Browsing by Author "Hostin, Richard"
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Item Open Access A standardized nomenclature for cervical spine soft-tissue release and osteotomy for deformity correction: clinical article.(Journal of neurosurgery. Spine, 2013-09) Ames, Christopher P; Smith, Justin S; Scheer, Justin K; Shaffrey, Christopher I; Lafage, Virginie; Deviren, Vedat; Moal, Bertrand; Protopsaltis, Themistocles; Mummaneni, Praveen V; Mundis, Gregory M; Hostin, Richard; Klineberg, Eric; Burton, Douglas C; Hart, Robert; Bess, Shay; Schwab, Frank J; International Spine Study GroupObject
Cervical spine osteotomies are powerful techniques to correct rigid cervical spine deformity. Many variations exist, however, and there is no current standardized system with which to describe and classify cervical osteotomies. This complicates the ability to compare outcomes across procedures and studies. The authors' objective was to establish a universal nomenclature for cervical spine osteotomies to provide a common language among spine surgeons.Methods
A proposed nomenclature with 7 anatomical grades of increasing extent of bone/soft tissue resection and destabilization was designed. The highest grade of resection is termed the major osteotomy, and an approach modifier is used to denote the surgical approach(es), including anterior (A), posterior (P), anterior-posterior (AP), posterior-anterior (PA), anterior-posterior-anterior (APA), and posterior-anterior-posterior (PAP). For cases in which multiple grades of osteotomies were performed, the highest grade is termed the major osteotomy, and lower-grade osteotomies are termed minor osteotomies. The nomenclature was evaluated by 11 reviewers through 25 different radiographic clinical cases. The review was performed twice, separated by a minimum 1-week interval. Reliability was assessed using Fleiss kappa coefficients.Results
The average intrarater reliability was classified as "almost perfect agreement" for the major osteotomy (0.89 [range 0.60-1.00]) and approach modifier (0.99 [0.95-1.00]); it was classified as "moderate agreement" for the minor osteotomy (0.73 [range 0.41-1.00]). The average interrater reliability for the 2 readings was the following: major osteotomy, 0.87 ("almost perfect agreement"); approach modifier, 0.99 ("almost perfect agreement"); and minor osteotomy, 0.55 ("moderate agreement"). Analysis of only major osteotomy plus approach modifier yielded a classification that was "almost perfect" with an average intrarater reliability of 0.90 (0.63-1.00) and an interrater reliability of 0.88 and 0.86 for the two reviews.Conclusions
The proposed cervical spine osteotomy nomenclature provides the surgeon with a simple, standard description of the various cervical osteotomies. The reliability analysis demonstrated that this system is consistent and directly applicable. Future work will evaluate the relationship between this system and health-related quality of life metrics.Item Open Access Adult Cervical Deformity Patients Have Higher Baseline Frailty, Disability, and Comorbidities Compared With Complex Adult Thoracolumbar Deformity Patients: A Comparative Cohort Study of 616 Patients.(Global spine journal, 2023-11) Smith, Justin S; Kelly, Michael P; Buell, Thomas J; Ben-Israel, David; Diebo, Bassel; Scheer, Justin K; Line, Breton; Lafage, Virginie; Lafage, Renaud; Klineberg, Eric; Kim, Han Jo; Passias, Peter; Gum, Jeffrey L; Kebaish, Khal; Mullin, Jeffrey P; Eastlack, Robert; Daniels, Alan; Soroceanu, Alex; Mundis, Gregory; Hostin, Richard; Protopsaltis, Themistocles S; Hamilton, D Kojo; Gupta, Munish; Lewis, Stephen J; Schwab, Frank J; Lenke, Lawrence G; Shaffrey, Christopher I; Burton, Douglas; Ames, Christopher P; Bess, Shay; International Spine Study GroupStudy design
Multicenter comparative cohort.Objective
Studies have shown markedly higher rates of complications and all-cause mortality following surgery for adult cervical deformity (ACD) compared with adult thoracolumbar deformity (ATLD), though the reasons for these differences remain unclear. Our objectives were to compare baseline frailty, disability, and comorbidities between ACD and complex ATLD patients undergoing surgery.Methods
Two multicenter prospective adult spinal deformity registries were queried, one ATLD and one ACD. Baseline clinical and frailty measures were compared between the cohorts.Results
616 patients were identified (107 ACD and 509 ATLD). These groups had similar mean age (64.6 vs 60.8 years, respectively, P = .07). ACD patients were less likely to be women (51.9% vs 69.5%, P < .001) and had greater Charlson Comorbidity Index (1.5 vs .9, P < .001) and ASA grade (2.7 vs 2.4, P < .001). ACD patients had worse VR-12 Physical Component Score (PCS, 25.7 vs 29.9, P < .001) and PROMIS Physical Function Score (33.3 vs 35.3, P = .031). All frailty measures were significantly worse for ACD patients, including hand dynamometer (44.6 vs 55.6 lbs, P < .001), CSHA Clinical Frailty Score (CFS, 4.0 vs 3.2, P < .001), and Edmonton Frailty Scale (EFS, 5.15 vs 3.21, P < .001). Greater proportions of ACD patients were frail (22.9% vs 5.7%) or vulnerable (15.6% vs 10.9%) based on EFS (P < .001).Conclusions
Compared with ATLD patients, ACD patients had worse baseline characteristics on all measures assessed (comorbidities/disability/frailty). These differences may help account for greater risk of complications and all-cause mortality previously observed in ACD patients and facilitate strategies for better preoperative optimization.Item Open Access After 9 Years of 3-Column Osteotomies, Are We Doing Better? Performance Curve Analysis of 573 Surgeries With 2-Year Follow-up.(Neurosurgery, 2018-07) Diebo, Bassel G; Lafage, Virginie; Varghese, Jeffrey J; Gupta, Munish; Kim, Han Jo; Ames, Christopher; Kebaish, Khaled; Shaffrey, Christopher; Hostin, Richard; Obeid, Ibrahim; Burton, Doug; Hart, Robert A; Lafage, Renaud; Schwab, Frank J; International Spine Study Group (ISSG) of Denver, ColoradoBackground
