Orthopaedics Surgery and Sports Medicine Department, FIFA Medical Center of Excellence, Croix-Rousse Hospital, Lyon University Hospital, 103 grande rue de la croix rousse, Hopital de La Croix Rousse, 69004, Lyon, France.
LBMC UMR_T9406, Univ Lyon, Claude Bernard Lyon 1 University, Gustave Eiffel University, 69622, Lyon, France.
Knee Surg Sports Traumatol Arthrosc. 2022 Aug;30(8):2806-2814. doi: 10.1007/s00167-021-06674-w. Epub 2021 Jul 22.
In total knee arthroplasty (TKA), knee phenotypes including joint line obliquity are of interest regarding surgical realignment strategies. The hypothesis of this study is that better clinical results, including decreased postoperative knee pain, will be observed for patients with a restored knee phenotype.
A retrospective analysis was performed on prospective data, including 1078 primary osteoarthritic knees in 936 patients. The male:female ratio was 780:298, mean age at surgery was 71.3 years ± 8.0. International Knee Society Scores and standardized long-leg radiographs (LLR) were collected preoperatively and at 2 years follow-up after TKA. Patients were categorized using the Coronal Plane Alignment of the Knee (CPAK) classification including the lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) measured on LLR by a single observer, allowing knee phenotypes to be categorized considering the arithmetic hip-knee-ankle (aHKA) angle (MPTA-LDFA) as measure of constitutional alignment, and joint line obliquity (JLO) (MPTA + LDFA). Clinical results were compared between patients with surgically restored preoperative constitutional knee phenotype to patients without restored constitutional knee phenotypes. Descriptive data analysis such as means, standard deviations and ranges were performed. T tests for independent samples were performed to compare group differences. Comparisons of categorical data were performed using the χ test. Significance was set at p < 0.05.
A third of patients (33.4%) had constitutional knee varus with apex distal JLO. 63.5% of patients had preoperative apex distal JLO. Postoperatively, 57.8% of patients had a neutral HKA (- 2° to 2°) and a neutral JLO (- 3° and 3°), with only 18% of patients with restored constitutional knee phenotype. Of these patients, statistically less postoperative pain was observed in patients where apex distal JLO was restored compared to non-restored apex distal JLO (pain score 46.7 vs. 44.6; p = 0.02) without clinical relevance. Other categories of restored JLO or arithmetic HKA angle were not associated with improved outcomes.
This study showed that performing mechanical alignment for primary TKA resulted in most cases in a change of the preoperative knee phenotype. These results emphasize the relevance of considering joint line obliquity to better understand preoperative knee deformity and better restore knee phenotypes with a more personalized realignment strategy to potentially improve TKA postoperative results.
III.
在全膝关节置换术（TKA）中，关节线倾斜等膝关节表型与手术对线策略有关。本研究的假设是，对于膝关节表型恢复的患者，将观察到更好的临床结果，包括术后膝关节疼痛减轻。
对前瞻性数据进行回顾性分析，包括 936 例 1078 例原发性骨关节炎膝关节。男女比例为 780:298，手术时的平均年龄为 71.3±8.0 岁。术前和 TKA 后 2 年随访时收集国际膝关节协会评分和标准化下肢全长 X 线片（LLR）。通过单一观察者在 LLR 上测量外侧远端股骨角（LDFA）和内侧近端胫骨角（MPTA），使用 Coronal Plane Alignment of the Knee（CPAK）分类对患者进行分类，允许考虑算术髋膝踝角（aHKA）角（MPTA-LDFA）作为固有对线的测量值，以及关节线倾斜（JLO）（MPTA+LDFA）对膝关节表型进行分类。将术前手术恢复固有膝关节表型的患者与未恢复固有膝关节表型的患者的临床结果进行比较。进行均值、标准差和范围等描述性数据分析。使用独立样本 t 检验比较组间差异。使用 χ²检验比较分类数据的差异。显著性水平设为 p<0.05。
三分之一的患者（33.4%）存在固有膝内翻，伴有尖端远端 JLO。63.5%的患者术前有尖端远端 JLO。术后，57.8%的患者有中立性 HKA（-2°至 2°）和中立性 JLO（-3°至 3°），只有 18%的患者恢复了固有膝关节表型。在这些患者中，与未恢复尖端远端 JLO 的患者相比，尖端远端 JLO 恢复的患者术后疼痛明显减轻（疼痛评分 46.7 与 44.6；p=0.02），但无临床意义。其他恢复 JLO 或算术 HKA 角度的类别与改善结果无关。
本研究表明，对于初次 TKA，进行机械对线通常会导致大多数情况下术前膝关节表型发生变化。这些结果强调了考虑关节线倾斜的重要性，以便更好地理解术前膝关节畸形，并通过更个性化的对线策略更好地恢复膝关节表型，从而有可能改善 TKA 术后结果。
III。
