Browsing by Author "Alas, Haddy"

Now showing 1 - 20 of 22
  • Thumbnail Image
    ItemOpen Access
    A Risk-Benefit Analysis of Increasing Surgical Invasiveness Relative to Frailty Status in Adult Spinal Deformity Surgery.
    (Spine, 2021-08) Passias, Peter G; Brown, Avery E; Bortz, Cole; Pierce, Katherine; Alas, Haddy; Ahmad, Waleed; Passfall, Lara; Kummer, Nicholas; Krol, Oscar; Lafage, Renaud; Lafage, Virginie; Burton, Douglas; Hart, Robert; Anand, Neel; Mundis, Gregory; Neuman, Brian; Line, Breton; Shaffrey, Christopher; Klineberg, Eric; Smith, Justin; Ames, Christopher; Schwab, Frank J; Bess, Shay; International Spine Study Group

    Study design

    Retrospective review of a prospectively enrolled multicenter Adult Spinal Deformity (ASD) database.

    Objective

    Investigate invasiveness and outcomes of ASD surgery by frailty state.

    Summary of background data

    The ASD Invasiveness Index incorporates deformity-specific components to assess correction magnitude. Intersections of invasiveness, surgical outcomes, and frailty state are understudied.

    Methods

    ASD patients with baseline and 3-year (3Y) data were included. Logistic regression analyzed the relationship between increasing invasiveness and major complications or reoperations and meeting minimal clinically important differences (MCID) for health-related quality-of-life measures at 3Y. Decision tree analysis assessed invasiveness risk-benefit cutoff points, above which experiencing complications or reoperations and not reaching MCID were higher. Significance was set to P < 0.05.

    Results

    Overall, 195 of 322 patients were included. Baseline demographics: age 59.9 ± 14.4, 75% female, BMI 27.8 ± 6.2, mean Charlson Comorbidity Index: 1.7 ± 1.7. Surgical information: 61% osteotomy, 52% decompression, 11.0 ± 4.1 levels fused. There were 98 not frail (NF), 65 frail (F), and 30 severely frail (SF) patients. Relationships were found between increasing invasiveness and experiencing a major complication or reoperation for the entire cohort and by frailty group (all P < 0.05). Defining a favorable outcome as no major complications or reoperation and meeting MCID in any health-related quality of life at 3Y established an invasiveness cutoff of 63.9. Patients below this threshold were 1.8[1.38-2.35] (P < 0.001) times more likely to achieve favorable outcome. For NF patients, the cutoff was 79.3 (2.11[1.39-3.20] (P < 0.001), 111 for F (2.62 [1.70-4.06] (P < 0.001), and 53.3 for SF (2.35[0.78-7.13] (P = 0.13).

    Conclusion

    Increasing invasiveness is associated with increased odds of major complications and reoperations. Risk-benefit cutoffs for successful outcomes were 79.3 for NF, 111 for F, and 53.3 for SF patients. Above these, increasing invasiveness has increasing risk of major complications or reoperations and not meeting MCID at 3Y.Level of Evidence: 3.
  • Thumbnail Image
    ItemOpen Access
    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.
  • Thumbnail Image
    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.
  • Thumbnail Image
    ItemOpen Access
    Development of a Novel Cervical Deformity Surgical Invasiveness Index.
    (Spine, 2020-01) Passias, Peter G; Horn, Samantha R; Soroceanu, Alexandra; Oh, Cheongeun; Ailon, Tamir; Neuman, Brian J; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Line, Breton; Bortz, Cole A; Segreto, Frank A; Brown, Avery; Alas, Haddy; Pierce, Katherine E; Eastlack, Robert K; Sciubba, Daniel M; Protopsaltis, Themistocles S; Klineberg, Eric O; Burton, Douglas C; Hart, Robert A; Schwab, Frank J; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study Group
    STUDY DESIGN:Retrospective review. OBJECTIVE:The aim of this study was to develop a novel surgical invasiveness index for cervical deformity (CD) surgery that incorporates CD-specific parameters. SUMMARY OF BACKGROUND DATA:There has been a surgical invasiveness index for general spine surgery and adult spinal deformity, but a CD index has not been developed. METHODS:CD was defined as at least one of the following: C2-C7 Cobb >10°, cervical lordosis (CL) >10°, cervical sagittal vertical axis (cSVA) >4 cm, chin brow vertical angle >25°. Consensus from experienced spine and neurosurgeons selected weightings for each variable that went into the invasiveness index. Binary logistic regression predicted high operative time (>338 minutes), estimated blood loss (EBL) (>600 mL), or length of stay (LOS) >5 days) based on the median values of operative time, EBL, and LOS. Multivariable regression modeling was utilized to construct a final model incorporating the strongest combination of factors to predict operative time, LOS, and EBL. RESULTS:Eighty-five CD patients were included (61 years, 66% females). The variables in the newly developed CD invasiveness index with their corresponding weightings were: history of previous cervical surgery (3), anterior cervical discectomy and fusion (2/level), corpectomy (4/level), levels fused (1/level), implants (1/level), posterior decompression (2/level), Smith-Peterson osteotomy (2/level), three-column osteotomy (8/level), fusion to upper cervical spine (2), absolute change in T1 slope minus cervical lordosis, cSVA, T4-T12 thoracic kyphosis (TK), and sagittal vertical axis (SVA) from baseline to 1-year. The newly developed CD-specific invasiveness index strongly predicted long LOS (R = 0.310, P < 0.001), high EBL (R = 0.170, P = 0.011), and extended operative time (R = 0.207, P = 0.031). A second analysis used multivariable regression modeling to determine which combination of factors in the newly developed index were the strongest determinants of operative time, LOS, and EBL. The final predictive model included: number of corpectomies, levels fused, decompression, combined approach, and absolute changes in SVA, cSVA, and TK. This model predicted EBL (R = 0.26), operative time (R = 0.12), and LOS (R = 0.13). CONCLUSION:Extended LOS, operative time, and high blood loss were strongly predicted by the newly developed CD invasiveness index, incorporating surgical factors and radiographic parameters clinically relevant for patients undergoing CD corrective surgery. LEVEL OF EVIDENCE:4.
  • Thumbnail Image
    ItemOpen Access
    Does Patient Frailty Status Influence Recovery Following Spinal Fusion for Adult Spinal Deformity?: An Analysis of Patients With 3-Year Follow-up.
    (Spine, 2020-04) Pierce, Katherine E; Passias, Peter G; Alas, Haddy; Brown, Avery E; Bortz, Cole A; Lafage, Renaud; Lafage, Virginie; Ames, Christopher; Burton, Douglas C; Hart, Robert; Hamilton, Kojo; Kelly, Michael; Hostin, Richard; Bess, Shay; Klineberg, Eric; Line, Breton; Shaffrey, Christopher; Mummaneni, Praveen; Smith, Justin S; Schwab, Frank A; International Spine Study Group (ISSG)

    Study design

    Retrospective review of a prospective database.