In spinal deformity treatment, the increased utilization of 3-column (3CO) osteotomies reflects greater comfort and better training among surgeons. This study aims to evaluate the longitudinal performance and adverse events (complications or revisions) for a multicenter group following a decade of 3CO.Objective
To investigate if performance of 3CO surgeries improves with years of practice.Methods
Patients who underwent 3CO for spinal deformity with intra/postoperative and revision data collected up to 2 yr were included. Patients were chronologically divided into 4 even groups. Demographics, baseline deformity/correction, and surgical metrics were compared using Student t-test. Postoperative and revision rates were compared using Chi-square analysis.Results
Five hundred seventy-three patients were stratified into: G1 (n = 143, 2004-2008), G2 (n = 142, 2008-2009), G3 (n = 144, 2009-2010), G4 (n = 144 2010-2013). The most recent patients were more disabled by Oswestry disability index (G4 = 49.2 vs G1 = 38.3, P = .001), and received a larger osteotomy resection (G4 = 26° vs G1 = 20°, P = .011) than the earliest group. There was a decrease in revision rate (45%, 35%, 33%, 30%, P = .039), notably in revisions for pseudarthrosis (16.7% G1 vs 6.9% G4, P = .007). Major complication rates also decreased (57%, 50%, 46%, 39%, P = .023) as did excessive blood loss (>4 L, 27.2 vs 16.7%, P = .023) and bladder/bowel deficit (4.2% vs 0.7% P = .002). Successful outcomes (no complications or revision) significantly increased (P = .001).Conclusion
Over 9 yr, 3COs are being performed on an increasingly disabled population while gaining a greater correction at the osteotomy site. Revisions and complication rate decreased while success rate improved during the 2-yr follow-up period.Item Open Access Alignment Targets, Curve Proportion and Mechanical Loading: Preliminary Analysis of an Ideal Shape Toward Reducing Proximal Junctional Kyphosis.(Global spine journal, 2022-07) Katsuura, Yoshihiro; Lafage, Renaud; Kim, Han Jo; Smith, Justin S; Line, Breton; Shaffrey, Christopher; Burton, Douglas C; Ames, Christopher P; Mundis, Gregory M; Hostin, Richard; Bess, Shay; Klineberg, Eric O; Passias, Peter G; Lafage, Virginie; International Spine Study Group (ISSG)Study design
Retrospective cohort study.Objective
Investigate risk factors for PJK including theoretical kyphosis, mechanical loading at the UIV and age adjusted offset alignment.Methods
373 ASD patients (62.7 yrs ± 9.9; 81%F) with 2-year follow up and UIV of at least L1 and LIV of sacrum were included. Images of patients without PJK, with PJK and with PJF were compared using standard spinopelvic parameters before and after the application of the validated virtual alignment method which corrects for the compensatory mechanisms of PJK. Age-adjusted offset, theoretical thoracic kyphosis and mechanical loading at the UIV were then calculated and compared between groups. A subanalysis was performed based on the location of the UIV (upper thoracic (UT) vs. Lower thoracic (LT)).Results
At 2-years 172 (46.1%) had PJK, and 21 (5.6%) developed PJF. As PJK severity increased, the post-operative global alignment became more posterior secondary to increased over-correction of PT, PI-LL, and SVA (all P < 0.005). Also, a larger under correction of the theoretical TK (flattening) and a smaller bending moment at the UIV (underloading of UIV) was found. Multivariate analysis demonstrated that PI-LL and bending moment offsets from normative values were independent predictors of PJK/PJF in UT group; PT and bending moment difference were independent predictors for LT group.Conclusions
Spinopelvic over correction, under correction of TK (flattening), and under loading of the UIV (decreased bending moment) were associated with PJK and PJF. These differences are often missed when compensation for PJK is not accounted for in post-operative radiographs.Item Open Access Alterations in Magnitude and Shape of Thoracic Kyphosis Following Surgical Correction for Adult Spinal Deformity.(Global spine journal, 2023-11) Lafage, Renaud; Song, Junho; Diebo, Bassel; Daniels, Alan H; Passias, Peter G; Ames, Christopher P; Bess, Shay; Eastlack, Robert; Gupta, Munish C; Hostin, Richard; Kebaish, Khaled; Kim, Han Jo; Klineberg, Eric; Mundis, Gregory M; Smith, Justin S; Shaffrey, Christopher; Schwab, Frank; Lafage, Virginie; Burton, Douglas; International Spine Study GroupStudy design
Retrospective review of prospective multicenter data.Objectives
This study aimed to investigate the shape of TK before and after fusion in ASD patients treated with long fusion.Methods
ASD patients undergoing posterior spinal fusions including at least T5 to L1 without prior fusion extending to the thoracic spine were included. Patients were categorized based on the preoperative T1-T12 kyphosis into: Hypo-TK (if < 30°), Normal-TK, and Hyper-TK (if > 70°). Regional kyphosis at T10-L1 (Distal), T5-T10 (Middle), and T1-T5 (Proximal) and their relative contributions to total kyphosis were compared between groups, and the pre-to postoperative changes were investigated using paired t test.Results
