Department of Orthopaedic Surgery, St. Luke's University Health Network, Bethlehem, PA.
Department of Orthopedic Surgery, University of Texas Houston McGovern School of Medicine, Houston.
J Pediatr Orthop. 2024 Feb 1;44(2):94-98. doi: 10.1097/BPO.0000000000002530. Epub 2023 Oct 2.
Triplane fractures are rare enough that large homogeneous series to support management decisions are lacking. During initial evaluation, the addition of computed tomography (CT) to conventional X-rays (XR) does not always alter the patient's clinical course. Therefore, routine use of CT is controversial. This study aims to: (1) clarify quantitative relationships between articular displacement measured on XR versus CT and (2) identify whether metaphyseal displacement on the lateral XR predicts clinically relevant articular displacement on a CT scan.
A 10-year retrospective review of consecutive triplane fractures was performed at a level 1 pediatric trauma center. Maximum articular and metaphyseal displacement were recorded from XR and CT. Quantitative relationships between XR and CT measurements were compared among imaging modalities and radiographically operative versus nonoperative fractures.
Eighty-seven patients met the inclusion criteria. XR underestimated articular displacement by 229% in the sagittal plane (1 mm on XR vs 3.3 mm on CT; P < 0.05) and 17% in the coronal plane (2.3 mm on XR vs 2.7 mm on CT; P < 0.05). XR underestimated articular step-off by 184% in the coronal plane and 177% in the sagittal plane ( P < 0.05). CT measurements more often differentiated patients who did or did not undergo surgery at our institution. Metaphyseal displacement was significantly higher in patients with traditionally operative articular displacement (≥2.5 mm on CT) versus those with articular displacement below traditionally operative thresholds (2.4 vs 0.9 mm, P = 0.001). Sixty patients had metaphyseal displacement >1 mm on the lateral XR, of whom 56 had surgical-magnitude articular displacement (≥2.5 mm) on CT (positive predictive value = 94%).
Conventional radiographs underestimate the true articular displacement of triplane fractures. Surgical-magnitude articular step-off is rare, and the largest articular gap is usually visualized on the axial CT image. Metaphyseal displacement >1 mm, which is easily measured on a lateral XR, is strongly predictive of clinically relevant articular displacement on CT. This radiographic finding should prompt advanced imaging before proceeding with nonoperative management.
Level III.
三平面骨折较为罕见，缺乏支持管理决策的大型同质系列研究。在初始评估中，将计算机断层扫描（CT）与常规 X 射线（XR）相结合并不总是改变患者的临床病程。因此，常规使用 CT 存在争议。本研究旨在：（1）阐明 XR 与 CT 测量的关节移位之间的定量关系；（2）确定外侧 XR 上的干骺端移位是否可预测 CT 扫描上的临床相关关节移位。
在一家 1 级儿科创伤中心进行了一项连续三平面骨折的 10 年回顾性研究。从 XR 和 CT 中记录最大关节和干骺端移位。比较了不同影像学方法和影像学手术与非手术骨折之间 XR 和 CT 测量值之间的定量关系。
87 名患者符合纳入标准。XR 在矢状面低估了 229%的关节移位（XR 上为 1mm，CT 上为 3.3mm；P<0.05），在冠状面低估了 17%的关节移位（XR 上为 2.3mm，CT 上为 2.7mm；P<0.05）。XR 在冠状面和矢状面分别低估了 184%和 177%的关节台阶（P<0.05）。CT 测量值更能区分我院手术和非手术患者。传统手术关节移位（CT 上≥2.5mm）患者的干骺端移位明显高于传统手术阈值以下的患者（2.4mm 比 0.9mm，P=0.001）。60 名患者的侧位 XR 上有>1mm 的干骺端移位，其中 56 名患者的 CT 上有手术相关的关节移位（≥2.5mm）（阳性预测值=94%）。
常规 X 线片低估了三平面骨折的真实关节移位。手术相关的关节台阶很少见，最大的关节间隙通常在轴向 CT 图像上可见。侧位 XR 上易于测量的>1mm 干骺端移位与 CT 上的临床相关关节移位有很强的相关性。这种影像学发现应促使在进行非手术治疗之前进行高级影像学检查。
III 级。
