C3 and osteoarthritis: The relevance of complement in osteoarthritis has also been confirmed in animal models: C5-deficient and C6-deficient mice, but not C3-deficient animals, were protected against osteoarthritis induced by medial meniscectomy while mice deficient in CD59a developed a more severe phenotype of osteoarthritis (Gobezie et al., 2007; Wang et al., 2011).