In total, 329 patients were included in this analysis (mean age: 57 ± 16 years, 79.6% female). Preoperative T1-T12 TK for the entire cohort was 40.9 ± 2° (32% Hypo-TK, 11% Hyper-TK, 57% Normal-TK). The Hypo-TK group had the smallest distal TK (5.9 vs 17.1 & 26.0), and middle TK (8.0 vs 25.3 & 45.4), but the percentage of contribution to total kyphosis was not significantly different (Distal: 24.1% vs 34.1% vs 32.8%; Middle: 46.6% vs 53.9% vs 56.8%, all P > .1). Postoperatively, T1-12 TK increased significantly (40.9 ± 2.0° vs 57.8 ± 17.6°). Each group had a decrease in distal kyphosis (Hypo-TK 2.6 ± 10.4°; Normal-TK 8.9 ± 11.5°; Hyper-TK 14.9 ± 12°, all P < .05). The middle kyphosis significantly decreased for Hyper-TK (11.8 ± 12.4) and increased for both Normal-TK and Hypo-TK (3.8 ± 11° and 14.2 ± 11°). Proximal TK increased significantly for all groups by 14-18°. Deterioration from Normal-TK to Hyper-TK postoperatively was associated with lower rate of patient satisfaction (59.6% vs 77.3%, P = .032).Conclusions
Posterior spinal fusion for ASD alters the magnitude and shape of thoracic kyphosis. While 60% of patients had a normal TK at baseline, 30% of those patients developed iatrogenic hyperkyphosis postoperatively. Patients with baseline hypokyphosis were more likely to be corrected to normal TK than hyperkyphotic patients. Future research should investigate TK restoration in ASD and its impact on clinical outcomes and complications.Item Open Access Analysis of tranexamic acid usage in adult spinal deformity patients with relative contraindications: does it increase the risk of complications?(JOURNAL OF NEUROSURGERY-SPINE, 2024) Mullin, Jeffrey P; Soliman, Mohamed AR; Smith, Justin S; Kelly, Michael P; Buell, Thomas J; Diebo, Bassel; Scheer, Justin K; Line, Breton; Lafage, Virginie; Lafage, Renaud; Klineberg, Eric; Kim, Han Jo; Passias, Peter G; Gum, Jeffrey L; Kebaish, Khaled; Eastlack, Robert K; Daniels, Alan H; Soroceanu, Alex; Mundis, Gregory; Hostin, Richard; Protopsaltis, Themistocles S; Hamilton, D Kojo; Gupta, Munish C; Lewis, Stephen J; Schwab, Frank J; Lenke, Lawrence G; Shaffrey, Christopher I; Bess, Shay; Ames, Christopher P; Burton, DouglasItem Open Access Analysis of tranexamic acid usage in adult spinal deformity patients with relative contraindications: does it increase the risk of complications?(Journal of neurosurgery. Spine, 2024-03) Mullin, Jeffrey P; Soliman, Mohamed AR; Smith, Justin S; Kelly, Michael P; Buell, Thomas J; Diebo, Bassel; Scheer, Justin K; Line, Breton; Lafage, Virginie; Lafage, Renaud; Klineberg, Eric; Kim, Han Jo; Passias, Peter G; Gum, Jeffrey L; Kebaish, Khaled; Eastlack, Robert K; Daniels, Alan H; Soroceanu, Alex; Mundis, Gregory; Hostin, Richard; Protopsaltis, Themistocles S; Hamilton, D Kojo; Gupta, Munish C; Lewis, Stephen J; Schwab, Frank J; Lenke, Lawrence G; Shaffrey, Christopher I; Bess, Shay; Ames, Christopher P; Burton, DouglasObjective
Complex spinal deformity surgeries may involve significant blood loss. The use of antifibrinolytic agents such as tranexamic acid (TXA) has been proven to reduce perioperative blood loss. However, for patients with a history of thromboembolic events, there is concern of increased risk when TXA is used during these surgeries. This study aimed to assess whether TXA use in patients undergoing complex spinal deformity correction surgeries increases the risk of thromboembolic complications based on preexisting thromboembolic risk factors.Methods
Data were analyzed for adult patients who received TXA during surgical correction for spinal deformity at 21 North American centers between August 2018 and October 2022. Patients with preexisting thromboembolic events and other risk factors (history of deep venous thrombosis [DVT], pulmonary embolism [PE], myocardial infarction [MI], stroke, peripheral vascular disease, or cancer) were identified. Thromboembolic complication rates were assessed during the postoperative 90 days. Univariate and multivariate analyses were performed to assess thromboembolic outcomes in high-risk and low-risk patients who received intravenous TXA.Results
Among 411 consecutive patients who underwent complex spinal deformity surgery and received TXA intraoperatively, 130 (31.6%) were considered high-risk patients. There was no significant difference in thromboembolic complications between patients with and those without preexisting thromboembolic risk factors in univariate analysis (high-risk group vs low-risk group: 8.5% vs 2.8%, p = 0.45). Specifically, there were no significant differences between groups regarding the 90-day postoperative rates of DVT (high-risk group vs low-risk group: 1.5% vs 1.4%, p = 0.98), PE (2.3% vs 1.8%, p = 0.71), acute MI (1.5% vs 0%, p = 0.19), or stroke (0.8% vs 1.1%, p > 0.99). On multivariate analysis, high-risk status was not a significant independent predictor for any of the thromboembolic complications.Conclusions
Administration of intravenous TXA during the correction procedure did not change rates of thromboembolic events, acute MI, or stroke in this cohort of adult spinal deformity surgery patients.Item Open Access Assessment of Surgical Treatment Strategies for Moderate to Severe Cervical Spinal Deformity Reveals Marked Variation in Approaches, Osteotomies, and Fusion Levels.(World neurosurgery, 2016-07) Smith, Justin S; Klineberg, Eric; Shaffrey, Christopher I; Lafage, Virginie; Schwab, Frank J; Protopsaltis, Themistocles; Scheer, Justin K; Ailon, Tamir; Ramachandran, Subaraman; Daniels, Alan; Mundis, Gregory; Gupta, Munish; Hostin, Richard; Deviren, Vedat; Eastlack, Robert; Passias, Peter; Hamilton, D Kojo; Hart, Robert; Burton, Douglas C; Bess, Shay; Ames, Christopher P; International Spine Study GroupObjective
Although previous reports suggest that surgery can improve the pain and disability of cervical spinal deformity (CSD), techniques are not standardized. Our objective was to assess for consensus on recommended surgical plans for CSD treatment.Methods
