Staple半侧加压造成山羊胸椎不平衡发展的组织学观察

Histology of thoracic vertebral imbalanced development in goats after hemiepiphyseal staple compression

目的通过对Staple固定、加压生长期山羊胸椎的组织学观察,探讨加压侧对脊柱生长发育的影响。方法 9只未成年雌性山羊随机分为实验组(n=6)和对照组(n=3);实验组采用单侧多节段(T6-T11)跨椎间隙Staple固定;对照组只作相同切口暴露,不进行固定。4个月后获取T8、T9间隙(对照组相应节段)椎间盘及生长板,采用HE、Giemsa染色,镜下观察生长板及椎间盘情况。结果对照组未出现脊柱侧凸畸形,两侧生长板高度以及生长板肥大层细胞和终板软骨细胞形态无明显差异。实验组出现轻度脊柱侧凸畸形,术后4个月Cobb角为17.9°±5.6°;椎间隙上方生长板高度:加压侧(1.27±0.34)mm低于非加压侧的(2.05±0.19)mm,椎间隙下方生长板高度加压侧(0.77±0.31)mm也低于非加压侧的(2.1±0.29)mm;加压侧生长板肥大层细胞数量少、形态异常、排列不规则,非加压侧生长板肥大层细胞排列整齐,细胞形态饱满,胞质丰富,细胞核完整,与对照组无差别;终板软骨细胞也呈同样变化,加压侧与非加压侧软骨细胞数量明显减少,排列不紧密,细胞体积小,胞质较少,胞核扁平。结论半侧固定、加压抑制了固定侧脊柱生长板及终板软骨细胞的发育,可造成脊柱两侧不平衡发展。

Objective To study the effect of hemiepiphyseal compression on spinal growth by observing the histology of thoracic vertebrae after staple fixation. Methods Nine premature female goats were randomly divided into experimental group （n=6） and control group （n=3）. Thoracic vertebrae of T6-Tll in experimental group were fixed with unilateral multi-segment cross intervertebral space staple fixation and those in control group were exposed but not fixed. Intervertebral disc and growth plates were taken from T8-T9 4 months after operation and observed with H＆E and Giemsa staining. Results No scoliosis occurred in control group with no significant difference found in the height of growth plate, morphology of mastocytes in growth plate and chondrocytes in end plate. Mild scoliosis occurred with a Cobb angle of 17.9 °±5.6° in experimental group 4 months after operation. The height of growth plate over and below the intervertebral disc was significantly shorter in the compression side than in the non- compression side （1.27 ±0.34 mm vs 2.05 ±0.19 mm, 0.77 ±0.31 mm vs 2.1 ±0.29 mm）. The number of mastocytes was smaller in the compression side than in the non-compression side with no significant difference between experimental group and control group. The morphology of mastocytes in growth plate was abnormal and the mastocytes in growth plate were irregularly arranged while the mastocytes in growth plate were regularly arranged and their morphology was normal with rich cytoplasm and intact nuclei in the compressed side of experimental group. The number, volume and cytoplasm of chondrocytes were smaller, the chondrocytes were less compactly arranged in end plate and the nuclei of chondrocytes were flatter in the compression side than in the non-compression side of experimental group. Conclusion Unilateral fixation of thoracic verterbrae and hemiepiphyseal compression inhibit the growth of growth plate and development of chondrocytes, thus leading to imbalanced development of spine at both sides.