Browsing by Author "Elysee, Jonathan"

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    ItemOpen Access
    Author Correction: Sagittal age-adjusted score (SAAS) for adult spinal deformity (ASD) more effectively predicts surgical outcomes and proximal junctional kyphosis than previous classifications.
    (Spine deformity, 2023-03) Lafage, Renaud; Smith, Justin S; Elysee, Jonathan; Passias, Peter; Bess, Shay; Klineberg, Eric; Kim, Han Jo; Shaffrey, Christopher; Burton, Douglas; Hostin, Richard; Mundis, Gregory; Ames, Christopher; Schwab, Frank; Lafage, Virginie; International Spine Study Group (ISSG)
    In Fig. 4 of this article signs for points associated in all 3 components are incorrect and should be reversed, e.g. + 2 should be − 2 and vise versa; Fig. 4 should have appeared as shown below. The original article has been corrected
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    ItemOpen Access
    Complication rate evolution across a 10-year enrollment period of a prospective multicenter database.
    (Journal of neurosurgery. Spine, 2021-12) Lafage, Renaud; Fong, Alex M; Klineberg, Eric; Smith, Justin S; Bess, Shay; Shaffrey, Christopher I; Burton, Douglas; Kim, Han Jo; Elysee, Jonathan; Mundis, Gregory M; Passias, Peter; Gupta, Munish; Hostin, Richard; Schwab, Frank; Lafage, Virginie

    Objective

    Adult spinal deformity is a complex pathology that benefits greatly from surgical treatment. Despite continuous innovation, little is known regarding continuous changes in surgical techniques and the complications rate. The objective of the current study was to investigate the evolution of the patient profiles and surgical complications across a single prospective multicenter database.

    Methods

    This study is a retrospective review of a prospective, multicenter database of surgically treated patients with adult spinal deformity (thoracic kyphosis > 60°, sagittal vertical axis > 5 cm, pelvic tilt > 25°, or Cobb angle > 20°) with a minimum 2-year follow-up. Patients were stratified into 3 equal groups by date of surgery. The three groups' demographic data, preoperative data, surgical information, and complications were then compared. A moving average of 320 patients was used to visualize and investigate the evolution of the complication across the enrollment period.

    Results

    A total of 928/1260 (73.7%) patients completed their 2-year follow-up, with an enrollment rate of 7.7 ± 4.1 patients per month. Across the enrollment period (2008-2018) patients became older (mean age increased from 56.7 to 64.3 years) and sicker (median Charlson Comorbidity Index rose from 1.46 to 2.08), with more pure sagittal deformity (type N). Changes in surgical treatment included an increased use of interbody fusion, more anterior column release, and a decrease in the 3-column osteotomy rate, shorter fusion, and more supplemental rods and bone morphogenetic protein use. There was a significant decrease in major complications associated with a reoperation (from 27.4% to 17.1%) driven by a decrease in radiographic failures (from 12.3% to 5.2%), despite a small increase in neurological complications. The overall complication rate has decreased over time, with the lowest rate of any complication (51.8%) during the period from August 2014 to March 2017. Major complications associated with reoperation decreased rapidly in the 2014-2015. Major complications not associated with reoperation had the lowest level (21.0%) between February 2014 and October 2016.

    Conclusions

    Despite an increase in complexity of cases, complication rates did not increase and the rate of complications leading to reoperation decreased. These improvements reflect the changes in practice (supplemental rod, proximal junctional kyphosis prophylaxis, bone morphogenetic protein use, anterior correction) to ensure maintenance of status or improved outcomes.
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    ItemOpen Access
    Patterns of Lumbar Spine Malalignment Leading to Revision Surgery for Proximal Junctional Kyphosis: A Cluster Analysis of Over- Versus Under-Correction.
    (Global spine journal, 2022-02) Lafage, Renaud; Passias, Peter; Sheikh Alshabab, Basel; Bess, Shay; Smith, Justin S; Klineberg, Eric; Kim, Han Jo; Elysee, Jonathan; Shaffrey, Christopher; Burton, Douglas; Hostin, Richard; Mundis, Gregory; Schwab, Frank; Lafage, Virginie; International Spine Study Group

    Study design

    Retrospective cohort study.

