Browsing by Subject "Lordosis"
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Item Open Access A comparative analysis of the prevalence and characteristics of cervical malalignment in adults presenting with thoracolumbar spine deformity based on variations in treatment approach over 2 years.(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, 2016-08) Jalai, Cyrus M; Passias, Peter G; Lafage, Virginie; Smith, Justin S; Lafage, Renaud; Poorman, Gregory W; Diebo, Bassel; Liabaud, Barthélemy; Neuman, Brian J; Scheer, Justin K; Shaffrey, Christopher I; Bess, Shay; Schwab, Frank; Ames, Christopher P; International Spine Study Group (ISSG)Purpose
Characteristics specific to cervical deformity (CD) concomitant with adult thoracolumbar deformity (TLD) remains uncertain, particularly regarding treatment. This study identifies cervical malalignment prevalence following surgical and conservative TLD treatment through 2 years.Methods
Retrospective analysis of a prospective, multicenter adult spinal deformity (ASD) database. CD was defined in operative and non-operative ASD patients according to the following criteria: T1 Slope minus Cervical Lordosis (T1S-CL) ≥20°, C2-C7 Cervical Sagittal Vertical Axis (cSVA) ≥40 mm, C2-C7 kyphosis >10°. Differences in rates, demographics, health-related quality of life (HRQoL) scores for Oswestry Disability Index (ODI) and Scoliosis Research Society Questionnaire (SRS-22r), and radiographic variables were assessed between treatment groups (Op vs. Non-Op) and follow-up periods (baseline, 1-year, 2-year).Results
Three hundred and nineteen (200 Op, 199 Non-Op) ASD patients were analyzed. Op patients' CD rates at 1 and 2 years were 78.9, and 63.0 %, respectively. Non-Op CD rates were 21.1 and 37.0 % at 1 and 2 years, respectively. T1S-CL mismatch and cSVA malalignment characterized Op CD at 1 and 2 years (p < 0.05). Op and Non-Op CD groups had similar cervical/global alignment at 1 year (p > 0.05 for all), but at 2 years, Op CD patients had worse thoracic kyphosis (TK), T1S-CL, CL, cSVA, C2-T3 SVA, and global SVA compared to Non-Ops (p < 0.05). Op CD patients had worse ODI, and SRS Activity at 1 and 2 years post-operative (p < 0.05), but had greater 2-year SRS Satisfaction scores (p = 0.019).Conclusions
In the first study to compare cervical malalignment at extended follow-up between ASD treatments, CD rates rose overall through 2 years. TLD surgery, resulting in higher CD rates characterized by T1S-CL and cSVA malalignment, produced poorer HRQoL. This information can aid in treatment method decision-making when cervical deformity is present concomitant with TLD.Item Open Access A comparison of the reliability and vulnerability of 3D sterEOS and 2D EOS when measuring the sagittal spinal alignment of patients with adolescent idiopathic scoliosis.(Spine deformity, 2022-09) Machida, Masayoshi; Rocos, Brett; Zabjek, Karl; Lebel, David EPurpose
An essential component of making the diagnosis of adolescent idiopathic scoliosis (AIS) is standing anteroposterior and lateral radiographs. Two-dimensional (2D) radiographs inevitably fail to reflect every plane of the three-dimensional (3D) deformity in scoliosis. We have tested the hypothesis that there is no difference in the assessment of the sagittal plane deformity when measured with either 2D or 3D EOS radiography.Methods
A retrospective radiographic analysis was performed on patients diagnosed with AIS, with subdivided into three groups according to the coronal angular deformity (mild group: 45°-69°, moderate group: 70°-89°, and severe group: 90° +). The sagittal parameters were compared between manual measurement with 2D sterEOS and those made using computer-aided 3D reconstruction.Results
Fifty-two patients were included in each group. The inter-study reliability when measuring the thoracic Kyphosis (TK) and lumbar lordosis (LL) between the two study modalities was excellent in mild group (ICC: 0.90, 95% CI 0.82 ~ 0.94 and ICC: 0.84, 95% CI 0.74 ~ 0.91), excellent in TK and fair in LL in moderate group (ICC: 0.76, 95% CI 0.61 ~ 0.85 and ICC: 0.70, 95% CI 0.53 ~ 0.81), and fair in TK and LL in severe group, respectively (ICC: 0.74, 95% CI 0.57 ~ 0.84 and ICC: 0.65, 95% CI 0.46 ~ 0.84). A Bland-Altman plot showed proportional bias in TK measurements in each group and LL in moderate group, which means the measured value is underestimated in 2D method when the angle is small.Conclusion
3D sterEOS is less vulnerable to the influence of coronal plane than 2D EOS in evaluating the sagittal spinal parameters of patients with a coronal deformity exceeding 70°.Level of evidence: 4
Item Open 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 GroupObjective
