Biomechanical analysis of conventional anchor revision after all-suture anchor pullout: a human cadaveric shoulder model Dimitris Ntalos, MD a, *, Gerd Huber, PhD b , Kay Sellenschloh, Dipl Ing b , Daniel Briem, MD c , Klaus P € uschel, MD d , Michael M. Morlock, PhD b , Karl-Heinz Frosch, MD a , Darius M. Thiesen, MD a , Till O. Klatte, MD a a Department of Trauma-, Hand-, and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany b Institute of Biomechanics, Hamburg University of Technology (TUHH), Hamburg, Germany c Asklepios Westklinikum Hamburg, Hamburg, Germany d Department of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany Hypothesis and background: The possibility of implanting a conventional anchor at the pullout site following all-suture anchor failure was evaluated in a biomechanical cadaveric model. The hypothesis of the study was that anchor revision would yield equal biomechanical properties. Methods: Ten human humeri were obtained, and bone density was determined via computed tomogra- phy. After all-suture anchor (n ¼ 5) and conventional 4.5-mm anchor (n ¼ 5) insertion, biomechanical testing was conducted. Following all-suture anchor pullout, a conventional 5.5-mm anchor was inserted at the exact site of pullout (n ¼ 5) and biomechanical testing was reinitiated. Testing was conducted using an initial preload of 20 N, followed by an unlimited cyclic protocol, with a stepwise increasing force of 0.05 N for each cycle at a rate of 1 Hz until system failure. The number of cycles, maximum load to failure, stiffness, displacement, and failure mode, as well as macroscopic observation at the fail- ure site including diameter, shape, and cortical destruction, were registered. Results: The defect following all-suture pullout showed a mean diameter of 4 mm, and conventional revision was possible in each sample. There was no significant difference between the initial all- suture anchor implantation and the conventional anchor implantation or the conventional revision following all-suture failure regarding mean pullout strength, stiffness, displacement, or total number of cycles until failure. Conclusion: Conventional anchor revision at the exact same site where all-suture anchor pullout occurred is possible and exhibits similar biomechanical properties. Level of evidence: Basic Science Study; Biomechanics Ó 2019 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved. Keywords: Shoulder surgery; arthroscopy; rotator cuff; suture anchor; all suture; pullout Approval of the institutional review board was obtained from the Ethical Review Committee (Hamburg, Germany; study no. WF-27/17). *Reprint requests: Dimitris Ntalos, MD, Department of Trauma-, Hand-, and Reconstructive Surgery, University Medical Center Hamburg- Eppendorf, Martinistraße 52, 20246 Hamburg, Germany. E-mail address: d.ntalos@uke.de (D. Ntalos). J Shoulder Elbow Surg (2019) -, 1–5 www.elsevier.com/locate/ymse 1058-2746/$ - see front matter Ó 2019 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved. https://doi.org/10.1016/j.jse.2019.04.053