This study examined the hypothesis that meniscal allograft transplantation serves a "chondroprotective" role and prevents the histological and biomechanical changes of the articular cartilage following meniscectomy. Skeletally mature mongrel dogs underwent total medial meniscectomy and received either a fresh meniscal allograft ( n=10) or no further treatment ( n=10). Semiquantitative histology and biomechanical analysis of the femoral articular cartilage was used to assess cartilage pathology 12 weeks following surgery. Histological analysis showed significant changes in cartilage structure that did not differ between the meniscectomy and allograft transplantation groups. Similarly, the tensile modulus of the surface zone cartilage was significantly lower than that in unoperated controls following either meniscectomy or allograft transplantation. A significant correlation was observed between the biomechanical and histological changes, suggesting that degenerative changes in cartilage structure and mechanical function are interrelated. Our findings do not support the hypothesis that meniscal allograft transplantation provides chondroprotection of the femoral condyle and also suggest that it does not lead to increased degenerative changes.