TY - JOUR
T1 - When can we expect global sagittal alignment to reach a stable value following cervical deformity surgery?
AU - International Spine Study Group (ISSG)
AU - Lafage, Renaud
AU - Smith, Justin S.
AU - Alshabab, Basel Sheikh
AU - Ames, Christopher
AU - Passias, Peter G.
AU - Shaffrey, Christopher I.
AU - Mundis, Gregory
AU - Protopsaltis, Themistocles
AU - Gupta, Munish
AU - Klineberg, Eric
AU - Kim, Han Jo
AU - Bess, Shay
AU - Schwab, Frank
AU - Lafage, Virginie
N1 - Funding Information:
The International Spine Study Group (ISSG) is funded through research grants from DePuy Synthes (current), NuVasive (current), K2M (current), Innovasis (past), Biomet (past), and individual donations. Authors reported the following. Renaud Lafage: ownership of Nemaris. Justin S. Smith: consultant for Zimmer Biomet, NuVasive, Stryker, DePuy Synthes, Cerapedics, Carlsmed; royalties from Zimmer Biomet, NuVasive, Thieme; direct stock ownership in Alphatec, NuVasive; receiving support of non- study-related clinical or research effort overseen by author from DePuy Synthes, ISSG, AO Spine, NuVasive, Stryker; clinical or research support for study described (includes equipment or material) from DePuy Synthes/ISSGF; fellowship funding from AO Spine; editorial board membership in Neurosurgery, Operative Neurosurgery, Journal of Neurosurgery Spine; board of directors membership in the Scoliosis Research Society. Christopher Ames: employee of UCSF; royalties from Stryker, Biomet Zimmer Spine, NuVasive, DePuy Synthes, Next Orthosurgical, K2M, Medicrea; consultant for DePuy Synthes, Medtronic, Medicrea, K2M; research for Titan Spine, DePuy Synthes, ISSG; editorial board member of Operative Neurosurgery; grant funding from SRS; executive committee member of ISSG; director of Global Spinal Analytics. Peter G. Passias: consultant for Globus, Royal Biologics, Spine Wave. Christopher I. Shaffrey: consultant for Medtronic, NuVasive, SI Bone; direct stock ownership in NuVasive; patent holder in Medtronic, NuVasive, Zimmer Biomet; royalties from Medtronic, NuVasive. Gregory Mundis Jr.: consultant for NuVasive, Viseon, SeaSpine, Carlsmed; direct stock ownership in Alphatec, SeaSpine; patent holder in Stryker, SeaSpine. Themistocles S. Protopsaltis: consultant for Globus, Stryker K2M, NuVasive, Medicrea, Medtronic; royalties from Altus; stock options in SpineAlign. Munish Gupta: consultant for DePuy, Globus, Medtronic; royalties from Innomed, DePuy, Globus; honoraria from AO Spine; direct stock ownership in J&J, P&G; travel reimbursement from Scoliosis Research Society, DePuy, Globus, Medtronic, AO Spine. Eric Klineberg: consultant for Depuy Synthes, Stryker, Medicrea/Medtronic; honoraria from AO Spine; fellowship grant from AO Spine. Shay Bess: consultant for K2M Stryker, Mirus; patent holder in K2M, Stryker, NuVasive; clinical or research support for study described (includes equipment or material) from K2M Stryker, NuVasive, ISSGF, DePuy Synthes; support of non-study-related clinical or research effort overseen by author from Medtronic, Globus, ISSGF, SI Bone, SeaSpine; speakers bureau for K2M, Stryker; royalties from K2M, Stryker, NuVasive. Frank Schwab: consultant for MSD, Zimmer Biomet; royalties from Zimmer Biomet, Medtronic; ownership in VFT Solutions, SeaSpine; executive committee of International Spine Study Group. Virginie Lafage: consultant for Globus Medical; royalties from NuVasive; honoraria from Depuy Synthes, Implanet.
