Scholarlink

Introduction <p>Achieving an accurate mediolateral soft tissue balance is essential for stability, kinematics and long-term outcomes in total knee arthroplasty (TKA); however, existing classification systems are often complex and lack intraoperative usability. This study introduces and internally validates the Knee Balancing Score (KBS), a&#xa0;simplified and reproducible method based solely on mediolateral gap asymmetry measured at full extension (when achievable) and 90° flexion using a&#xa0;robotic-assisted platform.</p> Methods <p>A&#xa0;prospective series of 285 robotic-assisted TKAs performed between 2022 and 2025 was analyzed. Medial and lateral joint gaps were recorded at full extension (when achievable) and 90° flexion under standardized varus-valgus stress. The KBS was derived from the absolute gap difference (∆Gap = |L − M|, mm) and classified separately for extension (E1–E4) and flexion (F1–F4). Correlations between ∆Gap and alignment parameters, including the hip-knee-ankle angle (HKA), arithmetic HKA, medial proximal tibial angle (mPTA), lateral distal femoral angle (LDFA), and joint line orientation (JLO), were calculated (<i>P</i> &lt; 0.05).</p> Results <p>The mean ∆Gap was 3.02 ± 2.25 mm in extension and 3.47 ± 2.63 mm in flexion (<i>P</i> = 0.021). Symmetry (E1) was observed in 21.8% of knees, while mild lateral opening (E2) occurred in 36.1%. In flexion, physiological lateral laxity (F2) was observed in 29.5% and pathological imbalance (F3–F4) in 51.6%. Valgus morphotypes showed greater asymmetry in both planes (<i>P</i> &lt; 0.01). The ∆Gap correlated inversely with the HKA angle (r = −0.28 to −0.40) and mPTA (r = −0.34 to −0.39), confirming construct validity.</p> Conclusion <p>The KBS offers a&#xa0;practical, physiological and objective system to quantify intraoperative balance, transforming subjective perception into a&#xa0;standardized and reproducible assessment applicable in modern TKA practice.</p> Graphic abstract <p></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

Intraoperative balance in total knee arthroplasty

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年3月31日

查看全文
  • Andreas Bell,
  • Luise Schäfer,
  • Andrea Nobili,
  • Daniel Kämmer,
  • Jens Schneider,
  • Moritz Bell,
  • Filippo Migliorini

摘要

Introduction

Achieving an accurate mediolateral soft tissue balance is essential for stability, kinematics and long-term outcomes in total knee arthroplasty (TKA); however, existing classification systems are often complex and lack intraoperative usability. This study introduces and internally validates the Knee Balancing Score (KBS), a simplified and reproducible method based solely on mediolateral gap asymmetry measured at full extension (when achievable) and 90° flexion using a robotic-assisted platform.

Methods

A prospective series of 285 robotic-assisted TKAs performed between 2022 and 2025 was analyzed. Medial and lateral joint gaps were recorded at full extension (when achievable) and 90° flexion under standardized varus-valgus stress. The KBS was derived from the absolute gap difference (∆Gap = |L − M|, mm) and classified separately for extension (E1–E4) and flexion (F1–F4). Correlations between ∆Gap and alignment parameters, including the hip-knee-ankle angle (HKA), arithmetic HKA, medial proximal tibial angle (mPTA), lateral distal femoral angle (LDFA), and joint line orientation (JLO), were calculated (P < 0.05).

Results

The mean ∆Gap was 3.02 ± 2.25 mm in extension and 3.47 ± 2.63 mm in flexion (P = 0.021). Symmetry (E1) was observed in 21.8% of knees, while mild lateral opening (E2) occurred in 36.1%. In flexion, physiological lateral laxity (F2) was observed in 29.5% and pathological imbalance (F3–F4) in 51.6%. Valgus morphotypes showed greater asymmetry in both planes (P < 0.01). The ∆Gap correlated inversely with the HKA angle (r = −0.28 to −0.40) and mPTA (r = −0.34 to −0.39), confirming construct validity.

Conclusion

The KBS offers a practical, physiological and objective system to quantify intraoperative balance, transforming subjective perception into a standardized and reproducible assessment applicable in modern TKA practice.

Graphic abstract