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
Department of Orthopedic Surgery, Hospital for Special Surgery, New York, NY.
Department of Orthopedic Surgery, Northwell Health, Lenox Hill Hospital, New York, NY.
Spine (Phila Pa 1976). 2023 Mar 15;48(6):414-420. doi: 10.1097/BRS.0000000000004564. Epub 2022 Dec 28.
Diagnostic binary threshold analysis.
(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.
Previous definitions of PJK have been arbitrarily selected and then tested through retrospective case series, often showing little correlation with clinical outcomes.
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.
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%).
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.
诊断二元阈值分析。
（1）进行敏感性分析，展示近端交界角（PJA）大小和变化的任何组合的测试性能指标；（2）提出一种新的近端交界后凸畸形（PJK）标准。
先前对PJK的定义是任意选择的，然后通过回顾性病例系列进行测试，结果往往显示与临床结果相关性不大。
纳入前瞻性多中心数据库的接受手术治疗的成人脊柱畸形患者（融合≥4个节段），在至少2年的随访中评估近端交界失败（PJF）情况。以PJF作为感兴趣的结果，使用不同的交界周椎体组合，计算PJA大小和变化的所有组合的测试性能指标，包括敏感性、阳性预测值和F1指标（精确率和召回率的调和均值）。选择F1分数最高的组合作为新的PJK标准。比较先前PJK定义和新PJK定义的性能指标。
共纳入669例患者进行回顾。PJF发生率为10%。总体而言，测量上位固定椎-1（UIV-1）/UIV+2角时F1分数最高。对于下胸椎病例，在所有测试的PJA和大小/变化组合中，UIV-1/UIV+2大小为-28°且变化为-20°时F1分数最高。对于上胸椎病例，UIV-1/UIV+2大小为-30°且变化为-24°时F1分数最高。以PJF作为结果，术后6周符合这一新标准的患者（11.5%）在术后2年的生存率最低（74.7%），而Glattes标准组为84.4%，Bridwell标准组为77.4%。
在所有可能的PJA大小和变化组合中，不按上胸椎与下胸椎融合分层，大小≤-28°且变化≤-22°为预测PJF提供了最佳测试性能指标。