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.Item Open 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.Item Open Access Alignment Risk Factors for Proximal Junctional Kyphosis and the Effect of Lower Thoracic Junctional Tethers for Adult Spinal Deformity.(World neurosurgery, 2019-01) Buell, Thomas J; Chen, Ching-Jen; Quinn, John C; Buchholz, Avery L; Mazur, Marcus D; Mullin, Jeffrey P; Nguyen, James H; Taylor, Davis G; Bess, Shay; Line, Breton G; Ames, Christopher P; Schwab, Frank J; Lafage, Virginie; Shaffrey, Christopher I; Smith, Justin SObjective
The aims of this retrospective cohort study were to 1) identify new alignment risk factors for proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) patients with lower thoracic upper instrumented vertebra (UIV) and 2) determine the effect of junctional tethers on PJK and UIV alignment.Methods
We analyzed consecutive ASD patients who underwent posterior instrumented fusion with lower thoracic UIV (T9-T11). Posteriorly anchored junctional tethers were used more recently for ligamentous augmentation to prevent PJK. In addition to regional and global parameters, upper segmental lumbar lordosis (ULL) versus lower segmental lumbar lordosis and UIV angle (measured from UIV inferior endplate to horizontal) were assessed. Primary outcome of PJK was defined as proximal junctional angle >10° and >10° greater than the corresponding preoperative measurement. Univariable and multivariable analyses were performed.Results
The study cohort comprised 120 ASD patients (mean age, 67 years) with minimum 1-year follow-up. Preoperative ULL (P = 0.034) and UIV angle (P = 0.026) were associated with PJK. No independent preoperative alignment risk factors of PJK were identified in multivariable analysis. Tether use was protective against PJK (odds ratio, 0.063 [0.016-0.247]; P < 0.001). PJK in tethered patients was more common with greater postoperative ULL (P = 0.047) and UIV angle (P = 0.026).Conclusions
Junctional tethers significantly reduced PJK in ASD patients with lower thoracic UIV. In tethered patients, PJK was more common with greater postoperative lordosis of the upper lumbar spine and greater UIV angle. This finding suggests potential benefit of tethers to mitigate effects of segmental lumbar and focal UIV malalignment that may occur after deformity surgery.Item Open Access Approach Selection: Multiple Anterior Lumbar Interbody Fusion to Recreate Lumbar Lordosis Versus Pedicle Subtraction Osteotomy: When, Why, How?(Neurosurgery clinics of North America, 2018-07) Chan, Andrew K; Mummaneni, Praveen V; Shaffrey, Christopher IRestoration of physiologic lumbar lordosis is a fundamental principle of spinal deformity surgery. Techniques using multilevel anterior lumbar interbody fusion or pedicle subtraction osteotomy (PSO) are described. Multilevel anterior lumbar interbody fusion provides a gradual multilevel correction and avoids the morbidity associated with PSO but necessitates familiarity with the anterior approach or an approach surgeon. PSO provides a large angular correction at a single level, requires only one approach, and allows for simultaneous multiplanar correction and open posterior decompression. This article provides guidance on the appropriate use of each technique for restoration of lumbar lordosis in patients with degenerative lumbar deformity.Item Open Access Are the Arbeitsgemeinschaft Für Osteosynthesefragen (AO) Principles for Long Bone Fractures Applicable to 3-Column Osteotomy to Reduce Rod Fracture Rates?(Clinical spine surgery, 2022-06) Virk, Sohrab; Lafage, Renaud; Bess, Shay; Shaffrey, Christopher; Kim, Han J; Ames, Christopher; Burton, Doug; Gupta, Munish; Smith, Justin S; Eastlack, Robert; Klineberg, Eric; Mundis, Gregory; Schwab, Frank; Lafage, Virginie; International Spine Study GroupObjective
The aim was to determine whether applying Arbeitsgemeinschaft für Osteosynthesefragen (AO) principles for external fixation of long bone fracture to patients with a 3-column osteotomy (3CO) would be associated with reduced rod fracture (RF) rates.Summary of background data
AO dictate principles to follow when fixating long bone fractures: (1) decrease bone-rod distance; (2) increase the number of connecting rods; (3) increase the diameter of rods; (4) increase the working length of screws; (5) use multiaxial fixation. We hypothesized that applying these principles to patients undergoing a 3CO reduces the rate of RF.Methods
Patients were categorized as having RF versus no rod fracture (non-RF). Details on location and type of instrumentation were collected. Dedicated software was used to calculate the distance between osteotomy site and adjacent pedicle screws, angle between screws and the distance between the osteotomy site and rod. Classic sagittal spinopelvic parameters were evaluated.Results
