PURPOSE Given the goal of achieving optimal correction and alignment after knee arthroplasty or high tibial osteotomy, literature focusing on the inter-individual variability of the native knee, tibia and femur with regards to the coronal or sagittal alignment is lacking. The aim of this study was to analyse normal angular values in the healthy middle-aged population and determine differences of angular values according to inter-individual features. The first hypothesis was that common morphological patterns may be identified in the healthy middle-aged non-osteoarthritic population. The second hypothesis was that high inter-individual variability exists with regards to gender, ethnicity and alignment phenotype. METHODS A CT scan-based modelling and analysis system was used to examine the lower limb of 758 normal healthy patients (390 men, 368 women; mean age 58.5 ± 16.4 years) with available data concerning angular values and retrieved from the SOMA database. The hip-knee-ankle angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), posterior distal femoral angle (PDFA), posterior proximal tibial angle (PPTA) and non weight-bearing joint line convergence angle (nwJLCA) were then measured for each patient. Results were analysed for the entire cohort and based on gender, ethnicity and phenotype. RESULTS The mean HKA was 179.4° ± 2.6°, LDFA: 85.8° ± 2.0°, MPTA: 85.6° ± 2.4°, PDFA: 85.2° ± 1.5°, PPTA: 83.8° ± 2.9° and nwJLCA: 1.09° ± 0.9°. Gender was associated with higher LDFA and lower HKA for men. Ethnicity was associated with greater proximal tibial vara and distal femoral valgus for Asian patients. Patients with an overall global varus alignment had more tibia vara and less femoral valgus than patients with an overall valgus alignment. CONCLUSION Even if significant differences were found based on subgroup analysis (gender, ethnicity or phenotype), this study demonstrated that neutral alignment is the main morphological pattern in the healthy middle-aged population. This neutrality is the result from tibia vara compensated by an ipsilateral femoral valgus. LEVEL OF CLINICAL EVIDENCE III, retrospective cohort study.

中文翻译：

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胫骨腔和相对的股外翻产生的中性对齐是健康中年患者的主要形态学模式：对3D-CT数据库的探索。

目的考虑到在膝关节置换术或高胫骨截骨术之后实现最佳矫正和对准的目标，目前缺乏针对冠状或矢状对准的天然膝，胫骨和股骨个体间差异的文献。这项研究的目的是分析健康的中年人口的正常角度值，并根据个体间特征确定角度值的差异。第一个假设是，可以在健康的中年非骨关节炎人群中识别出常见的形态学模式。第二个假设是在性别，种族和比对表型方面存在很高的个体差异。方法使用基于CT扫描的建模和分析系统检查758名正常健康患者（390名男性，368名女性；平均年龄58.5±16.4岁），并提供有关角度值的可用数据，并可以从SOMA数据库中获取。髋膝踝角（HKA），股骨远端远侧角（LDFA），胫骨近端内侧角（MPTA），股骨后外侧角（PDFA），胫骨近端后角（PPTA）和非承重关节线融合然后为每个患者测量角度（nwJLCA）。分析了整个队列的结果，并根据性别，种族和表型进行了分析。结果平均HKA为179.4°±2.6°，LDFA：85.8°±2.0°，MPTA：85.6°±2.4°，PDFA：85.2°±1.5°，PPTA：83.8°±2.9°，nwJLCA：1.09°±0.9° 。性别与男性的LDFA升高和HKA降低相关。种族与亚洲患者的胫骨近端静脉增大和股骨远端外翻相关。整体外翻排列的患者比整体外翻排列的患者胫骨距离更大，股骨外翻更少。结论即使根据亚组分析（性别，种族或表型）发现了显着差异，该研究也证明中性排列是健康中年人群的主要形态学模式。这种中立性是由同侧股外翻所补偿的胫腓骨的结果。临床证据水平III，回顾性队列研究。这种中立性是由同侧股外翻所补偿的胫腓骨的结果。临床证据水平III，回顾性队列研究。这种中立性是由同侧股外翻所补偿的胫腓骨的结果。临床证据水平III，回顾性队列研究。