Table 1.

Demographic data of all patients who have undergone drilling

Patient	Sex	Age at event	Splenectomy	Genotype	Enzyme replacement therapy at event	Affected bone	ARCO stage at diagnosis a
1	M	26	No	1226/1226	Yes	Femoral head	1
2	M	21	No	1226/84GG	No	Femoral head	2
3	F	33	No	1226/84GG	Yes	Proximal tibia	2
4	M	47	Yes	1226/1226	No	Femoral head	2
5	F	32	No	1226/1448	Yes	Humeral head	1
6	M	41	No	1226/1226	No	Humeral heads	2, 2
7	M	42	Yes	1226/IVS	No	Femoral head	2
8	M	36	No	1226/?	No	Femoral head	1
9	M	15	Yes	1226/84GG	No	Femoral head	1
10	M	26	No	1226/1226	No	Femoral head	1
11	M	31	No	1226/1226	No	Femoral head	1

^a for explanation of ARCO staging, see text.