Funding Information:
The International Spine Study Group (ISSG) is funded through research grants from DePuy Synthes (current), NuVasive (current), K2M (current), Innovasis (past), Biomet (past), and individual donations. Authors reported the following. Renaud Lafage: ownership of Nemaris. Justin S. Smith: consultant for Zimmer Biomet, NuVasive, Stryker, DePuy Synthes, Cerapedics, Carlsmed; royalties from Zimmer Biomet, NuVasive, Thieme; direct stock ownership in Alphatec, NuVasive; receiving support of non– study-related clinical or research effort overseen by author from DePuy Synthes, ISSG, AO Spine, NuVasive, Stryker; clinical or research support for study described (includes equipment or material) from DePuy Synthes/ISSGF; fellowship funding from AO Spine; editorial board membership in Neurosurgery, Operative Neurosurgery, Journal of Neurosurgery Spine; board of directors membership in the Scoliosis Research Society. Christopher Ames: employee of UCSF; royalties from Stryker, Biomet Zimmer Spine, NuVasive, DePuy Synthes, Next Orthosurgical, K2M, Medicrea; consultant for DePuy Synthes, Medtronic, Medicrea, K2M; research for Titan Spine, DePuy Synthes, ISSG; editorial board member of Operative Neurosurgery; grant funding from SRS; executive committee member of ISSG; director of Global Spinal Analytics. Peter G. Passias: consultant for Globus, Royal Biologics, Spine Wave. Christopher I. Shaffrey: consultant for Medtronic, NuVasive, SI Bone; direct stock ownership in NuVasive; patent holder in Medtronic, NuVasive, Zimmer Biomet; royalties from Medtronic, NuVasive. Gregory Mundis Jr.: consultant for NuVasive, Viseon, SeaSpine, Carlsmed; direct stock own- ership in Alphatec, SeaSpine; patent holder in Stryker, SeaSpine. Themistocles S. Protopsaltis: consultant for Globus, Stryker K2M, NuVasive, Medicrea, Medtronic; royalties from Altus; stock options in SpineAlign. Munish Gupta: consultant for DePuy, Globus, Medtronic; royalties from Innomed, DePuy, Globus; honoraria from AO Spine; direct stock ownership in J&J, P&G; travel reimbursement from Scoliosis Research Society, DePuy, Globus, Medtronic, AO Spine. Eric Klineberg: consultant for Depuy Synthes, Stryker, Medicrea/Medtronic; honoraria from AO Spine; fellowship grant from AO Spine. Shay Bess: consultant for K2M Stryker, Mirus; patent holder in K2M, Stryker, NuVasive; clinical or research support for study described (includes equipment or material) from K2M Stryker, NuVasive, ISSGF, DePuy Synthes; support of non–study-related clinical or research effort overseen by author from Medtronic, Globus, ISSGF, SI Bone, SeaSpine; speakers bureau for K2M, Stryker; royalties from K2M, Stryker, NuVasive. Frank Schwab: consultant for MSD, Zimmer Biomet; royalties from Zimmer Biomet, Medtronic; ownership in VFT Solutions, SeaSpine; executive committee of International Spine Study Group. Virginie Lafage: consultant for Globus Medical; royalties from NuVasive; honoraria from Depuy Synthes, Implanet.
Publisher Copyright:
© 2022 American Association of Neurological Surgeons. All rights reserved.
