TY - JOUR
T1 - Changes in thoracic kyphosis negatively impact sagittal alignment after lumbar pedicle subtraction osteotomy
T2 - A comprehensive radiographic analysis
AU - Lafage, Virginie
AU - Ames, Christopher
AU - Schwab, Frank
AU - Klineberg, Eric
AU - Akbarnia, Behrooz
AU - Smith, Justin
AU - Boachie-Adjei, Oheneba
AU - Burton, Douglas
AU - Hart, Robert
AU - Hostin, Richard
AU - Shaffrey, Christopher
AU - Wood, Kirkham
AU - Bess, Shay
PY - 2012/2/1
Y1 - 2012/2/1
N2 - Study Design.: Consecutive, multicenter retrospective review. Objective.: To evaluate if change in thoracic kyphosis (TK) has a positive or negative impact on spinopelvic alignment after lumbar pedicle subtraction osteotomy (PSO) with short fusions. Summary of Background Data.: In the setting of sagittal malalignment, the effect of large vertebral resections can now be anticipated in long fusions, but their impact on unfused segments (reciprocal changes [RC]) remains poorly understood. Methods.: A total of 34 adult patients (mean age = 54 years; SD = 12) who underwent lumbar PSO with upper instrumented vertebra below T10 were included. Radiographic analysis included pre- and postassessment of TK, lumbar lordosis (LL), sagittal vertical axis (SVA), T1 spinopelvic inclination (T1SPI), pelvic tilt (PT), and pelvic incidence (PI). Final SVA and PT were analyzed to determine successful realignment. RC in the thoracic spine was designated favorable or unfavorable on the basis of impact on final SVA and PT. Results.: Mean PSO resection was 26°. LL increased from 20° to 49° (P < 0.001). SVA improved from 14 to 4 cm (P < 0.001), and PT improved from 33° to 25° (P < 0.001). Mean increase in TK was 13° (P = 0.002) but was unchanged in 11 patients. Five patients had a favorable RC, and 18 patients had an unfavorable RC. Unfavorable RC was attributed to junctional failure in 6 of 18 patients. Significant differences in the unfavorable RC group included age and greater preoperative PT, PI, SVA, and T1SPI. Conclusion.: Significant postoperative alignment changes can occur through unfused thoracic spinal segments after lumbar PSO. Unfavorable RC may limit optimal correction and lead to clinical failures. Risk factors for unfavorable thoracic RC include older patients, larger preoperative PI and PT, and worse preoperative T1SPI and are not simply due to junctional failure. Care should be taken with selective lumbar fusion and PSO in older patients and in those with severe preoperative spinopelvic parameters.
AB - Study Design.: Consecutive, multicenter retrospective review. Objective.: To evaluate if change in thoracic kyphosis (TK) has a positive or negative impact on spinopelvic alignment after lumbar pedicle subtraction osteotomy (PSO) with short fusions. Summary of Background Data.: In the setting of sagittal malalignment, the effect of large vertebral resections can now be anticipated in long fusions, but their impact on unfused segments (reciprocal changes [RC]) remains poorly understood. Methods.: A total of 34 adult patients (mean age = 54 years; SD = 12) who underwent lumbar PSO with upper instrumented vertebra below T10 were included. Radiographic analysis included pre- and postassessment of TK, lumbar lordosis (LL), sagittal vertical axis (SVA), T1 spinopelvic inclination (T1SPI), pelvic tilt (PT), and pelvic incidence (PI). Final SVA and PT were analyzed to determine successful realignment. RC in the thoracic spine was designated favorable or unfavorable on the basis of impact on final SVA and PT. Results.: Mean PSO resection was 26°. LL increased from 20° to 49° (P < 0.001). SVA improved from 14 to 4 cm (P < 0.001), and PT improved from 33° to 25° (P < 0.001). Mean increase in TK was 13° (P = 0.002) but was unchanged in 11 patients. Five patients had a favorable RC, and 18 patients had an unfavorable RC. Unfavorable RC was attributed to junctional failure in 6 of 18 patients. Significant differences in the unfavorable RC group included age and greater preoperative PT, PI, SVA, and T1SPI. Conclusion.: Significant postoperative alignment changes can occur through unfused thoracic spinal segments after lumbar PSO. Unfavorable RC may limit optimal correction and lead to clinical failures. Risk factors for unfavorable thoracic RC include older patients, larger preoperative PI and PT, and worse preoperative T1SPI and are not simply due to junctional failure. Care should be taken with selective lumbar fusion and PSO in older patients and in those with severe preoperative spinopelvic parameters.
KW - PSO
KW - junctional failure
KW - pelvic tilt
KW - sagittal imbalance
KW - selective fusion
KW - spinopelvic alignment
UR - http://www.scopus.com/inward/record.url?scp=84856737153&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84856737153&partnerID=8YFLogxK
U2 - 10.1097/BRS.0b013e318225b926
DO - 10.1097/BRS.0b013e318225b926
M3 - Article
C2 - 21673626
AN - SCOPUS:84856737153
SN - 0362-2436
VL - 37
SP - E180-E187
JO - Spine
JF - Spine
IS - 3
ER -