无移位型股骨颈骨折空间移位程度的三维重建研究

Three-dimensional reconstruction study of the displacement of undisplaced femoral neck fractures

目的对无移位型股骨颈骨折股骨头空间移位参数进行测量，从而重新认识无移位型股骨颈骨折。方法选取2010年1月至2011年6月80例无移位型股骨颈骨折患者，其中GardenⅠ型40例，GardenⅡ型40例。所有患者双侧股骨近端行CT薄层扫描并将原始数据导入相关软件进行三维重建，将健侧模型与骨折侧镜像模型相配准，在配准后的两个模型上进行关键点的标记并行三维测量，距离和角度的测量精度分别为0．01mm和0．01°。对两组患者股骨头空间移位参数分别采用独立样本t检验。结果80例患者在X线片上未发现股骨头旋转移位，通过三维重建显示30．0％（24／80）的患者（Ⅰ型18例、Ⅱ型6例）股骨头发生了旋转移位。10例骨折在X线片上表现为不完全骨折，三维重建模型显示仅3例为不完全骨折。GardenⅠ型患者平均股骨头空间移位角度18°±11°；平均股骨头中心移位距离（6±3）mm；平均股骨头凹最深点移位距离（10±6）mm。GardenⅡ型患者平均股骨头空间移位角度17°±10°；平均股骨头中心移位距离（7±5）mm；平均股骨头凹最深点移位距离（13±8）mm。GardenⅠ型骨折组与Ⅱ型骨折组之间股骨头空间移位角度、股骨头凹最深点移位距离、股骨头中心移位距离差异均无统计学意义（P〉0．05）。结论三维重建数字化测量技术能够更加准确、高效地显示及测量股骨颈骨折的真实空间移位程度，对股骨颈骨折的诊疗具有重要的临床意义。经典的股骨颈骨折Garden分型对于无移位型骨折的认识存在一定的不足，具有一定的局限性。

Objective To measure the displacement parameters of femoral head in space through three-dimensional reconstruction so as to reunderstand undisplaced femoral neck fractures. Methods The clinical data of 80 undisplaced femoral neck fractures from January 2010 to June 2011 were selected, included Garden Ⅰ 40 cases （ group Garden Ⅰ ） and Garden 11 40 cases （ group Garden Ⅱ）, bilateral proximal femurs of everyone were scanned by CT and reconstructed by professional software. Registered the normal femur and fracture with mirror model, marked key points in the model and measured the displacement parameters of femoral head. The measurement accuracy of distance and angle were 0. 01 mm and 0. 01°, respectively. The parameters of femoral head displacement between group Garden Ⅰ and Garden Ⅱwere analyzed by independent-sample t-test. Results Eighty cases on X-ray films were not found rotated displacement. But 24 cases of them （30. 0% ） showed rotated displacement and rotation direction of the femoral head through three-dimensional reconstruction. Ten cases showed incomplete fractures on X-ray films, but only 3 cases were incomplete fractures with three-dimensional reconstruction. In group Garden Ⅰ , the femoral head displacement angle was 18° -11°, the average displacement distance of femoral head center and deepest point of fovea capitis were （6 ±3） mm and （10 ±6） mm respectively. In group Garden Ⅱ , the femoral head displacement angle was 17° ± 10°, the average displacement distance of femoral head center and deepest point of fovea eapitis were （7 ± 5 ） mm and （13 ± 8 ） mm respectively. There were not statistical significance of the parameters of femoral head displacement between group Garden Ⅰ and Garden Ⅱ（P 〉 0.05 ） . Conclusions Three-dimensional reconstruction and digital measurement is a precise, efficient method for the measurement of femoral head displacement parameters in femoral neck fractures, has important clinical significance in the diagnosis and treatment of the femoral neck fractures. There are certain defects and limitations of the classical Garden classification for undisplaced femoral neck fractures.