    Objective

    The aim of this study was to evaluate postop clinical recovery among adult spinal deformity (ASD) patients between frailty states undergoing primary procedures SUMMARY OF BACKGROUND DATA.: Frailty severity may be an important determinant for impaired recovery after corrective surgery.

    Methods

    It included ASD patients with health-related quality of life (HRQLs) at baseline (BL), 1 year (1Y), and 3 years (3Y). Patients stratified by frailty by ASD-frailty index scale 0-1(no frailty: <0.3 [NF], mild: 0.3-0.5 [MF], severe: >0.5 [SF]). Demographics, alignment, and SRS-Schwab modifiers were assessed with χ/paired t tests to compare HRQLs: Scoliosis Research Society 22-question Questionnaire (SRS-22), Numeric Rating Scale (NRS) Back/Leg Pain, Oswestry Disability Index (ODI). Area-under-the-curve (AUC) method generated normalized HRQL scores at baseline (BL) and f/u intervals (1Y, 3Y). AUC was calculated for each f/u, and total area was divided by cumulative f/u, generating one number describing recovery (Integrated Health State [IHS]).

    Results

    A total of 191 patients were included (59 years, 80% females). Breakdown of patients by frailty status: 43.6% NF, 40.8% MF, 15.6% SF. SF patients were older (P = 0.003), >body mass index (P = 0.002). MF and SF were significantly (P < 0.001) more malaligned at BL: pelvic tilt (NF: 21.6°; MF: 27.3°; SF: 22.1°), pelvic incidence and lumbar lordosis (7.4°, 21.2°, 19.7°), sagittal vertical axis (31 mm, 87 mm, 82 mm). By SRS-Schwab, NF were mostly minor (40%), and MF and SF markedly deformed (64%, 57%). Frailty groups exhibited BL to 3Y improvement in SRS-22, ODI, NRS Back/Leg (P < 0.001). After HRQL normalization, SF had improvement in SRS-22 at year 1 and year 3 (P < 0.001), and NRS Back at 1Y. 3Y IHS showed a significant difference in SRS-22 (NF: 1.2 vs. MF: 1.32 vs. SF: 1.69, P < 0.001) and NRS Back Pain (NF: 0.52, MF: 0.66, SF: 0.6, P = 0.025) between frailty groups. SF had more complications (79%). SF/marked deformity had larger invasiveness score (112) compared to MF/moderate deformity (86.2). Controlling for baseline deformity and invasiveness, SF showed more improvement in SRS-22 IHS (NF: 1.21, MF: 1.32, SF: 1.66, P < 0.001).

    Conclusion

    Although all frailty groups exhibited improved postop disability/pain scores, SF patients recovered better in SRS-22 and NRS Back. Despite SF patients having more complications and larger invasiveness scores, they had overall better patient-reported outcomes, signifying that with frailty severity, patients have more room for improvement postop compared to BL quality of life.

    Level of evidence

    3.
  • Thumbnail Image
    ItemOpen Access
    Effect of age-Adjusted alignment goals and distal inclination angle on the fate of distal junctional kyphosis in cervical deformity surgery
    (Journal of Craniovertebral Junction and Spine, 2021-01-01) Passias, Peter Gust; Horn, Samantha R; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Line, Breton G; Protopsaltis, Themistocles S; Soroceanu, Alex; Bortz, Cole; Segreto, Frank A; Ahmad, Waleed; Naessig, Sara; Pierce, Katherine E; Brown, Avery E; Alas, Haddy; Kim, Han Jo; Daniels, Alan H; Klineberg, Eric O; Burton, Douglas C; Hart, Robert A; Schwab, Frank J; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study Group
    Background: Age-Adjusted alignment targets in the context of distal junctional kyphosis (DJK) development have yet to be investigated. Our aim was to assess age-Adjusted alignment targets, reciprocal changes, and role of lowest instrumented level orientation in DJK development in cervical deformity (CD) patients. Methods: CD patients were evaluated based on lowest fused level: cervical (C7 or above), upper thoracic (UT: T1-T6), and lower thoracic (LT: T7-T12). Age-Adjusted alignment targets were calculated using published formulas for sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis (PI-LL), pelvic tilt (PT), T1 pelvic angle (TPA), and LL-Thoracic kyphosis (TK). Outcome measures were cervical and global alignment parameters: Cervical SVA (cSVA), cervical lordosis, C2 slope, C2-T3 angle, C2-T3 SVA, TS-CL, PI-LL, PT, and SVA. Subanalysis matched baseline PI to assess age-Adjusted alignment between DJK and non-DJK. Results: Seventy-six CD patients included. By 1Y, 20 patients developed DJK. Non-DJK patients had 27% cervical lowest instrumented vertebra (LIV), 68% UT, and 5% LT. DJK patients had 25% cervical, 50% UT, and 25% LT. There were no baseline or 1Y differences for PI, PI-LL, SVA, TPA, or PT for actual and age-Adjusted targets. DJK patients had worse baseline cSVA and more severe 1Y cSVA, C2-T3 SVA, and C2 slope (P < 0.05). The distribution of over/under corrected patients and the offset between actual and ideal alignment for SVA, PT, TPA, PI-LL, and LL-TK were similar between DJK and non-DJK patients. DJK patients requiring reoperation had worse postoperative changes in all cervical parameters and trended toward larger offsets for global parameters. Conclusion: CD patients with severe baseline malalignment went on to develop postoperative DJK. Age-Adjusted alignment targets did not capture differences in these populations, suggesting the need for cervical-specific goals.
  • Thumbnail Image
    ItemOpen Access
    Global spinal deformity from the upper cervical perspective. What is "Abnormal" in the upper cervical spine?
    (Journal of craniovertebral junction & spine, 2019-07) Passias, Peter G; Alas, Haddy; Lafage, Renaud; Diebo, Bassel G; Chern, Irene; Ames, Christopher P; Park, Paul; Than, Khoi D; Daniels, Alan H; Hamilton, D Kojo; Burton, Douglas C; Hart, Robert A; Bess, Shay; Line, Breton G; Klineberg, Eric O; Shaffrey, Christopher I; Smith, Justin S; Schwab, Frank J; Lafage, Virginie

    Hypothesis

    Reciprocal changes in the upper cervical spine correlate with adult TL deformity modifiers.

    Design

    This was a retrospective review.

    Introduction

    The upper cervical spine has remarkable adaptability to wide ranges of thoracolumbar (TL) deformity.

    Methods

    Patients >18 years with adult spinal deformity (ASD) and complete radiographic data at baseline (BL) and 1 year were identified. Patients were grouped into component types of the Roussouly classification system (Type 1: Pelvic incidence [PI] <45° and lumbar lordosis [LL] apex below L4; Type 2: PI <45° and LL apex above L4; Type 3:45°65°). Patients were categorized by increasing severity of Schwab modifiers at BL (0, +, and ++) and further grouped by regional malalignment moving cranially (P: pelvic only; LP: lumbopelvic; TL: thoracic and LP; C: subaxial and TL). Analysis of variance and Pearson's r assessed changes in BL upper cervical parameters (C0-2, C0 slope, McGregor's Slope [MGS], and CBVA) across groups.

