Scholarlink

Background <p> Robot-assisted total knee arthroplasty (TKA) enables high-precision osteotomy, but the clinical choice between pursuing a population-wide optimal posterior tibial slope (PTS) and individualizing the restoration of the native anatomical PTS remains debated. This study quantified the dose-response relationship between PTS deviation from native anatomy and the Forgotten Joint Score-12 (FJS-12), comparing outcomes between robot-assisted and conventional manual TKA.</p> Methods <p>A retrospective cohort study analyzed 240 patients who underwent primary unilateral posterior-stabilized TKA, divided equally into conventional manual (<i>n</i> = 120) and robot-assisted (<i>n</i> = 120) groups. Postoperative PTS and absolute osteotomy errors were measured via CT scans. At the 1-year follow-up, the primary outcomes assessed were maximum active flexion and FJS-12 scores. Multivariate linear and quadratic regressions were utilized to map the association between postoperative PTS, absolute native deviation, and functional outcomes. Subgroup analysis was conducted using a 2° PTS deviation (Δ) threshold.</p> Results <p> The robot-assisted group demonstrated a significantly lower absolute osteotomy error than the conventional group (1.2° ± 0.9° vs. 2.8° ± 1.6°, <i>P</i> &lt; 0.001). Although the robotic cohort showed statistically greater maximum flexion and FJS-12 scores, objective functional metrics (KSS, OKS, WOMAC) did not significantly differ between groups. Regression analysis revealed a linear correlation between PTS and flexion (<i>β</i> = 1.9) and a quadratic (inverted U-shaped) relationship between PTS and FJS-12, peaking at approximately 5.3°. Crucially, greater deviation from the native PTS independently impaired FJS-12 scores (<i>β</i> = − 2.4). Subgroup analysis confirmed that patients with a precise reconstruction (Δ ≤ 2°) achieved distinctly higher FJS-12 scores compared to high-deviation groups (Δ &gt; 2°), regardless of the surgical modality employed.</p> Conclusions <p>The postoperative PTS exhibits a nonlinear relationship with subjective joint awareness, with a population-level optimum of approximately 5.3°. However, anatomical deviation from the native PTS is an independent predictor of worsening FJS-12 scores. While robotic assistance is highly effective at minimizing extreme biomechanical outliers, surgical planning should prioritize the precise restoration of individualized native anatomy over universally fixed targets to maximize patient satisfaction.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Deviation from native medial posterior tibial slope and dose-response relationships with forgotten joint score-12 in Robot-assisted versus conventional manual total Knee arthroplasty: A retrospective cohort study

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年6月18日

查看全文
  • Boyi Chen,
  • Lin Jing,
  • Hongmei Zhang,
  • Qi Yan,
  • Yuanyuan Li,
  • Siye Liu,
  • Ximing Yu

摘要

Background

Robot-assisted total knee arthroplasty (TKA) enables high-precision osteotomy, but the clinical choice between pursuing a population-wide optimal posterior tibial slope (PTS) and individualizing the restoration of the native anatomical PTS remains debated. This study quantified the dose-response relationship between PTS deviation from native anatomy and the Forgotten Joint Score-12 (FJS-12), comparing outcomes between robot-assisted and conventional manual TKA.

Methods

A retrospective cohort study analyzed 240 patients who underwent primary unilateral posterior-stabilized TKA, divided equally into conventional manual (n = 120) and robot-assisted (n = 120) groups. Postoperative PTS and absolute osteotomy errors were measured via CT scans. At the 1-year follow-up, the primary outcomes assessed were maximum active flexion and FJS-12 scores. Multivariate linear and quadratic regressions were utilized to map the association between postoperative PTS, absolute native deviation, and functional outcomes. Subgroup analysis was conducted using a 2° PTS deviation (Δ) threshold.

Results

The robot-assisted group demonstrated a significantly lower absolute osteotomy error than the conventional group (1.2° ± 0.9° vs. 2.8° ± 1.6°, P < 0.001). Although the robotic cohort showed statistically greater maximum flexion and FJS-12 scores, objective functional metrics (KSS, OKS, WOMAC) did not significantly differ between groups. Regression analysis revealed a linear correlation between PTS and flexion (β = 1.9) and a quadratic (inverted U-shaped) relationship between PTS and FJS-12, peaking at approximately 5.3°. Crucially, greater deviation from the native PTS independently impaired FJS-12 scores (β = − 2.4). Subgroup analysis confirmed that patients with a precise reconstruction (Δ ≤ 2°) achieved distinctly higher FJS-12 scores compared to high-deviation groups (Δ > 2°), regardless of the surgical modality employed.

Conclusions

The postoperative PTS exhibits a nonlinear relationship with subjective joint awareness, with a population-level optimum of approximately 5.3°. However, anatomical deviation from the native PTS is an independent predictor of worsening FJS-12 scores. While robotic assistance is highly effective at minimizing extreme biomechanical outliers, surgical planning should prioritize the precise restoration of individualized native anatomy over universally fixed targets to maximize patient satisfaction.