The Hospital of University of Abant Izzet Baysal, Department of Orthopaedics and Traumatology, 14280 Bolu, Turkey.
Orthop Traumatol Surg Res. 2010 Feb;96(1):21-7. doi: 10.1016/j.rcot.2009.11.004.
Tip-apex distance greater than 25 mm is accepted as a strong predictor of screw cut-out in patients with intertrochanteric femoral fracture treated by dynamic hip screw. The aim of this retrospective study was to evaluate the position of the screw in the femoral head and its effect on cut-out failure especially in patients with inconvenient tip-apex distance.
Sixty-five patients (42 males, 23 females; mean age of 57.6 years) operated by dynamic hip screw for intertrochanteric femoral fractures were divided in two groups taking into consideration the tip-apex distance less (group A; 14 patients) or more (group B; 51 patients) than 25 mm. Patient's age and gender, follow-up period, fracture type, degree of osteoporosis, reduction quality of the fracture, position of the screw in the femoral head, number of patients with cut-out failure and Harris hip score were compared.
The average follow-up time was 41.7 months. The mean tip-apex distance was 17.14 mm in group A and 36.67 mm in group B. One (7.1%) patient in group A and three (5.8%) patients in group B had screw cut-out. Except the screw position, no statistical differences were observed between the two groups with regards to study data. The screw was placed in femoral head more inferiorly (p=0.045) on frontal and more posteriorly (p=0.013) on sagital planes in group B, while central placement of the screw was present in group A. The common characteristics of three patients with screw cut-out in group B was the position of the screw which was located in femoral head more superiorly and anteriorly after an acceptable fracture reduction.
Peripheral placement of the screw in femoral head increases tip-apex distance. However posterior and inferior locations may help to support posteromedial cortex and calcar femoral in unstable intertrochanteric fractures and reduce the risk of cut-out failure.
IV, retrospective series.
在接受动力髋螺钉治疗的股骨转子间骨折患者中，尖顶距大于 25mm 被认为是螺钉切出的强预测因子。本回顾性研究的目的是评估螺钉在股骨头中的位置及其对切出失败的影响，特别是在尖顶距不方便的患者中。
将 65 例（男性 42 例，女性 23 例；平均年龄 57.6 岁）接受动力髋螺钉治疗的股骨转子间骨折患者分为两组，考虑尖顶距小于（A 组，14 例）或大于（B 组，51 例）25mm。比较患者年龄、性别、随访时间、骨折类型、骨质疏松程度、骨折复位质量、螺钉在股骨头中的位置、切出失败患者数和 Harris 髋关节评分。
平均随访时间为 41.7 个月。A 组尖顶距平均为 17.14mm，B 组为 36.67mm。A 组 1 例（7.1%）患者和 B 组 3 例（5.8%）患者出现螺钉切出。除螺钉位置外，两组间研究数据无统计学差异。B 组螺钉在冠状面上更靠后（p=0.045），在矢状面上更靠下（p=0.013），而 A 组螺钉则位于中心。B 组 3 例螺钉切出患者的共同特点是在可接受的骨折复位后，螺钉位于股骨头更靠上和更靠前的位置。
螺钉在股骨头中的偏置会增加尖顶距。然而，在后下方的位置可能有助于支撑股骨转子间不稳定骨折的后内侧皮质和股骨距，降低切出失败的风险。
IV，回顾性系列研究。