    Results

    A total of 343 ASD patients were analyzed. When grouped by BL Schwab and Roussouly, Group P had the lowest BL disability compared to other Groups, while Roussouley Type 1 correlated with higher BL disability compared to Type 2. Moving cranially up the spine, Group P, Group LP, and Group TL did not differ in C0-2 angle, C0 slope, MGS, or CBVA. Group C had a significantly smaller C0-C2, and more negative MGS, C0 slope, and CBVA than noncervical groups. Type 1 trended slightly higher CBVA and MGS than types 2-4, but no differences in cervical lordosis, C0-C2, or C0S were found. MGS (r = -0.131, P = 0.015), CBVA (r = -0.473, P < 0.001), and C0S (r = -0.099, P = 0.042) correlated most strongly with sagittal vertical axis (SVA) compared to other Schwab modifiers. We found SVA > 34 mm predicted a 1 unit (°°) decrease in MGS (odds ratio [OR]: 0.970 [0.948-0.993], P = 0.010), while cervical SVA >51 mm predicted a 1 unit increase in MGS (OR: 1.25 [1.12-1.38], P < 0.001).

    Conclusions

    Our study suggests that upper cervical alignment remains relatively stable through most broad variations of adult TL deformity. Changes in SVA correlated most with upper cervical changes.
  • Thumbnail Image
    ItemOpen Access
    Increasing Cost Efficiency in Adult Spinal Deformity Surgery: Identifying Predictors of Lower Total Costs.
    (Spine, 2022-01) Passias, Peter G; Brown, Avery E; Bortz, Cole; Alas, Haddy; Pierce, Katherine; Ahmad, Waleed; Naessig, Sara; Lafage, Renaud; Lafage, Virginie; Hassanzadeh, Hamid; Labaran, Lawal A; Ames, Christopher; Burton, Douglas C; Gum, Jeffrey; Hart, Robert; Hostin, Richard; Kebaish, Khaled M; Neuman, Brian J; Bess, Shay; Line, Breton; Shaffrey, Christopher; Smith, Justin; Schwab, Frank; Klineberg, Eric; International Spine Study Group

    Study design

    Retrospective study of a prospective multicenter database.

    Objective

    The purpose of this study was to identify predictors of lower total surgery costs at 3 years for adult spinal deformity (ASD) patients.

    Summary of background data

    ASD surgery involves complex deformity correction.

    Methods

    Inclusion criteria: surgical ASD (scoliosis ≥20°, sagittal vertical axis [SVA] ≥5 cm, pelvic tilt ≥25°, or thoracic kyphosis ≥60°) patients >18 years. Total costs for surgery were calculated using the PearlDiver database. Cost per quality-adjusted life year was assessed. A Conditional Variable Importance Table used nonreplacement sampling set of 20,000 Conditional Inference trees to identify top factors associated with lower cost surgery for low (LSVA), moderate (MSVA), and high (HSVA) SRS Schwab SVA grades.

    Results

    Three hundred sixtee of 322 ASD patients met inclusion criteria. At 3-year follow up, the potential cost of ASD surgery ranged from $57,606.88 to $116,312.54. The average costs of surgery at 3 years was found to be $72,947.87, with no significant difference in costs between deformity groups (P > 0.05). There were 152 LSVA patients, 53 MSVA patients, and 111 HSVA patients. For all patients, the top predictors of lower costs were frailty scores <0.19, baseline (BL) SRS Activity >1.5, BL Oswestry Disability Index <50 (all P < 0.05). For LSVA patients, no history of osteoporosis, SRS Activity scores >1.5, age <64, were the top predictors of lower costs (all P < 0.05). Among MSVA patients, ASD invasiveness scores <94.16, no past history of cancer, and frailty scores <0.3 trended toward lower total costs (P = 0.071, P = 0.210). For HSVA, no history of smoking and body mass index <27.8 trended toward lower costs (both P = 0.060).

    Conclusion

    ASD surgery has the potential for improved cost efficiency, as costs ranged from $57,606.88 to $116,312.54. Predictors of lower costs included higher BL SRS activity, decreased frailty, and not having depression. Additionally, predictors of lower costs were identified for different BL deformity profiles, allowing for the optimization of cost efficiency for all patients.Level of Evidence: 3.
  • Thumbnail Image
    ItemOpen Access
    Limited morbidity and possible radiographic benefit of C2 vs. subaxial cervical upper-most instrumented vertebrae
    (Journal of Spine Surgery, 2019-06-29) Passias, Peter G; Bortz, Cole A; Segreto, Frank; Horn, Samantha; Pierce, Katherine E; Alas, Haddy; Brown, Avery E; Lafage, Renaud; Lafage, Virginie; Smith, Justin S; Line, Breton; Eastlack, Robert; Sciubba, Daniel M; Klineberg, Eric O; Soroceanu, Alexandra; Burton, Douglas C; Schwab, Frank J; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P
    Background: The study aims to evaluate differences in alignment and clinical outcomes between surgical cervical deformity (CD) patients with a subaxial upper-most instrumented vertebra (UIV) and patients with a UIV at C2. Use of CD-corrective instrumentation in the subaxial cervical spine is considered risky due to narrow subaxial pedicles and vertebral artery anatomy. While C2 fixation provides increased stability, the literature lacks guidelines indicating extension of CD-corrective fusion from the subaxial spine to C2. Methods: Included: operative CD patients with baseline (BL) and 1-year postop (1Y) radiographic data, cervical UIV ≥ C2. Patients were grouped by UIV: C2 or subaxial (C3-C7) and propensity score matched (PSM) for BL cSVA. Mean comparison tests assessed differences in BL and 1Y patient-related, radiographic, and surgical data between UIV groups, and BL-1Y changes in alignment and clinical outcomes. Results: Following PSM, 31 C2 UIV and 31 subaxial UIV patients undergoing CD-corrective surgery were included. Groups did not differ in BL comorbidity burden (P=0.175) or cSVA (P=0.401). C2 patients were older (64 vs. 58 yrs, P=0.010) and had longer fusions (9 vs. 6 levels, P=0.002). Overall, patients showed BL-1Y improvements in TS-CL (P<0.001), cSVA (P=0.005), McGS (P=0.004). Cervical flexibility was maintained at 1Y regardless of UIV, assessed by CL flexion (−0.2° vs. 6.0°, P=0.115) and extension (13.9° vs. 9.9°, P=0.366). While both subaxial and C2 patients showed BL-1Y improvements in McGS (both P<0.030), C2 patients improved to a larger degree (7.3° vs. 6.2°). Between UIV groups, there were no differences in BL-1Y changes in HRQLs, overall complication rates, or operative complication rates (all P>0.05). Conclusions: C2 UIV patients showed similar cervical range of motion and baseline to 1-year functional outcomes as patients with a subaxial UIV. C2 UIV patients also showed greater baseline to 1-year horizontal gaze improvement and had complication profiles similar to subaxial UIV patients, demonstrating the radiographic benefit and minimal functional loss associated with extending fusion constructs to C2. In the treatment of adult cervical deformities, extension of the reconstruction construct to the axis may allow for certain clinical benefits with less morbidity than previously acknowledged.
  • Thumbnail Image
    ItemOpen Access
    Patient-related and radiographic predictors of inferior health-related quality-of-life measures in adult patients with nonoperative spinal deformity.
    (Journal of neurosurgery. Spine, 2021-04) Passias, Peter G; Alas, Haddy; Bess, Shay; Line, Breton G; Lafage, Virginie; Lafage, Renaud; Ames, Christopher P; Burton, Douglas C; Brown, Avery; Bortz, Cole; Pierce, Katherine; Ahmad, Waleed; Naessig, Sara; Kelly, Michael P; Hostin, Richard; Kebaish, Khaled M; Than, Khoi D; Nunley, Pierce; Shaffrey, Christopher I; Klineberg, Eric O; Smith, Justin S; Schwab, Frank J; International Spine Study Group