    Objective

    Investigate the patterns of fused lumbar alignment in patients requiring revision surgery for proximal junctional kyphosis (PJK).

    Methods

    Fifty patients (67.8 yo, 76% female) with existing thoraco-lumbar fusion (T10/12 to pelvis) and indicated for surgical correction for PJK were included. To investigate patterns of radiographic alignment prior to PJK revision, unsupervised 2-step cluster analysis was run on parameters describing the fused lumbar spine (PI-LL) to identify natural independent groups within the cohort. Clusters were compared in terms of demographics, pre-operative alignment, surgical parameters, and post-operative alignment. Associations between pre- and post-revision PJK angles were investigated using a Pearson correlation analysis.

    Results

    Analysis identified 2 distinct patterns: Under-corrected (UC, n = 12, 32%) vs over-corrected (OC, n = 34, 68%) with a silhouette of .5. The comparison demonstrated similar pelvic incidence (PI) and PJK angle but significantly greater deformity for the UC vs OC group in terms of PI-LL, PI-LL offset, pelvic tilt, and sagittal vertebral axis. The surgical strategy for PJK correction did not differ between the 2 groups in terms of approach, American Society of Anesthesiologists grade, decompression, use of osteotomy, interbody fusion, or fusion length. The post-revision PJK angle significantly correlated with the amount of PJK correction within the OC group but not within the UC group.

    Conclusions

    This study identified 2 patterns of lumbar malalignment associated with severe PJK: over vs under corrected. Despite the difference in PJK etiology, both patterns underwent the same revision strategy. Future analysis should look at the effect of correcting focal deformity alone vs correcting focal deformity and underlying malalignment simultaneously on recurrent PJK rate.
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    ItemOpen Access
    Predicting Mechanical Failure Following Cervical Deformity Surgery: A Composite Score Integrating Age-Adjusted Cervical Alignment Targets.
    (Global spine journal, 2022-03) Lafage, Renaud; Smith, Justin S; Soroceanu, Alexandra; Ames, Christopher; Passias, Peter; Shaffrey, Christopher; Mundis, Gregory; Alshabab, Basel Sheikh; Protopsaltis, Themistocles; Klineberg, Eric; Elysee, Jonathan; Kim, Han Jo; Bess, Shay; Schwab, Frank; Lafage, Virginie; International Spine Study Group (ISSG)

    Study design

    Retrospective cohort study.

    Objectives

    Investigate a composite score to evaluate the relationship between alignment proportionality and risk of distal junctional kyphosis (DJK).

    Methods

    84 patients with minimum 1 year follow-up were included (age = 61.1 ± 10.3 years, 64.3% women). The Cervical Score was constructed using offsets from age-adjusted normative values for sagittal vertical axis (SVA), T1 Slope (TS), and TS minus cervical lordosis (CL). Individual points were assigned based on offset with age-adjusted alignment targets and summed to generate the Cervical Score. Rates of mechanical failure (DJK revision or severe DJK [DJK> 20° and ΔDJK> 10°]) were assessed overall and based on Cervical Score. Logistical regressions assessed associations between early radiographic alignment and 1-year failure rate.

    Results

    Mechanical failure rate was 21.4% (N = 18), 10.7% requiring revision. By multivariate logistical regression: 3-month T1S (OR: .935), TS-CL (OR:0.882), and SVA (OR:1.015) were independent predictors of 1-year failure (all P < .05). Cervical Score ranged (-6 to 6), 37.8% of patients between -1 and 1, and 50.0% with 2 or higher. DJK patients had significantly higher Cervical Score (4.1 ± 1.3 vs .6 ± 2.2, P < .001). Patients with a score ≥3 were significantly more likely to develop a failure (71.4%) with OR of 38.55 (95%CI [7.73; 192.26]) and Nagelkerke r2 .524 (P < .001).

