Browsing by Author "Protopsaltis, Themistocles"

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    ItemOpen Access
    1-Year Post-Operative Radiographic and Patient-Reported Outcomes following Cervical Deformity Correction are not Affected by a Short-Term Unplanned Return to the OR.
    (Spine, 2023-02) Fourman, Mitchell S; Lafage, Renaud; Ames, Christopher; Smith, Justin S; Passias, Peter G; Shaffrey, Christopher I; Mundis, Gregory; Protopsaltis, Themistocles; Gupta, Munish; Klineberg, Eric O; Bess, Shay; Lafage, Virginie; Kim, Han Jo; International Spine Study Group

    Study design

    Retrospective analysis of a prospectively-collected multi-center database.

    Objective

    Assess the radiographic and health-related quality of life (HRQoL) impact of a short term (<1 y) return to the OR after adult cervical spine deformity (ACSD) surgery.

    Summary of background data

    Returns to the OR within a year of ACSD correction can be particularly devastating to these vulnerable hosts as they often involve compromise of the soft tissue envelope, neurologic deficits or hardware failure. This work sought to assess the impact of a short-term reoperation on 1-year radiographic and HRQoL outcomes.

    Methods

    Patients operated on from 1/1/2013 to 1/1/2019 with at least 1-year of follow-up were included. The primary outcome was a short-term return to the OR. Variables of interest included patient demographics, Charlson Comorbidity Index (CCI), HRQoL measured with the Modified Japanese Orthopaedic Association (mJOA), Neck Disability Index (NDI) and EuroQuol-5D visual analogue scale (EQ-5D VAS) and radiographic outcomes, including T1-slope (TS), C2-C7 sagittal cobb angle (CL), TS-CL and cervical sagittal vertical axis (cSVA). Comparisons between those who did versus did not require a 1-year reoperation were performed using paired t-tests. A Kaplan Meier survival curve was used to estimate reoperation-free survival up to 2-years post-operatively.

    Results

    A total of 121 patients were included in this work (age 61.9±10.1 y, BMI 28.4±6.9, CCI 1.0±1.4, 62.8% female). A 1-year unplanned return to the OR was required for 28 (23.1%) patients, of whom 19 followed-up for at least 1-year. Indications for a return to the OR were most commonly for neurologic complications (5%), infectious/wound complications (5.8%) and junctional failure (6.6%) No differences in demographics, comorbidities, pre-operative or 1-year post-operative HRQoL or radiographic outcomes were seen between operative groups.

    Conclusion

    Reoperation <1 year after ACSD surgery did not influence 1-year radiographic outcomes or HRQoL.
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    ItemOpen Access
    A Comparison of Three Different Positioning Techniques on Surgical Corrections and Postoperative Alignment in Cervical Spinal Deformity (CD) Surgery.
    (Spine, 2021-05) Morse, Kyle W; Lafage, Renaud; Passias, Peter; Ames, Christopher P; Hart, Robert; Shaffrey, Christopher I; Mundis, Gregory; Protopsaltis, Themistocles; Gupta, Munish; Klineberg, Eric; Burton, Doug; Lafage, Virginie; Kim, Han Jo; International Spine Study Group

    Study design

    Retrospective review of a prospective multicenter cervical deformity database.

    Objective

    To examine the differences in sagittal alignment correction between three positioning methods in cervical spinal deformity surgery (CD).

    Summary of background data

    Surgical correction for CD is technically demanding and various techniques are utilized to achieve sagittal alignment objectives. The effect of different patient positioning techniques on sagittal alignment correction following CD remains unknown.

    Methods

    Patients with sagittal deformity who underwent a posterior approach (with and without anterior approach) with an upper instrumented vertebra of C6 or above. Patients with Grade 5, 6, or 7 osteotomies were excluded. Positioning groups were Mayfield skull clamp, bivector traction, and halo ring. Preoperative lower surgical sagittal curve (C2-C7), C2-C7 sagittal vertical axis (cSVA), cervical scoliosis, T1 slope minus cervical lordosis (TS-CL), T1 slope (T1S), chin-brow vertebral angle (CBVA), C2-T3 curve, and C2-T3 SVA was assessed and compared with postoperative radiographs. Segmental changes were analyzed using the Fergusson method.

    Results

    Eighty patients (58% female) with a mean age of 60.6 ± 10.5 years (range, 31-83) were included. The mean postoperative C2-C7 lordosis was 7.8° ± 14 and C2-C7 SVA was 34.1 mm ± 15. There were overall significant changes in cervical alignment across the entire cohort, with improvements in T1 slope (P < 0.001), C2-C7 (P < 0.001), TS-CL (P < 0.001), and cSVA (P = 0.006). There were no differences postoperatively of any radiographic parameter between positioning groups (P > 0.05). The majority of segmental lordotic correction was achieved at C4-5-6 (mean 6.9° ± 11). Additionally, patients who had bivector traction applied had had significantly more segmental correction at C7-T1-T2 compared with Mayfield and halo traction (4.2° vs. 0.3° vs. -1.7° respectively, P < 0.027).