Eighteen CSD cases were assembled, including a clinical vignette, cervical imaging (radiography, computed tomography/magnetic resonance imaging), and full-length standing radiography. Fourteen deformity surgeons (10 orthopedic, 4 neurosurgery) were queried regarding recommended surgical plans.Results
There was marked variation in treatment plans across all deformity types. Even for the least complex deformities (moderate midcervical apex kyphosis), there was lack of agreement on approach (50% combined anterior-posterior, 25% anterior only, 25% posterior only), number of anterior (range, 2-6) and posterior (range, 4-16) fusion levels, and types of osteotomies. As the kyphosis apex moved caudally (cervical-thoracic junction/upper thoracic spine) and for cases with chin-on-chest kyphosis, >80% of surgeons agreed on a posterior-only approach and >70% recommended a pedicle subtraction osteotomy or vertebral column resection, but the range in number of anterior (4-8) and posterior (4-27) fusion levels was exceptionally broad. Cases of cervical/cervical-thoracic scoliosis had the least agreement for approach (48% posterior only, 33% combined anterior-posterior, 17% anterior-posterior-anterior or posterior-anterior-posterior, 2% anterior only) and had broad variation in the number of anterior (2-5) and posterior (6-19) fusion levels, and recommended osteotomies (41% pedicle subtraction osteotomy/vertebral column resection).Conclusions
Among a panel of deformity surgeons, there was marked lack of consensus on recommended surgical approach, osteotomies, and fusion levels for CSD. Further study is warranted to assess whether specific surgical treatment approaches are associated with better outcomes.Item Open Access Author Correction: Sagittal age-adjusted score (SAAS) for adult spinal deformity (ASD) more effectively predicts surgical outcomes and proximal junctional kyphosis than previous classifications.(Spine deformity, 2023-03) Lafage, Renaud; Smith, Justin S; Elysee, Jonathan; Passias, Peter; Bess, Shay; Klineberg, Eric; Kim, Han Jo; Shaffrey, Christopher; Burton, Douglas; Hostin, Richard; Mundis, Gregory; Ames, Christopher; Schwab, Frank; Lafage, Virginie; International Spine Study Group (ISSG)In Fig. 4 of this article signs for points associated in all 3 components are incorrect and should be reversed, e.g. + 2 should be − 2 and vise versa; Fig. 4 should have appeared as shown below. The original article has been correctedItem Open Access Benchmark Values for Construct Survival and Complications by Type of ASD Surgery.(Spine, 2024-04) Bass, Robert Daniel; Lafage, Renaud; Smith, Justin S; Ames, Christopher; Bess, Shay; Eastlack, Robert; Gupta, Munish; Hostin, Richard; Kebaish, Khaled; Kim, Han Jo; Klineberg, Eric; Mundis, Gregory; Okonkwo, David; Shaffrey, Christopher; Schwab, Frank; Lafage, Virginie; Burton, Douglas; International Spine Study GroupObjective
Provide benchmarks for the rates of complications by type of surgery performed.Study design
Prospective multicenter database.Background
We have previously examined overall construct survival and complication rates for ASD surgery. However, the relationship between type of surgery and construct survival warrants more detailed assessment.Methods
Eight surgical scenarios were defined based on the levels treated, previous fusion status (primary [P] vs. revision [R]), and 3-column osteotomy use [3CO]: Short Lumbar fusion, LT-Pelvis with 5-12 levels treated (P, R or 3CO), UT-Pelvis with 13 levels treated (P, R or 3CO), and Thoracic to Lumbar fusion without pelvic fixation, representing 92.4% of the case in the cohort. Complication rates for each type were calculated and Kaplan Meier curves with multivariate Cox regression analysis was used to evaluate the effect of the case characteristics on construct survival rate, while controlling for patient profile.Results
1073 of 1494 patients eligible for 2-year follow-up (71.8%) were captured. Survival curves for major complications (with or without reoperation), while controlling for demographics differed significantly among surgical types (P<0.001). Fusion procedures short of the pelvis had the best survival rate, while UT-Pelvis with 3CO had the worst survival rate. Longer fusions and more invasive operations were associated with lower 2-year complication-free survival, however there were no significant associations between type of surgery and renal, cardiac, infection, wound, gastrointestinal, pulmonary, implant malposition or neurologic complications (all P>0.5).Conclusion
This study suggests that there is an inherent increased risk of complication for some types of ASD surgery independent of patient profile. The results of this paper can be used to produce a surgery-adjusted benchmark for ASD surgery with regard to complications and survival. Such a tool can have very impactful applications for surgical decision making and more informed patient counseling.Item Open Access Calibration of a comprehensive predictive model for the development of proximal junctional kyphosis and failure in adult spinal deformity patients with consideration of contemporary goals and techniques.(Journal of neurosurgery. Spine, 2023-06) Tretiakov, Peter S; Lafage, Renaud; Smith, Justin S; Line, Breton G; Diebo, Bassel G; Daniels, Alan H; Gum, Jeffrey; Protopsaltis, Themistocles; Hamilton, D Kojo; Soroceanu, Alex; Scheer, Justin K; Eastlack, Robert K; Mundis, Gregory; Nunley, Pierce D; Klineberg, Eric O; Kebaish, Khaled; Lewis, Stephen; Lenke, Lawrence; Hostin, Richard; Gupta, Munish C; Ames, Christopher P; Hart, Robert A; Burton, Douglas; Shaffrey, Christopher I; Schwab, Frank; Bess, Shay; Kim, Han Jo; Lafage, Virginie; Passias, Peter GObjective
The objective of this study was to calibrate an updated predictive model incorporating novel clinical, radiographic, and prophylactic measures to assess the risk of proximal junctional kyphosis (PJK) and failure (PJF).Methods
