Browsing by Author "Lovecchio, Francis"

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    ItemOpen Access
    Optimizing the Definition of Proximal Junctional Kyphosis: A Sensitivity Analysis.
    (Spine, 2023-03) Lovecchio, Francis; Lafage, Renaud; Line, Breton; Bess, Shay; Shaffrey, Christopher; Kim, Han Jo; Ames, Christopher; Burton, Douglas; Gupta, Munish; Smith, Justin S; Eastlack, Robert; Klineberg, Eric; Mundis, Gregory; Schwab, Frank; Lafage, Virginie; International Spine Study Group ISSG

    Study design

    Diagnostic binary threshold analysis.

    Objective

    (1) Perform a sensitivity analysis demonstrating the test performance metrics for any combination of proximal junctional angle (PJA) magnitude and change; (2) Propose a new proximal junctional kyphosis (PJK) criteria.

    Summary of background data

    Previous definitions of PJK have been arbitrarily selected and then tested through retrospective case series, often showing little correlation with clinical outcomes.

    Materials and methods

    Surgically treated adult spinal deformity patients (≥4 levels fused) enrolled into a prospective, multicenter database were evaluated at a minimum 2-year follow-up for proximal junctional failure (PJF). Using PJF as the outcome of interest, test performance metrics including sensitivity, positive predictive value, and F1 metrics (harmonic mean of precision and recall) were calculated for all combinations of PJA magnitude and change using different combinations of perijunctional vertebrae. The combination with the highest F1 score was selected as the new PJK criteria. Performance metrics of previous PJK definitions and the new PJK definition were compared.

    Results

    Of the total, 669 patients were reviewed. PJF rate was 10%. Overall, the highest F1 scores were achieved when the upper instrumented vertebrae -1 (UIV-1)/UIV+2 angle was measured. For lower thoracic cases, out of all the PJA and magnitude/change combinations tested, a UIV-1/UIV+2 magnitude of -28° and a change of -20° was associated with the highest F1 score. For upper thoracic cases, a UIV-1/UIV+2 magnitude of -30° and a change of -24° were associated with the highest F1 score. Using PJF as the outcome, patients meeting this new criterion (11.5%) at 6 weeks had the lowest survival rate (74.7%) at 2 years postoperative, compared with Glattes (84.4%) and Bridwell (77.4%).

    Conclusions

    Out of all possible PJA magnitude and change combinations, without stratifying by upper thoracic versus lower thoracic fusions, a magnitude of ≤-28° and a change of ≤-22° provide the best test performance metrics for predicting PJF.
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    ItemOpen Access
    Revision Free Loss of Sagittal Correction > 3 Years After Adult Spinal Deformity Surgery: Who and Why?
    (Spine, 2023-10) Lovecchio, Francis; Lafage, Renaud; Kim, Han Jo; Bess, Shay; Ames, Christopher; Gupta, Munish; Passias, Peter; Klineberg, Eric; Mundis, Gregory; Burton, Douglas; Smith, Justin S; Shaffrey, Christopher; Schwab, Frank; Lafage, Virginie; International Spine Study Group

    Study design

    Multicenter retrospective cohort study.

    Objective

    To investigate risk factors for loss of correction within the instrumented lumbar spine following ASD surgery.

    Summary of background data

    The sustainability of adult deformity (ASD) surgery remains a health care challenge. Malalignment is a major reason for revision surgery.

    Methods

    321 patients who underwent fusion of the lumbar spine (≥5 levels, LIV pelvis) with a revision-free follow-up ≥3 years were identified. Patients were stratified by change in PI-LL from 6 weeks to 3 years postop as Maintained vs. Loss >5°. Those with instrumentation failure (broken rod, screw pullout, etc.) were excluded before comparisons. Demographics, surgical data, and radiographic alignment were compared. Repeated measure ANOVA was performed to evaluate the maintenance of the correction for L1-L4 and L4-S1. Multivariate logistic regression was conducted to identify independent surgical predictors of correction loss.

    Results

    The cohort had a mean age of 64 yrs, mean BMI 28 kg/m 2 , 80% female. 82 patients (25.5%) lost >5° of PI-LL correction (mean loss 10±5°). After exclusion of patients with instrumentation failure, 52 Loss were compared to 222 Maintained. Demographics, osteotomies, 3CO, IBF, use of BMP, rod material, rod diameter, and fusion length were not significantly different. L1-S1 screw orientation angle was 1.3±4.1 from early postop to 3 years ( P =0.031), but not appreciably different at L4-S1 (-0.1±2.9 P =0.97). Lack of a supplemental rod (OR 4.0, P =0.005) and fusion length (OR 2.2, P =0.004) were associated with loss of correction.

    Conclusions

    Approximately a quarter of revision-free patients lose an average of 10° of their 6-week correction by 3 years. Lordosis is lost proximally through the instrumentation (i.e. tulip/shank angle shifts and/or rod bending). The use of supplemental rods and avoiding sagittal overcorrection may help mitigate this loss.