Novais Eduardo N, Borden Timothy, Pauyo Thierry, Ferrer Mariana G, Miller Patricia, Daniel Maranho
Department of Orthopedic Surgery Boston Children's Hospital, Boston, MA, USA.
Department of Pediatric Orthopedics Memorial Hermann Hospital, Bellaire, TX, USA.
J Pediatr Soc North Am. 2025 May 23;12:100204. doi: 10.1016/j.jposna.2025.100204. eCollection 2025 Aug.
Managing the contralateral hip in patients with unilateral slipped capital femoral epiphysis (SCFE) involves balancing the risks of prophylactic pinning against the potential for a subsequent slip. This study aimed to evaluate the role of radiographic methods in predicting contralateral slips in patients with unilateral SCFE.
We assessed frog-leg radiographs from 312 patients with unilateral SCFE, measuring the Billings, Southwick, Posterior Sloping Angle (PSA), and tilt angles. Seventy patients (22%) experienced contralateral slips, with a median follow-up of 42 months (range, 18-70 months). Radiographs were evaluated independently by four raters at two separate time points. The radiographic parameters were compared between patients who developed contralateral slips and those who did not, and the diagnostic utility of each radiographic measure was assessed through receiver operating characteristic (ROC) curve analysis, with area under the ROC curve (AUC) values calculated for each method. Sensitivity, specificity, and predictive values were also determined using literature-based cutoffs for the angles (tilt angle >10°, Billings >12°, PSA >14°, Southwick >12°).
ROC analysis showed discriminatory ability for all measures, with AUCs ranging from 0.61 to 0.66. The Tilt angle had the highest overall accuracy (77%; 95% CI = 72-82%) and specificity (93%) but the lowest sensitivity (21%). The Billings angle was the most sensitive (83%; 95% CI = 72-92%). All methods displayed good negative predictive values (NPV) between 80 and 90% and excellent interrater (ICC = 0.92-0.99) and intrarater (ICC = 0.84-0.98) reliability.
Each radiographic method provides reliable predictive information regarding the risk of contralateral slip in unilateral SCFE. Surgeons who aim to minimize the risk of missing a contralateral slip should consider using the Billings angle with a cutoff of 12°, accepting that this may lead to some unnecessary pinning of hips that would not have slipped. Conversely, those who prioritize avoiding unnecessary surgery may prefer the tilt angle with a cutoff of 10°, understanding that this approach could result in missing some hips that will later develop a slip. These findings provide valuable guidance for decision-making regarding managing the contralateral hip in patients with unilateral SCFE.
1.Radiographic Predictive Measurements for Contralateral SCFE: The study evaluates the diagnostic utility of various radiographic angles (Epiphyseal Tilt, Billing's, Posterior Sloping, and Southwick angle) in predicting contralateral slips in unilateral SCFE cases, highlighting their sensitivity, specificity, and clinical implications.2.Interrater and Intrarater Reliability of radiographic measurements: The study demonstrates excellent interrater and intrarater reliability across all radiographic measurements, emphasizing the consistency and reproducibility of these methods for clinical use.3.Limitations of Current Predictive Radiographic Measurements: The study highlights the limitations of existing radiographic methods in achieving perfect predictive accuracy, advocating for future research to explore advanced imaging techniques like 3D MRI or CT to improve the identification of contralateral slip risk.4.Trade-Off Between Sensitivity and Specificity: The findings emphasize the critical trade-off between minimizing missed contralateral slips versus avoiding unnecessary prophylactic pinning.5.Clinical Decision-Making Guidance: By providing detailed accuracy and predictive values for each measurement, the study offers practical guidance for orthopaedic surgeon. Surgeons who aim to minimize the risk of missing a contralateral slip should consider using the Billings angle with a cutoff of 12°, accepting that this may lead to some unnecessary pinning of hips that would not have slipped. Conversely, those who prioritize avoiding unnecessary surgery may prefer the tilt angle with a cutoff of 10°, understanding that this approach could result in missing some hips that will later develop a slip.
Level III retrospective cohort study.
对于单侧股骨头骨骺滑脱（SCFE）患者，对侧髋关节的处理需要在预防性固定的风险与后续发生滑脱的可能性之间进行权衡。本研究旨在评估影像学方法在预测单侧SCFE患者对侧滑脱中的作用。
我们评估了312例单侧SCFE患者的蛙式位X线片，测量了比林斯角、索思威克角、后倾角度（PSA）和倾斜角。70例患者（22%）发生了对侧滑脱，中位随访时间为42个月（范围18 - 70个月）。四位评估者在两个不同时间点独立评估X线片。比较发生对侧滑脱和未发生对侧滑脱的患者的影像学参数，并通过受试者操作特征（ROC）曲线分析评估每种影像学测量方法的诊断效用，计算每种方法的ROC曲线下面积（AUC）值。还使用基于文献的角度临界值（倾斜角>10°、比林斯角>12°、PSA>14°、索思威克角>12°）确定敏感性、特异性和预测值。
ROC分析显示所有测量方法均具有鉴别能力，AUC范围为0.61至0.66。倾斜角总体准确性最高（77%；95%CI = 72 - 82%）和特异性最高（93%），但敏感性最低（21%）。比林斯角最敏感（83%；95%CI = 72 - 非必要手术的患者可能更喜欢临界值为10°的倾斜角，同时要明白这种方法可能会遗漏一些随后会发生滑脱的髋关节。这些发现为单侧SCFE患者对侧髋关节处理的决策提供了有价值的指导。
1.对侧SCFE的影像学预测测量：本研究评估了各种影像学角度（骨骺倾斜角、比林斯角、后倾角度和索思威克角）在预测单侧SCFE病例对侧滑脱中的诊断效用，突出了它们的敏感性、特异性和临床意义。2.影像学测量的评估者间和评估者内可靠性：本研究证明了所有影像学测量均具有出色的评估者间和评估者内可靠性，强调了这些方法在临床应用中的一致性和可重复性。3.当前预测性影像学测量的局限性：本研究突出了现有影像学方法在实现完美预测准确性方面的局限性，提倡未来研究探索如三维MRI或CT等先进成像技术以改善对侧滑脱风险的识别。4.敏感性和特异性之间的权衡：研究结果强调了在尽量减少漏诊对侧滑脱与避免不必要的预防性固定之间的关键权衡。5.临床决策指导：通过为每种测量提供详细的准确性和预测值，本研究为骨科医生提供了实用指导。旨在尽量减少漏诊对侧滑脱风险的外科医生应考虑使用临界值为12°的比林斯角，同时要接受这可能会导致对一些不会发生滑脱的髋关节进行一些不必要的固定。相反，那些优先考虑避免不必要手术的患者可能更喜欢临界值为10°的倾斜角，同时要明白这种方法可能会遗漏一些随后会发生滑脱的髋关节。
III级回顾性队列研究。 92%）。所有方法的阴性预测值（NPV）在80%至90%之间，评估者间（ICC = 0.92 - 0.99）和评估者内（ICC = 0.84 - 0.98）可靠性均极佳。
每种影像学方法都提供了关于单侧SCFE患者对侧滑脱风险的可靠预测信息。旨在将漏诊对侧滑脱风险降至最低的外科医生应考虑使用临界值为12°的比林斯角，同时要接受这可能会导致对一些不会发生滑脱的髋关节进行一些不必要的固定。相反，那些优先考虑避免
