a decreasing trendp = 2.17 × 10 –3
Calcifications vary by pathological stage Both lattice parameters (‘a’ and ‘c’ axes) for HAP showed a decreasing trend with increasing pathological stage, with a significant weak negative correlation between the ‘c’ axis and pathological stage (r τ = − 0.284, p = 2.17 × 10 –3 ) (Fig. 4 a,b).