骨软骨镶嵌成形术修复骨软骨复合缺损的比较研究

目的观察采用骨软骨镶嵌成形术（Mosaicplasty）修复膝关节中等和大面积骨软骨复合缺损的效果,为临床应用提供理论依据。方法24只成年山羊随机分成3组（n=8）。中等面积缺损组在股骨内髁制造直径6mm缺损,植入直径2mm骨软骨柱修复;大面积缺损组于股骨内髁制造9mm直径缺损,以直径3mm骨软骨柱修复;对照组于股骨内髁制造直径6mm缺损后不修复。自股骨髁间窝和滑车沟两侧非负重区用自制Mosaicplasty器械钻取骨软骨柱,推出器嵌入缺损处镶嵌填满。术后4、8、16及24周处死动物,取修复骨软骨组织行大体观察、HE及甲苯胺蓝染色。术后24周,取大面积缺损组和对照组膝关节摄X线片,观察骨软骨缺损修复情况,并分别取修复组织及正常软骨组织行蛋白聚糖（glycosaminogly cans,GAG）含量测定。结果中等面积缺损组术后4周,移植的骨软骨柱与基底部骨床结合牢固;8-24周软骨层之间以及与正常软骨间界限仍清晰。大面积缺损组术后4周,移植的骨软骨柱与基底骨床结合牢固,部分骨软骨柱被压入骨床内;8-24周压陷程度加重,与股骨髁相对关节面的部分软骨被磨损。对照组24周缺损仍无明显修复迹象,与股骨髁相对关节面的软骨磨损剥脱。组织学观察结果类似大体观察,术后24周中等及大面积缺损组软骨柱间均有缝隙存在,大面积缺损组毗邻软骨细胞稀疏肥大。术后24周,X线片可见大面积缺损组软骨下骨愈合良好,而对照组仍可见骨质缺损,与股骨髁相对关节面的软骨局部骨质硬化;软骨GAG含量测定显示正常软骨和大面积缺损组修复组织间差异无统计学意义（P〉0.05）;前两者与对照组修复组织比较,差异均有统计学差异（P〈0.05）。结论Mosaicplasty可修复中等面积骨软骨复合缺损,但无法有效修复大面积缺损,效果有待改进。

COMPARATIVE STUDY ON REPAIR OF MEDIUM AND LARGE-SIZED OSTEOCHONDRAL COMPOUND DEFECTS WITH MOSAICPLASTY

Objective To investigate the effectiveness of mosaicplasty in repair of large-sized osteochondral compound defects and the integrity of transplanted tissue with recipient sites so as to lay a foundation for clinical application. Methods Twenty-four adult goats were divided into 3 groups randomly. The diameters of defect were 6 mm for the medium-sized defects and 9 mm for the large-sized defects, which were created by a trepan. All of the defects were repaired with osteochondral plugs in diameters of 2 mm(the medium-sized defects) or 3 mm(the large-sized defects). The osteochondral plugs were harvested around the intercondylar fossa or intertrochlea groove, and pressed into the recipient sites by specialized instruments in a mosaic mode. No internal fixation was needed and the animal were allowed to move freely after operation. From 4 to 24 weeks postoperatively, the specimens were observed in gross and under electromicroscopy. X-ray detection and glycosaminoglycan(GAG) analysis were also performed to testify the healing process and the integrity of the cartilage and subchondral bone. Results The transplanted subchondral bone was integrated firmly with each other or with recipient sites in both mosaicplasty groups. But 24 weeks postoperatively, transplanted cartilage was not integrate with each other apparently. Obvious cleavage between cartilage plugs could be seen. But in the large-sized defect groups, some of the osteochondral plugs were relapsed into the defects leaving the recipient sites some steps, leading to some degree of abrasion in the opposing articular cartilage. There was no significant difference in the GAG content between the transplanted cartilage and normal cartilage. X-ray analysis also demonstrated the healing process between the subchondral bone. Conclusion Mosaicplasty can repair the medium or small-sized osteochondral defects efficiently.