Table 6.

Differences in lower extremity compensatory mechanisms (SFA, KA, AA, PS, GSA) by age group.

Compensatory Mechanism and Age Group, y	Pre- to Postoperative Change	P
			TK
<40	–1.8	0.410
40–65	–0.79	0.502
≥65	–2.0	0.676
SFA
<40	5.5	0.075
40–65	6.5	0.275
≥65	–2.3	0.088
KA
<40	–2.5	0.264
40–65	5.4	0.275
≥65	–0.12	0.931
AA
<40	–0.44	0.757
40–65	1.14	0.002a
≥65	–0.74	0.241
PS
<40	–6.4	0.517
40–65	–4.9	0.149
≥65	6.5	0.521
GSA
<40	–0.48	0.004a
40–65	–2.8	0.224
≥65	0.37	0.629

^aStatistically significant.

AA, ankle angle; CD, cervical deformity; GSA, global sagittal angle; KA, knee angle; PS, pelvic shift; SFA, sacrofemoral angle; TK, thoracic kyphosis.