The study included 170 patients (34=RF, 136=non-RF). There was no difference in age (P=0.224), sagittal vertical axis correction (P=0.287), or lumbar lordosis correction (P=0.36). There was no difference in number of screws cephalad (P=0.62) or caudal (P=0.31) to 3CO site. There was a lower rate of RF for patients with >2 rods versus 2 rods (P<0.001). Patients with multiplanar rod fixation had a lower rod fracture rate (P=0.01). For patients with only 2 rods (N=68), the non-RF cohort had adjacent screws that trended to have less angulation to each other (P=0.06) and adjacent screws that had a larger working length (P=0.03).Conclusions
A portion of AO principles can be applied to 3CO to reduce RF rates. Placing more rods around a 3CO site, placing rods in multiple planes, and placing adjacent screws with a larger working length around the 3CO site is associated with lower RF rates.Item Open 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.Item Open Access Association between preoperative cervical sagittal deformity and inferior outcomes at 2-year follow-up in patients with adult thoracolumbar deformity: analysis of 182 patients.(Journal of neurosurgery. Spine, 2016-01) Scheer, Justin K; Passias, Peter G; Sorocean, Alexandra M; Boniello, Anthony J; Mundis, Gregory M; Klineberg, Eric; Kim, Han Jo; Protopsaltis, Themistocles S; Gupta, Munish; Bess, Shay; Shaffrey, Christopher I; Schwab, Frank; Lafage, Virginie; Smith, Justin S; Ames, Christopher P; International Spine Study GroupObjective
A high prevalence of cervical deformity (CD) has been identified among adult patients with thoracolumbar spinal deformity undergoing surgical treatment. The clinical impact of this is uncertain. This study aimed to quantify the differences in patient-reported outcomes among patients with adult spinal deformity (ASD) based on presence of CD prior to treatment.Methods
A retrospective review was conducted of a multicenter prospective database of patients with ASD who underwent surgical treatment with 2-year follow-up. Patients were grouped by the presence of preoperative CD: 1) cervical positive sagittal malalignment (CPSM) C2-7 sagittal vertical axis ≥ 4 cm; 2) cervical kyphosis (CK) C2-7 angle > 0; 3) CPSM and CK (BOTH); and 4) no baseline CD (NONE). Health-related quality of life (HRQOL) scores included the Physical Component Summary and Mental Component Summary (PCS and MCS) scores of the 36-Item Short Form Health Survey (SF-36), Oswestry Disability Index (ODI), Scoliosis Research Society-22 questionnaire (SRS-22), and minimum clinically important difference (MCID) of these scores at 2 years. Standard radiographic measurements were conducted for cervical, thoracic, and thoracolumbar parameters.Results
One hundred eighty-two patients were included in this study: CPSM, 45; CK, 37; BOTH, 16; and NONE, 84. Patients with preoperative CD and those without had similar baseline thoracolumbar radiographic measurements and similar correction rates at 2 years. Patients with and without preoperative CD had similar baseline HRQOL and on average both groups experienced some HRQOL improvement. However, those with preoperative CPSM had significantly worse postoperative ODI, PCS, SRS-22 Activity, SRS-22 Appearance, SRS-22 Pain, SRS-22 Satisfaction, and SRS-22 Total score, and were less likely to meet MCID for ODI, PCS, SRS-22 Activity, and SRS-22 Pain scores with the following ORs and 95% CIs: ODI 0.19 (0.07-0.58), PCS 0.17 (0.06-0.47), SRS-22 Activity 0.23 (0.09-0.62), SRS-22 Pain 0.20 (0.08-0.53), and SRS-22 Appearance 0.34 (0.12-0.94). Preoperative CK did not have an effect on outcomes. Interestingly, despite correction of the thoracolumbar deformity, 53.3% and 51.4% of patients had persistent CPSM and persistent CK, respectively.Conclusions
Patients with thoracolumbar deformity without preoperative CD are likely to have greater improvements in HRQOL after surgery than patients with concomitant preoperative CD. Cervical positive sagittal alignment in adult patients with thoracolumbar deformity is strongly associated with inferior outcomes and failure to reach MCID at 2-year follow-up despite having similar baseline HRQOL to patients without CD. This was the first study to assess the impact of concomitant preoperative cervical malalignment in adult patients with thoracolumbar deformity. These results can help surgeons educate patients at risk for inferior outcomes and direct future research to identify an etiology and improve patient outcomes. Investigation into the etiology of the baseline cervical malalignment may be warranted in patients who present with thoracolumbar deformity.Item Open Access At What Point Should the Thoracolumbar Region Be Addressed in Patients Undergoing Corrective Cervical Deformity Surgery?(Spine, 2021-10) Passias, Peter G; Pierce, Katherine E; Naessig, Sara; Ahmad, Waleed; Passfall, Lara; Lafage, Renaud; Lafage, Virginie; Kim, Han Jo; Daniels, Alan; Eastlack, Robert; Klineberg, Eric; Line, Breton; Mummaneni, Praveen; Hart, Robert; Burton, Douglas; Bess, Shay; Schwab, Frank; Shaffrey, Christopher; Smith, Justin S; Ames, Christopher P; International Spine Study GroupStudy design