Operative patients with adult spinal deformity (ASD) and baseline and 2-year postoperative data were included. PJK was defined as ≥ 10° in sagittal Cobb angle between the inferior uppermost instrumented vertebra (UIV) endplate and superior endplate of the UIV + 2 vertebrae. PJF was radiographically defined as a proximal junctional sagittal Cobb angle ≥ 15° with the presence of structural failure and/or mechanical instability, or PJK with reoperation. Backstep conditional binary supervised learning models assessed baseline demographic, clinical, and surgical information to predict the occurrence of PJK and PJF. Internal cross validation of the model was performed via a 70%/30% cohort split. Conditional inference tree analysis determined thresholds at an alpha level of 0.05.Results
Seven hundred seventy-nine patients with ASD (mean 59.87 ± 14.24 years, 78% female, mean BMI 27.78 ± 6.02 kg/m2, mean Charlson Comorbidity Index 1.74 ± 1.71) were included. PJK developed in 50.2% of patients, and 10.5% developed PJF by their last recorded visit. The six most significant demographic, radiographic, surgical, and postoperative predictors of PJK/PJF were baseline age ≥ 74 years, baseline sagittal age-adjusted score (SAAS) T1 pelvic angle modifier > 1, baseline SAAS pelvic tilt modifier > 0, levels fused > 10, nonuse of prophylaxis measures, and 6-week SAAS pelvic incidence minus lumbar lordosis modifier > 1 (all p < 0.015). Overall, the model was deemed significant (p < 0.001), and internally validated receiver operating characteristic analysis returned an area under the curve of 0.923, indicating robust model fit.Conclusions
PJK and PJF remain critical concerns in ASD surgery, and efforts to reduce the occurrence of PJK and PJF have resulted in the development of novel prophylactic techniques and enhanced clinical and radiographic selection criteria. This study demonstrates a validated model incorporating such techniques that may allow for the prediction of clinically significant PJK and PJF, and thus assist in optimizing patient selection, enhancing intraoperative decision making, and reducing postoperative complications in ASD surgery.Item Open Access Can unsupervised cluster analysis identify patterns of complex adult spinal deformity with distinct perioperative outcomes?(Journal of neurosurgery. Spine, 2023-05) Lafage, Renaud; Fourman, Mitchell S; Smith, Justin S; Bess, Shay; Shaffrey, Christopher I; Kim, Han Jo; Kebaish, Khaled M; Burton, Douglas C; Hostin, Richard; Passias, Peter G; Protopsaltis, Themistocles S; Daniels, Alan H; Klineberg, Eric O; Gupta, Munish C; Kelly, Michael P; Lenke, Lawrence G; Schwab, Frank J; Lafage, Virginie; International Spine Study GroupObjective
The objective of this study was to use an unsupervised cluster approach to identify patterns of operative adult spinal deformity (ASD) and compare the perioperative outcomes of these groups.Methods
A multicenter data set included patients with complex surgical ASD, including those with severe deformities, significant surgical complexity, or advanced age who underwent a multilevel fusion. An unsupervised cluster analysis allowing for 10% outliers was used to identify different deformity patterns. The perioperative outcomes of these clusters were then compared using ANOVA, Kruskal-Wallis, and chi-square tests, with p values < 0.05 considered significant.Results
Two hundred eighty-six patients were classified into four clusters of deformity patterns: hyper-thoracic kyphosis (hyper-TK), severe coronal, severe sagittal, and moderate sagittal. Hyper-TK patients had the lowest disability (mean Oswestry Disability Index [ODI] 32.9 ± 17.1) and pain scores (median numeric rating scale [NRS] back score 6, leg score 1). The severe coronal cluster had moderate functional impairment (mean physical component score 34.4 ± 12.3) and pain (median NRS back score 7, leg score 4) scores. The severe sagittal cluster had the highest levels of disability (mean ODI 49.3 ± 15.6) and low appearance scores (mean 2.3 ± 0.7). The moderate cluster (mean 68.8 ± 7.8 years) had the highest pain interference subscores on the Patient-Reported Outcomes Measurement Information System (mean 65.2 ± 5.8). Overall 30-day adverse events were equivalent among the four groups. Fusion to the pelvis was most common in the moderate sagittal (89.4%) and severe sagittal (97.5%) clusters. The severe coronal cluster had more osteotomies per case (median 11, IQR 6.5-14) and a higher rate of 30-day implant-related complications (5.5%). The severe sagittal and hyper-TK clusters had more three-column osteotomies (43% and 32.3%, respectively). Hyper-TK patients had shorter hospital stays.Conclusions
This cohort of patients with complex ASD surgeries contained four natural clusters of deformity, each with distinct perioperative outcomes.Item Open Access Cell Saver for Adult Spinal Deformity Surgery Reduces Cost.(Spine deformity, 2017-07) Gum, Jeffrey L; Carreon, Leah Yacat; Kelly, Michael P; Hostin, Richard; Robinson, Chessie; Burton, Douglas C; Polly, David W; Shaffrey, Christopher I; LaFage, Virginie; Schwab, Frank J; Ames, Christopher P; Kim, Han Jo; Smith, Justin S; Bess, R Shay; International Spine Study GroupStudy design
Retrospective cohort.Objectives
To determine if the use of cell saver reduces overall blood costs in adult spinal deformity (ASD) surgery.Summary of background data
Recent studies have questioned the clinical value of cell saver during spine procedures.Methods
ASD patients enrolled in a prospective, multicenter surgical database who had complete preoperative and surgical data were identified. Patients were stratified into (1) cell saver available during surgery, but no intraoperative autologous infusion (No Infusion group), or (2) cell saver available and received autologous infusion (Infusion group).Results