    Conclusion

    This study developed a composite alignment score predictive of mechanical failures in CD surgery. A score ≥3 at 3 months following surgery was associated with a marked increase in failure rate. The Cervical Score can be used to analyze sagittal alignment and help define realignment objectives to reduce mechanical failure.
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    ItemOpen Access
    Quantifying the Contribution of Lower Limb Compensation to Upright Posture: What Happens if Adult Spinal Deformity Patients Do Not Compensate?
    (Spine, 2023-03) Lafage, Renaud; Duvvuri, Priya; Elysee, Jonathan; Diebo, Bassel; Bess, Shay; Burton, Douglas; Daniels, Alan; Gupta, Munish; Hostin, Richard; Kebaish, Khaled; Kelly, Michael; Kim, Han Jo; Klineberg, Eric; Lenke, Lawrence; Lewis, Stephen; Ames, Christopher; Passias, Peter; Protopsaltis, Themistocles; Shaffrey, Christopher; Smith, Justin S; Schwab, Frank; Lafage, Virginie; International Spine Study Group

    Study design

    This is a multicenter, prospective cohort study.

    Objective

    This study tests the hypothesis that elimination of lower limb compensation in patients with adult spinal deformity (ASD) will significantly increase the magnitude of sagittal malalignment.

    Summary of background data

    ASD affects a significant proportion of the elderly population, impairing functional sagittal alignment and inhibiting overall quality of life. To counteract these effects, patients with ASD use their spine, pelvis, and lower limbs to create a compensatory posture that allows for standing and mobility. However, the degree to which each of the hips, knees, and ankles contributes to these compensatory mechanisms has yet to be determined.

    Methods

    Patients undergoing corrective surgery for ASD were included if they met at least one of the following criteria: complex surgical procedure, geriatric deformity surgery, or severe radiographic deformity. Preoperative full-body x-rays were evaluated, and age and PI-adjusted normative values were used to model spine alignment based upon three positions: compensated (all lower extremity compensatory mechanisms maintained), partially compensated (removal of ankle dorsiflexion and knee flexion, with maintained hip extension), and uncompensated (ankle, knee, and hip compensation set to the age and PI norms).

    Results

    288 patients were included (mean age 60 y, 70.5% females). As the model transitioned from the compensated to uncompensated position, initial posterior translation of the pelvis decreased significantly to an anterior translation versus the ankle (P.Shift: 30 to -7.6 mm). This was associated with a decrease in pelvic retroversion (PT: 24.1 to 16.1), hip extension (SFA: 203 to 200), knee flexion (KA: 5.5 to-0.4), and ankle dorsiflexion (AA: 5.3 to 3.7). As a result, the anterior malalignment of the trunk significantly increased: SVA (65 to 120 mm) and G-SVA (C7-Ankle from 36 to 127 mm).

    Conclusion

    Removal of lower limbs compensation revealed an unsustainable truncal malalignment with two-fold greater SVA.
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    ItemOpen Access
    Radiographic Characteristics of Cervical Deformity (CD) Using a Discriminant Analysis: The Value of Extension Radiographs.
    (Clinical spine surgery, 2022-06) Lafage, Renaud; Virk, Sohrab; Elysee, Jonathan; Passias, Peter; Ames, Christopher; Hart, Robert; Shaffrey, Christopher; Mundis, Gregory; Protopsaltis, Themistocles; Gupta, Munish; Klineberg, Eric; Burton, Douglas; Schwab, Frank; Lafage, Virginie; ISSG

    Study design

    This was a retrospective review of a prospectively collected database.

    Objective

    The aim of this study was to delineate radiographic parameters that distinguish severe cervical spine deformity (CSD).

    Summary of background data

    Our objective was to define parameters that distinguish severe CSD using a consensus approach combined with discriminant analysis as no system currently exists in the literature.