Retrospective cohort study.Objective
The aim of this study was to investigate the impact of cervical to thoracolumbar ratios on poor outcomes in cervical deformity (CD) corrective surgery.Summary of background data
Consideration of distal regional and global alignment is a critical determinant of outcomes in CD surgery. For operative CD patients, it is unknown whether certain thoracolumbar parameters play a significant role in poor outcomes and whether addressing such parameters is warranted.Methods
Included: surgical CD patients (C2-C7 Cobb >10°, cervical lordosis [CL] >10°, C2-C7 sagittal vertical axis (cSVA) >4 cm, or chin-brow vertical angle >25°) with baseline and 1-year data. Patients were assessed for ratios of preop cervical and global parameters including: C2 Slope/T1 slope, T1 slope minus C2-C7 lordosis (TS-CL)/mismatch between pelvic incidence and lumbar lordosis (PI-LL), cSVA/sagittal vertical axis (SVA). Deformity classification ratios of cervical (Ames-ISSG) to spinopelvic (SRS-Schwab) were investigated: cSVA modifier/SVA modifier, TS-CL modifier/PI-LL modifier. Cervical to thoracic ratios included C2-C7 lordosis/T4-T12 kyphosis. Correlations assessed the relationship between ratios and poor outcomes (major complication, reoperation, distal junctional kyphosis (DJK), or failure to meet minimal clinically important difference [MCID]). Decision tree analysis through multiple iterations of multivariate regressions assessed cut-offs for ratios for acquiring suboptimal outcomes.Results
A total of 110 CD patients were included (61.5 years, 66% F, 28.8 kg/m2). Mean preoperative radiographic ratios calculated: C2 slope/T1 slope of 1.56, TS-CL/PI-LL of 11.1, cSVA/SVA of 5.4, CL/thoracic kyphosis (TK) of 0.26. Ames-ISSG and SRS-Schwab modifier ratios: cSVA/SVA of 0.1 and TS-CL/PI-LL of 0.35. Pearson correlations demonstrated a relationship between major complications and baseline TS-CL/PI-LL, Ames TS-CL/Schwab PI-LL modifiers, and the CL/TK ratios (P < 0.050). Reoperation had significant correlation with TS-CL/PI-LL and cSVA/SVA ratios. Postoperative DJK correlated with C2 slope/T1 slope and CL/TK ratios. Not meeting MCID for Neck Disability Index (NDI) correlated with CL/TK ratio and not meeting MCID for EQ5D correlated with Ames TS-CL/Schwab PI-LL.Conclusion
Consideration of cervical to global alignment is a critical determinant of outcomes in CD corrective surgery. Key ratios of cervical to global alignment correlate with suboptimal clinical outcomes. A larger cervical lordosis to TK predicted postoperative complication, DJK, and not meeting MCID for NDI.Level of Evidence: 4.Item Open Access Baseline Patient-Reported Outcomes Correlate Weakly With Radiographic Parameters: A Multicenter, Prospective NIH Adult Symptomatic Lumbar Scoliosis Study of 286 Patients.(Spine, 2016-11) Chapman, Todd M; Baldus, Christine R; Lurie, Jon D; Glassman, Steven D; Schwab, Frank J; Shaffrey, Christopher I; Lafage, Virginie; Boachie-Adjei, Oheneba; Kim, Han J; Smith, Justin S; Crawford, Charles H; Lenke, Lawrence G; Buchowski, Jacob M; Edwards, Charles; Koski, Tyler; Parent, Stefan; Lewis, Stephen; Kang, Daniel G; McClendon, Jamal; Metz, Lionel; Zebala, Lukas P; Kelly, Michael P; Spratt, Kevin F; Bridwell, Keith HStudy design
Prospective, cross-sectional study.Objective
The aim of the study was to determine which radiographic parameters drive patient-reported outcomes (PROs) in primary presentation adult symptomatic lumbar scoliosis (ASLS).Summary of background data
Previous literature suggests correlations between PROs and sagittal plane deformity (sagittal vertical axis [SVA], pelvic incidence-lumbar lordosis [PI-LL] mismatch, pelvic tilt [PT]). Prior work included revision and primary adult spinal deformity patients. The present study addresses only primary presentation ASLS.Methods
Prospective baseline data were analyzed on 286 patients enrolled in an NIH RO1 clinical trial by nine centers from 2010 to 2014.Inclusion criteria
40 to 80 years old, lumbar Cobb (LC) 30° or higher and Scoliosis Research Society-23 score 4.0 or less in Pain, Function or Self-Image domains, or Oswestry Disability Index (ODI) 20 or higher. Patients were primary presentation (no prior spinal deformity surgery) and had complete baseline data: standing coronal/sagittal 36" radiographs and PROs (ODI, Scoliosis Research Society-23, Short Form-12). Correlation coefficients were calculated to evaluate relations between radiographic parameters and PROs for the study population and a subset of patients with ODI 40 or higher. Analysis of variance was used to identify differences in PROs for radiographic modifier groups.Results
