Necrotic and inflammatory changes in metal-on-metal resurfacing hip arthroplasties

Figures & data

Details of revised hip resurfacings including patient demographics and duration “in situ” for each group of patients

	No. of hips	Primary implant	Mean age [SD] (range)	Sex	Mean time to revision in months [SD] (range)
Pseudotumor	13	8 BHR, 4 Conserve Plus, 1 Cormet	55 [13] (30–69)	13 F	34 [23] (9–79)
Fracture	21	13 BHR, 8 Conserve Plus	57 [11] (29–76)	8 F, 13 M	7 [11] (0.6–42)
Component loosening	9	4 BHR, 3 Conserve Plus, 2 Cormet	59 [13] (30–76)	6 F, 3 M	27 [15] (1.4–45)
Other	9	5 BHR, 4 Conserve Plus	60 [8] (46–66)	4 F, 3 M	30 [29] (0.1–76)

Figure 1.  Necrosis in peri-implant soft tissues of an MoM hip resurfacing. (a) Necrosis of superficial fibrous tissue that is covered by fibrin in a case of component loosening. (b) Coagulative necrosis in which ghost-like outlines of plump macrophages are evident in a case of pseudotumor.

Figure 2.  Inflammation in the pseudomembrane from a case of component loosening showing (a) macrophage infiltration and metal particles (arrowed); (b) macrophage and giant cell expression of CD68; and (c) discrete granuloma formation.

Figure 3.  Macrophage and giant cell (arrowed) granulomatous response around an area of coagulative necrosis (top) in a case of MoM-implant associated pseudotumor.

Figure 4.  Pseudomembrane from a case of MoM implant component loosening showing (a) numerous perivascular lymphoid aggregates and a diffuse lymphocyte infiltrate; (b) expression of CD3 by lymphocytes in the diffuse inflammatory cell infiltrate; and (c) CD20-expressing B lymphocytes in lymphoid aggregates.

Figure 5.  Femoral bone marrow from a revised MoM hip resurfacing showing (a) a collection of macrophages containing metal particles (arrowed); (b) a small lymphoid aggregate; and (c) a discrete macrophage and giant cell granuloma.