    Conclusion

    Postoperative cervical sagittal correction or alignment was not affected by patient position. The majority of segmental correction occurred at C4-5-6 across all positioning methods, while bivector traction had the largest corrective ability at the cervicothoracic junction.Level of Evidence: 4.
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    ItemOpen Access
    A New Piece of the Puzzle to Understand Cervical Sagittal Alignment: Utilizing a Novel Angle δ to Describe the Relationship among T1 Vertebral Body Slope, Cervical Lordosis, and Cervical Sagittal Alignment.
    (Neurosurgery, 2020-03) Goldschmidt, Ezequiel; Angriman, Federico; Agarwal, Nitin; Trevisan, Marcos; Zhou, James; Chen, Katherine; Gerszten, Peter C; Kanter, Adam S; Okonkwo, David O; Passias, Peter; Scheer, Justin; Protopsaltis, Themistocles; Lafage, Virginie; Lafage, Renaud; Schwab, Frank; Bess, Shay; Ames, Christopher; Smith, Justin S; Shaffrey, Christopher I; Miller, Emily; Jain, Amit; Neuman, Brian; Sciubba, Daniel M; Burton, Douglas; Hamilton, D Kojo; International Spine Study Group (ISSG)
    Cervical alignment has become increasingly important in the planning of spine surgery. A relationship between the slope of T1 (T1S), the cervical lordosis (CL), and the overall cervical sagittal vertical axis (cSVA) has previously been demonstrated, but the exact nature of this relationship is poorly understood. In this study, we derive theoretical and empirical equations to better understand how T1S and CL affect cSVA. The first equation was developed on a theoretical basis using inherent trigonometric relationships of the cervical spine. By treating the cervical spine as the arc of a circumference, and by taking into account the cervical height (CH), the geometric relationship between theT1S, CL, and cSVA was described via a trigonometric identity utilizing a novel angle δ subtended by the CH and cSVA (δ = T1S-CL/2). The second equation was developed on an empiric basis by performing a multiple linear regression on data obtained from a retrospective review of a large multicenter deformity database. The theoretical equation determined that the value of cSVA could be expressed as: $cSVA\ = \ CH*{\rm{tan}}( {\pi /180*( {T1S - CL/2} )} )$. The empirical equation determined that value of cSVA could be expressed as: $cSVA=({1.1*T1} )\ - ( {0.43*CL} ) + 6.69$. In both, the sagittal alignment of the head over the shoulders is directly proportional to the T1S and inversely proportional to CL/2. These 2 equations may allow surgeons to better understand how the CL compensates for the T1S, to accurately predict the postoperative cSVA, and to customize cervical interbody grafts by taking into consideration each individual patient's specific cervical spine parameters.
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    ItemOpen Access
    A Novel Tool for Deformity Surgery Planning: Determining the Magnitude of Lordotic Correction Required to Achieve a Desired Sagittal Vertical Axis.
    (World neurosurgery, 2017-08) Goldschmidt, Ezequiel; Angriman, Federico; Agarwal, Nitin; Zhou, James; Chen, Katherine; Tempel, Zachary J; Gerszten, Peter C; Kanter, Adam S; Okonkwo, David O; Passias, Peter; Scheer, Justin; Protopsaltis, Themistocles; Lafage, Virginie; Lafage, Renaud; Schwab, Frank; Bess, Shay; Ames, Christopher; Smith, Justin S; Shaffrey, Christopher I; Miller, Emily; Jain, Amit; Neuman, Brian; Sciubba, Daniel M; Burton, Douglas; Hamilton, D Kojo; International Spine Study Group

    Objective

    We sought to create a model capable of predicting the magnitude of pelvic incidence-lumbar lordosis (PI-LL) correction necessary to achieve a desired change in sagittal vertical axis (SVA).

    Methods

    A retrospective review was conducted of a prospectively maintained multicenter adult spinal deformity database collected by the International Spine Study Group between 2009 and 2014. The independent variable of interest was the degree of correction achieved in the PI-LL mismatch 6 weeks after surgery. Primary outcome was the change in global sagittal alignment 6 weeks and 1 year after surgery. We used a linear mixed-effects model to determine the extent to which corrections in the PI-LL relationship affected postoperative changes in SVA.

    Results

    A total of 1053 adult patients were identified. Of these patients, 590 were managed surgically. Eighty-seven surgically managed patients were excluded because of incomplete or missing PI-LL measurements on follow-up; the remaining 503 patients were selected for inclusion. For each degree of improvement in the PI-LL mismatch at 6 weeks, the SVA decreased by 2.18 mm (95% confidence interval, -2.56, -1.79; P < 0.01) and 1.67 mm (95% confidence interval, -2.07, -1.27; P < 0.01) at 6 weeks and 12 months, respectively. A high SVA measurement (>50 mm) 1 year after surgery was negatively associated with health-related quality of life as measured by the Scoliosis Research Society 22 outcomes assessment.

    Conclusions

    We describe a novel model that shows how surgical correction of the PI-LL relationship affects postoperative changes in SVA. This model may enable surgeons to determine preoperatively the amount of LL necessary to achieve a desired change in SVA.
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    ItemOpen 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 Group

    Object

    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.
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    ItemOpen Access
    Adult Spinal Deformity Surgery Is Associated with Increased Productivity and Decreased Absenteeism From Work and School.
    (Spine, 2022-02) Durand, Wesley M; Babu, Jacob M; Hamilton, David K; Passias, Peter G; Kim, Han Jo; Protopsaltis, Themistocles; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Shaffrey, Christopher; Gupta, Munish; Kelly, Michael P; Klineberg, Eric O; Schwab, Frank; Gum, Jeffrey L; Mundis, Gregory; Eastlack, Robert; Kebaish, Khaled; Soroceanu, Alex; Hostin, Richard A; Burton, Doug; Bess, Shay; Ames, Christopher; Hart, Robert A; Daniels, Alan H; International Spine Study Group (ISSG)

    Study design

    Retrospective cohort study.

