Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL 60611, USA.
Am J Sports Med. 2012 Dec;40(12):2731-6. doi: 10.1177/0363546512461749. Epub 2012 Oct 17.
Since lateral tibial slope (LTS) affects the amount of anterior tibial translation and anterior cruciate ligament (ACL) strain during a dynamic maneuver, accurate measurements of LTS may be beneficial in screening people at a higher risk for ACL injury. Methods for measuring LTS on magnetic resonance imaging (MRI) scans of the proximal tibia include the midpoint and circle methods. No current studies have validated different LTS measurement methods using a proximal tibia MRI scan.
We tested the null hypotheses that (1) LTS measurements were independent of the length of tibia imaged using the midpoint method, and (2) LTS measurements calculated from different methods (midpoint, circle, and full tibia) would not differ significantly.
Controlled laboratory study.
Blinded observers measured LTS from 3-tesla, 3-dimensional MRIs from 40 size-matched donors according to 1 circle method and 3 midpoint methods. Outcomes were then compared with the full-tibial anatomic axis (line connecting the center of 2 circles fit within the proximal and distal tibia) in 11 donors. Bonferroni-corrected paired t tests (significance, P < .005) were used to compare the 5 methods.
The circle and full-tibia methods had the lowest interobserver and intraobserver variability, whereas the midpoint method with 10-cm tibia was the most variable. The midpoint method with 10-cm and 15-cm proximal tibia closely resembled LTS measurements with the full-tibial anatomic axis. The circle method, although repeatable, provided smaller numerical LTS measurements than the full-tibia and midpoint methods.
Although LTS measurements using the midpoint method can resemble measurements made using the full tibia, the reliability of the midpoint method depends on the length of proximal tibia used. The circle method may be the preferred method for future studies since it was the most repeatable method and is independent of proximal tibial length.
LTS measurements vary depending on the method used.
由于胫骨外侧倾斜度（LTS）会影响动态运动中胫骨前移位量和前交叉韧带（ACL）的应变，因此准确测量 LTS 可能有助于筛选 ACL 损伤风险较高的人群。在胫骨近端磁共振成像（MRI）扫描上测量 LTS 的方法包括中点法和圆法。目前尚无研究使用胫骨近端 MRI 扫描验证不同 LTS 测量方法的准确性。
我们测试了以下两个零假设：（1）使用中点法测量的 LTS 与成像胫骨的长度无关；（2）根据不同方法（中点法、圆法和全胫骨法）计算得出的 LTS 测量值之间不会有显著差异。
对照实验室研究。
40 名匹配身高的供体在 3T 磁共振上进行 3 维扫描，由 2 名观察者分别使用 1 种圆法和 3 种中点法进行 LTS 测量。在另外 11 名供体中，使用 LTS 与全胫骨解剖轴（连接胫骨近端和远端内圈中心的线）进行比较，以评估结果。使用 Bonferroni 校正配对 t 检验（显著性 P<.005）对 5 种方法进行比较。
圆法和全胫骨法的观察者间和观察者内变异性最小，而胫骨 10cm 长的中点法变异性最大。胫骨 10cm 和 15cm 长的中点法与全胫骨解剖轴的 LTS 测量值非常相似。圆法虽然具有可重复性，但提供的 LTS 数值比全胫骨法和中点法小。
尽管使用中点法测量的 LTS 可以与全胫骨法相似，但中点法的可靠性取决于使用的胫骨近端长度。圆法可能是未来研究的首选方法，因为它是最具重复性的方法，且与胫骨近端长度无关。
LTS 测量值因使用的方法而异。
