Reduced longitudinal growth and trabecular bone in ADA−/− mice. (A) ADA−/− femora and tibiae (not shown) are significantly shorter compared with wild-type (cm). ***P < .001. Metaphyseal bone sections of ADA+/+ (B) and ADA−/− (C) femora (original magnification ×2.5). Scale bar represents 600 μm and original magnification ×20 of ADA+/+ (D) and ADA−/− (E). Scale bar represents 50 μm; indicates defects in ossification but not in cartilage formation. Histomorphologic analyses were performed on ADA+/+ (n = 5) and ADA−/− (n = 5) femora. BV TV indicates trabecular bone volume (%); Tb Th, trabecular thickness (μm); Tb N, trabecular number (1/mm); Tb S, trabecular separation (mm).