Beynon Rhona A, Alomar Faten, Saunders Fiona R, Ebsim Raja, Faber Benjamin G, Jung Mijin, Gregory Jennifer S, Lindner Claudia, Abram Simon G F, Aspden Richard M, Harvey Nicholas C, Cootes Timothy, Tobias Jonathan H
University of Bristol, Musculoskeletal Research Unit, Bristol Medical School, Bristol, United Kingdom.
The University of Manchester, Division of Informatics, Imaging & Data Sciences, School of Health Sciences, Manchester, United Kingdom.
Osteoarthr Cartil Open. 2025 Aug 21;7(4):100667. doi: 10.1016/j.ocarto.2025.100667. eCollection 2025 Dec.
Lower limb alignment may predispose to, or exacerbate, symptoms of knee osteoarthritis. To examine the role of this and other joint shape variation, we conducted a cross-sectional study investigating relationships between radiographic knee osteoarthritis (rKOA) and knee shape in dual-energy X-ray absorptiometry (DXA) images from UK Biobank (UKB).
Associations between the first ten knee shape modes (KSMs), derived from statistical shape modelling, and rKOA grade were analysed using logistic regression, adjusting for age, sex, height, weight, and ethnicity. An additional model included adjustment for hip-knee-ankle (HKA) angle, derived from total body DXA scans, to reflect knee alignment. Composite figures illustrate knee shape characteristics associated with each rKOA grade.
19,053 individuals were included (mean 63.7 years, 48 % males), of whom 80.7 %, 14.6 %, 3.6 % and 1.2 % had rKOA grades 0, 1, 2 and 3-4, respectively. Several KSMs were associated with rKOA in confounder-adjusted analyses, with higher grades showing stronger relationships. These associations were attenuated by adjustment for HKA. As expected, composite shape models revealed that higher rKOA grades were associated with greater varus malalignment. After HKA adjustment, composite shape models showed less varus alignment, with other shape differences, such as altered proximal tibial metaphysis and lateral patella displacement, emerging in higher-grade rKOA.
Our cross-sectional analyses between joint shape and DXA-derived rKOA grade showed expected relationships with varus malalignment, which were attenuated after adjusting for HKA. Other shape differences, particularly in higher-grade rKOA, emerged independently of alignment, warranting further investigation.
下肢对线可能会诱发或加重膝关节骨关节炎的症状。为了研究这种情况以及其他关节形状变化的作用，我们进行了一项横断面研究，调查英国生物银行（UKB）双能X线吸收法（DXA）图像中膝关节X线骨关节炎（rKOA）与膝关节形状之间的关系。
使用逻辑回归分析从统计形状建模中得出的前十种膝关节形状模式（KSMs）与rKOA等级之间的关联，并对年龄、性别、身高、体重和种族进行调整。另一个模型包括对从全身DXA扫描得出的髋-膝-踝（HKA）角进行调整，以反映膝关节对线情况。合成图展示了与每个rKOA等级相关的膝关节形状特征。
纳入了19053名个体（平均年龄63.7岁，48%为男性），其中分别有80.7%、14.6%、3.6%和1.2%的个体rKOA等级为0、1、2和3-4级。在混杂因素调整分析中，几种KSMs与rKOA相关，等级越高关系越强。这些关联在对HKA进行调整后减弱。正如预期的那样，合成形状模型显示较高的rKOA等级与更大的内翻畸形相关。在对HKA进行调整后，合成形状模型显示内翻对线减少，在较高等级的rKOA中出现了其他形状差异，如近端胫骨干骺端改变和髌骨外侧移位。
我们对关节形状与DXA衍生的rKOA等级之间的横断面分析显示了与内翻畸形的预期关系，在对HKA进行调整后这种关系减弱。其他形状差异，特别是在较高等级的rKOA中，独立于对线情况出现，值得进一步研究。
