Background:Increased tibial slope has been shown to lead to higher rates of anterior cruciate ligament graft failure. A slope-decreasing osteotomy can reduce in situ anterior cruciate ligament force and may mitigate this risk. However, how this procedure may affect the length change behavior of the medial ligamentous structures is unknown.Purpose/Hypothesis:The purpose of this study was to examine the effect of anterior slope–modifying osteotomies on the medial ligamentous structures. It was hypothesized that (1) decreasing the tibial slope would lead to shortening of the superficial medial collateral ligament (sMCL), (2) while the fibers of the posterior oblique ligament (POL) would be unaffected.Study Design:Descriptive laboratory study.Methods:Eight fresh-frozen cadaveric knee specimens underwent anatomic dissection to precisely identify the medial ligamentous structures. The knees were mounted in a custom-made kinematics rig with the quadriceps muscle and iliotibial tract loaded. An anterior slope–modifying osteotomy was performed and fixed using an external fixator, which allowed modification of the wedge height between −15 and +10 mm in 5-mm increments. Threads were mounted between pins positioned at the anterior, middle, and posterior parts of the tibial and femoral attachments of the sMCL and POL. For different tibial slope modifications, length changes between the tibiofemoral pin combinations were recorded using a rotary encoder as the knee was flexed between 0° and 120°.Results:All sMCL fiber regions shortened with slope reduction ( P < .001) and lengthened with slope increase ( P < .001), with the anterior sMCL fibers more affected than the posterior sMCL fibers. A 15-mm anterior closing-wedge high tibial osteotomy (ACWHTO) resulted in a 6.9% ± 3.0% decrease in the length of the anterior sMCL fibers compared with a 3.6% ± 2.3% decrease for the posterior sMCL fibers. A 10-mm anterior opening-wedge high tibial osteotomy (AOWHTO) increased anterior sMCL fiber length by 5.9% ± 2.3% and posterior sMCL fiber length by 1.6% ± 1.0%. The POL fibers were not significantly affected by a slope-modifying osteotomy.Conclusion:Tibial slope–modifying osteotomies changed the length change pattern of the sMCL such that an AOWHTO increased whereas an ACWHTO decreased the sMCL strain. This effect was most pronounced for the anterior fibers of the sMCL. The length change pattern of the POL remained unaffected by slope-modifying osteotomy.Clinical Relevance:Surgeons should be aware that anterior tibial slope–modifying osteotomies affect the biomechanics of the sMCL. After an extensive ACWHTO, patients may develop a medial or anteromedial instability, while an AOWHTO may overconstrain the medial compartment.

中文翻译：

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前坡改良截骨术改变浅表内侧副韧带的长度变化行为：一项生物力学研究


背景： 胫骨斜率增加已被证明会导致前交叉韧带移植失败的发生率更高。减小斜率的截骨术可以减少原位前交叉韧带力，并可能减轻这种风险。然而，该程序如何影响内侧韧带结构的长度变化行为尚不清楚。目的/假设： 本研究的目的是检查前斜面修饰截骨术对内侧韧带结构的影响。据推测，（1） 降低胫骨斜率会导致浅表内侧副韧带 （sMCL） 缩短，（2） 而后斜韧带 （POL） 的纤维不受影响。研究设计： 描述性实验室研究。方法： 对 8 例新鲜冰冻尸体膝关节标本进行解剖学解剖，以精确识别内侧韧带结构。膝盖安装在定制的运动学装置中，加载股四头肌和髂胫束。进行前斜面改良截骨术并使用外固定器固定，允许以 5 mm 的增量将楔形高度修改在 -15 至 +10 mm 之间。螺纹安装在位于 sMCL 和 POL 的胫骨和股骨附件的前、中和后部的销钉之间。对于不同的胫骨斜率修改，当膝关节在 0° 和 120° 之间弯曲时，使用旋转编码器记录胫股针组合之间的长度变化。结果： 所有 sMCL 纤维区域均随斜率减小而缩短 （ P < .001） 和随斜率增加而延长 （ P < .001），其中前部 sMCL 纤维比后部 sMCL 纤维受影响更大。15 mm 前闭合楔形高位胫骨截骨术 （ACWHTO） 导致 6.9% ± 3。前部 sMCL 纤维的长度减少 0%，而后部 sMCL 纤维减少 3.6% ± 2.3%。10 mm 前开口楔形高位胫骨截骨术 （AOWHTO） 使前 sMCL 纤维长度增加 5.9% ± 2.3%，后 sMCL 纤维长度增加 1.6% ± 1.0%。POL 纤维不受斜率改变截骨术的显着影响。结论： 胫骨斜率改良截骨术改变了 sMCL 的长度变化模式，使得 AOWHTO 增加，而 ACWHTO 降低 sMCL 应变。这种影响对于 sMCL 的前纤维最为明显。POL 的长度变化模式不受斜率修改截骨术的影响。临床相关性： 外科医生应该意识到胫骨前斜面改变截骨术会影响 sMCL 的生物力学。在广泛的 ACWHTO 后，患者可能会出现内侧或前内侧不稳定，而 AOWHTO 可能会过度约束内侧隔室。