    Objective

    We hypothesized that adult spinal deformity (ASD) surgery would be associated with improved work- and school-related productivity, as well as decreased rates of absenteeism.

    Summary of background data

    ASD patients experience markedly decreased health-related quality of life along many dimensions.

    Methods

    Only patients eligible for 2-year follow-up were included, and those with a history of previous spinal fusion were excluded. The primary outcome measures in this study were Scoliosis Research Society-22r score (SRS-22r) questions 9 and 17. A repeated measures mixed linear regression was used to analyze responses over time among patients managed operatively (OP) versus nonoperatively (NON-OP).

    Results

    In total, 1188 patients were analyzed. 66.6% were managed operatively. At baseline, the mean percentage of activity at work/school was 56.4% (standard deviation [SD] 35.4%), and the mean days off from work/school over the past 90 days was 1.6 (SD 1.8). Patients undergoing ASD surgery exhibited an 18.1% absolute increase in work/school productivity at 2-year follow-up versus baseline (P < 0.0001), while no significant change was observed for the nonoperative cohort (P > 0.5). Similarly, the OP cohort experienced 1.1 fewer absent days over the past 90 days at 2 years versus baseline (P < 0.0001), while the NON-OP cohort showed no such difference (P > 0.3). These differences were largely preserved after stratifying by baseline employment status, age group, sagittal vertical axis (SVA), pelvic incidence minus lumbar lordosis (PI-LL), and deformity curve type.

    Conclusion

    ASD patients managed operatively exhibited an average increase in work/school productivity of 18.1% and decreased absenteeism of 1.1 per 90 days at 2-year follow-up, while patients managed nonoperatively did not exhibit change from baseline. Given the age distribution of patients in this study, these findings should be interpreted as pertaining primarily to obligations at work or within the home. Further study of the direct and indirect economic benefits of ASD surgery to patients is warranted.Level of Evidence: 3.
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    ItemOpen Access
    Artificial intelligence clustering of adult spinal deformity sagittal plane morphology predicts surgical characteristics, alignment, and outcomes.
    (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, 2021-08) Durand, Wesley M; Lafage, Renaud; Hamilton, D Kojo; Passias, Peter G; Kim, Han Jo; Protopsaltis, Themistocles; Lafage, Virginie; Smith, Justin S; Shaffrey, Christopher; Gupta, Munish; Kelly, Michael P; Klineberg, Eric O; Schwab, Frank; Gum, Jeffrey L; Mundis, Gregory; Eastlack, Robert; Kebaish, Khaled; Soroceanu, Alex; Hostin, Richard A; Burton, Doug; Bess, Shay; Ames, Christopher; Hart, Robert A; Daniels, Alan H; International Spine Study Group (ISSG)

    Purpose

    AI algorithms have shown promise in medical image analysis. Previous studies of ASD clusters have analyzed alignment metrics-this study sought to complement these efforts by analyzing images of sagittal anatomical spinopelvic landmarks. We hypothesized that an AI algorithm would cluster preoperative lateral radiographs into groups with distinct morphology.

    Methods

    This was a retrospective review of a multicenter, prospectively collected database of adult spinal deformity. A total of 915 patients with adult spinal deformity and preoperative lateral radiographs were included. A 2 × 3, self-organizing map-a form of artificial neural network frequently employed in unsupervised classification tasks-was developed. The mean spine shape was plotted for each of the six clusters. Alignment, surgical characteristics, and outcomes were compared.

    Results

    Qualitatively, clusters C and D exhibited only mild sagittal plane deformity. Clusters B, E, and F, however, exhibited marked positive sagittal balance and loss of lumbar lordosis. Cluster A had mixed characteristics, likely representing compensated deformity. Patients in clusters B, E, and F disproportionately underwent 3-CO. PJK and PJF were particularly prevalent among clusters A and E. Among clusters B and F, patients who experienced PJK had significantly greater positive sagittal balance than those who did not.

    Conclusions

    This study clustered preoperative lateral radiographs of ASD patients into groups with highly distinct overall spinal morphology and association with sagittal alignment parameters, baseline HRQOL, and surgical characteristics. The relationship between SVA and PJK differed by cluster. This study represents significant progress toward incorporation of computer vision into clinically relevant classification systems in adult spinal deformity.

    Level of evidence iv

    Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.
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    ItemOpen Access
    Artificial Intelligence Models Predict Operative Versus Nonoperative Management of Patients with Adult Spinal Deformity with 86% Accuracy.
    (World neurosurgery, 2020-09) Durand, Wesley M; Daniels, Alan H; Hamilton, David K; Passias, Peter; Kim, Han Jo; Protopsaltis, Themistocles; LaFage, Virginie; Smith, Justin S; Shaffrey, Christopher; Gupta, Munish; Klineberg, Eric; Schwab, Frank; Burton, Doug; Bess, Shay; Ames, Christopher; Hart, Robert; International Spine Study Group

    Objective

    Patients with ASD show complex and highly variable disease. The decision to manage patients operatively is largely subjective and varies based on surgeon training and experience. We sought to develop models capable of accurately discriminating between patients receiving operative versus nonoperative treatment based only on baseline radiographic and clinical data at enrollment.

