Clinical Report: The Grand Piano Ratio in Total Knee Arthroplasty

Overview

This study evaluates the intraoperative grand piano ratio as a tool for identifying excessive external rotation of the femoral component in total knee arthroplasty (TKA). It aims to explore the relationship between this ratio and postoperative femoral component rotation measured by sTEA-referenced advanced imaging.

Background

Correct rotational alignment of the femoral component in TKA is crucial for ensuring knee stability and preventing complications such as chronic pain and revision surgery. Malrotation is a common cause of patient dissatisfaction post-surgery. The grand piano sign serves as a visual verification mechanism to assess femoral rotation.

Data Highlights

No numerical or trial data presented in the article.

Key Findings

• The grand piano sign is characterized by an asymmetrical bimodal shape of the trochlea following an ideal external rotational cut.
• Intraoperative grand piano ratio measurements have not been extensively correlated with postoperative femoral component rotation in clinical settings.
• The study explores a correlation between the grand piano ratio and femoral component rotation assessed by advanced imaging.
• Accurate intraoperative assessment of femoral rotation is critical to avoid complications associated with malrotation.
• Previous studies have suggested varying ideal medial-lateral ratios for the grand piano sign.

Clinical Implications

The study discusses the potential use of the grand piano ratio as an intraoperative tool for assessing femoral component rotation during TKA.

Conclusion

The study aims to assess the intraoperative grand piano ratio as a tool for femoral component rotation in TKA.

Related Resources & Content

1. Evaluation of Anatomical Axes Versus Navigated Functional Rotation Axis Based on Ligament Tension for Aligning Rotational Femoral Components in Cadaveric Knee Arthroplasty, 2024
2. Impact of Retaining the Posterior Cruciate Ligament on Femoral Rotational Alignment in Total Knee Arthroplasty with a Gap-Balancing Approach, 2014
3. Impact of Internal Rotation of the Femoral Component on Load Distribution in Total Knee Arthroplasty: A Cadaveric Study Utilizing the Verasense System, 2017
4. Femur rotational alignment in total knee arthroplasty: Delphi consensus statements from European knee society (EKS), 2023
5. Evaluating Clinical Results of Patient-Specific Instrumentation: A Five-Year Retrospective Analysis of 298 Knee Arthroplasties
6. External femoral rotation of 2 degrees is associated with the lowest stuffing rates around the femur in functionally aligned TKA
7. Gender-Based Quantitative Analysis of the Grand Piano Sign in Mechanically Aligned Total Knee Arthroplasty in Asians
8. Femur rotational alignment in total knee arthroplasty: Delphi consensus statements from European knee society (EKS) - PubMed