Results of histomorphometrical analysis: median tissue area fraction (range) and coefficient of variance (CV) in percent

		New bone	Osteoid	Bone marrow	Fibrous tissue	Vessels	Scaffold/Artifacts
Autograft
Average of observers:	control	55 (44–68)	2.5 (1.1–4.3)	9.6 (4.4–19)	18 (13–28)	0.4 (0.2–1.9)	10 (0.9–21)
	EPO	58 (45–70)	2.7 (0.6–6.1)	9.3 (2.1–23)	21 (7.0–43)	0.6 (0.1–2.7)	9 (2.5–13)
CV a	control	4.6; 0.7; 0.7	25; 3.6; 14	24; 0.9; 7.4	18; 0.2; 2.9	44; 26; 15	17; 22; 8.4
	EPO	4.1; 1.7: 1.7	20; 6.4; 2.4	15; 5.0; 5.9	10; 4.3; 1.0	34; 14; 11	20; 21; 5.2
Collagen
Average of observers:	control	39 (19–57)	3.0 (1.5–9.0)	11 (1.8–20)	43 (20–71)	0.7 (0.2–2.5)	4.2 (2.2–7.0)
	EPO	40 (21–48)	4.5 (2.3–9.3)	6 (0.9–17)	39 (33–73)	1.1 (0.1–1.7)	4.1 (0.9–18)
CV a	control	4.6; 2.1; 0.7	13; 2.8; 4.6	18; 6.2; 9.7	8.8; 1.7; 3.9	27; 19; 18	40; 5.6; 14
	EPO	7.3; 1.8; 0.8	18; 1.7; 15	16; 4.8; 6.8	3.0; 3.1; 2.0	56; 33; 36	25; 18; 7.4

^a Coefficient of variance in percent of inter-observer; intra-observer 1; intra-observer 2