    Objective

    Patients with nonoperative (N-Op) adult spinal deformity (ASD) have inferior long-term spinopelvic alignment and clinical outcomes. Predictors of lower quality-of-life measures in N-Op populations have yet to be sufficiently investigated. The aim of this study was to identify patient-related factors and radiographic parameters associated with inferior health-related quality-of-life (HRQOL) scores in N-Op ASD patients.

    Methods

    N-Op ASD patients with complete radiographic and outcome data at baseline and 2 years were included. N-Op patients and operative (Op) patients were propensity score matched for baseline disability and deformity. Patient-related factors and radiographic alignment parameters (pelvic tilt [PT], sagittal vertical axis [SVA], pelvic incidence [PI]-lumbar lordosis [LL] mismatch, mismatch between cervical lordosis and T1 segment slope [TS-CL], cervical-thoracic pelvic angle [PA], and others) at baseline and 2 years were analyzed as predictors for moderate to severe 2-year Oswestry Disability Index (ODI > 20) and failing to meet the minimal clinically importance difference (MCID) for 2-year Scoliosis Research Society Outcomes Questionnaire (SRS) scores (< 0.4 increase from baseline). Conditional inference decision trees identified predictors of each HRQOL measure and established cutoffs at which factors have a global effect. Random forest analysis (RFA) generated 5000 conditional inference trees to compute a variable importance table for top predictors of inferior HRQOL. Statistical significance was set at p < 0.05.

    Results

    Six hundred sixty-two patients with ASD (331 Op patients and 331 N-Op patients) with complete radiographic and HRQOL data at their 2-year follow-up were included. There were no differences in demographics, ODI, and Schwab deformity modifiers between groups at baseline (all p > 0.05). N-Op patients had higher 2-year ODI scores (27.9 vs 20.3, p < 0.001), higher rates of moderate to severe disability (29.3% vs 22.4%, p = 0.05), lower SRS total scores (3.47 vs 3.91, p < 0.001), and higher rates of failure to reach SRS MCID (35.3% vs 15.7%, p < 0.001) than Op patients at 2 years. RFA ranked the top overall predictors for moderate to severe ODI at 2 years for N-Op patients as follows: 1) frailty index > 2.8, 2) BMI > 35 kg/m2, T4PA > 28°, and 4) Charlson Comorbidity Index > 1. Top radiographic predictors were T4PA > 28° and C2-S1 SVA > 93 mm. RFA also ranked the top overall predictors for failure to reach 2-year SRS MCID for N-Op patients, as follows: 1) T12-S1 lordosis > 53°, 2) cervical SVA (cSVA) > 28 mm, 3) C2-S1 angle > 14.5°, 4) TS-CL > 12°, and 5) PT > 23°. The top radiographic predictors were T12-S1 Cobb angle, cSVA, C2-S1 angle, and TS-CL.

