Abstract
STUDY DESIGN.: Retrospective review of a prospective multicenter database. OBJECTIVE.: To develop a method to analyze sagittal alignment, free of PJKʼs influence, and then compare PJK to non-PJK patients using this method. SUMMARY OF BACKGROUND DATA.: Proximal Junctional Kyphosis (PJK) following Adult Spinal Deformity (ASD) surgery remains problematic as it alters sagittal alignment. This study proposes a novel virtual modeling technique that attempts to eliminate the confounding effects of PJK on postoperative spinal alignment. METHODS.: A virtual spinal modeling technique was developed on a retrospective ASD cohort of patients with multilevel spinal fusions to the pelvis with at least 2 year post-operative follow-up. The virtual post-op alignment (VIRTUAL) was created from the post-op alignment of the instrumented segments and the pre-op alignment of the unfused segments. VIRTUAL was validated by comparisons to actual 2-year post-op alignment (REAL) in NOPJK patients. Patients were then divided into two groups: PJK and NOPJK based on the presence/absence of PJK at 2 years post-op. PJK and NOPJK patients were compared using VIRTUAL and REAL. RESULTS.: 458 patients (78F, mean 57.9y) were analyzed. The validation of VIRTUAL versus REAL demonstrated correlation coefficients above 0.7 for all measures except SVA (r?=?0.604). At 2-years, REAL alignment in PJK patients demonstrated a smaller PI-LL and a larger thoracic kyphosis than NOPJK patients, but similar SVA, TPA, and PT. An analysis of VIRTUAL demonstrated that PJK patients had a smaller PI-LL, PT, SVA, and TPA than NOPJK patients (p?<?0.05). CONCLUSION.: This technique demonstrated strong correlations with actual postoperative alignment. Comparisons between REAL and VIRTUAL alignments revealed that postoperative PJK may develop partially as a compensatory mechanism to the over-correction of sagittal deformities. Future research will evaluate the appropriate thresholds for deformity correction according to age and ASD severity.Level of Evidence: 3
| Original language | English (US) |
|---|---|
| Journal | Spine |
| DOIs | |
| State | Accepted/In press - Feb 9 2017 |
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ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Clinical Neurology
Cite this
Virtual Modeling of Postoperative Alignment Following Adult Spinal Deformity (ASD) Surgery Helps Predict associations between Compensatory Spinopelvic Alignment Changes, Overcorrection and Proximal Junctional Kyphosis (PJK). / Lafage, Renaud; Bess, Shay; Glassman, Steve; Ames, Christopher; Burton, Doug; Hart, Robert; Kim, Han Jo; Klineberg, Eric Otto; Henry, Jensen; Line, Breton; Scheer, Justin; Protopsaltis, Themistocles; Schwab, Frank; Lafage, Virginie.
In: Spine, 09.02.2017.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Virtual Modeling of Postoperative Alignment Following Adult Spinal Deformity (ASD) Surgery Helps Predict associations between Compensatory Spinopelvic Alignment Changes, Overcorrection and Proximal Junctional Kyphosis (PJK)
AU - Lafage, Renaud
AU - Bess, Shay
AU - Glassman, Steve
AU - Ames, Christopher
AU - Burton, Doug
AU - Hart, Robert
AU - Kim, Han Jo
AU - Klineberg, Eric Otto
AU - Henry, Jensen
AU - Line, Breton
AU - Scheer, Justin
AU - Protopsaltis, Themistocles
AU - Schwab, Frank
AU - Lafage, Virginie
PY - 2017/2/9
Y1 - 2017/2/9