    Methods

    Twelve CSD surgeons reviewed preoperative x-rays from a CSD database. A consensus was reached for categorizing patients into a severe cervical deformity (sCD), non-severe cervical deformity (non-sCD), or an indeterminate cohort. Radiographic parameters were found including classic cervical and spinopelvic parameters in neutral/flexion/extension alignment. To perform our discriminant analysis, we selected for parameters that had a significant difference between the sCD and non-sCD groups using the Student t test. A discriminant function analysis was used to determine which variables discriminate between the sCD versus non-sCD. A stepwise analysis was performed to build a model of parameters to delineate sCD.

    Results

    A total of 146 patients with cervical deformity were reviewed (60.5±10.5 y; body mass index: 29.8 kg/m2; 61.3% female). There were 83 (56.8%) classified as sCD and 51 (34.9%) as non-sCD. The comparison analysis led to 16 radiographic parameters that were different between cohorts, and 5 parameters discriminated sCD and non-sCD. These parameters were cervical sagittal vertical axis, T1 slope, maximum focal kyphosis in extension, C2 slope in extension, and number of kyphotic levels in extension. The canonical coefficient of correlation was 0.689, demonstrating a strong association between our model and cervical deformity classification. The accuracy of classification was 87.0%, and cross-validation was 85.2% successful.

    Conclusions

    More than one third of a series of CSD patients were not considered to have a sCD. Analysis of an initial 17 parameters showed that a subset of 5 parameters can discriminate between sCD versus non-sCD with 85% accuracy. Our study demonstrates that flexion/extension images are critical for defining severe CD.
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    ItemOpen Access
    Sagittal age-adjusted score (SAAS) for adult spinal deformity (ASD) more effectively predicts surgical outcomes and proximal junctional kyphosis than previous classifications.
    (Spine deformity, 2022-01) Lafage, Renaud; Smith, Justin S; Elysee, Jonathan; Passias, Peter; Bess, Shay; Klineberg, Eric; Kim, Han Jo; Shaffrey, Christopher; Burton, Douglas; Hostin, Richard; Mundis, Gregory; Ames, Christopher; Schwab, Frank; Lafage, Virginie; International Spine Study Group (ISSG)

    Background

    Several methodologies have been proposed to determine ideal ASD sagittal spinopelvic alignment (SRS-Schwab classification) global alignment and proportion (GAP) score, patient age-adjusted alignment). A recent study revealed the ability and limitations of these methodologies to predict PJK. The aim of the study was to develop a new approach, inspired by SRS classification, GAP score, and age-alignment to improve the evaluation of the sagittal plane.

    Method

    A multi-center ASD database was retrospectively evaluated for surgically treated ASD patients with complete fusion of the lumbar spine, and minimum 2 year follow-up. The Sagittal age-adjusted score (SAAS) methodology was created by assigning numerical values to the difference between each patient's postoperative sagittal alignment and ideal alignment defined by previously reported age generational norms for PI-LL, PT, and TPA. Postoperative HRQOL and PJK severity between each SAAS categories were evaluated.

    Results

    409 of 667 (61.3%) patients meeting inclusion criteria were evaluated. At 2 year SAAS score showed that 27.0% of the patients were under-corrected, 51.7% over-corrected, and 21.3% matched their age-adjusted target. SAAS score increased as PJK worsened (from SAAS = 0.2 for no-PJK, to 4.0 for PJF, p < 0.001). Post-operatively, HRQOL differences between SAAS groups included ODI, SRS pain, and SRS total.

    Conclusion

    Inspired by SRS classification, the concept of the GAP score, and age-adjusted alignment targets, the results demonstrated significant association with PJK and patient reported outcomes. With a lower rate of failure and better HRQOL, the SAAS seems to represent a "sweet spot" to optimize HRQOL while mitigating the risk of mechanical complications.
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    ItemOpen Access
    Surgical Planning for Adult Spinal Deformity: Anticipated Sagittal Alignment Corrections According to the Surgical Level.
    (Global spine journal, 2022-10) Lafage, Renaud; Schwab, Frank; Elysee, Jonathan; Smith, Justin S; Alshabab, Basel Sheikh; Passias, Peter; Klineberg, Eric; Kim, Han Jo; Shaffrey, Christopher; Burton, Douglas; Gupta, Munish; Mundis, Gregory M; Ames, Christopher; Bess, Shay; Lafage, Virginie; International Spine Study Group (ISSG)

    Study design

    Retrospective cohort study.