    Methods

    This study was a retrospective analysis of a multicenter consecutive cohort of patients with ASD. A total of 1503 patients were included, divided in a 70:30 split for training and testing. Patients receiving operative treatment were defined as those undergoing surgery up to 1 year after their baseline visit. Potential predictors included available demographics, past medical history, patient-reported outcome measures, and premeasured radiographic parameters from anteroposterior and lateral films. In total, 321 potential predictors were included. Random forest, elastic net regression, logistic regression, and support vector machines (SVMs) with radial and linear kernels were trained.

    Results

    Of patients in the training and testing sets, 69.0% (n = 727) and 69.1% (n = 311), respectively, received operative management. On evaluation with the testing dataset, performance for SVM linear (area under the curve =0.910), elastic net (0.913), and SVM radial (0.914) models was excellent, and the logistic regression (0.896) and random forest (0.830) models performed very well for predicting operative management of patients with ASD. The SVM linear model showed 86% accuracy.

    Conclusions

    This study developed models showing excellent discrimination (area under the curve >0.9) between patients receiving operative versus nonoperative management, based solely on baseline study enrollment values. Future investigations may evaluate the implementation of such models for decision support in the clinical setting.
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    ItemOpen Access
    Assessment of Patient Outcomes and Proximal Junctional Failure Rate of Adult Spinal Deformity Patients Undergoing Caudal Extension of Previous Spinal Fusion.
    (World neurosurgery, 2020-04-16) Daniels, Alan H; Reid, Daniel BC; Durand, Wesley M; Line, Breton; Passias, Peter; Kim, Han Jo; Protopsaltis, Themistocles; LaFage, Virginie; Smith, Justin S; Shaffrey, Christopher; Gupta, Munish; Klineberg, Eric; Schwab, Frank; Burton, Doug; Bess, Shay; Ames, Christopher; Hart, Robert A; International Spine Study Group
    OBJECT:This case series examined patients undergoing caudal extension of prior fusion without alteration of the prior UIV to assess patient outcomes and rates of PJK/PJF. METHODS:Patients eligible for 2-year minimum follow-up undergoing caudal extension of prior fusion with unchanged UIVs were identified. These patients were evaluated for PJK/PJF, and patient reported outcomes were recorded. RESULTS:In total, 40 patients were included. Mean follow-up duration was 2.2 years (SD 0.3). Patients in this cohort had poor preoperative sagittal alignment (PI-LL 26.7°, TPA 29.0°, SVA 93.4mm) and achieved substantial sagittal correction (ΔSVA -62.2mm, ΔPI-LL -19.8°, ΔTPA -11.1°) following caudal extension surgery. At final follow-up, there was a 0% rate of PJF among patients undergoing caudal extension of previous fusion without creation of a new UIV, but 27.5% of patients experienced PJK. Patients experienced significant improvement in both ODI and SRS-22r total score at 2-years post-operatively (p<0.05). In total, 7.5% (n=3) of patients underwent further revision, at an average of 1.1 years (SD 0.54) after the surgery with unaltered UIV. All three of these patients underwent revision for rod fracture with no revisions for PJK/PJF. CONCLUSIONS:Patients undergoing caudal extension of previous fusions for sagittal alignment correction have high rates of clinical success, low revision surgery rates, and very low rates of PJF. Minimizing repetitive tissue trauma at the UIV may result in decreased PJF risk, as the PJF rate in this cohort of unaltered UIV patients is below historical PJF rates of patients undergoing sagittal balance correction.
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    ItemOpen 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 Group

    Objective

    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.
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    ItemOpen Access
    Baseline Frailty Status Influences Recovery Patterns and Outcomes Following Alignment Correction of Cervical Deformity.
    (Neurosurgery, 2021-05) Pierce, Katherine E; Passias, Peter G; Daniels, Alan H; Lafage, Renaud; Ahmad, Waleed; Naessig, Sara; Lafage, Virginie; Protopsaltis, Themistocles; Eastlack, Robert; Hart, Robert; Burton, Douglas; Bess, Shay; Schwab, Frank; Shaffrey, Christopher; Smith, Justin S; Ames, Christopher

    Background

    Frailty severity may be an important determinant for impaired recovery after cervical spine deformity (CD) corrective surgery.

    Objective

    To evaluate postop clinical recovery among CD patients between frailty states undergoing primary procedures.

    Methods

    Patients >18 yr old undergoing surgery for CD with health-related quality of life (HRQL) data at baseline, 3-mo, and 1-yr postoperative were identified. Patients were stratified by the modified CD frailty index scale from 0 to 1 (no frailty [NF] <0.3, mild/severe fraily [F] >0.3). Patients in NF and F groups were propensity score matched for TS-CL (T1 slope [TS] minus angle between the C2 inferior end plate and the C7 inferior end plate [CL]) to control for baseline deformity. Area under the curve was calculated for follow-up time intervals determining overall normalized, time-adjusted HRQL outcomes; Integrated Health State (IHS) was compared between NF and F groups.

