Table 1.

Pre and post-operative results for all measurements in the entire cohort, prior to sub grouping by pelvic balance

Variable	Pre-op	Post-op
Pelvic incidence (PI)	79° ± 11	78° ± 11
L5 Incidence (IL5)*	66° ± 21	51° ± 16
Lumbo-sacral angle (LSA)*	21° ± 19	4° ± 11
Grade (dome)*	67% ± 17	40% ± 21
Grade (flat)*	58% ± 18	28% ± 17
Sacral slope (SS)*	50° ± 11	53° ± 10
Pelvic tilt (PT)*	30° ± 10	26° ± 8
Lumbar lordosis (LL)*	77° ± 16	66° ± 13
Length of LL*	6 ± 2	5 ± 1
Thoracic kyphosis (TK)	38° ± 12	40° ± 10

Grade is expressed as percentage of displacement and provided for subjects with a flat and domed sacrum. Length of lumbar lordosis is determined by the number of vertebrae included in the lordotic segment

* Indicates a statistically significant difference (P < 0.01)