Objective: To determine the effect of intraoperative pre-tensioning of meniscal transplants on the tibial plateau in an animal experiment:

Material and Methods: Thirty-six sheep were used for this animal study. The animals were divided into 6 groups: -group A was the sham group; – in group B medial meniscectomy was performed; in group C-F medial meniscus transplantation with an autograft was carried out. In group C-F different defined pre-tensioning was applied to meniscal transplants via bone tunnel sutures (0N, 20N, 40N and 60N respectively). After 6 months the animals were sacrificed. The lower limb specimen were placed in a material testing machine under standard conditions in 30, 60 and 90 degrees of flexion and loaded through the femoral axis to 500N. For determining contact area a thin film pressure transducer (Tekscan) was positioned underneath the medial meniscus. Statistical analysis was performed using Mann-Whitney test.

Results: The mean contact pressure of the sham group and the groups with the transplanted meniscus was significantly lower in relation to meniscectomized knees. Significant increases in contact area and reductions in in peak contact pressure could be identified. At greater flexion angles only the meniscal transplantation group with the 40N pretension showed a significant increase of contact area and/or very strong trend in relation to meniscectomized knees. Concerning peak contact pressure, all meniscal transplantated groups with exception th 0N pre-tension group showed significant reduction in comparison to the meniscectomized group.

Conclusion: Regarding the results we can conclude that the biological ingrowth has an influence on the biomechanical effect of meniscal transplantation. For this animal model and with the compressive load of 500N especially 40N pre-tension of meniscal transplants seems to be efficient to provide load transmission function of the meniscus.