Bylski-Austrow Donita I, Wall Eric J, Glos David L, Ballard Edgar T, Montgomery Andrea, Crawford Alvin H
Division of Pediatric Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA.
J Bone Joint Surg Am. 2009 Mar 1;91(3):584-93. doi: 10.2106/JBJS.G.01256.
Hemiepiphysiodesis is a potential method to treat idiopathic juvenile scoliosis early. The purpose of the present study was to investigate a mechanism of curve creation in the pig thoracic model of spinal hemiepiphysiodesis by determining whether the structure of the vertebral growth plate varied with distance from the stapled, concave side of the spine. The hypotheses were that the heights of the hypertrophic zone, hypertrophic cells, and disc would be decreased on the treated side of the treated level as compared with both an unstapled control level and the side opposite the staple.
Custom spine staples were implanted into six midthoracic vertebrae in each of five skeletally immature pigs. After eight weeks, the spines were harvested and histological sections were prepared. Hypertrophic zone height, hypertrophic cell height and width, and disc height were measured at discrete coronal plane locations at stapled and unstapled thoracic levels. Differences between stapled and unstapled levels and locations were compared with use of mixed linear modeling for repeated measures, followed by regression models to determine growth plate intercept and slope across the plane by thoracic level.
Zone height, cell height, and cell width were lowest on the stapled side of the stapled level, with significant differences in the overall statistical model (p < 0.02). Disc heights were significantly reduced (p < 0.0001) at the stapled levels across the coronal plane.
Unilateral control of intervertebral joint motion decreased growth plate height, cell size, and disc height.
半椎体骨骺阻滞术是早期治疗特发性青少年脊柱侧凸的一种潜在方法。本研究的目的是通过确定椎体生长板的结构是否随距脊柱固定凹侧的距离而变化，来研究猪胸椎半椎体骨骺阻滞模型中脊柱侧凸形成的机制。假设是与未固定的对照节段和固定钉对侧相比，在治疗节段的治疗侧，肥大带、肥大细胞和椎间盘的高度会降低。
将定制的脊柱固定钉植入5只骨骼未成熟猪的每只猪的6个胸椎中段椎体。8周后，取出脊柱并制备组织学切片。在固定和未固定的胸椎节段的离散冠状面位置测量肥大带高度、肥大细胞高度和宽度以及椎间盘高度。使用重复测量的混合线性模型比较固定和未固定节段及位置之间的差异，然后使用回归模型确定每个胸椎节段整个平面上生长板的截距和斜率。
在固定节段的固定侧，带高度、细胞高度和细胞宽度最低，在总体统计模型中有显著差异（p < 0.02）。在整个冠状面上，固定节段的椎间盘高度显著降低（p < 0.0001）。
单侧控制椎间关节运动可降低生长板高度、细胞大小和椎间盘高度。
