Table 1.

Demographic variables and migration indexes of 17 children with Down syndrome (n = 21 hips)

Patient	Sex	Age at surgery, yrs	Hip	Follow-up time, yrs	Migration index preoperative, %	Migration index postoperative, %	Delta migration index, %
1	Male	9	R	14.8	70	84	14
2	Male	6	R	8.3	29	20	-9
3	Male	9	R	6.6	40	44	4
4a	Male	4	R	8.2	10	29	19
4b	Male	4	L	8.2	24	10	-14
5	Male	12	R	6.5	33	35	2
6	Male	11	R	8.6	43	31	-12
7	Female	6	R	5.9	19	16	-3
8	Male	6	R	12.2	34	30	-4
9	Male	12	R	3.0	54	0	-54
10	Female	7	R	7.0	54	36	-18
11	Female	10	R	2.6	41	60	19
12	Female	8	R	5.9	35	39	4
13a	Female	7	R	2.6	100	100	0
13b	Female	7	L	2.6	75	100	25
14	Male	7	R	6.6	45	30	-15
15	Male	5	R	3.7	30	0	-30
16a	Male	14	R	8.1	40	14	-26
16b	Male	14	L	8.1	50	43	-7
17a	Female	4	R	13.3	100	33	-67
17b	Female	4	L	13.3	40	17	-23

Follow-up time from preoperative plain radiograph to most recent postoperative plain radiograph

R, right; L, left