TY - JOUR
T1 - Analysis of an unexplored group of sagittal deformity patients
T2 - low pelvic tilt despite positive sagittal malalignment
AU - Ferrero, Emmanuelle
AU - Vira, Shaleen
AU - Ames, Christopher P.
AU - Kebaish, Khaled
AU - Obeid, Ibrahim
AU - O’Brien, Michael F.
AU - Gupta, Munish C.
AU - Boachie-Adjei, Oheneba
AU - Smith, Justin S.
AU - Mundis, Gregory M.
AU - Challier, Vincent
AU - Protopsaltis, Themistocles S.
AU - Schwab, Frank J.
AU - Lafage, Virginie
AU - International Spine Study Group, Spine Study Group
N1 - Publisher Copyright:
© 2015, Springer-Verlag Berlin Heidelberg.
PY - 2016/11/1
Y1 - 2016/11/1
N2 - Purpose: In adult spinal deformity (ASD), patients increase pelvic tilt (PT) to maintain standing alignment. Previously, ASD patients with low PT and high disability were described. This study investigates this unusual population in terms of demographic, radiographic, and clinical features after three-column osteotomy (3CO). Methods: In this multicenter retrospective study, ASD patients underwent single lumbar 3CO. Since PT is proportional to pelvic incidence (PI), the low PT group (LowPT) was defined as having a baseline (BL) PT/PI <25th percentile. HRQOL and full spine x-rays were analyzed at BL and 1 year. LowPT patients were compared to those with high PT/PI (HighPT) in a matched range of T1 pelvic angle. Results: LowPT group had PT/PI <0.4 (n = 31). High disability was reported at baseline for both groups with significant improvement postoperatively, but without difference between groups. LowPT had significantly smaller lack lumbar lordosis but larger SVA, T1 spinopelvic inclination. Postoperatively, there were improvements in all sagittal modifiers except PT in LowPT. 33 % of LowPT had an increase in PT (>5°) postoperatively. This subset had more deformity at baseline, achieving good T1SPi postoperative correction but without achieving the SRS-Schwab target SVA at 1 year. Conclusion: LowPT group had high levels of disability. After 3CO surgery, low PT patients experience only partial improvements in sagittal vertical axis (SVA) and 33 % of the group increased their PT. Further work is necessary to determine optimal realignment approaches for this unusual set of patients. It is unclear if neuromuscular pathology plays a role in the setting of high SVA without pelvic retroversion.
AB - Purpose: In adult spinal deformity (ASD), patients increase pelvic tilt (PT) to maintain standing alignment. Previously, ASD patients with low PT and high disability were described. This study investigates this unusual population in terms of demographic, radiographic, and clinical features after three-column osteotomy (3CO). Methods: In this multicenter retrospective study, ASD patients underwent single lumbar 3CO. Since PT is proportional to pelvic incidence (PI), the low PT group (LowPT) was defined as having a baseline (BL) PT/PI <25th percentile. HRQOL and full spine x-rays were analyzed at BL and 1 year. LowPT patients were compared to those with high PT/PI (HighPT) in a matched range of T1 pelvic angle. Results: LowPT group had PT/PI <0.4 (n = 31). High disability was reported at baseline for both groups with significant improvement postoperatively, but without difference between groups. LowPT had significantly smaller lack lumbar lordosis but larger SVA, T1 spinopelvic inclination. Postoperatively, there were improvements in all sagittal modifiers except PT in LowPT. 33 % of LowPT had an increase in PT (>5°) postoperatively. This subset had more deformity at baseline, achieving good T1SPi postoperative correction but without achieving the SRS-Schwab target SVA at 1 year. Conclusion: LowPT group had high levels of disability. After 3CO surgery, low PT patients experience only partial improvements in sagittal vertical axis (SVA) and 33 % of the group increased their PT. Further work is necessary to determine optimal realignment approaches for this unusual set of patients. It is unclear if neuromuscular pathology plays a role in the setting of high SVA without pelvic retroversion.
KW - 3 column osteotomy
KW - Clinical outcomes
KW - Compensatory mechanism
KW - Pelvic tilt
KW - Sagittal alignment
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U2 - 10.1007/s00586-015-4048-1
DO - 10.1007/s00586-015-4048-1
M3 - Article
C2 - 26026474
AN - SCOPUS:84930268291
SN - 0940-6719
VL - 25
SP - 3568
EP - 3576
JO - European Spine Journal
JF - European Spine Journal
IS - 11
ER -