    Results

    A total of 106 CD patients were included (61.7 yr, 66% F, 27.7 kg/m2)-by frailty group: 52.8% NF, 47.2% F. After propensity score matching for TS-CL (mean: 38.1°), 38 patients remained in each of the NF and F groups. IHS-adjusted HRQL outcomes from baseline to 1 yr showed a significant difference in Euro-Qol 5 Dimension scores (NF: 1.02, F: 1.07, P = .016). No significant differences were found in the IHS Neck Disability Index (NDI) and modified Japanese Orthopedic Association between frailty groups (P > .05). F patients had more postop major complications (31.3%) compared to the NF (8.9%), P = .004, though DJK occurrence and reoperation between the groups was not significant.

    Conclusion

    While all groups exhibited improved postop disability and pain scores, frail patients experienced greater amount of improvement in overall health state compared to baseline disability. This signifies that with frailty severity, patients have more room for improvement postop compared to baseline quality of life.
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    ItemOpen 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 G

    Objective

    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.
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    ItemOpen Access
    Cervical deformity patients with baseline hyperlordosis or hyperkyphosis differ in surgical treatment and radiographic outcomes
    (Journal of Craniovertebral Junction and Spine, 2022-07-01) Passias, Peter Gust; Alas, Haddy; Kummer, Nicholas; Tretiakov, Peter; Diebo, Bassel G; Lafage, Renaud; Ames, Christopher P; Line, Breton; Klineberg, Eric O; Burton, Douglas C; Uribe, Juan S; Kim, Han Jo; Daniels, Alan H; Bess, Shay; Protopsaltis, Themistocles; Mundis, Gregory M; Shaffrey, Christopher I; Schwab, Frank J; Smith, Justin S; Lafage, Virginie; International Spine Study Group
    Background: Patients with symptomatic cervical deformity (CD) requiring surgical correction often present with hyperkyphosis (HK), although patients with hyperlordotic curves may require surgery as well. Few studies have investigated differences in CD corrective surgery with regard to HK and hyperlordosis (HL). Objective: The objective of the study is to evaluate patterns in treatment for CD patients with baseline (BL) HK and HL and understand how extreme curvature of the spine may influence surgical outcomes. Materials and Methods: Operative CD patients with BL and 1-year (1Y) radiographic data were included in the study. Patients were stratified based on BL C2-C7 lordosis (CL) angle: those >1 standard deviation (SD) from the mean (-6.96 ± 21.47°) were hyperlordotic (>14.51°) or hyperkyphotic (<-28.43°) depending on directionality. Patients within 1SD were considered control group. Results: 102 surgical CD patients (61 years, 65% F, 30 kg/m 2) with BL and 1Y radiographic data were included. 20 patients met definitions for HK and 21 patients met definitions for HL. No differences in demographics or disability were noted. HK had higher estimated blood loss (EBL) with anterior approaches than HL but similar EBL with posterior approach. Operative time did not differ between groups. Control, HL, and HK groups differed in BL TS-CL (36.6° vs. 22.5° vs. 60.7°, P < 0.001) and BL-SVA (10.8 vs. 7.0 vs. -47.8 mm, P = 0.001). HL patients had less discectomies, less corpectomies, and similar osteotomy rates to HK. HL had 3x revisions of HK and controls (28.6 vs. 10.0 vs. 9.2%, respectively, P = 0.046). At 1Y, HL patients had higher cSVA and trended higher SVA and SS than HK. In terms of BL-upper cervical alignment, HK patients had higher McGregor's slope (MGS) (16.1° vs. 3.3°, P = 0.002) and C0-C2 Cobb (43.3° vs. 26.9°, P < 0.001), however, postoperative differences in MGS and C0-C2 were not significant. HK drivers of deformity were primarily C (90%), whereas HL had primary CT (38.1%), UT (23.8%), and C (14.3%) drivers. Conclusions: Hyperlodotic patients trended higher revision rates with greater radiographic malalignment at 1-year postoperative, perhaps due to undercorrection compared to kyphotic etiologies.
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    Cervical deformity patients with baseline hyperlordosis or hyperkyphosis differ in surgical treatment and radiographic outcomes
    (Journal of Craniovertebral Junction and Spine, 2021-07-01) Alas, Haddy; Passias, Peter Gust; Diebo, Bassel G; Brown, Avery E; Pierce, Katherine E; Bortz, Cole; Lafage, Renaud; Ames, Christopher P; Line, Breton; Klineberg, Eric O; Burton, Douglas C; Uribe, Juan S; Kim, Han Jo; Daniels, Alan H; Bess, Shay; Protopsaltis, Themistocles; Mundis, Gregory M; Shaffrey, Christopher I; Schwab, Frank J; Smith, Justin S; Lafage, Virginie
    Introduction: Patients with symptomatic cervical deformity (CD) requiring surgical correction often present with hyperkyphosis (HK), though patients with hyperlordotic curves may require surgery as well. Few studies have investigated differences in CD-corrective surgery with regards to HK and hyperlordosis (HL). Materials and Methods: Operative CD patients (C2-C7 Cobb >10°, cervical lordosis [CL] >10°, cervical sagittal vertical axis [cSVA] >4 cm, chin-brow vertical angle >25°) with baseline (BL) and 1Y radiographic data. Patients were stratified based on BL C2-7 lordosis (CL) angle: those >1 standard deviation (SD) from the mean (-6.96° ±21.47°) were hyperlordotic (>14.51°) or hyperkyphotic (≤28.43°) depending on directionality. Patients within 1 SD were considered the control group. Results: One hundred and two surgical CD pts (61 years, 65%F, 30 kg/m 2) with BL and 1Y radiographic data were included. Twenty pts met definitions for HK and 21 pts met definitions for HL. No differences in demographics or disability were noted. HK had higher estimated blood loss (EBL) with anterior approaches than HL but similar EBL with the posterior approach. Op-time did not differ between groups. Control, HL, and HK groups differed in BL TS-CL (36.6° vs. 22.5° vs. 60.7°, P < 0.001) and BL-sagittal vertical axis (SVA) (10.8 vs. 7.0 vs. -47.8 mm, P = 0.001). HL pts had less discectomies, less corpectomies, and similar osteotomy rates to HK. HL had × 3 revisions of HK and controls (28.6 vs. 10.0 vs. 9.2%, respectively, P = 0.046). At 1Y, HL pts had higher cSVA, and trended higher SVA and SS than HK. In terms of BL-upper cervical alignment, HK pts had higher McGregor's-slope (16.1° vs. -3.3°, P = 0.001) and C0-C2 Cobb (43.3° vs. 26.9°, P < 0.001), however postoperative differences in McGregor's slope and C0-C2 were not significant. HK drivers of deformity were primarily C (90%), whereas HL had primary computed tomography (38.1%), upper thoracic (23.8%), and C (14.3%) drivers. Conclusions: Hyperlodotic patients trended higher revision rates with greater radiographic malalignment at 1Y postoperative, perhaps due to undercorrection compared to kyphotic etiologies.
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    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 Group

