Stages of metamorphosis of muscle tissue into bone tissue in mouse model of heterotopic ossification (misplaced bone growth). A: Inflammation in muscle tissue (M = muscle cells). B: Destruction of muscle cells (FP = fibroproliferation). C: Formation of cartilage scaffold before bone formation (C = cartilage). D: Formation of mature bone (B = bone).
Image courtesy of the Journal of Bone and Joint Surgery