保留钙化层结构的猪股骨滑车全厚软骨缺损模型建立

AN ANIMAL MODEL FOUNDATION OF ARTICULAR FULL-THICKNESS CARTILAGE DEFECT BY SAVING CALCIFIED CARTILAGE ZONE ON FEMORAL TROCHLEA IN PORCINE

目的建立保留钙化层结构的猪股骨滑车全厚软骨缺损模型,为观察组织工程软骨在保留钙化层的膝关节软骨缺损模型中的修复效果提供良好的实验研究平台。方法选取6月龄清洁级贵州小香猪9只,体重40～50 kg,用标准的软骨缺损制作套件在其右后肢股骨滑车切迹旁制备直径6 mm、深0.2～0.5 mm、不伤及钙化层结构的圆柱形全厚软骨缺损模型。造模4周后行3.0T MRI观察,取材后进行大体、体视显微镜观察及固绿-番红O、阿利新蓝、天狼星红组织学染色观察缺损处软骨修复情况。结果造模后实验动物均存活,术后切口无感染,无髌骨脱位;术后即可下地行走并部分负重,1周后均能自由活动,无跛行。造模后4周,MRI检查可见滑车处有明显连续信号中断,异常信号深及软骨下骨,缺损周边深层未见明显信号异常。标本大体观察示缺损底部有少量填充物、出血点,与周围正常软骨界限清楚。体式显微镜观察示钙化层基本完整,缺损局部软骨下骨板有塌陷。普通显微镜下,固绿-番红O及阿利新蓝染色示缺损处无软骨细胞及染料着色;偏光显微镜下,天狼星红染色示缺损底部被连续、强折光性的纤维组织少量填充。结论通过该造模方法制作的不伤及钙化层结构的猪股骨滑车全厚软骨缺损模型,可用于骨关节炎早期软骨病变修复的研究及猪软骨钙化层结构作用研究的动物模型。

Objective To establish a porcine model of articular full-thickness cartilage defect characterized by remaining cartilage calcified zone on femoral trochlea, so as to provide a considerable and comparative control group for investigating repair effects of tissue engineered scaffolds in articular cartilage defects with cartilage calcified zone remaining. Methods The full-thickness cartilage column defects （6 mm in diameter, 0.2-0.5 mm in depth） without damage on calcified cartilage zone were made on the femoral trochlea in 9 clean-grade 6-month-old Guizhou minipigs by standard cartilage-defect- making suites. Microscopical observation was performed after modeling. Scanning were made by 3.0T MRI at 4 weeks. Then general observation, stereomicroscope, and histological staining were used to observe cartilage repair. Results All animals were alive. No infection of incisions or patellar dislocations occurred; they were able to walk with partial weight-bearing immediately after surgery and could move freely without limp at 1 week. Obvious signal discontinuity in trochlea and subchondral bone could be observed in MRI, without deep signal change in defects surrounding. Microscopical observation showed a few repair tissueand petechia at base of the defect with clear boundary. Nearly intact calcified zone of cartilage and zonal collapse of subchondral bone in defects could be observed with stereomicroscope. Under common microscope, no chondrocytes was found in defects, as well as negative staining of fast green-safranin 0 and alcian blue. Under polarized microscope, the bottom of defects were filled with a little of fibrous tissue presenting continuous and strong light-refraction by sirius red staining. Conclusion The animal model of articular full-thickness cartilage defect on femoral trochlea by standard cartilage-defect-making suites can be applied for the research of cartilage disease in early human osteoarthritis and function of calcified cartilage zone in pig.