23 February 2026
The Sense of Stability: A Talk with Prof. S. Eggli
Soft Tissue Balancing (STB) in Total Knee Arthroplasty (TKA) is more than a surgical technique; it is a philosophy that places patient-specific anatomy and stability at the center of decision-making. As part of Enovis’ campaign “Soft Tissue Balancing – the sense of stability”, we spoke with Prof. S . Eggli, Sonnenhof Clinic, Berne, Switzerland, a surgeon who has embraced this approach since the beginning.
“Soft tissue balancing in TKA refers to the systematic process of achieving proper tension and equal distribution of forces across the collateral ligaments and soft tissue envelope throughout the range of motion of the knee joint, independent from the anatomical axis,” he explained. For him, the essence of this philosophy lies in respecting the patient’s natural anatomy rather than forcing it into a predetermined alignment. “My philosophy emphasizes minimal soft tissue releases while accepting each patient’s individual morphotype. In my practice, this approach preserves natural kinematics, reduces complications, and delivers superior functional outcomes.”
Stability at 30° flexion is, in his view, the most critical checkpoint. “The three most critical elements of successful total knee arthroplasty are stability at 30° flexion, a centered patella on gravity testing, and achievement of full extension. Through soft tissue balancing techniques, I can consistently accomplish these fundamental goals without significantly altering the native axis or ligament tension.” This sequence of balancing first and positioning afterwards also shapes his surgical technique. “Femoral component positioning is directly determined by ligament tension. If soft tissue releases are necessary, I perform them before making the femoral cuts. This critical sequence significantly impacts polyethylene thickness selection and final component sizing.”
The clinical advantages of this approach are clear. “Proper balancing ensures stability throughout range of motion, prevents accelerated wear through even load distribution, and reduces revision rates. Well-balanced knees deliver superior patient satisfaction with natural feel and confident function.” Looking ahead, Prof. S. Eggli sees potential in enabling technologies, though he remains cautious. “Current robotic approaches with preoperative bony planning followed by soft tissue adaptation represent no real advancement. I expect intelligent systems providing intraoperative guidance on optimal positioning, balancing, and releases. Future technology must respect ‘balancing first, positioning afterwards’, integrating multiple data points to guide real-time decisions.”
This first interview highlights how soft tissue balancing transforms TKA outcomes by prioritizing stability, respecting anatomy, and influencing surgical sequencing. As part of our campaign, we will continue to share perspectives from other surgeons who believe in this philosophy, demonstrating how Soft Tissue Balancing - the sense of stability is shaping the future of knee arthroplasty.
To learn more: Balansys BICON | Bicondylar Knee System – Enovis Surgical
