论文标题:低强度脉冲超声促进兔膝关节软骨缺损修复的实验研究
Low-Intensity Pulsed Ultrasound Accelerates Repair of Articular Cartilage Defect
论文作者 贾小林
论文导师 陈文直；王智彪,论文学位 硕士,论文专业 肿瘤学
论文单位 重庆医科大学,点击次数 92,论文页数 63页File Size1281k
2003-05-01论文网 http://www.lw23.com/lunwen_177409967/ 低强度脉冲超声,关节软骨,缺损,修复,频率
LIPU,articular cartilage,defect,repair,frequency
背景和目的：关节软骨损伤自我修复能力极其有限，其修复是矫形外科的难题之一, 迄今仍无令人满意的治疗方法。较多的研究表明低强度脉冲超声可以促进骨折愈合，其机理可能是加速了软骨内化骨的过程。同理，在软骨缺损的修复过程中，可以辅以低强度脉冲超声。为此，本课题的确立是基于以下目的：（1） 探讨低强度脉冲超声是否能促进关节软骨缺损修复。（2）在超声强度、治疗时间一致的条件下，筛选最佳的频率参数。方法：（1）造成33只成年新西兰兔双侧股骨髁间窝直径3.0mm、深5.0mm的骨软骨缺损，将其作为关节软骨缺损动物模型，并将实验兔随机分为3组。左后肢关节软骨缺损处以声强30mW/cm2、频率1.5MHz的低强度脉冲超声体外辐照，每天治疗一次，每次20分钟。右后肢予以假照作为对照。各组实验兔分别于术后２周、4周和8周处死。采用大体评分、组织学评分及甲苯胺蓝染色光密度值等指标评价软骨缺损修复情况。所有数据均采用配对t检验进行统计学分析。（2）以同样方法对30只成年新西兰兔进行造模，随机分为二组。其中一组共30条后肢随机分为3组，分别以0.6MHz 、1.0MHz及1.5MHz频率，30mW/cm2强度的超声体外照射，每天一次，每次20分钟。均于术后4周处死。进行大体评分、组织学评分及甲苯胺蓝染色光密度值等指标评价软骨缺损的修复情况。另一组共30条后肢也随机分为3组，进行同样的处理，取修复组织进行SDS-聚丙烯酰胺凝胶电泳，得到Ⅱ型胶原在样本中的相对含量比值。所有数据均进行分组设计方差分析，组间比较进行q检验。结果：（1）可行性研究中，各组实验侧大体评分及组织学评分均比对照侧高，结果有显著性差异(P＜0.05)。而且，第四周及第八周实验侧甲苯胺蓝染色光密度值均比对照侧高，差异有显著性(P＜0.05)。（2）筛选最佳频率参数的研究中，各组间大体评分和样本中Ⅱ型胶原相对含量比值无显著性差异（P＞0.05），但0.6MHz组组织学评分和甲苯胺蓝染色光密度值比其他两组高，差异有显著性（P＜0.05）。结论：（1）低强度脉冲超声对关节软骨缺损修复的各个阶段都有促进作用，可以提高关节软骨缺损修复组织基质中蛋白多糖含量，是一种无创、安全、方便、经济的治疗手段。（2）0.6MHz频率的低强度脉冲超声较1.0MHz和1.5MHz的超声明显提高关节软骨缺损修复组织基质中蛋白多糖的含量，这对恢复关节软骨功能有重要作用
Background and objectives: Repair of damaged articular cartilage is one of the most difficult problems in orthopaedics and no satisfactory treatment modality has been found in this field. Low-intensity pulsed ultrasound (LIPU) can accelerate bone healing via upregulation of cartilage formation and maturation phases of endochondral bone formation. In this study, we investigated if LIPU could accelerate repair of articular cartilage defect and found out the optimal parameter in frequency of LIPU to accelerate repair.Methods: (1) 33 healthy adult New Zealand White rabbits with 3.0 mm in diameter by 5.0 mm deep osteochondral defect in the intercondylar fossa of each femur were randomly assigned into 3 groups. Exterior LIPU exposure was made to the left femur intercondylar fossa with a intensity of 30 mW/cm 2 at a frequency of 1.5 MHz for 20 minutes daily. False exposure was made to the right as control. Groups of 11 animals each was sacrificed at 2, 4 and 8 weeks postoperatively for gross appearance grades, histological grades and toluidine blue staining to assess the effect of LIPU. All the data were analyzed by matched paired student test. (2) 30 healthy adult New Zealand White rabbits were divided into 2 groups randomly to investigate the effects of different frequencies. The first 30 knees with the same osteochondral defects, which wereto be treated by the ultrasound in the same way, were divided into 3 groups at random: 0.6MHz, 1.0MHz and 1.5MHz. The animals were sacrificed at 4 weeks postoperatively for gross appearance grades, histological grades and toluidine blue staining. The other 30 knees received the same disposal for SDS-PAGE, and then the ratios of collagen Ⅱ in the samples were got. All the data were analyzed by one way analysis of variance.Results: (1) Ultrasound-treated defects had significantly improved gross appearance grades and histological grades at 2, 4 and 8 weeks postoperatively and significantly improved optical density of toluidine blue at 4 and 8 weeks postoperatively compared with nontreated controls (both p < 0.05). (2) 0.6MHz-treated defects had significantly improved histological grades and optical density of toluidine blue compared with 1.0MHz and 1.5MHz (p < 0.05), while no significant differences were got in gross appearance grades and the ratios of collagen Ⅱ in the samples among different frequency groups.Conclusions: (1) LIPU can accelerate repair of articular cartilage defect with proteoglycan increased in the repaired tissues. LIPU is a noninvasive, safe, convenient and economical treat modality. (2) Different frequencies have different biological effects. LIPU with a frequency of 0.6MHz can increase more proteoglycan of repaired tissues, which is essential to the function of articular cartilage, than that of 1.0MHz and 1.5MHz
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