Martina Hansens Hospital, Box 23, 1306 Bærum, Norway.
Knee Surg Sports Traumatol Arthrosc. 2012 Feb;20(2):197-209. doi: 10.1007/s00167-011-1596-8. Epub 2011 Sep 3.
Discrepancies and variances in outcome following different surgical techniques for cartilage repair are poorly understood. Successful repair relies on proper tissue filling without initiating degenerative processes in the cartilage-bone unit. Consequently, the objective of the current study was to compare two available techniques for cartilage repair, i.e., microfracture technique and mosaic plasty, regarding tissue filling and subchondral bone changes in an experimental model.
A 4-mm pure chondral defect was created in the medial femoral condyle of both knees in New Zealand rabbits, aged 22 weeks. A stereomicroscope was used to optimize the preparation of the defects. In one knee (randomized), the defect was treated with microfracture technique whereas in the other with mosaic plasty. The animals were killed at 12, 24 and 36 weeks after surgery. Defect filling, new bone formation above the level of the tidemark and the density of subchondral mineralized tissue were estimated by histomorphometry.
Mosaic plasty resulted in a significantly 34% higher degree of tissue filling than microfracture technique at 36 weeks, SD of mean difference being 34%. Mosaic plasty resulted in significantly more new bone formation and reduced subchondral mineralized tissue density compared to microfracture technique. The differences between the two techniques were apparent mainly at the long-term follow-up.
Tissue filling is a limiting factor regarding microfracture technique when compared to mosaic plasty, whereas mosaic plasty resulted in more bone changes than microfracture technique-the implications of the latter remain to be settled. This study underlines the difficulty in predicting outcome in the single case with any of these two techniques, particularly in a long-term perspective.
不同软骨修复手术技术的结果差异和变异性尚未得到充分理解。成功的修复依赖于适当的组织填充，而不会在软骨-骨单元中引发退行性过程。因此，本研究的目的是比较两种可用的软骨修复技术，即微骨折技术和马赛克成形术，观察它们在实验模型中对组织填充和软骨下骨变化的影响。
在 22 周龄新西兰兔的双侧膝关节股骨内侧髁造成 4mm 的纯软骨缺损。使用立体显微镜优化缺陷的准备。在一侧膝关节（随机）中，采用微骨折技术处理缺陷，而在另一侧膝关节中，采用马赛克成形术处理缺陷。术后 12、24 和 36 周处死动物。通过组织形态计量学评估缺陷填充、潮线以上新骨形成和软骨下矿化组织密度。
在 36 周时，马赛克成形术的组织填充程度明显高于微骨折技术，平均差异的标准差为 34%，高出 34%。与微骨折技术相比，马赛克成形术导致更多的新骨形成和更低的软骨下矿化组织密度。两种技术之间的差异主要在长期随访中表现明显。
与马赛克成形术相比，微骨折技术的组织填充是一个限制因素，而马赛克成形术导致的骨变化比微骨折技术更多，后者的影响仍有待解决。本研究强调了在使用这两种技术中的任何一种对单个病例进行预测时的困难，特别是在长期来看。
