Orthopedic University Hospital Friedrichsheim gGmbH, Movement Analysis Laboratory, Frankfurt, Main, Germany.
Orthopedic University Hospital Friedrichsheim gGmbH, Movement Analysis Laboratory, Frankfurt, Main, Germany.
Gait Posture. 2020 May;78:80-88. doi: 10.1016/j.gaitpost.2020.03.012. Epub 2020 Apr 6.
Lower limb malalignment in the frontal plane is one of the major causes of developing knee osteoarthritis. Growing children can be treated by temporary hemiepiphysiodesis when diagnosed with lower limb malalignment.
Is there a difference between medial or lateral knee contact force (KCF) before (PRE) and after (POST) hemiepiphysiodesis in patients with valgus malalignment and compared to a typically developed control group (TD)? Does a linear relationship exist between the static radiographic mechanical axis angle and dynamic medial/lateral KCF?
In this prospective study, an OpenSim full body model with an adapted knee joint was used to calculate KCFs in the stance phase of 16 children with diagnosed genu valgum and 16 age- and sex-matched TDs. SPM was applied to compare KCFs before and after guided growth and to test a linear relationship between the mechanical axis angle and KCFs.
After the intervention, POST revealed a significantly increased medial KCF (p < 0.001, 4-97 % of stance) and decreased lateral KCF (p < 0.001, 6-98 %) compared to PRE. Comparing POST with TD, short phases with a significant difference were found (medial: p = 0.039, 84-88 %; lateral: p = 0.019, 3-11 %). The static mechanical axis angle showed a longer phase of a significant relation to KCFs for POST compared to PRE.
This study showed that temporary hemiepiphysiodesis in patients with valgus malalignment reduces the loading in the lateral compartment of the knee and thus the risk of developing osteoarthritis in this compartment. The determination of dynamic KCFs can be clinically relevant for the treatment of lower limb malalignment, especially for decision making before surgery, when compensatory mechanisms may play an important role. Additionally, the static radiographic mechanical axis angle does not necessarily represent the dynamic loading of the lateral knee compartment.
下肢在额状面的对线不良是导致膝关节骨关节炎发展的主要原因之一。当诊断出下肢对线不良时，生长发育期的儿童可以通过暂时的骺骺截骨术进行治疗。
在膝外翻患者中，与典型发育对照组（TD）相比，骺骺截骨术前后（PRE 和 POST），膝关节内侧和外侧接触力（KCF）是否存在差异？静态放射学机械轴角度与动态内侧/外侧 KCF 是否存在线性关系？
在这项前瞻性研究中，使用 OpenSim 全身模型和改良的膝关节来计算 16 例诊断为膝内翻和 16 例年龄和性别匹配的 TD 患者在站立相的 KCF。应用 SPM 比较引导生长前后的 KCF，并测试机械轴角度与 KCF 之间的线性关系。
干预后，POST 与 PRE 相比，内侧 KCF 显著增加（p < 0.001，占站立相的 4-97%），外侧 KCF 显著减少（p < 0.001，占站立相的 6-98%）。与 TD 相比，POST 显示出较短的相位有显著差异（内侧：p = 0.039，84-88%；外侧：p = 0.019，3-11%）。与 PRE 相比，静态机械轴角度在 POST 时与 KCF 有更长的相位相关。
本研究表明，骺骺截骨术可减少膝外翻患者膝关节外侧间室的负荷，从而降低该间室发生骨关节炎的风险。动态 KCF 的测定对于下肢对线不良的治疗具有临床相关性，尤其是在手术前，此时代偿机制可能发挥重要作用。此外，静态放射学机械轴角度不一定代表外侧膝关节间室的动态负荷。
