膝关节骨关节炎患者与正常人群膝关节冠状面对线分型的对比

Comparison of coronal plane alignment of the knee phenotypes between knee osteoarthritis patients and asymptomatic controls

摘要

目的 探讨膝关节骨关节炎(knee osteoarthritis, KOA)患者与正常人群的膝关节冠状面对线(coronal plane alignment of the knee, CPAK)分型的异同,以期发现KOA患者CPAK表型的规律。 方法 回顾性分析2019年1月1日至2024年12月31日苏州大学附属第一医院完成站立位双下肢全长片检查的研究对象2 166例,以KOA为第一诊断患者1 785例,其中行全膝关节置换术(total knee arthroplasty, TKA)患者1 299例(1 418膝)(TKA组),单髁置换术(unicompartmental knee arthroplasty, UKA)患者486例(551膝)(UKA组),正常对照组381例。采用影像测量软件测量胫骨近端内侧角(medial proximal tibial angle, MPTA)、股骨远端外侧角(lateral distal femoral angle, LDFA)、算术髋膝踝角(arithmetic hip-knee-ankle angle, aHKA)和关节线倾斜度(joint line obliquity, JLO),并依据CPAK分型标准进行分型。比较正常对照组、TKA组和UKA组术前解剖参数与CPAK分型分布差异;对具有术后站立位双下肢全长片资料的患者,进一步比较TKA组和UKA组手术前后解剖参数和CPAK分型变化。 结果 3组术前CPAK分布差异有统计学意义(P<0.001):正常对照组以Ⅲ型(281膝,36.88%)和Ⅱ型(216膝,28.35%)为主,TKA组以Ⅰ型(605膝,42.67%)和Ⅳ型(286膝,20.17%)为主,UKA组以Ⅰ型(232膝,42.11%)和Ⅱ型(119膝,21.60%)为主。3组术前MPTA、LDFA、aHKA和JLO差异均有统计学意义(P<0.001)。术后获得影像随访者中,TKA组768例(858膝),UKA组222例(265膝);两组术前术后CPAK分型分布均呈显著变化(P<0.001),且术后CPAK分型分布差异有统计学意义(P<0.001)。其中,TKA组术后主要转为Ⅳ型(242膝,28.21%)和Ⅴ型(248膝,28.90%),UKA组术后仍以Ⅰ型(102膝,38.49%)和Ⅱ型(83膝,31.32%)为主。 结论 CPAK分型有助于描述KOA相关冠状面形态特征及手术前后形态变化,但其在KOA发生风险评估及术式选择中的作用仍需进一步前瞻性研究验证。

Abstract

Objective To compare the distribution of coronal plane alignment of the knee(CPAK)phenotypes between patients with knee osteoarthritis(KOA)and asymptomatic controls,and to identify the phenotypic characteristics of CPAK distribution in patients with KOA. Methods This retrospective study included 2,166 individuals who underwent standing full-length lower-extremity radiography at The First Affiliated Hospital of Soochow University between January 1, 2019 and December 31, 2024. Among them, 1,785 patients were diagnosed with KOA as the primary diagnosis, who underwent total knee arthroplasty(TKA), involving 1,418 knees, and 486 patients who underwent unicompartmental knee arthroplasty(UKA), involving 551 knees. In addition, 381 normal controls were included. Medial proximal tibial angle(MPTA), lateral distal femoral angle(LDFA), arithmetic hip-knee-ankle angle(aHKA), and joint line obliquity(JLO)were measured, and CPAK phenotypes were assigned according to the established CPAK classification system. Preoperative anatomical parameters and CPAK phenotype distributions were compared among the control, TKA, and UKA groups. In patients with available postoperative images, preoperative-to-postoperative changes in anatomical parameters and CPAK phenotypes were further analyzed. Results CPAK phenotype distribution differed significantly among the three groups (P<0.001). The predominant phenotypes were type Ⅲ(281 knees, 36.88%)and type Ⅱ(216 knees, 28.35%)in the control group, type Ⅰ(605 knees, 42.67%)and type Ⅳ(286 knees, 20.17%)in the TKA group, and type Ⅰ(232 knees, 42.11%)and type Ⅱ(119 knees, 21.60%)in the UKA group. Preoperative MPTA, LDFA, aHKA, and JLO also differed significantly among the three groups(P<0.001). Postoperative imaging follow-up was available for 768 patients(858 knees)in the TKA group and 222 patients(265 knees)in the UKA group. CPAK phenotype distribution changed significantly from preoperative to postoperative in both groups(Bowker's symmetry test, both P<0.001), and postoperative phenotype distribution differed significantly between the two groups(P<0.001). Postoperatively, the TKA group mainly shifted to type Ⅳ(242 knees, 28.21%)and type Ⅴ(248 knees, 28.90%), whereas the UKA group remained predominantly type Ⅰ(102 knees, 38.49%)and type Ⅱ(83 knees, 31.32%). Conclusion CPAK phenotypes may help characterize KOA-related coronal alignment features and morphological changes before and after surgery; however, its value in assessing KOA risk and surgical decision-making still requires further validation in prospective studies.

关键词

膝关节骨关节炎 / 全膝关节置换术 / 单髁置换术 / 膝关节冠状面对线分型 / 下肢力线

Key words

Knee osteoarthritis / Total knee arthroplasty / Unicompartmental knee arthroplasty / Coronal plane alignment of the knee phenotypes / Lower limb alignment

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基金资助

江苏省基础研究计划资助(BK20251794)

苏州市“科教强卫”重点项目(ZDXM2024001)

苏州市临床重点病种诊疗技术专项(LCZX202302)