Mean age was 60.3 years. Mean spinopelvic parameters were: LL = -39.2°; SVA = 3.1 cm; sacral slope = 32.5°; PT = 23.9°; PI-LL mismatch = 16.8°. Only weak correlations (0.2-0.4) were identified between population sacral slope, SVA and SVA modifiers, and SRS function. SVA and SVA modifiers were weakly associated with ODI. Although there were more correlations in subset analysis of high-symptom patients, all were weak. Analysis of variance identified significant differences in ODI reported by SVA modifier groups.Conclusion
In primary presentation patients with ASLS and a subset of "high-symptom" patients (ODI ≥ 40), only weak associations between baseline PROs and radiographic parameters were identified. For this patient population, these results suggest regional radiographic parameters (LC, LL, PT, PI-LL mismatch) are not drivers of PROs and cannot be used to extrapolate effect on patient-perceived pathology.Level of evidence
2.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 radiographical alignment: comprehensive assessment techniques and potential importance in cervical myelopathy.(Spine, 2013-10) Ames, Christopher P; Blondel, Benjamin; Scheer, Justin K; Schwab, Frank J; Le Huec, Jean-Charles; Massicotte, Eric M; Patel, Alpesh A; Traynelis, Vincent C; Kim, Han Jo; Shaffrey, Christopher I; Smith, Justin S; Lafage, VirginieStudy design
Narrative review.Objective
To provide a comprehensive narrative review of cervical alignment parameters, the methods for quantifying cervical alignment, normal cervical alignment values, and how alignment is associated with cervical deformity and myelopathy with discussions of health-related quality of life.Summary of background data
Indications for surgery to correct cervical alignment are not well-defined and there is no set standard to address the amount of correction to be achieved. In addition, classifications of cervical deformity have yet to be fully established and treatment options defined and clarified.Methods
A survey of the cervical spine literature was conducted.Results
New normative cervical alignment values from an asymptomatic volunteer population are introduced, updated methods for quantifying cervical alignment are discussed, and describing the relationship between cervical alignment, disability, and myelopathy are outlined. Specifically, methods used to quantify cervical alignment include cervical lordosis, cervical sagittal vertical axis, and horizontal gaze with the chin-brow vertical angle. Updated methods include T1 slope. Evidence from a few recent studies suggests correlations between radiographical parameters in the cervical spine and health-related quality of life. Analysis of the cervical regional alignment with respect to overall spinal pelvic alignment is emerging and critical. Cervical myelopathy and sagittal alignment of the cervical spine are closely related as cervical deformity can lead to spinal cord compression and tension.Conclusion
Cervical deformity correction should take on a comprehensive approach in assessing global cervical-pelvic relationships and the radiographical parameters that effect health-related quality of life scores are not well-defined. Cervical alignment may be important in assessment and treatment of cervical myelopathy. Future work should concentrate on correlation of cervical alignment parameters to disability scores and myelopathy outcomes. SUMMARY STATEMENTS: STATEMENT 1: Cervical sagittal alignment (cervical SVA and kyphosis) is related to thoracolumbar spinal pelvic alignment and to T1 slope. STATEMENT 2: When significant deformity is clinically or radiographically suspected, regional cervical and relative global spinal alignment should be evaluated preoperatively via standing 3-foot scoliosis X-rays for appropriate operative planning. STATEMENT 3: Cervical sagittal alignment (C2-C7 SVA) is correlated to regional disability, general health scores and to myelopathy severity. STATEMENT 4: When performing decompressive surgery for CSM, consideration should be given to correction of cervical kyphosis and cervical sagittal imbalance (C2-C7 SVA) when present.Item Open Access Classifications for adult spinal deformity and use of the Scoliosis Research Society-Schwab Adult Spinal Deformity Classification.(Neurosurgery clinics of North America, 2013-04) Bess, Shay; Schwab, Frank; Lafage, Virginie; Shaffrey, Christopher I; Ames, Christopher PAdult spinal deformity (ASD) is a complex disease state that pathologically alters standing upright posture and is associated with substantial pain and disability. This article provides an overview of classification systems for spinal deformity, clarifies the need to differentiate between pediatric and adult classifications, and provides an explanation on the use of the Scoliosis Research Society-Schwab Adult Spinal Deformity Classification (SRS-Schwab ASD Classification). This information allows surgeons, researchers, and health care providers to (1) identify sources of pain and disability in patients with ASD and (2) accurately use the SRSeSchwab ASD Classification to evaluate patients with ASD.Item Open Access Clinical and Radiographic Outcomes for Patients with Cervical Adjacent Segment Disease Treated with Anterior Cervical Discectomy and Fusion with Integrated Interbody Spacers.(World neurosurgery, 2023-12) Zaidi, Saif E; Venkatraman, Vishal; Sykes, David AW; Albanese, Jessica; Erickson, Melissa M; Crutcher, Clifford L; Goodwin, C Rory; Groff, Michael W; Grossi, Peter; Than, Khoi D; Haglund, Michael M; Abd-El-Barr, Muhammad MIntroduction
