Nationwide Children's Hospital, Columbus, OH.
Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO.
J Pediatr Orthop. 2022;42(10):539-544. doi: 10.1097/BPO.0000000000002243. Epub 2022 Aug 29.
After treatment with in situ stabilization, slipped capital femoral epiphysis (SCFE) patients have variable degrees of deformity that can contribute to femoroacetabular impingement (FAI). To evaluate the severity of residual deformity most physicians currently use biplanar radiographs of an anteroposterior pelvis which profiles the lateral head-neck deformity and a frog lateral view which profiles the anterior head-neck deformity. However, the assessment of FAI morphology commonly relies on the 45-degree Dunn view to profile the anterolateral head-neck junction where FAI deformity is maximal. Therefore, the purpose of this study was to compare the magnitude of residual SCFE deformity detected on the frog lateral radiograph to the 45-degree Dunn radiograph.
A retrospective review of radiographic images of 50 hips (47 patients) diagnosed with SCFE at a single academic institution from 2014 to 2018 was performed. The group included 25 hips evaluated postoperatively after fixation (Group 1) and 25 hips presenting with residual symptomatic SCFE deformity after previous pinning (Group 2). The alpha angle was assessed on both the 45-degree Dunn and frog lateral views for comparison. The modified Southwick slip angle was assessed on the frog lateral view only as a measure of SCFE severity.
The Dunn view showed the maximal residual SCFE deformity as measured by the alpha angle in 88% (44/50) of cases. Overall, the mean alpha angle (70.7 degree vs. 60.1 degree, P <0.001) was significantly larger on the Dunn view as compared with frog lateral. Subgroup analysis showed a larger alpha angle on Dunn view compared with frog lateral in both immediate postoperative and residual SCFE deformities as well: Group 1 (69.5 degree vs. 60.9 degree, P <0.001) and Group 2 (71.9 degree vs. 59.3 degree, P <0.001).
In patients with SCFE, the maximal residual deformity of the proximal femur can typically be seen on the 45-degree Dunn view, rather than on the frog lateral view. Our findings suggest the 45-degree Dunn view may be beneficial part of the postoperative assessment of SCFEs to quantify the true maximal deformity present.
Level IV.
经过原位稳定治疗后，股骨头骨骺滑脱（SCFE）患者会出现不同程度的畸形，这些畸形可能导致股骨髋臼撞击（FAI）。为了评估残余畸形的严重程度，目前大多数医生都使用骨盆前后位的双平面 X 光片来评估侧头-颈畸形，以及蛙式侧位 X 光片来评估前头-颈畸形。然而，FAI 形态的评估通常依赖于 45 度 Dunn 位 X 光片来评估前侧头-颈交界处的最大 FAI 畸形。因此，本研究的目的是比较蛙式侧位 X 光片上检测到的残余 SCFE 畸形的严重程度与 45 度 Dunn 位 X 光片的结果。
对 2014 年至 2018 年在一家学术机构诊断为 SCFE 的 50 髋（47 例）的影像学图像进行回顾性研究。该组包括 25 例术后接受固定治疗（第 1 组）和 25 例因先前钢针固定出现残余症状性 SCFE 畸形（第 2 组）的患者。评估了两组患者的 45 度 Dunn 位和蛙式侧位 X 光片上的 alpha 角，进行比较。仅在蛙式侧位 X 光片上评估改良 Southwick 滑脱角，作为 SCFE 严重程度的衡量标准。
在 50 例病例中，Dunn 位 X 光片显示 88%（44/50）的病例存在最大的残余 SCFE 畸形，通过 alpha 角测量。总体而言，与蛙式侧位 X 光片相比，Dunn 位 X 光片上的平均 alpha 角（70.7 度 vs. 60.1 度，P <0.001）明显更大。亚组分析显示，无论是在术后即刻还是在残余 SCFE 畸形中，Dunn 位 X 光片上的 alpha 角都明显大于蛙式侧位 X 光片：第 1 组（69.5 度 vs. 60.9 度，P <0.001）和第 2 组（71.9 度 vs. 59.3 度，P <0.001）。
在 SCFE 患者中，近端股骨的最大残余畸形通常可以在 45 度 Dunn 位 X 光片上看到，而不是在蛙式侧位 X 光片上看到。我们的发现表明，45 度 Dunn 位 X 光片可能是评估 SCFE 术后评估的有益部分，可以量化存在的真实最大畸形。
IV 级。
