^(60)Coγ射线小剂量照射处理异体骨软骨移植修复关节软骨缺损的效果

Effects of low-dose irradiated osteochondral allograft with ^(60)Co gamma ray in the reparation of articular cartilage defect

目的:选择Coγ射线小剂量照射处理异体骨软骨移植物,观察辐射对60软骨组织形态的影响和移植修复关节软骨缺损的效果。方法:实验于2004-04在泰山医学院基础研究所完成。选取清洁级2～3月龄的新西兰兔47只,随机取17只作为供体,在内、外侧股骨髁关节面上切取柱状骨软骨块30块,分为5组:非辐射组、2.5Gy照射组、5.0Gy照射组、7.5Gy照射组、10Gy照射组,6块/。其余30只兔作为受组体。非辐射组不采取任何处理措施,剩余4组采用Co单次照射处理,60照射野3.5cm×3.5cm,照射距离76cm,照射剂量分别为2.5,5.07.5,,10Gy。照射后将每组移植物分为2份,一份直接进行组织形态学等项目检测,另一份植入受体兔膝关节内。结果:实验选取47只兔,17只作为供体制作柱状骨软骨块移植物30块,剩余30只兔作为受体进入结果分析。①移植物植入后各组膝关节大体观察:各组修复的关节均恢复原有轮廓,滑膜轻度增生,关节面平滑,与周围正常软骨相比无明显差异,可辨明与周围组织的分界。②移植物植入后各组组织形态学观察结果:各组均有一定程度的修复,以5.0Gy照射组修复效果最佳。③照射后各组移植物中透明软骨细胞计数的定量分析:非辐射组、2.5Gy照射组、5.0Gy照射组基本相似(P>0.05),但均明显高于7.5,10Gy照射组犤1001.33±62.47),((1061.50±74.58),(1075.33±83.87),(893.67±25.52),(882.50±46.75,)个P<0.05犦④照射后各组移植物中S-100阳性细胞计数的定量分析:。2.5Gy照射组、5.0Gy照射组基本相似(P>0.05),但均明显高于7.5Gy照射组、10Gy照射组及非辐射组犤301.33±18.49),(326.33±41.89),((289.83±22.44),(279.33±18.93284.50±27.65)个,P<0.05犦⑤照射),(。后各组移植物中Ⅱ型胶原含量百分比的测定:非辐射组及2.5,5.07.5,,10Gy照射组基本相似犤72.24±3.30)%,(72.20±2.16)%,(71.34±2.38)%,((72.66±3.77)%,(72.73±3.48)%,P>0.05犦⑥照射后各组移植物中Ⅱ型。胶原荧光强度定量分析:5.0Gy照射组明显高于2.5,5.0,7.5,10Gy照射组及非辐射组犤29.79±8.9116.74±3.5518.33±3.79),(19.23±4.74),(),(),((16.63±3.39)A,P<0.05犦。结论:经γ射线辐射处理后,移植物中仍有大量的软骨细胞存活,其修复关节软骨缺损的近期效果较好;以5.0Gy照射剂量修复效果最佳。

AIM： To observe the effect of irradiated osteochondral allograft with ^60Coγ ray at low dose on the formation of cartilage tissue and the reparative effect on articular cartilage defect. METHODS： The experiment was conducted at the Basic Institute of Taishan Medical Collage in April 2004. Forty-seven clean-grade New Zealand rabbits aged two to three months were selected. Seventeen of these rabbits were selected as donators at random. Thirty cylindrical grafts were harvested from the weight-bearing surface of both condyles of the medialis and lateral femur. These plugs taken from condyles were divided into 5 groups： non-irradiated group, 2.5 Gy group, 5.0 Gy group, 7.5 Gy group and 10 Gy group with 6 in each group. Other 30 rabbits were regarded as recipients. Rabbits in the non-irradiated group were not irradiated and those in the rest groups were singly irradiated with different dose of ^60Coγ ray： 2.5 Gy, 5.0 Gy, 7.5 Gy and 10 Gy with the irradiation field of 3.5 cm× 3.5 cm and irradiation distance of 76 cm. Then, the plugs of each group were divided into 2 portions. One portion was evaluated with histological and morphological detection; the other portion was implanted into knee joints of the receptors. RESULTS： Forty-seven rabbits were selected in the experiment, 30 cylindrical grafts were harvested from 17 of these rabbits as donators. The rest 30 rabbits were regarded as recipients and involved in the result analysis. ①The general observation of the knee joints of every group after implantation： Prosthetic joints in every group all recovered to the original outline. Synovial membrane was slightly hyperplasia. Surface of grafts was smooth and shining, indistingishable from the surrounding. The dividing line between grafts and surrounding tissue was distinguishable. ②The histological and morphological results of the implanted grafts in every group： All the experimental dose of gamma ray could promote the repair of full thickness cartilage defect and 5.0 Gy was the best. ③The quantitative analysis of hyaline cartilage cells in the irradiated grafts of every group： That in the non-irradiated group and 2.5 Gy group and 5.0 Gy group were similar （P 〉 0.05）, but the three groups were better than 7.5 Gy group and 10.0 Gy group [ （ 1001.33 ±62.47 ）, （ 1 061.50±74.58 ）, （ 1 075.33 ±83.87 ）, （893.67±25.52）, （882.50±46.75） pieces,P 〈 0.05]. ④The quantitative analysis of S-100 positive cells in the grafts of every group： That in the 2.5 Gy group was similar to that in the 5.0 Gy group （P 〉 0.05）, but was markedly better than the rest three groups [（301.33±18.49）, （326.33±41.89）, （ 289.83±22.44）, （ 279.33±18.93 ）, （ 284.50±27.65 ）piece, P 〈 0.05]. ⑤The determination of content percentage of type Ⅱ collagen in the grafts of every group： It was similar among the 5 groups [（72.24±3.30）, （72.20±2.16）,（71.34 ±2.38）, （72.66 ±3.77）, （72.73 ±3.48）% ,P 〉 0.05]. ⑥The quantitative analysis of fluorescence intensity of collagen Ⅱ in the irradiated grafts of every group： It in the 5.0 Gy group was the best in these groups [（29.79±8.91 ）, （ 16.74±3.55）, （18.33±3.79）, （ 19.23±4.74）, （ 16.63±3.39）A ,P 〈 0.05]. CONCLUSION： In the grafts, a large number of cartilage cells survive after the irradiation of γ ray. Immediate effect is better in the plerosis of articular cartilage defect, and 5.0 Gy is the best.