Anterior cervical discectomy and fusion (ACDF) is among the most common spine procedures. Adjacent segment disease (ASD), characterized by degenerative disease at an adjacent spinal level to a prior fusion, is a well-recognized and significant sequela following ACDF. Adjacent segment ACDF may be considered after the failure of non-surgical options for patients with symptomatic ASD. This study aimed to assess the incidence of dysphagia and other complications as well as radiographic outcomes in adult patients who have undergone ACDF with an integrated interbody spacer device for symptomatic ASD.Methods
This was a retrospective review of patients who underwent ACDF for symptomatic ASD with commercially available integrated interbody spacers by three spine surgeons at an academic institution from March 2018 to April 2022. Demographic, radiographic, and postoperative data were collected, including dysphagia, device-related complications, and the need for revision surgery.Results
There were 48 patients (26 male, 22 female) who met inclusion criteria (mean age 59.7 years, mean body mass index 19.5 kg/m2) who underwent ACDF for symptomatic ASD (1one-level, n = 44; 2-level, n = 4). Overall, 12 patients (25%) experienced dysphagia postoperatively before the first follow-up appointment. Nine of 44 (20.4%) of 1-level ACDF patients experienced dysphagia, and 3 of 4 (75%) of 2-level ACDF patients experienced dysphagia. Three patients had severe dysphagia which prompted an otolaryngology referral. Two of those patients remained symptomatic at 6 weeks postoperatively. Of 43 patients with prior plate cage systems, none required hardware removal at the time of surgery. Preoperative global and segmental lordosis were 9.07° ± 8.36° (P = 0.22) and 3.58° ± 4.57° (P = 0.14), respectively. At 6 weeks postoperatively, global and segmental lordosis were 11.44° ± 9.06° (P = 0.54) and 5.11° ± 4.44° (P = 0.44), respectively. This constitutes a change of +2.37° and +1.53° in global and segmental lordosis, respectively. The mean anterior disc height change between preoperative and immediate postoperative time points was 6.3 ± 3.1 mm. Between the immediate postoperative and 6-week postoperative time points, the mean anterior disc height change was -1.5 ± 2.7 mm. Between the immediate postoperative and 3-month postoperative time points, the mean anterior disc height change was -3.7 ± 5.0 mm. The posterior disc height changes at the same time points were 2.5 ± 1.7 mm, -0.4 ± 1.8. and -0.5 ± 1.4 mm, respectively. This fusion rate was 50% and 70% at 6 months and 1 year post-surgery, respectively.Conclusions
ACDF with integrated spacer is a viable alternative to traditional plate-cage systems for symptomatic ASD. An advantage over traditional plate-cage systems is that the removal of prior instrumentation is not needed in order to place implants. Based on a review of the literature, these standalone systems allowed for a shorter operative time and had less incidence of dysphagia than plate-cage systems for ASD after ACDF. The different standalone and plate-cage systems used in treating ASD after ACDF surgeries should be compared in prospective studies.Item Open Access 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 GroupObject
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.Item Open Access Comparison of Complications and Clinical and Radiographic Outcomes Between Nonobese and Obese Patients with Adult Spinal Deformity Undergoing Minimally Invasive Surgery.(World neurosurgery, 2016-03) Park, Paul; Wang, Michael Y; Nguyen, Stacie; Mundis, Gregory M; La Marca, Frank; Uribe, Juan S; Anand, Neel; Okonkwo, David O; Kanter, Adam S; Fessler, Richard; Eastlack, Robert K; Chou, Dean; Deviren, Vedat; Nunley, Pierce D; Shaffrey, Christopher I; Mummaneni, Praveen V; International Spine Study GroupObjective
Obesity can be associated with increased complications and potentially worse outcomes. We aimed to evaluate the impact of obesity on complications and outcomes in patients with adult spinal deformity (ASD) who underwent minimally invasive surgery (MIS).Methods
A multicenter database of patients with ASD treated via MIS was queried. Of 190 patients in the database, 77 fit the inclusion criteria of 3 or more spinal levels treated minimally invasively. Patients were divided by body mass index (BMI) <30 (nonobese; n = 59) and BMI ≥ 30 (obese; n = 18).Results