    Purpose

    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.
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    Characterizing Adult Cervical Deformity and Disability Based on Existing Cervical and Adult Deformity Classification Schemes at Presentation and Following Correction.
    (Neurosurgery, 2018-02) Passias, Peter G; Jalai, Cyrus M; Smith, Justin S; Lafage, Virginie; Diebo, Bassel G; Protopsaltis, Themistocles; Poorman, Gregory; Ramchandran, Subaraman; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; Schwab, Frank

    Background

    Adult cervical deformity (ACD) classifications have not been implemented in a prospective ACD population and in conjunction with adult spinal deformity (ASD) classifications.

    Objective

    To characterize cervical deformity type and malalignment with 2 classifications (Ames-ACD and Schwab-ASD).

    Methods

    Retrospective review of a prospective multicenter ACD database. Inclusion: patients ≥18 yr with pre- and postoperative radiographs. Patients were classified with Ames-ACD and Schwab-ASD schemes. Ames-ACD descriptors (C = cervical, CT = cervicothoracic, T = thoracic, S = coronal, CVJ = craniovertebral) and alignment modifiers (cervical sagittal vertical axis [cSVA], T1 slope minus cervical lordosis [TS-CL], modified Japanese Ortphopaedic Association [mJOA] score, horizontal gaze) were assigned. Schwab-ASD curve type stratification and modifier grades were also designated. Deformity and alignment group distributions were compared with Pearson χ2/ANOVA.

    Results

    Ames-ACD descriptors in 84 patients: C = 49 (58.3%), CT = 20 (23.8%), T = 9 (10.7%), S = 6 (7.1%). cSVA modifier grades differed in C, CT, and T deformities (P < .019). In C, TS-CL grade prevalence differed (P = .031). Among Ames-ACD modifiers, high (1+2) cSVA grades differed across deformities (C = 47.7%, CT = 89.5%, T = 77.8%, S = 50.0%, P = .013). Schwab-ASD curve type and presence (n = 74, T = 2, L = 6, D = 2) differed significantly in S deformities (P < .001). Higher Schwab-ASD pelvic incidence minus lumbar lordosis grades were less likely in Ames-ACD CT deformities (P = .027). Higher pelvic tilt grades were greater in high (1+2) cSVA (71.4% vs 36.0%, P = .015) and high (2+3) mJOA (24.0% vs 38.1%, P = .021) scores. Postoperatively, C and CT deformities had a trend toward lower cSVA grades, but only C deformities differed in TS-CL grade prevalence (0 = 31.3%, 1 = 12.2%, 2 = 56.1%, P = .007).

    Conclusion

    Cervical deformities displayed higher TS-CL grades and different cSVA grade distributions. Preoperative associations with global alignment modifiers and Ames-ACD descriptors were observed, though only cervical modifiers showed postoperative differences.
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    Comparing Quality of Life in Cervical Spondylotic Myelopathy with Other Chronic Debilitating Diseases Using the Short Form Survey 36-Health Survey.
    (World neurosurgery, 2017-10) Oh, Taemin; Lafage, Renaud; Lafage, Virginie; Protopsaltis, Themistocles; Challier, Vincent; Shaffrey, Christopher; Kim, Han Jo; Arnold, Paul; Chapman, Jens; Schwab, Frank; Massicotte, Eric; Yoon, Tim; Bess, Shay; Fehlings, Michael; Smith, Justin; Ames, Christopher

    Background

    Although cervical spondylotic myelopathy (CSM) can be devastating, its relative impact on general health remains unclear. Patient responses to the Short Form Survey 36-Health Survey (SF-36) Physical Component Summary (PCS)/Mental Component Summary (MCS) were compared between CSM and other diseases to evaluate their respective impacts on quality of life. The objective of this study was to compare SF-36 PCS/MCS scores in CSM with population and disease-specific norms.

