Affiliated hospital of Jining Medical University, Jining Medical University, No. 89, Guhuai Road, Jining, 272007, China.
Orthopedic Department of Shandong University of Traditional Chinese Medicine, No. 16369, Jingshi Road, Jinan, 250014, China.
BMC Musculoskelet Disord. 2023 Mar 10;24(1):180. doi: 10.1186/s12891-023-06292-2.
Those pelvic parameters of sacral slope (SS) and pelvic tilt (PT) correlated significantly to lumbar spine and hip joints respectively. We proposed the match between SS and PT, namely spinopelvic index (SPI), in order to investigate whether the SPI correlated to proximal junctional failure (PJF) in adult spinal deformity (ASD) after correction surgery.
Ninety-nine ASD patients who had undergone long-fusion (≥ 5 vertebras) surgeries were reviewed retrospectively in two medical institutions from January 2018 to December 2019. Those SPI were calculated with the equation: SPI = SS/PT, and analyzed using the receiver operating characteristic curve (ROC) analysis. All participants were subdivided into the observational and control group. Comparisons of demographics, surgical and radiographic data between the two groups were performed. A Kaplan-Meier curve and log-rank test was used to analyze the differences in PJF-free survival time, and the 95% confidence intervals (CI) were recorded respectively.
Nineteen patients suffering from PJF had much smaller postoperative SPI (P = 0.015), but much larger TK postoperatively (P < 0.001). ROC analysis determined the best cutoff value of 0.82 for SPI (sensitivity = 88.5%, specificity = 57.9%; AUC = 0.719, 95%CI: 0.612-0.864; P = 0.003). There were 19 and 80 cases in the observational (SPI ≤ 0.82) and control group (SPI > 0.82) respectively. The incidence of PJF in the observational group was much higher (11/19 VS 8/80, P < 0.001); further logistic regression analysis showed that SPI ≤ 0.82 was associated with increased odds of PJF (odds ratio: 12.375; 95%CI: 3.851-39.771). PJF-free survival time in the observational group decreased significantly (P < 0.001, log-rank test), moreover, multivariate analysis demonstrated that a value of SPI ≤ 0.82 (HR 6.626, 95%CI: 1.981-12.165) was significantly associated with PJF.
For ASD patients underwent long-fusion surgeries, the SPI should be over 0.82. The incidence of PJF may increase by 12-fold in such individuals with the immediate SPI ≤ 0.82 postoperatively.
骶骨倾斜角（SS）和骨盆倾斜角（PT）等骨盆参数与腰椎和髋关节均有显著相关性。为了研究脊柱矫形术后近端交界区失败（PJF）与 SS 和 PT 比值（SPI）的相关性，我们提出了 SPI 这一概念。
回顾性分析了 2018 年 1 月至 2019 年 12 月在两家医疗机构接受长节段（≥5 个椎体）融合术的 99 例 ASD 患者的临床资料。采用公式 SPI=SS/PT 计算 SPI，采用受试者工作特征曲线（ROC）分析 SPI。所有患者被分为观察组和对照组。比较两组患者的人口统计学、手术和影像学资料。采用 Kaplan-Meier 曲线和对数秩检验分析两组患者的无 PJF 生存时间，记录 95%置信区间（CI）。
19 例发生 PJF 的患者术后 SPI 较小（P=0.015），但术后 TK 较大（P<0.001）。ROC 分析确定 SPI 的最佳截断值为 0.82（灵敏度=88.5%，特异性=57.9%；AUC=0.719，95%CI：0.612-0.864；P=0.003）。观察组 SPI≤0.82 有 19 例，对照组 SPI>0.82 有 80 例。观察组的 PJF 发生率（11/19）明显高于对照组（8/80）（P<0.001）；进一步的 logistic 回归分析显示，SPI≤0.82 与 PJF 的发生几率增加有关（比值比：12.375；95%CI：3.851-39.771）。观察组的无 PJF 生存时间明显缩短（P<0.001，log-rank 检验），多因素分析表明，SPI≤0.82（HR 6.626，95%CI：1.981-12.165）是 PJF 的显著相关因素。
对于接受长节段融合术的 ASD 患者，SPI 应大于 0.82。术后即刻 SPI 值≤0.82 的患者，PJF 发生率可能增加 12 倍。
