Histological images under different magnifications of PEKK (a, b, c, d), PT20 (e, f, g, h) and PT40 (i, j, k, l) at week 4 (a, b, e, f, i. j) and 12 (c, d, g, h, k, l) after implanted in vivo, in which images (b, d, f, h, j and l) are the enlarged images of yellow small frame in images (a, c, e, g, i and k), NB represents new bone, and M represents materials. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)