2 mm group,and 11.90±2.80 and 14.448±5.17 in 3.2 mm group,respectively.There was no significant difference in femur lengths and valgus angles between 2 sides in each group(P>0.05).Both femur bone lengths in 3.2mm group were shorter than those in the 1.5 mm and 2.2 mm groups.No abnormalities of cartilage cells were observed,without obvious histological evidence of inflammation; only nonspecific foreign body reaction and macrophage infiltration were noticed.Conclusion: PDLLA rod itself does not cause any disturbance to the development of the epiphyseal plate.The growth disturbance of epiphyseal plate depends on the area of injured epiphyseal plate; a injured area over 7% of epiphyseal plate may cause the growth disturbance of epiphyseal plate. |
| Key words: poly-DL-lactic acid epiphyseal plate growth |