    Conclusions

    When controlling for baseline deformity in N-Op versus Op patients, subsequent deterioration in frailty, BMI, and radiographic progression over a 2-year follow-up were found to drive suboptimal patient-reported outcome measures in N-Op cohorts as measured by validated ODI and SRS clinical instruments.
  • Thumbnail Image
    ItemOpen Access
    Predicting extended operative time and length of inpatient stay in cervical deformity corrective surgery.
    (Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 2019-11) Horn, Samantha R; Passias, Peter G; Bortz, Cole A; Pierce, Katherine E; Lafage, Virginie; Lafage, Renaud; Brown, Avery E; Alas, Haddy; Smith, Justin S; Line, Breton; Deviren, Vedat; Mundis, Gregory M; Kelly, Michael P; Kim, Han Jo; Protopsaltis, Themistocles; Daniels, Alan H; Klineberg, Eric O; Burton, Douglas C; Hart, Robert A; Schwab, Frank J; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study Group
    It's increasingly common for surgeons to operate on more challenging cases and higher risk patients, resulting in longer op-time and inpatient LOS. Factors predicting extended op-time and LOS for cervical deformity (CD) patients are understudied. This study identified predictors of extended op-time and length of stay (LOS) after CD-corrective surgery. CD patients with baseline (BL) radiographic data were included. Patients were stratified by extended LOS (ELOS; >75th percentile) and normal LOS (N-LOS; <75th percentile). Op-time analysis excluded staged cases, cases >12 h. A Conditional Variable Importance Table used non-replacement sampling set of Conditional Inference trees to identify influential factors. Mean comparison tests compared LOS and op-time for top factors. 142 surgical CD patients (61 yrs, 62%F, 8.2 levels fused). Op-time and LOS were 358 min and 7.2 days; 30% of patients experienced E-LOS (14 ± 13 days). Overlapping predictors of E-LOS and op-time included levels fused (>7 increased LOS 2.7 days; >5 increased op-time 96 min, P < 0.001), approach (anterior reduced LOS 3.0 days; combined increased op-time 69 min, P < 0.01), BMI (>38 kg/m2 increased LOS 8.1 days; >39 kg/m2 increased op-time 17 min), and osteotomy (LOS 2.0 days, op-time 62 min, P < 0.005). BL cervical parameters increased LOS and op-time: cSVA (>42 mm increased LOS; >50 mm increased op-time, P < 0.030), C0 slope (>@-0.9° increased LOS, >0.3° increased op-time, P < 0.003.) Additional op-time predictors: prior cervical surgery (p = 0.004) and comorbidities (P = 0.015). Other predictors of E-LOS: EBL (P < 0.001), change in mental status (P = 0.001). Baseline cervical malalignment, levels fused, and osteotomy predicted both increased op-time and LOS. These results can be used to better optimize patient care, hospital efficiency, and resource allocation.
  • Thumbnail Image
    ItemOpen Access
    Predicting the Occurrence of Postoperative Distal Junctional Kyphosis in Cervical Deformity Patients.
    (Neurosurgery, 2020-01) Passias, Peter G; Horn, Samantha R; Oh, Cheongeun; Lafage, Renaud; Lafage, Virginie; Smith, Justin S; Line, Breton; Protopsaltis, Themistocles S; Yagi, Mitsuru; Bortz, Cole A; Segreto, Frank A; Alas, Haddy; Diebo, Bassel G; Sciubba, Daniel M; Kelly, Michael P; Daniels, Alan H; Klineberg, Eric O; Burton, Douglas C; Hart, Robert A; Schwab, Frank J; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P
    BACKGROUND:Distal junctional kyphosis (DJK) development after cervical deformity (CD)-corrective surgery is a growing concern for surgeons and patients. Few studies have investigated risk factors that predict the occurrence of DJK. OBJECTIVE:To predict DJK development after CD surgery using predictive modeling. METHODS:CD criteria was at least one of the following: C2-C7 Coronal/Cobb > 10°, C2-7 sagittal vertical axis (cSVA) > 4 cm, chin-brow vertical angle > 25°. DJK was defined as the development of an angle <-10° from the end of fusion construct to the second distal vertebra, and change in this angle by <-10° from baseline to postoperative. Baseline demographic, clinical, and surgical information were used to predict the occurrence of DJK using generalized linear modeling both as one overall model and as submodels using baseline demographic and clinical predictors or surgical predictors. RESULTS:One hundred seventeen CD patients were included. At any postoperative visit up to 1 yr, 23.1% of CD patients developed DJK. DJK was predicted with high accuracy using a combination of baseline demographic, clinical, and surgical factors by the following factors: preoperative neurological deficit, use of transition rod, C2-C7 lordosis (CL)<-12°, T1 slope minus CL > 31°, and cSVA > 54 mm. In the model using only baseline demographic/clinical predictors of DJK, presence of comorbidities, presence of baseline neurological deficit, and high preoperative C2-T3 angle were included in the final model (area under the curve = 87%). The final model using only surgical predictors for DJK included combined approach, posterior upper instrumented vertebrae below C4, use of transition rod, lack of anterior corpectomy, more than 3 posterior osteotomies, and performance of a 3-column osteotomy. CONCLUSION:Preoperative assessment and consideration should be given to these factors that are predictive of DJK to mitigate poor outcomes.
  • Thumbnail Image
    ItemOpen Access
    Predictors of serious, preventable, and costly medical complications in a population of adult spinal deformity patients.
    (The spine journal : official journal of the North American Spine Society, 2021-09) Alas, Haddy; Passias, Peter G; Brown, Avery E; Pierce, Katherine E; Bortz, Cole; Bess, Shay; Lafage, Renaud; Lafage, Virginie; Ames, Christopher P; Burton, Douglas C; Hamilton, D Kojo; Kelly, Michael P; Hostin, Richard; Neuman, Brian J; Line, Breton G; Shaffrey, Christopher I; Smith, Justin S; Schwab, Frank J; Klineberg, Eric O; International Spine Study Group

    Background context

    In 2008, the Centers for Medicare and Medicaid Services (CMS) established a list of hospital-acquired conditions (HACs) with significant deleterious effects on both patients and providers. Adult spinal deformity (ASD) surgery is complex and highly invasive, and as such may result in significant morbidity including these HACs.

    Purpose

    Identify predictors for developing the most common HACs among adult spinal deformity (ASD) patients undergoing corrective surgery.

    Study design/setting

    Retrospective analysis.

    Patient sample

    One thousand one hundred and seventy-one ASD patients.

    Outcome measures

    HACs, Health-Related Quality of Life scores(HRQLs), Reoperation, Integrated Health State (IHS) METHODS: ASD pts undergoing surgery (>18 years, scoliosis ≥20°, SVA ≥5 cm, PT ≥25° and/or TK >60°) with complete data at BL and up to 2 years post-op were included. Patients were stratified by presence of >1 HAC, defined as at least one superficial/deep SSI, UTI, DVT, or PE within a 30-day post-op window. Random forest analysis generated 5,000 Conditional Inference Trees to compute a variable importance table for top predictors of HACs. An area-under-the-curve (AUC) methodology compared normalized HRQL scores between groups to determine an IHS with 2-year follow-up.

    Results

    Total of 1,171 pts (59.8 years, 76.2%F, 28.1kg/m2) underwent corrective ASD surgery, with 1,053 pts in the non-HAC group and 118 in the HAC group. Of these pts, 25.4% had UTI, 15.4% DVT, 19.2% superficial SSI, 20.8% deep SSI, and 19.2% PE. HAC pts were on average older (63.5 vs 59.3, p=.004) and more often frail (51.3 vs 39.7%, p=.021) than non-HAC pts. Postop LOS and reoperation were most associated with HAC groups: [1] LOS >7 days [2] reoperation. Patient-related predictors of HACs were [3] age >50 yerr, [4] frailty, and [13] BMI >31. Procedure-related predictors of HACs were [5] operative-time >405 minutes, [6] levels fused >9, EBL >1450 mL, and [11] decompression. BL radiographic predictors were [7] PT >20°, [9] PI-LL>6°, [10] TL Cobb angle >15°, [12] SVA C7-S1 >29 mm. No differences were observed between groups with regards to IHS ODI (0.73 vs 0.74, p=.863), SRS (1.3 vs1.3, p=.374), NRS Back (0.6 vs 0.6, p=.158). HAC had higher rates of reoperation than non-HAC (0.08 vs 0.01, p=.066), and any HAC within 30-days of index was a significant predictor of reoperation (OR: 2.448 [1.94-3.09], p<.001).

    Conclusions

    In a population of ASD patients, HACs were associated with length of stay, reoperation, age, and frailty. Radiographic parameters such as pelvic tilt >20°, PI-LL >6°, & SVA >29 mm also increased odds of HACs, and should raise postoperative awareness for HAC development.
  • Thumbnail Image
    ItemOpen Access
    Predictors of Superior Recovery Kinetics in Adult Cervical Deformity Correction: An Analysis Using a Novel Area Under the Curve Methodology.
    (Spine, 2021-05) Pierce, Katherine E; Passias, Peter G; Brown, Avery E; Bortz, Cole A; Alas, Haddy; Lafage, Renaud; Lafage, Virginie; Ames, Christopher; Burton, Douglas C; Hart, Robert; Hamilton, Kojo; Gum, Jeffrey; Scheer, Justin; Daniels, Alan; Bess, Shay; Soroceanu, Alex; Klineberg, Eric; Shaffrey, Christopher; Line, Breton; Schwab, Frank A; Smith, Justin S; on behalf of the International Spine Study Group (ISSG)

    Study design

    Retrospective review of a prospective database.

    Objective

    The aim of this study was to identify demographic, surgical, and radiographic factors that predict superior recovery kinetics following cervical deformity (CD) corrective surgery.