    Objectives

    Establish simultaneous focal and regional corrective guidelines accounting for reciprocal global and pelvic compensation.

    Methods

    433 ASD patients (mean age 62.9 yrs, 81.3% F) who underwent corrective realignment (minimum L1-pelvis) were included. Sagittal parameters, and segmental and regional Cobb angles were assessed pre and post-op. Virtual postoperative alignment was generated by combining post-op alignment of the fused spine with the pre-op alignment on the unfused thoracic kyphosis and the pre-op pelvic retroversion. Regression models were then generated to predict the relative impact of segmental (L4-L5) and regional (L1-L4) corrections on PT, SVA (virtual), and TPA.

    Results

    Baseline analysis revealed distal (L4-S1) lordosis of 33 ± 15°, flat proximal (L1-L4) lordosis (1.7 ± 17°), and segmental kyphosis from L2-L3 to T10-T11. Post-op, there was no mean change in distal lordosis (L5-S1 decreased by 2°, and L4-L5 increased by 2°), while the more proximal lordosis increased by 18 ± 16°. Regression formulas revealed that Δ10° in distal lordosis resulted in Δ10° in TPA, associated with Δ100 mm in SVA or Δ3° in PT; Δ10° in proximal lordosis yielded Δ5° in TPA associated with Δ50 mm in SVA; and finally Δ10° in thoraco-lumbar junction yielded Δ2.5° in TPA associated with Δ25 mm in SVA and no impact on PT correction.