PY - 2022/4
Y1 - 2022/4
N2 - Objective: Cervical deformity (CD) is a complex condition with a clear impact on patient quality of life, which can be improved with surgical treatment. Previous study following thoracolumbar surgery demonstrated a spontaneous and maintained improvement in cervical alignment following lumbar pedicle subtraction osteotomy (PSO). In this study the authors aimed to investigate the complementary questions of whether cervical alignment induces a change in global alignment and whether this change stabilizes over time. Methods: To analyze spontaneous changes, this study included only patients with at least 5 levels remaining unfused following surgery. After data were obtained for the entire cohort, repeated-measures analyses were conducted between preoperative baseline and 3-month and 1-year follow-ups with a post hoc analysis and Bonferroni correction. A subanalysis of patients with 2-year follow-up was performed. Results: One-year follow-up data were available for 121 of 168 patients (72%), and 89 patients had at least 5 levels remaining unfused following surgery. Preoperatively there was a moderate anterior cervical alignment (C2-7, -7.7° [kyphosis]; T1 slope minus cervical lordosis, 37.1°; cervical sagittal vertebral axis [cSVA], 37 mm) combined with a posterior global alignment (SVA, -8 mm) with lumbar hyperextension (pelvic incidence [PI] minus lumbar lordosis [LL] mismatch [PI-LL], -0.6°). Patients underwent a significant correction of the cervical alignment (median ΔC2-7, 13.6°). Simultaneously, PI-LL, T1 pelvic angle (TPA), and SVA increased significantly (all p < 0.05) between baseline and 3-month and 1-year follow-ups. Post hoc analysis demonstrated that all of the changes occurred between baseline and 3 months. Subanalysis of patients with complete 2-year follow-up demonstrated similar results, with stable postoperative thoracolumbar alignment achieved at 3 months. Conclusions: Correction of cervical malalignment can have a significant impact on thoracolumbar regional and global alignment. Peak relaxation of compensatory mechanisms is achieved by the 3-month follow-up and tends to remain stable. Subanalysis with 2-year data further supports this finding. These findings can help to identify when the results of cervical surgery on global alignment can be best evaluated.
AB - Objective: Cervical deformity (CD) is a complex condition with a clear impact on patient quality of life, which can be improved with surgical treatment. Previous study following thoracolumbar surgery demonstrated a spontaneous and maintained improvement in cervical alignment following lumbar pedicle subtraction osteotomy (PSO). In this study the authors aimed to investigate the complementary questions of whether cervical alignment induces a change in global alignment and whether this change stabilizes over time. Methods: To analyze spontaneous changes, this study included only patients with at least 5 levels remaining unfused following surgery. After data were obtained for the entire cohort, repeated-measures analyses were conducted between preoperative baseline and 3-month and 1-year follow-ups with a post hoc analysis and Bonferroni correction. A subanalysis of patients with 2-year follow-up was performed. Results: One-year follow-up data were available for 121 of 168 patients (72%), and 89 patients had at least 5 levels remaining unfused following surgery. Preoperatively there was a moderate anterior cervical alignment (C2-7, -7.7° [kyphosis]; T1 slope minus cervical lordosis, 37.1°; cervical sagittal vertebral axis [cSVA], 37 mm) combined with a posterior global alignment (SVA, -8 mm) with lumbar hyperextension (pelvic incidence [PI] minus lumbar lordosis [LL] mismatch [PI-LL], -0.6°). Patients underwent a significant correction of the cervical alignment (median ΔC2-7, 13.6°). Simultaneously, PI-LL, T1 pelvic angle (TPA), and SVA increased significantly (all p < 0.05) between baseline and 3-month and 1-year follow-ups. Post hoc analysis demonstrated that all of the changes occurred between baseline and 3 months. Subanalysis of patients with complete 2-year follow-up demonstrated similar results, with stable postoperative thoracolumbar alignment achieved at 3 months. Conclusions: Correction of cervical malalignment can have a significant impact on thoracolumbar regional and global alignment. Peak relaxation of compensatory mechanisms is achieved by the 3-month follow-up and tends to remain stable. Subanalysis with 2-year data further supports this finding. These findings can help to identify when the results of cervical surgery on global alignment can be best evaluated.
KW - cervical deformity
KW - compensation
KW - maintenance of alignment
KW - reciprocal change
UR - http://www.scopus.com/inward/record.url?scp=85127496089&partnerID=8YFLogxK
U2 - 10.3171/2021.7.SPINE21306
DO - 10.3171/2021.7.SPINE21306
M3 - Article
C2 - 34740177
AN - SCOPUS:85127496089
SN - 1547-5654
VL - 36
SP - 616
EP - 623
JO - Journal of Neurosurgery: Spine
JF - Journal of Neurosurgery: Spine
IS - 4
ER -