Comparative study of the effect of deep-frozen meniscus and meniscal acellular matrix for allograft transplantation / 中国组织工程研究

ABSTRACT

BACKGROUND: Three kinds of donor meniscus are commonly used at present, namely cryopreserved, fresh and deep-frozen meniscus, which,however, almost invariably give rise to degenerative changes of various degrees after transplantation.OBJECTIVE: To compare the outcome of transplantation of allograft deep-frozen meniscus and meniscal acellular matrix to determine the most preferable means of allograft meniscus preservation.DESIGN: Randomized controlled experiment with rabbits.SETTING: Department of Orthopedics, Second Hospital Affiliated to Harbin Medical University.MATERIALS: Sixty-four male Japanese white rabbits with body mass of 3.0 - 3.5 kg.METHODS: This experiment was carried out in the Animal Experimental Center, Second Hospital Affiliated to Harbin Medical University between September 2002 and September 2003. Totally 64 adult rabbits were assigned into 32 pairs according to the body weight to served as the donor and the recipient animals, respectively. The medial menisci was obtained from the bilateral knees of the donor animals with the right one cryopreserved at -80 ℃ and the left prepared into acellular matrix for deep-frozen preservation. The donor menisci were respectively transplanted into the corresponding knee joints of the recipient animal's hindlimbs, with the left side taken as the experimental side and right as control. Gross observation,X-ray examination, and histological examination of the tissues were carried out at postoperative 4, 8, 12 and 16 weeks, respectively.MAIN OUTCOME MEASURES: Findings in X-ray, gross observation and histological observation of the grafted meniscus with meniscal measurement and findings in abdominal aorta perfusion.RFSULTS: All the 64 rabbits were observed for result analysis. X-ray examination of the grafted meniscus revealed no obvious changes in either the experimental and control side at 4 and 8 weeks postoperatively, but mild changes occurred on the control side at 12 weeks, which became obvious at 16 weeks, presented by joint space narrowing, hyperostosis and osteosclerosis below the cartilage of varied severities (with scores of 1.3 and 0.6, respectively, P ＜ 0.05). By gross observation, meniscal atrophy on the experimental side was milder and slower than the control side, with al so lower atrophy rate [(15.14±4.62) % vs (20.97±4.72) % at week 4, P ＜ 0.001, and (19.23±11.27) % vs (32.74±10.43) % at week 16, P ＜ 0.05].Perfusion of the abdominal aorta revealed no revascularization in the surrounding tissues of the meniscus by gross observation in either groups, but histologically, the experimental side showed more favorable structure than the control side at postoperative weeks 4, 8, 12 and 16.CONCLUSION: Meniscal acellular matrix may produce better outcome than deep-frozen meniscus after transplantation and can be a more practical means for preservation of the meniscus.