    Summary of background data

    Analyses of CD corrective surgery use area under the curve (AUC) to assess health-related quality of life (HRQL) metrics throughout recovery.

    Methods

    Outcome measures were baseline (BL) to 1-year (1Y) health-related quality of life (HRQL) (Neck Disability Index [NDI]). CD criteria were C2-7 Cobb angle >10°, coronal Cobb angle >10°, C2-C7 sagittal vertical axis (cSVA) >4 cm, TS-CL >10°, or chin-brow vertical angle >25°. AUC normalization divided BL and postoperative outcomes by BL. Normalized scores (y axis) were plotted against follow-up (x axis). AUC was calculated and divided by cumulative follow-up length to determine overall, time-adjusted recovery (Integrated Health State [IHS]). IHS NDI was stratified by quartile, uppermost 25% being "Superior" Recovery Kinetics (SRK) versus "Normal" Recovery Kinetics (NRK). BL demographic, clinical, and surgical information predicted SRK using generalized linear modeling.

    Results

    Ninety-eight patients included (62 ± 10 years, 28 ± 6 kg/m2, 65% females, Charlson Comorbidity Index: 0.95), 6% smokers, 31% smoking history. Surgical approach was: combined (33%), posterior (49%), anterior (18%). Posterior levels fused: 8.7, anterior: 3.6, estimated blood loss: 915.9ccs, operative time: 495 minutes. Ames BL classification: cSVA (53.2% minor deformity, 46.8% moderate), TS-CL (9.8% minor, 4.3% moderate, 85.9% marked), horizontal gaze (27.4% minor, 46.6% moderate, 26% marked). Relative to BL NDI (Mean: 47), normalized NDI decreased at 3 months (0.9 ± 0.5, P = 0.260) and 1Y (0.78 ± 0.41, P < 0.001). NDI IHS correlated with age (P = 0.011), sex (P = 0.042), anterior approach (P = 0.042), posterior approach (P = 0.042). Greater BL pelvic tilt (PT) (SRK: 25.6°, NRK: 17°, P = 0.002), pelvic incidence-lumbar lordosis (PI-LL) (SRK: 8.4°, NRK: -2.8°, P = 0.009), and anterior approach (SRK: 34.8%, NRK: 13.3%; P = 0.020) correlated with SRK. 69.4% met MCID for NDI (<Δ-15) and 63.3% met substantial clinical benefit for NDI (<Δ-10); 100% of SRK met both MCID and substantial clinical benefit. The predictive model for SRK included (AUC = 88.1%): BL visual analog scale (VAS) EuroQol five-dimensional descriptive system (EQ5D) (odds rario [OR] 0.96, 95% confidence interval [CI]: 0.92-0.99), BL swallow sleep score (OR: 1.04, 95% CI: 1.01-1.06), BL PT (OR: 1.12, 95% CI: 1.03-1.22), BL modified Japanese Orthopedic Association scale (mJOA) (OR: 1.5, 95% CI: 1.07-2.16), BL T4-T12, BL T10-L2, BL T12-S1, and BL L1-S1.

    Conclusion

    Superior recovery kinetics following CD surgery was predicted with high accuracy using BL patient-reported (VAS EQ5D, swallow sleep, mJOA) and radiographic factors (PT, TK, T10-L2, T12-S1, L1-S1). Awareness of these factors can improve decision-making and reduce postoperative neck disability.Level of Evidence: 3.
  • Thumbnail Image
    ItemOpen Access
    Prioritization of Realignment Associated With Superior Clinical Outcomes for Cervical Deformity Patients.
    (Neurospine, 2021-09) Pierce, Katherine E; Passias, Peter G; Brown, Avery E; Bortz, Cole A; Alas, Haddy; Passfall, Lara; Krol, Oscar; Kummer, Nicholas; Lafage, Renaud; Chou, Dean; Burton, Douglas C; Line, Breton; Klineberg, Eric; Hart, Robert; Gum, Jeffrey; Daniels, Alan; Hamilton, Kojo; Bess, Shay; Protopsaltis, Themistocles; Shaffrey, Christopher; Schwab, Frank A; Smith, Justin S; Lafage, Virginie; Ames, Christopher; International Spine Study Group (ISSG)

    Objective

    To prioritize the cervical parameter targets for alignment.

    Methods

    Included: cervical deformity (CD) patients (C2-7 Cobb angle > 10°, cervical lordosis > 10°, cervical sagittal vertical axis [cSVA] > 4 cm, or chin-brow vertical angle > 25°) with full baseline (BL) and 1-year (1Y) radiographic parameters and Neck Disability Index (NDI) scores; patients with cervical [C] or cervicothoracic [CT] Primary Driver Ames type. Patients with BL Ames classified as low CD for both parameters of cSVA ( < 4 cm) and T1 slope minus cervical lordosis (TS-CL) ( < 15°) were excluded. Patients assessed: meeting minimum clinically important differences (MCID) for NDI ( < -15 ΔNDI). Ratios of correction were found for regional parameters categorized by primary Ames driver (C or CT). Decision tree analysis assessed cutoffs for differences associated with meeting NDI MCID at 1Y.

    Results

    Seventy-seven CD patients (mean age, 62.1 years; 64% female; body mass index, 28.8 kg/m2). Forty-one point six percent of patients met MCID for NDI. A backwards linear regression model including radiographic differences as predictors from BL to 1Y for meeting MCID for NDI demonstrated an R2 of 0.820 (p = 0.032) included TS-CL, cSVA, McGregor's slope (MGS), C2 sacral slope, C2-T3 angle, C2-T3 SVA, cervical lordosis. By primary Ames driver, 67.5% of patients were C, and 32.5% CT. Ratios of change in predictors for MCID NDI patients for C and CT were not significant between the 2 groups (p > 0.050). Decision tree analysis determined cutoffs for radiographic change, prioritizing in the following order: ≥ 42.5° C2-T3 angle, > 35.4° cervical lordosis, < -31.76° C2 slope, < -11.57-mm cSVA, < -2.16° MGS, > -30.8-mm C2-T3 SVA, and ≤ -33.6° TS-CL.

    Conclusion

    Certain ratios of correction of cervical parameters contribute to improving neck disability. Prioritizing these radiographic alignment parameters may help optimize patient-reported outcomes for patients undergoing CD surgery.
  • Thumbnail Image
    ItemOpen Access
    Prioritization of realignment associated with superior clinical outcomes for surgical cervical deformity patients.
    (Journal of craniovertebral junction & spine, 2021-07) Pierce, Katherine E; Passias, Peter Gust; Brown, Avery E; Bortz, Cole A; Alas, Haddy; Lafage, Renaud; Krol, Oscar; Chou, Dean; Burton, Douglas C; Line, Breton; Klineberg, Eric; Hart, Robert; Gum, Jeffrey; Daniels, Alan; Hamilton, Kojo; Bess, Shay; Protopsaltis, Themistocles; Shaffrey, Christopher; Schwab, Frank A; Smith, Justin S; Lafage, Virginie; Ames, Christopher; International Spine Study Group

    Background

    To optimize quality of life in patients with cervical deformity (CD), there may be alignment targets to be prioritized.