    Conclusions

    Overall impact of lumbar lordosis restoration is critically determined by location of correction. Distal correction leads to a greater impact on global alignment and pelvic retroversion. More specifically, it can be assumed that 1° L4-S1 lordosis correction produces 1° change in TPA / 10 mm change in SVA and 0.5° in PT.
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    ItemOpen Access
    Surgical Strategy for the Management of Cervical Deformity Is Based on Type of Cervical Deformity.
    (Journal of clinical medicine, 2021-10) Kim, Han Jo; Virk, Sohrab; Elysee, Jonathan; Ames, Christopher; Passias, Peter; Shaffrey, Christopher; Mundis, Gregory; Protopsaltis, Themistocles; Gupta, Munish; Klineberg, Eric; Hart, Robert; Smith, Justin S; Bess, Shay; Schwab, Frank; Lafage, Renaud; Lafage, Virginie; On Behalf Of The International Spine Study Group
    Cervical deformity morphotypes based on type and location of deformity have previously been described. This study aimed to examine the surgical strategies implemented to treat these deformity types and identify if differences in treatment strategies impact surgical outcomes. Our hypothesis was that surgical strategies will differ based on different morphologies of cervical deformity. Adult patients enrolled in a prospective cervical deformity database were classified into four deformity types (Flatneck (FN), Focal kyphosis (FK), Cervicothoracic kyphosis (CTK) and Coronal (C)), as previously described. We analyzed group differences in demographics, preoperative symptoms, health-related quality of life scores (HRQOLs), and surgical strategies were evaluated, and postop radiographic and HROQLs at 1+ year follow up were compared. 90/109 eligible patients (mean age 63.3 ± 9.2, 64% female, CCI 1.01 ± 1.36) were evaluated. Group distributions included FN = 33%, FK = 29%, CTK = 29%, and C = 9%. Significant differences were noted in the surgical approaches for the four types of deformities, with FN and FK having a high number of anterior/posterior (APSF) approaches, while CTK and C had more posterior only (PSF) approaches. For FN and FK, PSF was utilized more in cases with prior anterior surgery (70% vs. 25%). For FN group, PSF resulted in inferior neck disability index compared to those receiving APSF suggesting APSF is superior for FN types. CTK types had more three-column osteotomies (3CO) (p < 0.01) and longer fusions with the LIV below T7 (p < 0.01). There were no differences in the UIV between all deformity types (p = 0.19). All four types of deformities had significant improvement in NRS neck pain post-op (p < 0.05) with their respective surgical strategies. The four types of cervical deformities had different surgical strategies to achieve improvements in HRQOLs. FN and FK types were more often treated with APSF surgery, while types CTK and C were more likely to undergo PSF. CTK deformities had the highest number of 3COs. This information may provide guidelines for the successful management of cervical deformities.
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    ItemOpen Access
    The morphology of cervical deformities: a two-step cluster analysis to identify cervical deformity patterns.
    (Journal of neurosurgery. Spine, 2019-11-15) Kim, Han Jo; Virk, Sohrab; Elysee, Jonathan; Passias, Peter; Ames, Christopher; Shaffrey, Christopher I; Mundis, Gregory; Protopsaltis, Themistocles; Gupta, Munish; Klineberg, Eric; Smith, Justin S; Burton, Douglas; Schwab, Frank; Lafage, Virginie; Lafage, Renaud; International Spine Study Group
    OBJECTIVE:Cervical deformity (CD) is difficult to define due to the high variability in normal cervical alignment based on postural- and thoracolumbar-driven changes to cervical alignment. The purpose of this study was to identify whether patterns of sagittal deformity could be established based on neutral and dynamic alignment, as shown on radiographs. METHODS:This study is a retrospective review of a prospective, multicenter database of CD patients who underwent surgery from 2013 to 2015. Their radiographs were reviewed by 12 individuals using a consensus-based method to identify severe sagittal CD. Radiographic parameters correlating with health-related quality of life were introduced in a two-step cluster analysis (a combination of hierarchical cluster and k-means cluster) to identify patterns of sagittal deformity. A comparison of lateral and lateral extension radiographs between clusters was performed using an ANOVA in a post hoc analysis. RESULTS:Overall, 75 patients were identified as having severe CD due to sagittal malalignment, and they formed the basis of this study. Their mean age was 64 years, their body mass index was 29 kg/m2, and 66% were female. There were significant correlations between focal alignment/flexibility of maximum kyphosis, cervical lordosis, and thoracic slope minus cervical lordosis (TS-CL) flexibility (r = 0.27, 0.31, and -0.36, respectively). Cluster analysis revealed 3 distinct groups based on alignment and flexibility. Group 1 (a pattern involving a flat neck with lack of compensation) had a large TS-CL mismatch despite flexibility in cervical lordosis; group 2 (a pattern involving focal deformity) had focal kyphosis between 2 adjacent levels but no large regional cervical kyphosis under the setting of a low T1 slope (T1S); and group 3 (a pattern involving a cervicothoracic deformity) had a very large T1S with a compensatory hyperlordosis of the cervical spine. CONCLUSIONS:Three distinct patterns of CD were identified in this cohort: flat neck, focal deformity, and cervicothoracic deformity. One key element to understanding the difference between these groups was the alignment seen on extension radiographs. This information is a first step in developing a classification system that can guide the surgical treatment for CD and the choice of fusion level.
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    ItemOpen Access
    Unsupervised Clustering of Adult Spinal Deformity Patterns Predicts Surgical and Patient-Reported Outcomes.
    (Global spine journal, 2024-10) Lafage, Renaud; Song, Junho; Elysee, Jonathan; Fourman, Mitchell S; Smith, Justin S; Ames, Christopher; Bess, Shay; Daniels, Alan H; Gupta, Munish; Hostin, Richard; Kim, Han Jo; Klineberg, Eric; Mundis, Gregory; Diebo, Bassel G; Shaffrey, Christopher; Schwab, Frank; Lafage, Virginie; Burton, Douglas; International Spine Study Group

    Study design

    Retrospective cohort study.

    Objectives

    To evaluate whether different radiographic clusters of adult spinal deformity identified using artificial intelligence-based clustering are associated with distinct surgical outcomes.

