Electron Microscopy and Microanalysis of Ovis Aries Knee Joint Meniscus: Does it Have Any Similarity with Human Meniscus?

Abstract

Background: Meniscus plays a pivotal role in normal function of knee joint and is exposed to heavy load of pressure and trauma. The aim in this study is to investigate ultrastructure of medial and lateral meniscus of Ovis aries, in addition to comparing the findings with human meniscal structure. Methods: 14 samples of freshly-excised meniscus of ovis aries were provided. After conventional preparation, the samples were studied via electron microscopy (EM) and its elements were microanalyzed. Results: In the macroscopic evaluation, the meniscus surface was completely smooth, but in the microscopic observation, longitudinal ridges and grooves were observed. In addition, several types of cells that were different morphologically and bundles of collagen fibers were observed. The major direction of collagen fibers was circumferentially, but there were radial fibers as well. In the microanalysis of the ovis aris meniscus, the following elements were present: sodium, carbon, and oxygen, with sodium having the highest percentage among the elements. In medial meniscus of the samples, a small amount of calcium was detected. Conclusion: By comparing the present findings with those of other studies, many similarities were observed between ultrastructure of ovis aries and human knee meniscus. The compatibility in the ultrastructures will imply the possibility of application of this specimen for xenograft meniscal transplant procedure.