N2 - STUDY DESIGN.: Retrospective review of a prospective multicenter database. OBJECTIVE.: To develop a method to analyze sagittal alignment, free of PJKʼs influence, and then compare PJK to non-PJK patients using this method. SUMMARY OF BACKGROUND DATA.: Proximal Junctional Kyphosis (PJK) following Adult Spinal Deformity (ASD) surgery remains problematic as it alters sagittal alignment. This study proposes a novel virtual modeling technique that attempts to eliminate the confounding effects of PJK on postoperative spinal alignment. METHODS.: A virtual spinal modeling technique was developed on a retrospective ASD cohort of patients with multilevel spinal fusions to the pelvis with at least 2 year post-operative follow-up. The virtual post-op alignment (VIRTUAL) was created from the post-op alignment of the instrumented segments and the pre-op alignment of the unfused segments. VIRTUAL was validated by comparisons to actual 2-year post-op alignment (REAL) in NOPJK patients. Patients were then divided into two groups: PJK and NOPJK based on the presence/absence of PJK at 2 years post-op. PJK and NOPJK patients were compared using VIRTUAL and REAL. RESULTS.: 458 patients (78F, mean 57.9y) were analyzed. The validation of VIRTUAL versus REAL demonstrated correlation coefficients above 0.7 for all measures except SVA (r?=?0.604). At 2-years, REAL alignment in PJK patients demonstrated a smaller PI-LL and a larger thoracic kyphosis than NOPJK patients, but similar SVA, TPA, and PT. An analysis of VIRTUAL demonstrated that PJK patients had a smaller PI-LL, PT, SVA, and TPA than NOPJK patients (p?<?0.05). CONCLUSION.: This technique demonstrated strong correlations with actual postoperative alignment. Comparisons between REAL and VIRTUAL alignments revealed that postoperative PJK may develop partially as a compensatory mechanism to the over-correction of sagittal deformities. Future research will evaluate the appropriate thresholds for deformity correction according to age and ASD severity.Level of Evidence: 3
AB - STUDY DESIGN.: Retrospective review of a prospective multicenter database. OBJECTIVE.: To develop a method to analyze sagittal alignment, free of PJKʼs influence, and then compare PJK to non-PJK patients using this method. SUMMARY OF BACKGROUND DATA.: Proximal Junctional Kyphosis (PJK) following Adult Spinal Deformity (ASD) surgery remains problematic as it alters sagittal alignment. This study proposes a novel virtual modeling technique that attempts to eliminate the confounding effects of PJK on postoperative spinal alignment. METHODS.: A virtual spinal modeling technique was developed on a retrospective ASD cohort of patients with multilevel spinal fusions to the pelvis with at least 2 year post-operative follow-up. The virtual post-op alignment (VIRTUAL) was created from the post-op alignment of the instrumented segments and the pre-op alignment of the unfused segments. VIRTUAL was validated by comparisons to actual 2-year post-op alignment (REAL) in NOPJK patients. Patients were then divided into two groups: PJK and NOPJK based on the presence/absence of PJK at 2 years post-op. PJK and NOPJK patients were compared using VIRTUAL and REAL. RESULTS.: 458 patients (78F, mean 57.9y) were analyzed. The validation of VIRTUAL versus REAL demonstrated correlation coefficients above 0.7 for all measures except SVA (r?=?0.604). At 2-years, REAL alignment in PJK patients demonstrated a smaller PI-LL and a larger thoracic kyphosis than NOPJK patients, but similar SVA, TPA, and PT. An analysis of VIRTUAL demonstrated that PJK patients had a smaller PI-LL, PT, SVA, and TPA than NOPJK patients (p?<?0.05). CONCLUSION.: This technique demonstrated strong correlations with actual postoperative alignment. Comparisons between REAL and VIRTUAL alignments revealed that postoperative PJK may develop partially as a compensatory mechanism to the over-correction of sagittal deformities. Future research will evaluate the appropriate thresholds for deformity correction according to age and ASD severity.Level of Evidence: 3
UR - http://www.scopus.com/inward/record.url?scp=85012115799&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85012115799&partnerID=8YFLogxK
U2 - 10.1097/BRS.0000000000002116
DO - 10.1097/BRS.0000000000002116
M3 - Article
C2 - 28187069
AN - SCOPUS:85012115799
JO - Spine
JF - Spine
SN - 0362-2436
ER -