Labronici P J, Pires R E, Franco M V, Freitas R, Araújo G C, Pires E Albuquerque R S, Gameiro V S, Jeray K
Department of Orthopedic Surgery and Traumatology - Federal Fluminense University, Niterói, Brazil.
Department of Orthopaedic Surgery and Traumatology - Hospital Santa Teresa, Petrópolis, Rio de Janeiro, Brazil.
Ann Med Health Sci Res. 2016 Sep-Oct;6(5):308-310. doi: 10.4103/amhsr.amhsr_41_16.
Medial malleolar fractures are frequent, and their treatment is familiar to the orthopedic surgeon. Lag screw fixation using partially threaded screws remains the standard treatment method for medial malleolar fractures. However, the literature lacks a defined method for selecting lag screw length, relying more so on the empiric choice of the surgeon.
The aim of this study is to help define the ideal lag screw length for medial melleolar fracture fixation.
One hundred and sixteen anatomic specimens were included in the study. A transverse cut was performed in the distal third of the tibia, roughly 1 and a half times the distal tibial plafond width from the ankle joint. A coronal cut was then performed using the center of the medial malleolus. Three observers measured the distance between the medial malleolus tip and beginning of the medullary canal in all anatomic specimens. Differences in measurements were statistically compared, level of ( ≤ 0.05). Interclass correlation coefficient (ICC) significance level was set at < 0.05.
Measurement average was 55 mm between the medial malleolus tip and the medullary canal, with a standard deviation of 10 mm. High concordance (ICC: 0.819) was achieved among all pairs of observers ( < 0.01). The systematic difference among measurements was absent, and random distribution around general measurements was observed.
The authors recommend a screw length of no more than 45 mm to optimize the location of the screw threads in the best cancellous bone in an effort to obtain the most compression.
内踝骨折很常见，骨科医生对其治疗方法较为熟悉。使用部分螺纹螺钉进行拉力螺钉固定仍然是内踝骨折的标准治疗方法。然而，文献中缺乏选择拉力螺钉长度的明确方法，更多地依赖于外科医生的经验选择。
本研究的目的是帮助确定内踝骨折固定的理想拉力螺钉长度。
本研究纳入了116个解剖标本。在胫骨远端三分之一处进行横向切割，距踝关节约为胫骨远端关节面宽度的1.5倍。然后以内踝中心为中心进行冠状切割。三名观察者测量了所有解剖标本中内踝尖与髓腔起始处之间的距离。对测量差异进行统计学比较，显著性水平为（≤0.05）。组内相关系数（ICC）显著性水平设定为<0.05。
内踝尖与髓腔之间的平均测量值为55mm，标准差为10mm。所有观察者对之间均达到了高度一致性（ICC：0.819）（<0.01）。测量之间不存在系统差异，观察到围绕总体测量值的随机分布。
作者建议螺钉长度不超过45mm，以优化螺钉螺纹在最佳松质骨中的位置，从而获得最大的压缩力。
