Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University.
Department of Pediatric Orthopaedics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou.
J Pediatr Orthop. 2022 Mar 1;42(3):149-157. doi: 10.1097/BPO.0000000000002018.
The correlation between the number, size, and location of cannulated screws and the incidence of avascular necrosis (AVN) in children with femoral neck fractures treated surgically is uncertain.
We retrospectively reviewed 153 children (mean age: 10.6±3.7 y) with femoral neck fractures treated by internal fixation with 2 (n=112) or 3 (n=41) cannulated screws. The severity of initial displacement was divided into incomplete (type I) and complete (type II, angulation <50 degrees; type III, angulation >50 degrees) fractures. The diameter of the screw was measured and recorded as a percentage of the femoral neck width. The distance (D) between the mid-point of each screw at the base (B) of the femoral neck and at the tip (T) of each screw and the superior and anterior cortices of the femoral neck, respectively, were measured on anteroposterior (AP) and lateral (L) radiographs. Values were expressed as the ratio between the measured distance and the width of the femoral neck (BDAP%, TDAP%, BDL%, and TDL%). The correlation between the number, size, and location of the screws and AVN was analyzed.
Patients with type II of initial displacement treated with 2 cannulated screws had a lower AVN rate (21.4%) than those treated with 3 screws (44.8%) (P=0.027). Screw diameter (19%) in patients with AVN was larger than (17%) in patients without AVN (P<0.001); patients with AVN had a lower BDAP% (48.6%) than those without AVN (56.4%) (P<0.001). Screw size and BDAP% were risk factors for AVN (P<0.05). Further, screw diameter >16.5% and BDAP% <51.6% of the femoral neck width were the cutoff values for an increased AVN rate (P<0.05).
Patients treated with 2 cannulated screws showed a lower rate of AVN than patients treated with 3 screws. Screws of larger size and screws closer to the piriformis fossa on AP radiographs increased the risk of AVN in children with femoral neck fractures treated surgically.
Level III.
经手术治疗的儿童股骨颈骨折患者，其空心螺钉的数量、大小和位置与骨坏死（AVN）的发生率之间的相关性尚不确定。
我们回顾性分析了 153 例儿童（平均年龄：10.6±3.7 岁）股骨颈骨折病例，这些患儿均采用 2 枚（n=112）或 3 枚（n=41）空心螺钉进行内固定治疗。初始移位的严重程度分为不完全（I 型）和完全（II 型，角度<50 度；III 型，角度>50 度）骨折。测量并记录螺钉的直径，以占股骨颈宽度的百分比表示。在前后位（AP）和侧位（L）X 线片上，测量股骨颈底部（B）和顶部（T）每个螺钉中点到股骨颈上、前皮质的距离（D），分别表示为测量距离与股骨颈宽度的比值（BDAP%、TDAP%、BDL%和 TDL%）。分析螺钉的数量、大小和位置与 AVN 的相关性。
初始移位为 II 型的患者采用 2 枚空心螺钉治疗的 AVN 发生率（21.4%）低于采用 3 枚螺钉治疗的患者（44.8%）（P=0.027）。发生 AVN 的患者的螺钉直径（19%）大于未发生 AVN 的患者（17%）（P<0.001）；发生 AVN 的患者的 BDAP%（48.6%）低于未发生 AVN 的患者（56.4%）（P<0.001）。螺钉大小和 BDAP%是 AVN 的危险因素（P<0.05）。进一步分析显示，螺钉直径>16.5%和 BDAP%<51.6%的股骨颈宽度为 AVN 发生率增加的截断值（P<0.05）。
与采用 3 枚空心螺钉治疗的患者相比，采用 2 枚空心螺钉治疗的患者 AVN 发生率更低。在接受手术治疗的股骨颈骨折患儿中，螺钉尺寸较大和 AP 位上更靠近梨状窝的螺钉会增加 AVN 的风险。
III 级。
