Objectives: 

To describe malreduction of supracondylar distal femur fractures stabilized with lateral femoral locking plates and determine whether a mismatch in axial lateral distal femur anatomy and lateral distal femoral plate design contributes to supracondylar distal femoral fracture malreduction.

Materials and Methods: 

OTA/AO 33A were simulated in 7 cadaver femurs and fixed with a lateral distal locking femoral plate placed flush to the lateral femoral condyle (group 1). In group 2, the anterior flange of the plate was externally rotated 10 degrees in relation to the lateral condyle. A motion capture system measured translation and rotation of the articular segment as shaft screws were applied, reducing plate to femoral diaphysis. Articular segment movement was compared between groups using paired Student t test, P < 0.05. A large database of 3D scans of 800 femurs was used to define the relationship of the lateral femoral condyle to the lateral cortical surface of the human femur.

Results: 

Malreduction was observed with anatomic plate application results from medial translation (17 mm) and external rotation (12.2 degrees) (group 1). Modifying plate geometry to match lateral femur anatomy (group 2) improved medial translation by 46% and external rotation by 80%. An analysis of the shape of the 800 distal femurs showed that the average posterior anterior inclination is 16.5 degrees.

Conclusions: 

Anatomic application of distal femoral plates results in significant malreduction. Modifying the plate design to accommodate 10 degrees slope of lateral distal femur results in partial correction of deformity. Future studies should investigate other means of correcting the malalignment, especially considering the 16.5-degree posterior anterior inclination of the condyle.

中文翻译：

---

股骨远端骨折的轴向和旋转复位不良（高尔夫球杆畸形）

目标： 

描述使用股骨远端锁定钢板固定的股骨远端髁上骨折复位不良，并确定股骨远端轴向外侧解剖结构和股骨远端外侧钢板设计的不匹配是否会导致股骨远端髁上骨折复位不良。

材料和方法： 

OTA/AO 33A 在 7 具尸体股骨中进行模拟，并用与股骨外侧髁齐平放置的外侧远端锁定股骨板固定（第 1 组）。在第 2 组中，钢板的前缘相对于外侧髁向外旋转 10 度。当应用轴螺钉时，运动捕捉系统测量关节段的平移和旋转，将钢板复位至股骨骨干。使用配对学生t检验比较各组之间的关节段运动， P < 0.05。使用包含 800 个股骨 3D 扫描的大型数据库来定义股骨外侧髁与人类股骨外侧皮质表面的关系。

结果： 

由于内侧平移（17 毫米）和外旋（12.2 度）（第 1 组），解剖钢板应用结果观察到复位不良。修改板的几何形状以匹配外侧股骨解剖结构（第 2 组）将内侧平移提高了 46%，将外侧旋转提高了 80%。对 800 根远端股骨的形状分析表明，平均后倾角为 16.5 度。

结论： 

远端股骨板的解剖应用导致显着的复位不良。修改板设计以适应外侧股骨远端 10 度的斜度导致畸形的部分矫正。未来的研究应该研究矫正排列不齐的其他方法，特别是考虑到髁突的 16.5 度后前倾角。