Meniscus scoring system

In order to compare the macroscopical, histological, and immunohistochemical results after repair of meniscal lesions, a validated meniscus scoring system was used that was developed and published for the evaluation of meniscal defects [11, 12, 28]. Subgroups in macroscopical assessment were “stability” and “defect filling with repair tissue”; for histological analysis the “quality of the surface area”, “integration”, “cellularity”, “cell morphology”; and for immunohistochemical characterization the “expression of proteoglycan and moderate collagen type II in the repair tissue”. The repair was graded by summing up the scores from 0–3 of eight individual subgroups. Consequently, the final scores were between 0 points (no repair) and maximal 24 points (complete reconstitution of the meniscus). The data were collected from two blinded scorers, both experienced in knee anatomy of rabbits and in histological assessment.