Department of Adult Joint Reconstruction, Beijing Jishuitan Hospital, Capital Medical University, Fourth Clinical College of Peking University, Beijing, China.
Bone Joint J. 2024 Jan 1;106-B(1):19-27. doi: 10.1302/0301-620X.106B1.BJJ-2023-0640.R1.
The aim of this study was to evaluate the reliability and validity of a patient-specific algorithm which we developed for predicting changes in sagittal pelvic tilt after total hip arthroplasty (THA).
This retrospective study included 143 patients who underwent 171 THAs between April 2019 and October 2020 and had full-body lateral radiographs preoperatively and at one year postoperatively. We measured the pelvic incidence (PI), the sagittal vertical axis (SVA), pelvic tilt, sacral slope (SS), lumbar lordosis (LL), and thoracic kyphosis to classify patients into types A, B1, B2, B3, and C. The change of pelvic tilt was predicted according to the normal range of SVA (0 mm to 50 mm) for types A, B1, B2, and B3, and based on the absolute value of one-third of the PI-LL mismatch for type C patients. The reliability of the classification of the patients and the prediction of the change of pelvic tilt were assessed using kappa values and intraclass correlation coefficients (ICCs), respectively. Validity was assessed using the overall mean error and mean absolute error (MAE) for the prediction of the change of pelvic tilt.
The kappa values were 0.927 (95% confidence interval (CI) 0.861 to 0.992) and 0.945 (95% CI 0.903 to 0.988) for the inter- and intraobserver reliabilities, respectively, and the ICCs ranged from 0.919 to 0.997. The overall mean error and MAE for the prediction of the change of pelvic tilt were -0.3° (SD 3.6°) and 2.8° (SD 2.4°), respectively. The overall absolute change of pelvic tilt was 5.0° (SD 4.1°). Pre- and postoperative values and changes in pelvic tilt, SVA, SS, and LL varied significantly among the five types of patient.
We found that the proposed algorithm was reliable and valid for predicting the standing pelvic tilt after THA.
本研究旨在评估我们开发的一种用于预测全髋关节置换术后矢状位骨盆倾斜变化的患者特异性算法的可靠性和有效性。
本回顾性研究纳入了 2019 年 4 月至 2020 年 10 月期间接受 171 例全髋关节置换术的 143 例患者，所有患者术前和术后 1 年均接受了全身体位侧位 X 线片检查。我们测量骨盆入射角（PI）、矢状垂直轴（SVA）、骨盆倾斜度、骶骨倾斜度（SS）、腰椎前凸角（LL）和胸椎后凸角，将患者分为 A、B1、B2、B3 和 C 型。根据 A、B1、B2 和 B3 型 SVA 的正常范围（0 毫米至 50 毫米）以及 C 型患者 PI-LL 差值绝对值的三分之一预测骨盆倾斜的变化。使用 Kappa 值和组内相关系数（ICC）分别评估患者分类和骨盆倾斜变化预测的可靠性。使用预测骨盆倾斜变化的总平均误差和平均绝对误差（MAE）评估有效性。
观察者间和观察者内可靠性的 Kappa 值分别为 0.927（95%置信区间 0.861 至 0.992）和 0.945（95%置信区间 0.903 至 0.988），ICC 范围为 0.919 至 0.997。预测骨盆倾斜变化的总平均误差和 MAE 分别为-0.3°（SD 3.6°）和 2.8°（SD 2.4°）。骨盆倾斜的总绝对变化为 5.0°（SD 4.1°）。五种类型患者的骨盆倾斜、SVA、SS 和 LL 的术前和术后值以及变化均有显著差异。
我们发现，所提出的算法可靠且有效，可用于预测全髋关节置换术后的站立骨盆倾斜。