There were 427 patients in the Infusion group and 153 in the No infusion group. Patients in both groups had similar demographics. Mean autologous infusion volume was 698 mL. The Infusion group had a higher percentage of EBL relative to the estimated blood volume (42.2%) than the No Infusion group (19.6%, p < .000). Allogeneic transfusion was more common in the Infusion group (255/427, 60%) than the No Infusion group (67/153, 44%, p = .001). The number of allogeneic blood units transfused was also higher in the Infusion group (2.4) than the No Infusion group (1.7, p = .009). Total blood costs ranged from $396 to $2,146 in the No Infusion group and from $1,262 to $5,088 in the Infusion group. If the cost of cell saver blood was transformed into costs of allogeneic blood, total blood costs for the Infusion group would range from $840 to $5,418. Thus, cell saver use yielded a mean cost savings ranging from $330 to $422 (allogeneic blood averted). Linear regression showed that after an EBL of 614 mL, cell saver becomes cost-efficient.Conclusion
Compared to transfusing allogeneic blood, cell saver autologous infusion did not reduce the proportion or the volume of allogeneic transfusion for patients undergoing surgery for adult spinal deformity. The use of cell saver becomes cost-efficient above an EBL of 614 mL, producing a cost savings of $330 to $422.Level of evidence
Level III.Item Open Access Cervical compensatory alignment changes following correction of adult thoracic deformity: a multicenter experience in 57 patients with a 2-year follow-up.(Journal of neurosurgery. Spine, 2015-06) Oh, Taemin; Scheer, Justin K; Eastlack, Robert; Smith, Justin S; Lafage, Virginie; Protopsaltis, Themistocles S; Klineberg, Eric; Passias, Peter G; Deviren, Vedat; Hostin, Richard; Gupta, Munish; Bess, Shay; Schwab, Frank; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study GroupOBJECT Alignment changes in the cervical spine that occur following surgical correction for thoracic deformity remain poorly understood. The purpose of this study was to evaluate such changes in a cohort of adults with thoracic deformity treated surgically. METHODS The authors conducted a multicenter retrospective analysis of consecutive patients with thoracic deformity. Inclusion criteria for this study were as follows: corrective osteotomy for thoracic deformity, upper-most instrumented vertebra (UIV) between T-1 and T-4, lower-most instrumented vertebra (LIV) at or above L-5 (LIV ≥ L-5) or at the ilium (LIV-ilium), and a minimum radiographic follow-up of 2 years. Sagittal radiographic parameters were assessed preoperatively as well as at 3 months and 2 years postoperatively, including the C-7 sagittal vertical axis (SVA), C2-7 cervical lordosis (CL), C2-7 SVA, T-1 slope (T1S), T1S minus CL (T1S-CL), T2-12 thoracic kyphosis (TK), apical TK, lumbar lordosis (LL), pelvic incidence (PI), PI-LL, pelvic tilt (PT), and sacral slope (SS). RESULTS Fifty-seven patients with a mean age of 49.1 ± 14.6 years met the study inclusion criteria. The preoperative prevalence of increased CL (CL > 15°) was 48.9%. Both 3-month and 2-year apical TK improved from baseline (p < 0.05, statistically significant). At the 2-year follow-up, only the C2-7 SVA increased significantly from baseline (p = 0.01), whereas LL decreased from baseline (p < 0.01). The prevalence of increased CL was 35.3% at 3 months and 47.8% at 2 years, which did not represent a significant change. Postoperative cervical alignment changes were not significantly different from preoperative values regardless of the LIV (LIV ≥ L-5 or LIV-ilium, p > 0.05 for both). In a subset of patients with a maximum TK ≥ 60° (35 patients) and 3-column osteotomy (38 patients), no significant postoperative cervical changes were seen. CONCLUSION Increased CL is common in adult spinal deformity patients with thoracic deformities and, unlike after lumbar corrective surgery, does not appear to normalize after thoracic corrective surgery. Cervical sagittal malalignment (C2-7 SVA) also increases postoperatively. Surgeons should be aware that spontaneous cervical alignment normalization might not occur following thoracic deformity correction.Item Open Access Cervical mismatch: the normative value of T1 slope minus cervical lordosis and its ability to predict ideal cervical lordosis.(Journal of neurosurgery. Spine, 2018-10) Staub, Blake N; Lafage, Renaud; Kim, Han Jo; Shaffrey, Christopher I; Mundis, Gregory M; Hostin, Richard; Burton, Douglas; Lenke, Lawrence; Gupta, Munish C; Ames, Christopher; Klineberg, Eric; Bess, Shay; Schwab, Frank; Lafage, Virginie; International Spine Study GroupOBJECTIVE: Numerous studies have attempted to delineate the normative value for T1S-CL (T1 slope minus cervical lordosis) as a marker for both cervical deformity and a goal for correction similar to how PI-LL (pelvic incidence-lumbar lordosis) mismatch informs decision making in thoracolumbar adult spinal deformity (ASD). The goal of this study was to define the relationship between T1 slope (T1S) and cervical lordosis (CL). METHODS: This is a retrospective review of a prospective database. Surgical ASD cases were initially analyzed. Analysis across the sagittal parameters was performed. Linear regression analysis based on T1S was used to provide a clinically applicable equation to predict CL. Findings were validated using the postoperative alignment of the ASD patients. Further validation was then performed using a second, normative database. The range of normal alignment associated with horizontal gaze was derived from a multilinear regression on data from asymptomatic patients. RESULTS: A total of 103 patients (mean