Mean BMI was 24.6 nonobese and 35.0 obese (P < 0.001). There were mean 3.8 interbody fusions nonobese and 4.7 obese (P = 0.065). Levels treated posteriorly averaged 5.8 nonobese and 5.9 obese (P = 0.502). Mean follow-up was 34.4 months nonobese and 35.3 months obese (P = 0.976). Baseline radiographic parameters were similar between groups. Postoperatively, SVA averaged 83.9 mm obese and 20.4 mm nonobese (P = 0.002). Postoperative lumbar lordosis-pelvic incidence mismatch averaged 17.9° obese and 9.9° nonobese (P = 0.028). Both groups had improvement in Oswestry Disability Index (ODI) scores with no difference in postoperative ODI scores between groups (P = 0.090). Similarly, both groups had decreased VAS scores for back and leg pain with no difference between groups postoperatively. Twenty (33.9%) nonobese patients versus 7 (38.9%) obese patients had complications (P = 0.452).Conclusions
Our results suggest that obesity does not negatively impact complication rate or clinical outcomes in patients with ASD treated via MIS approaches.Item Open Access Degenerative Spinal Deformity.(Neurosurgery, 2015-10) Ailon, Tamir; Smith, Justin S; Shaffrey, Christopher I; Lenke, Lawrence G; Brodke, Darrel; Harrop, James S; Fehlings, Michael; Ames, Christopher PDegenerative spinal deformity afflicts a significant portion of the elderly and is increasing in prevalence. Recent evidence has revealed sagittal plane malalignment to be a key driver of pain and disability in this population and has led to a significant shift toward a more evidence-based management paradigm. In this narrative review, we review the recent literature on the epidemiology, evaluation, management, and outcomes of degenerative adult spinal deformity (ASD). ASD is increasing in prevalence in North America due to an aging population and demographic shifts. It results from cumulative degenerative changes focused in the intervertebral discs and facet joints that occur asymmetrically to produce deformity. Deformity correction focuses on restoration of global alignment, especially in the sagittal plane, and decompression of the neural elements. General realignment goals have been established, including sagittal vertical axis <50 mm, pelvic tilt <22°, and lumbopelvic mismatch <±9°; however, these should be tailored to the patient. Operative management, in carefully selected patients, yields satisfactory outcomes that appear to be superior to nonoperative strategies. ASD is characterized by malalignment in the sagittal and/or coronal plane and, in adults, presents with pain and disability. Nonoperative management is recommended for patients with mild, nonprogressive symptoms; however, evidence of its efficacy is limited. Surgery aims to restore global spinal alignment, decompress neural elements, and achieve fusion with minimal complications. The surgical approach should balance the desired correction with the increased risk of more aggressive maneuvers. In well-selected patients, surgery yields excellent outcomes.Item Open Access Despite worse baseline status depressed patients achieved outcomes similar to those in nondepressed patients after surgery for cervical deformity.(Neurosurgical focus, 2017-12) Poorman, Gregory W; Passias, Peter G; Horn, Samantha R; Frangella, Nicholas J; Daniels, Alan H; Hamilton, D Kojo; Kim, Hanjo; Sciubba, Daniel; Diebo, Bassel G; Bortz, Cole A; Segreto, Frank A; Kelly, Michael P; Smith, Justin S; Neuman, Brian J; Shaffrey, Christopher I; LaFage, Virginie; LaFage, Renaud; Ames, Christopher P; Hart, Robert; Mundis, Gregory M; Eastlack, Robert; International Spine Study GroupOBJECTIVE Depression and anxiety have been demonstrated to have negative impacts on outcomes after spine surgery. In patients with cervical deformity (CD), the psychological and physiological burdens of the disease may overlap without clear boundaries. While surgery has a proven record of bringing about significant pain relief and decreased disability, the impact of depression and anxiety on recovery from cervical deformity corrective surgery has not been previously reported on in the literature. The purpose of the present study was to determine the effect of depression and anxiety on patients' recovery from and improvement after CD surgery. METHODS The authors conducted a retrospective review of a prospective, multicenter CD database. Patients with a history of clinical depression, in addition to those with current self-reported anxiety or depression, were defined as depressed (D group). The D group was compared with nondepressed patients (ND group) with a similar baseline deformity determined by propensity score matching of the cervical sagittal vertical axis (cSVA). Baseline demographic, comorbidity, clinical, and radiographic data were compared among patients using t-tests. Improvement of symptoms was recorded