    Methods

    Retrospective analysis of a prospective, multicenter AOSpine North American CSM Study database. Inclusion criteria were symptomatic disease, age older than 18 years, cord compression on magnetic resonance imaging or computed tomography myelography, and baseline SF-36 values. SF-36 PCS/MCS scores in CSM were compared with national normative values and disease-specific norms using Student t test. Analysis of variance was used to assess differences across age groups and offsets from age-matched controls. Threshold for significance was P < 0.05.

    Results

    There were 285 patients who met the inclusion criteria. The mean age was 56.6 ± 12.0 years, with male predominance (60%). SF-36 scores revealed significant baseline disability (PCS: 34.5 ± 9.8; MCS: 41.5 ± 14.4). Although there were no differences across age groups, when compared with age-matched normative data, younger patients had a larger PCS offset than older patients. CSM caused worse physical disability than most diseases except heart failure. Only back pain/sciatica induced worse mental disability.

    Conclusions

    CSM affects quality of life to an extent greater than diabetes or cancer. Although mean impact of CSM does not vary with age, younger patients suffer from greater differences in baseline function. This study highlights the impact of myelopathy on patient function, particularly among younger age groups, and suggests that CSM merits a similar caliber of healthy policy attention as more well-studied diseases.
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    Comparison of Best Versus Worst Clinical Outcomes for Adult Cervical Deformity Surgery
    (Global Spine Journal, 2019-05-01) Smith, Justin S; Shaffrey, Christopher I; Kim, Han Jo; Passias, Peter; Protopsaltis, Themistocles; Lafage, Renaud; Mundis, Gregory M; Klineberg, Eric; Lafage, Virginie; Schwab, Frank J; Scheer, Justin K; Kelly, Michael; Hamilton, D Kojo; Gupta, Munish; Deviren, Vedat; Hostin, Richard; Albert, Todd; Riew, K Daniel; Hart, Robert; Burton, Doug; Bess, Shay; Ames, Christopher P
    Study Design: Retrospective cohort study. Objective: Factors that predict outcomes for adult cervical spine deformity (ACSD) have not been well defined. To compare ACSD patients with best versus worst outcomes. Methods: This study was based on a prospective, multicenter observational ACSD cohort. Best versus worst outcomes were compared based on Neck Disability Index (NDI), Neck Pain Numeric Rating Scale (NP-NRS), and modified Japanese Orthopaedic Association (mJOA) scores. Results: Of 111 patients, 80 (72%) had minimum 1-year follow-up. For NDI, compared with best outcome patients (n = 28), worst outcome patients (n = 32) were more likely to have had a major complication (P =.004) and to have undergone a posterior-only procedure (P =.039), had greater Charlson Comorbidity Index (P =.009), and had worse postoperative C7-S1 sagittal vertical axis (SVA; P =.027). For NP-NRS, compared with best outcome patients (n = 26), worst outcome patients (n = 18) were younger (P =.045), had worse baseline NP-NRS (P =.034), and were more likely to have had a minor complication (P =.030). For the mJOA, compared with best outcome patients (n = 16), worst outcome patients (n = 18) were more likely to have had a major complication (P =.007) and to have a better baseline mJOA (P =.030). Multivariate models for NDI included posterior-only surgery (P =.006), major complication (P =.002), and postoperative C7-S1 SVA (P =.012); models for NP-NRS included baseline NP-NRS (P =.009), age (P =.017), and posterior-only surgery (P =.038); and models for mJOA included major complication (P =.008). Conclusions: Factors distinguishing best and worst ACSD surgery outcomes included patient, surgical, and radiographic factors. These findings suggest areas that may warrant greater awareness to optimize patient counseling and outcomes.
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    Comparison of best versus worst clinical outcomes for adult spinal deformity surgery: a retrospective review of a prospectively collected, multicenter database with 2-year follow-up.
    (Journal of neurosurgery. Spine, 2015-09) Smith, Justin S; Shaffrey, Christopher I; Lafage, Virginie; Schwab, Frank; Scheer, Justin K; Protopsaltis, Themistocles; Klineberg, Eric; Gupta, Munish; Hostin, Richard; Fu, Kai-Ming G; Mundis, Gregory M; Kim, Han Jo; Deviren, Vedat; Soroceanu, Alex; Hart, Robert A; Burton, Douglas C; Bess, Shay; Ames, Christopher P; International Spine Study Group

    Object

    Although recent studies suggest that average clinical outcomes are improved following surgery for selected adult spinal deformity (ASD) patients, these outcomes span a broad range. Few studies have specifically addressed factors that may predict favorable clinical outcomes. The objective of this study was to compare patients with ASD with best versus worst clinical outcomes following surgical treatment to identify distinguishing factors that may prove useful for patient counseling and optimization of clinical outcomes.