age 54.7 years) were included. Analysis revealed a strong correlation between T1S and C0-7 lordosis (r = 0.886), C2-7 lordosis (r = 0.815), and C0-2 lordosis (r = 0.732). There was no significant correlation between T1S and T1S-CL. Linear regression analysis revealed that T1S-CL assumed a constant value of 16.5° (R2 = 0.664, standard error 2°). These findings were validated on the postoperative imaging (mean absolute error [MAE] 5.9°). The equation was then applied to the normative database (MAE 6.7° controlling for McGregor slope [MGS] between -5° and 15°). A multilinear regression between C2-7, T1S, and MGS demonstrated a range of T1S-CL between 14.5° and 26.5° was necessary to maintain horizontal gaze. CONCLUSIONS: Normative CL can be predicted via the formula CL = T1S - 16.5° ± 2°. This implies a threshold of deformity and aids in providing a goal for surgical correction. Just as pelvic incidence (PI) can be used to determine the ideal LL, T1S can be used to predict ideal CL. This formula also implies that a kyphotic cervical alignment is to be expected for individuals with a T1S < 16.5°.Item Open Access Cervical sagittal deformity develops after PJK in adult thoracolumbar deformity correction: radiographic analysis utilizing a novel global sagittal angular parameter, the CTPA.(European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, 2017-04) Protopsaltis, Themistocles; Bronsard, Nicolas; Soroceanu, Alex; Henry, Jensen K; Lafage, Renaud; Smith, Justin; Klineberg, Eric; Mundis, Gregory; Kim, Han Jo; Hostin, Richard; Hart, Robert; Shaffrey, Christopher; Bess, Shay; Ames, Christopher; International Spine Study GroupPurpose
To describe reciprocal changes in cervical alignment after adult spinal deformity (ASD) correction and subsequent development of proximal junctional kyphosis (PJK). This study also investigated these changes using two novel global sagittal angular parameters, cervical-thoracic pelvic angle (CTPA) and the T1 pelvic angle (TPA).Methods
Multicenter, retrospective consecutive case series of ASD patients undergoing thoracolumbar three-column osteotomy (3CO) with fusion to the pelvis. Radiographs were analyzed at baseline and 1 year post-operatively. Patients were substratified into upper thoracic (UT; UIV T6 and above) and lower thoracic (LT; UIV below T6). PJK was defined by >10° angle between UIV and UIV + 2 and >10° change in the angle from baseline to post-op.Results
PJK developed in 29 % (78 of 267) of patients. CTPA was linearly correlated with cervical plumbline (CPL) as a measure of cervical sagittal alignment (R = 0.826, p < 0.001). PJK patients had significantly greater post-operative CTPA and SVA than patients without PJK (NPJK) (p = 0.042; p = 0.021). For UT (n = 141) but not LT (n = 136), PJK patients at 1 year had larger CTPA (4.9° vs. 3.7°, p = 0.015) and CPL (5.1 vs. 3.8 cm, p = 0.022) than NPJK patients, despite similar corrections in PT and PI-LL.Conclusions
The prevalence of PJK was 29 % at 1 year follow-up. CTPA, which correlates with CPL as a global analog of cervical sagittal balance, and TPA describe relative proportions of cervical and thoracolumbar deformities. Patients who develop PJK in the upper thoracic spine after thoracolumbar 3CO also develop concomitant cervical sagittal deformity, with increases in CPL and CTPA.Item Open Access Cervical, Thoracic, and Spinopelvic Compensation After Proximal Junctional Kyphosis (PJK): Does Location of PJK Matter?(Global spine journal, 2020-02) Kim, Han Jo; York, Philip J; Elysee, Jonathan C; Shaffrey, Christopher; Burton, Douglas C; Ames, Christopher P; Mundis, Gregory M; Hostin, Richard; Bess, Shay; Klineberg, Eric; Smith, Justin S; Passias, Peter; Schwab, Frank; Lafage, Renaud; International Spine Study Group(ISSG)Study design
Retrospective case series.Objective
Compensatory changes above a proximal junctional kyphosis (PJK) have not been defined. Understanding these mechanisms may help determine optimal level selection when performing revision for PJK. This study investigates how varying PJK location changes proximal spinal alignment.Methods
Patients were grouped by upper instrumented vertebrae (UIV): lower thoracic (LT; T8-L1) or upper thoracic (UT; T1-7). Alignment parameters were compared. Correlation analysis was performed between PJK magnitude and global/cervical alignment.Results
A total of 369 patients were included; mean age of 63 years, body mass index 28, and 81% female, LT (n = 193) versus UT (n = 176). The rate of radiographic PJK was 49%, higher in the LT group (55% vs 42%, P = .01). The UT group displayed significant differences in all cervical radiographic parameters (P < .05) between PJK versus non-PJK patients, while the LT group displayed significant differences in T1S and C2-T3 sagittal vertical axis (SVA) (CTS). In comparing UT versus LT patients, UT had more posterior global alignment (smaller TPA [T1 pelvic angle], SVA, and larger PT [pelvic tilt]) and larger anterior cervical alignment (greater cSVA [cervical SVA], T1S-CL [T1 slope-cervical lordosis] mismatch, CTS) compared to LT. Correlation analysis of PJK magnitude and location demonstrated a correlation with increases in CL, T1S, and CTS in the UT group. In the LT group, PT increased with PJK angle (r = 0.17) and no significant correlations were noted to SVA, cSVA, or T1S-CL.Conclusions
PJK location influences compensation mechanisms of the cervical and thoracic spine. LT PJK results in increased PT and CL with decreased CTS. UT PJK increases CL to counter increases in T1S with continued T1S-CL mismatch and elevated cSVA.Item Open Access Change in classification grade by the SRS-Schwab Adult Spinal Deformity Classification predicts impact on health-related quality of life measures: prospective analysis of operative and nonoperative treatment.(Spine, 2013-09) Smith, Justin S; Klineberg, Eric; Schwab, Frank; Shaffrey, Christopher I; Moal, Bertrand; Ames, Christopher P; Hostin, Richard; Fu, Kai-Ming G; Burton, Douglas; Akbarnia, Behrooz; Gupta, Munish; Hart, Robert; Bess, Shay; Lafage, Virginie; International Spine Study GroupStudy design
