Stability of knee ligament complex of Thiel-embalmed cadaver compared to in vivo knee. (July 2017)

• Record Type: Journal Article
• Authors: Völlner, Florian; Pilsl, Ulrike; Craiovan, Benjamin; Zeman, Florian; Schneider, Michael; Wörner, Michael; Grifka, Joachim; Weber, Markus
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 71(2017)
• Page Start: 392
• Page End: 396
• Publication Date: 2017-07
• Subjects: aFTA Anatomical femorotibial angle -- CI Confidence interval -- CLC Cadaver lateral compartment -- CMC Cadaver medial compartment -- PLC Patient lateral compartment -- PMC Patient medial compartment -- TKA Total knee arthroplasty; In vivo – in vitro -- Ligament balance -- Ligament stiffness -- Soft-tissue balance -- Thiel-embalmed cadavers -- Total knee arthroplasty; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2017.04.009
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: Background: The first biomechanical evaluation of new implants is usually carried out with cadavers. Fixation of Thiel-embalmed cadavers is supposed to preserve the histological structure, colour and consistency of the tissue and has a low risk of infection and toxicity. However, the biomechanical properties of Thiel-fixated tissue are still unknown. The aim of this study was to quantify the effect of the Thiel-embalming method on the elastic properties of the ligament complex of the knee compared to in vivo knees during total knee arthroplasty. Methods: The results of biomechanical tensile tests with 10 Thiel-embalmed knees were compared with the findings of 10 patients who underwent total knee arthroplasty with a standardised knee balancer at our department. We reconstructed the force-elongation curves of the medial and lateral ligament complex and calculated the stiffness in direct correlation with overall soft tissue stability in full extension and in 90° of flexion. Results: All curves consisted of a non-linear part at the beginning and a linear part from about 80 N onwards. In full extension, median stiffness in the cadavers was 26.6 N/mm for the medial compartment and 31.6 N/mm for the lateral compartment. The values for in vivo were 25.7 N/mm for the medial compartment and 25.3 N/mm for the lateral compartment (p=0.684 for the medial compartment and p=0.247 for the lateral compartment). In 90° of flexion, median stiffness in the cadaver group was 24.7 N/mm for the medial compartment and 22.2 N/mm for the lateral compartment. In vivo, median stiffness was 30.3 N/mm for the medial compartment and 29.2 N/mm for the lateral compartment (p=0.009 for the medial compartment and p=0.143 for the lateral compartment). Conclusion: Stiffness of the medial and lateral ligament complex in the knee was comparable between Thiel-embalmed cadavers and in vivo patients during total knee arthroplasty. Thiel fixation seems to preserve the soft tissue properties similar to those in vivo. Graphical abstract: Highlights: First study comparing Thiel-embalmed specimens with in vivo measurements. Reconstruction of force-elongation curves of the medial and lateral knee ligament complex. Examination in full extension and 90° of flexion. Thiel fixation maintains the force-elongation characteristic of ligaments. The stiffness of Thiel-embalmed specimen is comparable to in vivo knee.