    Objective

    To prioritize the cervical parameter targets for alignment.

    Methods

    Included: CD patients (C2-C7 Cobb >10°°, C2-C7 lordosis [CL] >10°°, cSVA > 4 cm, or chin-brow vertical angle >25°°) with full baseline (BL) and 1-year (1Y) radiographic parameters and Neck Disability Index (NDI) scores; patients with cervical (C) or cervicothoracic (CT) Primary Driver Ames type. Patients with BL Ames classified as low CD for both parameters of cSVA (<4 cm) and T1 slope minus CL (TS-CL) (<15°°) were excluded. Patients assessed: Meeting Minimal Clinically Important Difference (MCID) for NDI (<-15 ΔNDI). Ratios of correction were found for regional parameters categorized by Primary Ames Driver (C or CT). Decision tree analysis assessed cut-offs for differences associated with meeting NDI MCID at 1Y.

    Results

    Seventy-seven CD patients (62.1 years, 64%F, 28.8 kg/m2). 41.6% met MCID for NDI. A backward linear regression model including radiographic differences as predictors from BL to 1Y for meeting MCID for NDI demonstrated an R 2= 0.820 (P = 0.032) included TS-CL, cSVA, MGS, C2SS, C2-T3 angle, C2-T3 sagittal vertical axis (SVA), CL. By primary Ames driver, 67.5% of patients were C, and 32.5% CT. Ratios of change in predictors for MCID NDI patients for C and CT were not significant between the two groups (P > 0.050). Decision tree analysis determined cut-offs for radiographic change, prioritizing in the following order: ≥42.5° C2-T3 angle, >35.4° CL, <-31.76° C2 slope, <-11.57 mm cSVA, <-2.16° MGS, >-30.8 mm C2-T3 SVA, and ≤-33.6° TS-CL.

    Conclusions

    Certain ratios of correction of cervical parameters contribute to improving neck disability. Prioritizing these radiographic alignment parameters may help optimize patient-reported outcomes for patients undergoing CD surgery.
  • Thumbnail Image
    ItemOpen Access
    Radiographic benefit of incorporating the inflection between the cervical and thoracic curves in fusion constructs for surgical cervical deformity patients
    (Journal of Craniovertebral Junction and Spine, 2020-04-01) Bortz, Cole; Passias, Peter G; Pierce, Katherine Elizabeth; Alas, Haddy; Brown, Avery; Naessig, Sara; Ahmad, Waleed; Lafage, Renaud; Ames, Christopher P; Diebo, Bassel G; Line, Breton G; Klineberg, Eric O; Burton, Douglas C; Eastlack, Robert K; Kim, Han Jo; Sciubba, Daniel M; Soroceanu, Alex; Bess, Shay; Shaffrey, Christopher I; Schwab, Frank J; Smith, Justin S; Lafage, Virginie; International Spine Study Group
    Purpose: The aim is to assess the relationship between cervicothoracic inflection point and baseline disability, as well as the relationship between clinical outcomes and pre- to postoperative changes in inflection point. Methods: Cervical deformity (CD) patients with baseline and 3-month (3M) postoperative radiographic, clinical, and inflection data were grouped by region of inflection point: C6 or above, C6-C7 to C7-T1, T1, or below. Inflection was defined as: Distal-most level where cervical lordosis (CL) changes to thoracic kyphosis (TK). Differences in alignment and patient factors across pre- and postoperative inflection point groups were assessed, as were outcomes by the inclusion of inflection in the CD-corrective fusion construct. Results: A total of 108 patients were included. Preoperative inflection breakdown: C6 or above (42%), C6-C7 to C7-T1 (44%), T1 or below (15%). Surgery was associated with a caudal migration of inflection by 3M: C6 or above (8%), C6-C7 to C7-T1 (58%), T1 or below (33%). For patients with preoperative inflection T1 or below, the inclusion of inflection in the fusion construct was associated with improvements in horizontal gaze (McGregor's Slope included: -11.3° vs. not included: 1.6°, P = 0.038). The inclusion of preoperative inflection in fusion was associated with the superior cervical sagittal vertical axis (cSVA) changes for C6-C7 to C7-T1 patients (-5.2 mm vs. 3.2 mm, P = 0.018). The location of postoperative inflection was associated with variation in 3M alignment: Inflection C6 or above was associated with less Pelvic Tilt (PT), PT and a trend of larger cSVA. Location of inflection or inclusion in fusion was not associated with reoperation or distal junctional kyphosis. Conclusions: Incorporating the inflection point between CL and TK in the fusion construct was associated with superior restoration of cervical alignment and horizontal gaze for surgical CD patients.
  • Thumbnail Image
    ItemOpen Access
    Redefining cervical spine deformity classification through novel cutoffs: An assessment of the relationship between radiographic parameters and functional neurological outcomes.
    (Journal of craniovertebral junction & spine, 2021-04) Passias, Peter Gust; Pierce, Katherine E; Brown, Avery E; Bortz, Cole A; Alas, Haddy; Lafage, Renaud; Lafage, Virginie; Line, Breton; Klineberg, Eric O; Burton, Douglas C; Hart, Robert; Daniels, Alan H; Bess, Shay; Diebo, Bassel; Protopsaltis, Themistocles; Eastlack, Robert; Shaffrey, Christopher I; Schwab, Frank J; Smith, Justin S; Ames, Christopher; On Behalf Of The International Spine Study Group

    Purpose

    The aim is to investigate the relationship between cervical parameters and the modified Japanese Orthopedic Association scale (mJOA).

    Materials and methods

    Surgical adult cervical deformity (CD) patients were included in this retrospective analysis. After determining data followed a parametric distribution through the Shapiro-Wilk Normality (P = 0.15, P > 0.05), Pearson correlations were run for radiographic parameters and mJOA. For significant correlations, logistic regressions were performed to determine a threshold of radiographic measures for which the correlation with mJOA scores was most significant. mJOA score of 14 and <12 reported cut-off values for moderate (M) and severe (S) disability. New modifiers were compared to an existing classification using Spearman's rho and logistic regression analyses to predict outcomes up to 2 years.

    Results

    A total of 123 CD patients were included (60.5 years, 65%F, 29.1 kg/m2). For significant baseline factors from Pearson correlations, the following thresholds were predicted: MGS (M:-12 to-9° and 0°-19°, P = 0.020; S: >19° and <-12°, χ2= 4.291, P = 0.036), TS-CL (M: 26°to 45°, P = 0.201; S: >45°, χ2= 7.8, P = 0.005), CL (M:-21° to 3°, χ2= 8.947, P = 0.004; S: <-21°, χ2= 9.3, P = 0.009), C2-T3 (M: -35° to -25°, χ2= 5.485, P = 0.046; S: <-35°, χ2= 4.1, P = 0.041), C2 Slope (M: 33° to 49°, P = 0.122; S: >49°, χ2= 5.7, P = 0.008), and Frailty (Mild: 0.18-0.27, P = 0.129; Severe: >0.27, P = 0.002). Compared to existing Ames- International Spine Study Group classification, the novel thresholds demonstrated significant predictive value for reoperation and mortality up to 2 years.

