CNRS, institut des sciences du mouvement Étienne-Jules Marey, UMR 7287, Aix-Marseille université, 163, avenue de Luminy, 13009 Marseille, France; Institut du membre inférieur et de l'appareil locomoteur, APHM, hôpital Sainte-Marguerite, 270, boulevard de Sainte-Marguerite, 13009 Marseille, France; Newclip Technics, PA de la Lande Saint-Martin, 45, rue des Garottières, 44115 Haute-Goulaine, France.
Département de chirurgie orthopédique du membre inférieur, CHU de Montpellier, hôpital Lapeyronie, 371 avenue du Doyen Gaston-Giraud, 39295 Montpellier cedex 05, France; Laboratoire de mécanique et génie civil (LMGC), université de Montpellier, 860, rue de Saint-Priest, 34090 Montpellier, France.
Orthop Traumatol Surg Res. 2023 Sep;109(5):103482. doi: 10.1016/j.otsr.2022.103482. Epub 2022 Nov 23.
Existence of a relationship between knee and hindfoot alignments is commonly accepted, but not clearly proven. While studied in the coronal plane using 2D imaging, axial alignment has not been studied yet, likely requiring 3D measurements. We aimed to investigate how knee and hindfoot rotational alignments are related using 3D biometrics and modern 3D weight-bearing technologies.
Hindfoot alignment is correlated with femoral and tibial torsions.
All patients who underwent both weight-bearing CT (WBCT) and low dose biplanar radiographs (LDBR) were selected in this retrospective observational study, resulting in a cohort of 157 lower limbs from 99 patients. Patients' pathologies were stratified in subgroups and those with a history of trauma or surgery affecting lower limb alignment were excluded. Foot Ankle Offset was calculated from WBCT; femoral and tibial torsions and coronal alignment were calculated from LDBR, respectively.
Overall, mean Foot Ankle Offset was 1.56% (SD 7.4), mean femoral anteversion was 15.6° (SD 9.5), and mean external tibial torsion was 32.6° (SD 7.6). Moderate negative correlation between Tibial Torsion and Foot Ankle Offset was found in the whole series (rho=-0.23, p=0.003) and for non-pathologic patients (rho=-0.27, p=0.01). Linear models to estimate Tibial Torsion with Foot Ankle Offset and conversely were found, with a low adjusted R (3%<R<7%). No relationship was found between FAO and femoral torsion.
External tibial rotation was associated with varus hindfoot configuration in the group without pathologies, suggesting that compensatory mechanisms may occur between knee and hindfoot alignments. In pathological cases, however, the same relationship wasn't found, raising concerns about compensatory failure in spite of the numbers available. We didn't find similar correlations with the femur possibly because the hip has a degree of liberty in the axial plane.
III, retrospective comparative study.
膝关节和后足对线之间存在关系已被普遍接受，但尚未得到明确证实。虽然已经在冠状面使用二维成像进行了研究，但尚未研究轴向对线，这可能需要三维测量。我们旨在使用三维生物测量和现代三维负重技术研究膝关节和后足旋转对线之间的关系。
后足对线与股骨和胫骨扭转有关。
本回顾性观察研究中选择了同时进行负重 CT（WBCT）和低剂量双平面射线照相（LDBR）的所有患者，共纳入了 99 例患者的 157 条下肢。将患者的病理情况分为亚组，排除了有影响下肢对线的创伤或手术史的患者。从 WBCT 计算足踝偏移量；从 LDBR 分别计算股骨和胫骨扭转以及冠状对线。
总体而言，平均足踝偏移量为 1.56%（SD 7.4），平均股骨前倾角为 15.6°（SD 9.5），平均胫骨外旋为 32.6°（SD 7.6）。在整个系列中发现胫骨扭转与足踝偏移量之间存在中度负相关（rho=-0.23，p=0.003），在非病理患者中也存在中度负相关（rho=-0.27，p=0.01）。发现了可以用足踝偏移量和相反方向来估计胫骨扭转的线性模型，调整后的 R 值较低（3%<R<7%）。未发现 FAO 与股骨扭转之间存在关系。
在没有病理情况的患者中，胫骨外旋与内翻后足形态有关，这表明膝关节和后足对线之间可能存在代偿机制。然而，在病理情况下，并未发现相同的关系，这引起了人们对代偿失败的担忧，尽管可用的病例数有限。我们没有发现与股骨类似的相关性，这可能是因为髋关节在轴向平面上具有一定的自由度。
III，回顾性比较研究。
