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Meniscal allograft transplantation: a review of the current literature.

INTRODUCTION
Patients who have previously undergone meniscectomy are known to potentially suffer subsequent knee problems including degenerative changes. Meniscal transplantation has been proposed as a possible solution to these problems. This article aims to review the current literature to consolidate the evidence surrounding the use of human meniscal allograft transplantation.


MATERIALS AND METHODS
Three databases (PubMed, Embase and Medline) were searched to find English language articles pertaining to meniscal allograft transplantation. Each article was critiqued by two authors using a structured appraisal tool, and stratified according to the level of evidence.


RESULTS
No Level I or II studies were identified. Many studies had small study groups with limited follow-up and patient selection and description of patient factors varied greatly. This made comparing data difficult. There were also very few papers concentrating on isolated meniscal transplantation. Four types of graft are used--fresh, fresh-frozen, cryopreserved and freeze-dried (lyophilised) graft. Cryopreserved and fresh-frozen allografts are deemed most suitable. Most authors advocate the use of non-irradiated grafts from screened donors to reduce transmission of infection. Best results occur when using bony anchors to fix the graft, although this requires accurate graft positioning. Patients have an improved outcome if they have less severe degenerative changes within the knee prior to transplantation.


CONCLUSIONS
No statistically significant studies looking at isolated meniscal transplantations have been found. The evidence suggests that meniscal allograft transplantation provides improvement of pain and function in the short and intermediate term. The effect on future joint degeneration is still unknown. The ideal patient group includes patients less than 40 years of age with knee pain, proven meniscal injury and a normally aligned, stable joint without severe degenerative changes.