    Methods

    This is a retrospective review of a prospectively collected, multicenter, database of consecutively enrolled patients with ASD who were treated operatively. Inclusion criteria were age > 18 years and ASD. For patients with a minimum of 2-year follow-up, those with best versus worst outcomes were compared separately based on Scoliosis Research Society-22 (SRS-22) and Oswestry Disability Index (ODI) scores. Only patients with a baseline SRS-22 ≤ 3.5 or ODI ≥ 30 were included to minimize ceiling/floor effects. Best and worst outcomes were defined for SRS-22 (≥ 4.5 and ≤ 2.5, respectively) and ODI (≤ 15 and ≥ 50, respectively).

    Results

    Of 257 patients who met the inclusion criteria, 227 (88%) had complete baseline and 2-year follow-up SRS-22 and ODI outcomes scores and radiographic imaging and were analyzed in the present study. Of these 227 patients, 187 had baseline SRS-22 scores ≤ 3.5, and 162 had baseline ODI scores ≥ 30. Forthe SRS-22, best and worst outcomes criteria were met at follow-up for 25 and 27 patients, respectively. For the ODI, best and worst outcomes criteria were met at follow-up for 43 and 51 patients, respectively. With respect to the SRS-22, compared with best outcome patients, those with worst outcomes had higher baseline SRS-22 scores (p < 0.0001), higher prevalence of baseline depression (p < 0.001), more comorbidities (p = 0.012), greater prevalence of prior surgery (p = 0.007), a higher complication rate (p = 0.012), and worse baseline deformity (sagittal vertical axis [SVA], p = 0.045; pelvic incidence [PI] and lumbar lordosis [LL] mismatch, p = 0.034). The best-fit multivariate model for SRS-22 included baseline SRS-22 (p = 0.033), baseline depression (p = 0.012), and complications (p = 0.030). With respect to the ODI, compared with best outcome patients, those with worst outcomes had greater baseline ODI scores (p < 0.001), greater baseline body mass index (BMI; p = 0.002), higher prevalence of baseline depression (p < 0.028), greater baseline SVA (p = 0.016), a higher complication rate (p = 0.02), and greater 2-year SVA (p < 0.001) and PI-LL mismatch (p = 0.042). The best-fit multivariate model for ODI included baseline ODI score (p < 0.001), 2-year SVA (p = 0.014) and baseline BMI (p = 0.037). Age did not distinguish best versus worst outcomes for SRS-22 or ODI (p > 0.1).

    Conclusions

    Few studies have specifically addressed factors that distinguish between the best versus worst clinical outcomes for ASD surgery. In this study, baseline and perioperative factors distinguishing between the best and worst outcomes for ASD surgery included several patient factors (baseline depression, BMI, comorbidities, and disability), as well as residual deformity (SVA), and occurrence of complications. These findings suggest factors that may warrant greater awareness among clinicians to achieve optimal surgical outcomes for patients with ASD.
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    Cost-effectiveness of Surgical Treatment of Adult Spinal Deformity: Comparison of Posterior-only versus Antero-posterior Approach.
    (The spine journal : official journal of the North American Spine Society, 2020-04-11) Ogura, Yoji; Gum, Jeffrey L; Hostin, Richard A; Robinson, Chessie; Ames, Christopher P; Glassman, Steven D; Burton, Douglas C; Bess, R Shay; Shaffrey, Christopher I; Smith, Justin S; Yeramaneni, Samrat; Lafage, Virginie F; Protopsaltis, Themistocles; Passias, Peter G; Schwab, Frank J; Carreon, Leah Y; International Spine Study Group (ISSG)
    BACKGROUND CONTEXT:Considerable debate exists regarding the optimal surgical approach for adult spinal deformity (ASD). It remains unclear which approach, posterior-only or combined anterior-posterior (AP), is more cost-effective. Our goal is to determine the 2-year cost per quality-adjusted life year (QALY) for each approach. PURPOSE:To compare the 2-year cost-effectiveness of surgical treatment for ASD between the posterior-only approach and combined AP approach. STUDY DESIGN:Retrospective economic analysis of a prospective, multicenter database PATIENT SAMPLE: From a prospective, multicenter surgical database of ASD, patients undergoing 5 or more level fusions through a posterior-only or AP approach were identified and compared. METHODS:QALYs gained were determined using baseline, 1-year, and 2-year post-operative Short Form 6D. Cost was calculated from actual, direct hospital costs including any subsequent readmission or revision. Cost-effectiveness was determined using cost/QALY gained. RESULTS:The AP approach showed significantly higher index cost than the posterior-only approach ($84,329 vs $64,281). This margin decreased at 2-year follow-up with total costs of $89,824 and $73,904, respectively. QALYs gained at two years were similar with 0.21 and 0.17 in the posterior-only and the AP approaches, respectively. The cost/QALY at two years after surgery was significantly higher in the AP approach ($525,080) than in the posterior-only approach ($351,086). CONCLUSIONS:We assessed 2-year cost-effectiveness for the surgical treatment through posterior-only and AP approaches. The posterior-only approach is less expensive both for the index surgery and at 2-year follow-up. The QALY gained at 2-years was similar between the two approaches. Thus, posterior-only approach was more cost-effective than the AP approach under our study parameters. However, both approaches were not cost-effective at 2-year follow-up.