    Conclusions

    Collectively, these radiographic values can be utilized in refining existing classifications and developing collective understanding of severity and surgical targets in corrective surgery for adult CD.
  • Thumbnail Image
    ItemOpen Access
    The impact of osteotomy grade and location on regional and global alignment following cervical deformity surgery
    (Journal of Craniovertebral Junction and Spine, 2019-07-01) Passias, Peter G; Horn, Samantha R; Raman, Tina; Brown, Avery E; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Bortz, Cole A; Segreto, Frank A; Pierce, Katherine E; Alas, Haddy; Line, Breton G; Diebo, Bassel G; Daniels, Alan H; Kim, Han Jo; Soroceanu, Alex; Mundis, Gregory M; Protopsaltis, Themistocles S; Klineberg, Eric O; Burton, Douglas C; Hart, Robert A; Schwab, Frank J; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study Group
    Introduction: Correction of cervical deformity (CD) often involves different types of osteotomies to address sagittal malalignment. This study assessed the relationship between osteotomy grade and vertebral level on alignment and clinical outcomes. Methods: Retrospective review of a multi-center prospectively collected CD database. CD was defined as at least one of the following: C2-C7 Cobb >10°, cervical lordosis (CL) >10°, C2-C7 sagittal vertical axis (cSVA) >4 cm, and chin-brow vertical angle > 25°. Patients were evaluated for level and type of cervical osteotomy. Results: 86 CD patients were included (61.4 ± 10.6 years, 66.3% female, body mass index 29.1 kg/m2). 141 osteotomies were in the cervical spine and 79 were in the thoracic spine. There were 19 major osteotomies performed, with 47% at T1. Patients with an osteotomy in the cervical spine improved in T1 slope minus CL (TS - CL), CL, and C2 slope (all P < 0.05). Patients with upper thoracic osteotomies improved in TS - CL, cSVA, C2-T3, C2-T3 sagittal vertical axis (SVA), and C2 slope (all P < 0.05). Minor osteotomies in the upper thoracic spine showed improvement in cSVA (63 mm to 49 mm, P = 0.022), C2-T3 ( P = 0.007), and SVA (-16 mm to 27 mm, P < 0.001). The greatest amount of C2-T3 angular change occurred for patients with a major osteotomy at T2 (39.1° change), then T3 (15.7°), C7 (16.9°°), and T1 (13.5°°). Patients with a major osteotomy in the upper thoracic spine showed similar radiographic changes from pre- to post-operative as patients with three or more minor osteotomies, although C2-T3 SVA trended toward greater improvement with a major osteotomy (-22.5 mm vs. +5.9 mm, P = 0.058) due to lever arm effect. Conclusions: CD patients undergoing osteotomies in the cervical and upper thoracic spine experienced improvement in TS - CL and C2 slope. In the upper thoracic spine, multiple minor osteotomies achieved similar alignment changes to major osteotomies at a single level, while a major osteotomy focused at T2 had the greatest overall impact in cervicothoracic and global alignment in CD patients.
  • Thumbnail Image
    ItemOpen Access
    The impact of postoperative neurologic complications on recovery kinetics in cervical deformity surgery.
    (Journal of craniovertebral junction & spine, 2021-10) Passias, Peter Gust; Brown, Avery E; Alas, Haddy; Pierce, Katherine E; Bortz, Cole A; Diebo, Bassel; Lafage, Renaud; Lafage, Virginie; Burton, Douglas C; Hart, Robert; Kim, Han Jo; Bess, Shay; Moattari, Kevin; Joujon-Roche, Rachel; Krol, Oscar; Williamson, Tyler; Tretiakov, Peter; Imbo, Bailey; Protopsaltis, Themistocles S; Shaffrey, Christopher; Schwab, Frank; Eastlack, Robert; Line, Breton; Klineberg, Eric; Smith, Justin; Ames, Christopher; International Spine Study Group

    Objective

    The objective of the study is to investigate which neurologic complications affect clinical outcomes the most following cervical deformity (CD) surgery.

    Methods

    CD patients (C2-C7 Cobb >10°, CL >10°, cSVA >4 cm or chin-brow vertical angle >25°) >18 years with follow-up surgical and health-related quality of life (HRQL) data were included. Descriptive analyses assessed demographics. Neurologic complications assessed were C5 motor deficit, central neurodeficit, nerve root motor deficits, nerve sensory deficits, radiculopathy, and spinal cord deficits. Neurologic complications were classified as major or minor, then: intraoperative, before discharge, before 30 days, before 90 days, and after 90 days. HRQL outcomes were assessed at 3 months, 6 months, and 1 year. Integrated health state (IHS) for the neck disability index (NDI), EQ5D, and modified Japanese Orthopaedic Association (mJOA) were assessed using all follow-up time points. A subanalysis assessed IHS outcomes for patients with 2Y follow-up.

    Results

    153 operative CD patients were included. Baseline characteristics: 61 years old, 63% female, body mass index 29.7, operative time 531.6 ± 275.5, estimated blood loss 924.2 ± 729.5, 49% posterior approach, 18% anterior approach, 33% combined. 18% of patients experienced a total of 28 neurologic complications in the postoperative period (15 major). There were 7 radiculopathy, 6 motor deficits, 6 sensory deficits, 5 C5 motor deficits, 2 central neurodeficits, and 2 spinal cord deficits. 11.2% of patients experienced neurologic complications before 30 days (7 major) and 15% before 90 days (12 major). 12% of neurocomplication patients went on to have revision surgery within 6 months and 18% within 2 years. Neurologic complication patients had worse mJOA IHS scores at 1Y but no significant differences between NDI and EQ5D (0.003 vs. 0.873, 0.458). When assessing individual complications, central neurologic deficits and spinal cord deficit patients had the worst outcomes at 1Y (2.6 and 1.8 times worse NDI scores, P = 0.04, no improvement in EQ5D, 8% decrease in EQ5D). Patients with sensory deficits had the best NDI and EQ5D outcomes at 1Y (31% decrease in NDI, 8% increase in EQ5D). In a subanalysis, neurologic patients trended toward worse NDI and mJOA IHS outcomes (P = 0.263, 0.163).

    Conclusions

    18% of patients undergoing CD surgery experienced a neurologic complication, with 15% within 3 months. Patients who experienced any neurologic complication had worse mJOA recovery kinetics by 1 year and trended toward worse recovery at 2 years. Of the neurologic complications, central neurologic deficits and spinal cord deficits were the most detrimental.