目的

探讨术前冠状位力线与牛津单髁膝关节置换术（UKA）术后力线之间的关系，探索预测术后力线的方法。

方法

纳入2021年1月至2022年12月山西医科大学第二医院130名（156膝）因膝关节前内侧骨关节炎行牛津活动平台UKA的患者，并排除影像资料不完整或有外伤骨折史的患者。根据术后髋膝踝（HKA）角将其分为中立组（-1°≤HKA<3°）68例、适度内翻组（3°≤HKA≤7°）74例，过度内翻组（HKA>7°）14例。回顾性研究纳入病例的影像资料，通过Kruskal-Wallis H检验进行组间比较并使用Spearman相关性分析术前HKA角（pre-HKA）、股骨远端外侧角（LDFA）、胫骨近端内侧角（MPTA）、算数HKA（aHKA）与术后力线之间规律。

结果

术后力线中立位组、适度内翻组、过度内翻组的pre-HKA（H=51.836，P<0.001）、MPTA（H=39.764，P<0.001）、LDFA（H=31.401，P<0.001）、aHKA（H=81.992，P<0.001）差异均有统计学意义，进一步通过Spearman相关性分析发现aHKA与术后HKA相关性最强（r=-0.805，P<0.001），术后HKA=-0.7×aHKA+0.5。

结论

术前膝关节冠状面力线对牛津单髁术后力线有影响，可通过aHKA预测术后HKA。当aHKA接近或大于2.1时需警惕膝关节外翻的可能性，当aHKA<-9.3时可能出现较大术后内翻畸形。

Objective

To investigate the relationship between preoperative coronal alignment and postoperative alignment following Oxford unicompartmental knee arthroplasty (UKA), and to explore methods for predicting postoperative alignment.

Methods

This retrospective study enrolled 130 patients (156 knees) who underwent Oxford mobile-bearing UKA for anteromedial knee osteoarthritis at the Second Hospital of Shanxi Medical University between January 2021 and December 2022. Patients with incomplete imaging data or a history of trauma or fractures were excluded. Based on postoperative hip-knee-ankle (HKA) angles, the patients were categorized into three groups: neutral alignment group (-1°≤HKA<3°, n=68), moderate varus group (3°≤HKA≤7°, n=74), and excessive varus group (HKA>7°, n=14). Imaging data of the patients were retrospective analyzed for the intergroup differences in preoperative HKA (pre-HKA), lateral distal femoral angle (LDFA),medial proximal tibial angle (MPTA), and arithmetic HKA (aHKA) using the Kruskal-Wallis H test. Spearman correlation analysis was performed to identify associations between preoperative parameters and postoperative alignment.

Results

Statistically significant differences were observed among the three groups in pre-HKA(H=51.836, P<0.001), MPTA (H=39.764, P<0.001), LDFA (H=31.401, P<0.001), and aHKA (H=81.992,P<0.001). Spearman analysis revealed the strongest correlation between aHKA and postoperative HKA (r=-0.805,P<0.001), with the regression equation: post-HKA=-0.7×aHKA+0.5.

Conclusions

Preoperative coronal alignment significantly influences postoperative alignment in Oxford UKA. aHKA serves as a reliable predictor of postoperative HKA. Caution is warranted when aHKA approaches or exceeds 2.1°(risk of valgus alignment)or falls below -9.3° (risk of excessive postoperative varus deformity).