at 3 months, 6 months, and 1 year postoperatively. All health-related quality of life (HRQOL) scores collected at these follow-up time points were compared using t-tests. RESULTS Sixty-six patients were matched for baseline radiographic parameters: 33 with a history of depression and/or current depression, and 33 without. Depressed patients had similar age, sex, race, and radiographic alignment: cSVA, T-1 slope minus C2-7 lordosis, SVA, and T-1 pelvic angle (p > 0.05). Compared with nondepressed individuals, depressed patients had a higher incidence of osteoporosis (21.2% vs 3.2%, p = 0.028), rheumatoid arthritis (18.2% vs 3.2%, p = 0.012), and connective tissue disorders (18.2% vs 3.2%, p = 0.012). At baseline, the D group had greater neck pain (7.9 of 10 vs 6.6 on a Numeric Rating Scale [NRS], p = 0.015), lower mean EQ-5D scores (68.9 vs 74.7, p < 0.001), but similar Neck Disability Index (NDI) scores (57.5 vs 49.9, p = 0.063) and myelopathy scores (13.4 vs 13.9, p = 0.546). Surgeries performed in either group were similar in terms of number of levels fused, osteotomies performed, and correction achieved (baseline to 3-month measurements) (p < 0.05). At 3 months, EQ-5D scores remained lower in the D group (74.0 vs 78.2, p = 0.044), and NDI scores were similar (48.5 vs 39.0, p = 0.053). However, neck pain improved in the D group (NRS score of 5.0 vs 4.3, p = 0.331), and modified Japanese Orthopaedic Association (mJOA) scores remained similar (14.2 vs 15.0, p = 0.211). At 6 months and 1 year, all HRQOL scores were similar between the 2 cohorts. One-year measurements were as follows: NDI 39.7 vs 40.7 (p = 0.878), NRS neck pain score of 4.1 vs 5.0 (p = 0.326), EQ-5D score of 77.1 vs 78.2 (p = 0.646), and mJOA score of 14.0 vs 14.2 (p = 0.835). Anxiety/depression levels reported on the EQ-5D scale were significantly higher in the depressed cohort at baseline, 3 months, and 6 months (all p < 0.05), but were similar between groups at 1 year postoperatively (1.72 vs 1.53, p = 0.416). CONCLUSIONS Clinical depression was observed in many of the study patients with CD. After matching for baseline deformity, depression symptomology resulted in worse baseline EQ-5D and pain scores. Despite these baseline differences, both cohorts achieved similar results in all HRQOL assessments 6 months and 1 year postoperatively, demonstrating no clinical impact of depression on recovery up until 1 year after CD surgery. Thus, a history of depression does not appear to have an impact on recovery from CD surgery.Item Open Access Development of Risk Stratification Predictive Models for Cervical Deformity Surgery.(Neurosurgery, 2022-12) Passias, Peter G; Ahmad, Waleed; Oh, Cheongeun; Imbo, Bailey; Naessig, Sara; Pierce, Katherine; Lafage, Virginie; Lafage, Renaud; Hamilton, D Kojo; Protopsaltis, Themistocles S; Klineberg, Eric O; Gum, Jeffrey; Schoenfeld, Andrew J; Line, Breton; Hart, Robert A; Burton, Douglas C; Bess, Shay; Schwab, Frank J; Smith, Justin S; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study GroupBackground
As corrective surgery for cervical deformity (CD) increases, so does the rate of complications and reoperations. To minimize suboptimal postoperative outcomes, it is important to develop a tool that allows for proper preoperative risk stratification.Objective
To develop a prognostic utility for identification of risk factors that lead to the development of major complications and unplanned reoperations.Methods
CD patients age 18 years or older were stratified into 2 groups based on the postoperative occurrence of a revision and/or major complication. Multivariable logistic regressions identified characteristics that were associated with revision or major complication. Decision tree analysis established cutoffs for predictive variables. Models predicting both outcomes were quantified using area under the curve (AUC) and receiver operating curve characteristics.Results
A total of 109 patients with CD were included in this study. By 1 year postoperatively, 26 patients experienced a major complication and 17 patients underwent a revision. Predictive modeling incorporating preoperative and surgical factors identified development of a revision to include upper instrumented vertebrae > C5, lowermost instrumented vertebrae > T7, number of unfused lordotic cervical vertebrae > 1, baseline T1 slope > 25.3°, and number of vertebral levels in maximal kyphosis > 12 (AUC: 0.82). For developing a major complication, a model included a current smoking history, osteoporosis, upper instrumented vertebrae inclination angle < 0° or > 40°, anterior diskectomies > 3, and a posterior Smith Peterson osteotomy (AUC: 0.81).Conclusion
Revisions were predicted using a predominance of radiographic parameters while the occurrence of major complications relied on baseline bone health, radiographic, and surgical characteristics.