    Methods

    Patients were classified based on the results of a previously conducted analysis that examined clusters of deformity, including Moderate Sagittal (Mod Sag), Severe Sagittal (Sev Sag), Coronal, and Hyper-Thoracic Kyphosis (Hyper-TK). The surgical data, HRQOL, and complication outcomes of these clusters were then compared.

    Results

    The final analysis included 1062 patients. Similar to published results on a different patient sample, Mod Sag and Sev Sag patients were older, more likely to have a history of previous spine surgery, and more disabled. By 2-year, all clusters improved in HRQOL and reached a similar rate of minimal clinically important difference (MCID).The Sev Sag cluster had the highest rate major complications (53% vs 34-40%), and complications leading to reoperation (29% vs 17-23%), implant failures (20% vs 8-11%), and operative complications (27% vs 10-17%). Coronal patients had the highest rate of pulmonary complications (9% vs 3-6%) but the lowest rate of X-ray imbalance (10% vs 19-21%). No significant differences were found in neurological complications, infection rate, gastrointestinal, or cardiac events (all P > .1). Kaplan-Meier survival curves demonstrated a lower time to first complications for the Sev Sag cluster.

    Conclusions

    All clusters of adult spinal deformity benefit similarly from surgery as they all achieved similar rates of MCID. Although the rates of complications varied among the clusters, the types of complications were not significantly different.
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    ItemOpen Access
    Upper versus Lower Lumbar Lordosis Corrections in Relation to Pelvic Tilt - An Essential Element in Surgical Planning for Sagittal Plane Deformity.
    (Spine, 2022-08) Kim, Han Jo; Alluri, R Kiran; Lafage, Renaud; Elysee, Jonathan; Smith, Justin S; Mundis, Gregory M; Shaffrey, Christopher I; Ames, Christopher P; Burton, Douglas C; Klineberg, Eric O; Bess, Shay; Schwab, Frank; Gupta, Munish; Lafage, Virginie; International Spine Study Group (ISSG)

    Study design

    Retrospective study of a multicenter Adult Spinal Deformity (ASD) Database.

    Objective

    To investigate the change in Pelvic tilt (PT) imparted by regional changes in lumbar lordosis at 2-year minimum follow up.

    Summary of background data

    The distribution of lumbar lordosis between L1-4 and L4-S1 is known to vary based on pelvic incidence (PI). However, the extent to which regional changes effect PT is not clearly elucidated. This information can be useful for ASD surgical planning.

    Methods

    Operative patients from a multicenter ASD database were included with Lowest Instrumented Vertebrae (LIV) S1/Ilium, >5 levels of fusion, Proximal Junction Kyphosis (PJK) angle < 20, and >5 degrees of change in lumbar lordosis from L4-S1 and L1-4. Radiographic analysis was performed evaluating Thoracic Kyphosis (TK), T10-L2 kyphosis (TL), L1-S1 lordosis (LL), L4-S1 lordosis, L1-4 lordosis, sagittal vertical axis (SVA) and PI-LL from preoperative to postoperative, and change at 2-years follow-up. Stepwise regression analysis was performed in order to determine the relationship between PT and the above radiographic parameters. Health-related quality of life (HRQOL) outcomes were also compared between preoperative and postoperative timepoints at 2 years.

    Results

    103 patients met inclusion for the study. There was improvement in all the radiographic parameters and HRQOLs at 2 years follow-up (p < 0.01). Stepwise regression model showed an inverse relationship between PT and LL change (r = 0.71, p < 0.01). Regionally, an increase in 10 degrees from L4-S1 correlated with a 2.4 degree decrease in PT (p < 0.01), while an increase in 10 degrees from L1-4 resulted in a 1.6 degree decrease in PT (p < 0.01).

    Conclusion

    In the surgical planning for ASD, our data demonstrated significant correlational difference between corrections in the upper (L1-4) and lower (L4-S1) lumbar spine and PT changes. These calculations can be useful in planning sagittal plane corrections for ASD.