Multicenter, prospective, consecutive series.Objective
To evaluate responsiveness of the Scoliosis Research Society (SRS)-Schwab adult spinal deformity (ASD) classification to changes in health-related quality of life (HRQOL) after treatment for ASD.Summary of background data
Ideally, a classification system should describe and be responsive to changes in a disease state. We hypothesized that the SRS-Schwab classification is responsive to changes in HRQOL measures after treatment for ASD.Methods
A multicenter, prospective, consecutive series from the International Spine Study Group.Inclusion criteria
ASD, age more than 18, operative or nonoperative treatment, baseline and 1-year radiographs, and HRQOL measures (Oswestry Disability Index [ODI], SRS-22, Short Form [SF]-36). The SRS-Schwab classification includes a curve descriptor and 3 sagittal spinopelvic modifiers (sagittal vertical axis [SVA], pelvic tilt, pelvic incidence/lumbar lordosis [PI-LL] mismatch). Changes in modifiers at 1 year were assessed for impact on HRQOL from pretreatment values based on minimal clinically important differences.Results
Three hundred forty-one patients met criteria (mean age = 54; 85% females; 177 operative and 164 nonoperative). Change in pelvic tilt modifier at 1-year follow-up was associated with changes in ODI and SRS-22 (total and appearance scores) (P ≤ 0.034). Change in SVA modifier at 1 year was associated with changes in ODI, SF-36 physical component score, and SRS-22 (total, activity, and appearance scores) (P ≤ 0.037). Change in PI-LL modifier at 1 year was associated with changes in SF-36 physical component score and SRS-22 (total, activity, and appearance scores) (P ≤ 0.03). Patients with improvement of pelvic tilt, SVA, or PI-LL modifiers were significantly more likely to achieve minimal clinically important difference for ODI, SF-36 physical component score (SVA and PI-LL only), SRS activity, and SRS pain (PI-LL only).Conclusion
The SRS-Schwab classification provides a validated system to evaluate ASD, and the classification components correlate with HRQOL measures. This study demonstrates that the classification modifiers are responsive to changes in disease state and reflect significant changes in patient-reported outcomes.Level of evidence
3.Item Open Access Changes in thoracic kyphosis negatively impact sagittal alignment after lumbar pedicle subtraction osteotomy: a comprehensive radiographic analysis.(Spine, 2012-02) Lafage, Virginie; Ames, Christopher; Schwab, Frank; Klineberg, Eric; Akbarnia, Behrooz; Smith, Justin; Boachie-Adjei, Oheneba; Burton, Douglas; Hart, Robert; Hostin, Richard; Shaffrey, Christopher; Wood, Kirkham; Bess, Shay; International Spine Study GroupStudy 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.Item Open Access Comparing and Contrasting the Clinical Utility of Sagittal Spine Alignment Classification Frameworks: Roussouly Versus SRS-Schwab.(Spine, 2022-03) Passias, Peter G; Bortz, Cole; Pierce, Katherine E; Passfall, Lara; Kummer, Nicholas A; Krol, Oscar; Lafage, Renaud; Diebo, Bassel G; Lafage, Virginie; Ames, Christopher P; Burton, Douglas C; Gupta, Munish C; Sciubba, Daniel M; Schoenfeld, Andrew J; Bess, Shay; Hostin, Richard; Shaffrey, Christopher I; Line, Breton G; Klineberg, Eric O; Smith, Justin S; Schwab, Frank J; International Spine Study GroupStudy design
Retrospective cohort study of a prospectively collected database.Objective
To compare clinical utility of two common classification systems for adult spinal deformity (ASD) and determine whether both should be considered in surgical planning to improve patient outcomes.Summary of background data
Surgical restoration of appropriate Roussouly classification shape or SRS-Schwab ASD classification may improve outcomes.Methods
ASD patients with pre- and 2-year postop (2Y) radiographic/health-related quality of life (HRQL) data were grouped by "theoretical" and "current" Roussouly type. Univariate analyses assessed outcomes of patients who mismatched Roussouly types at both pre- and 2Y intervals (Mismatched) and those of preoperative mismatched patients who matched at 2-years (Matched). Subanalysis assessed outcomes of patients who improved in Schwab modifiers, and patients who both improved in both Schwab modifiers and matched Roussouly type by 2Y.Results
Included: 515 ASD patients (59 ± 14 yrs, 80% F). Preoperative breakdown of "current" Roussouly types: Type 1 (10%), 2 (54%), 3 (24%), and 4 (12%). Matched and Mismatched groups did not differ in rates of reaching MCID for any HRQL metrics by 2Y (all P > 0.10). Reoperation, PJK, and complications did not differ between Matched and Mismatched (all P > 0.10), but Roussouly Matched patients had toward lower rates of instrumentation failure (17.2% vs. 24.8%, P = 0.038). By 2Y, 28% of patients improved in PT Schwab modifier, 37% in SVA, and 46% in PI-LL. Patients who both Matched Roussouly at 2Y and improved in all Schwab modifiers met MCID for Oswestry Disability Index (ODI) and Scoliosis Research Society (SRS) activity at higher rates than patients who did not.Conclusion
Isolated restoration per the Roussouly system was not associated with superior outcomes. Patients who both matched Roussouly type and improved in Schwab modifiers had superior patient-reported outcomes at 2-years. Concurrent consideration of both systems may offer utility in establishing optimal realignment goals.Level of Evidence: 3.