A consensus-based classification of minor complications, major complications, and failure after anterior cruciate ligament reconstruction: A modified delphi study
Year: 2026
Type: article
Abstract: INTRODUCTION: The aim of this study was to establish a consensus-based classification of postoperative events following anterior cruciate ligament reconstruction (ACLR), clearly distinguishing no complication/normal clinical course, minor complication, major complication, and failure, using a structured Delphi methodology among international experts in anterior cruciate ligament (ACL) surgery. METHODS: A three-round modified Delphi process was conducted involving international high-volume ACL surgeons. An initial set of statements addressing potential postoperative events after ACLR was developed by a working group based on clinical expertise and contemporary literature. Panelists classified each statement as no complication/normal clinical course, minor complication, major complication, or failure. Consensus was predefined as ≥75% agreement within a single category. Statements reaching consensus were retained, whereas non-consensus statements were revised and re-evaluated in subsequent rounds. RESULTS: Thirty-nine experts completed the first and second Delphi rounds, and 30 (76.9%) completed the third round. The initial 52 statements were expanded to 67 in round two and refined to 46 in round three. Consensus was achieved for 14 statements (26.9%) in round one, 21 statements (31.3%) in round two, and 20 statements (43.5%) in round three. Overall, consensus was reached for 55 statements, forming the final classification framework. The panel clearly distinguished graft failure-defined as graft insufficiency or symptomatic instability-from major complications requiring surgical intervention or associated with substantial morbidity, and from minor complications or expected postoperative findings. Notably, traumatic graft rupture following a clearly documented new injury was not considered a postoperative complication. CONCLUSIONS: This international Delphi consensus establishes a standardized and clinically meaningful classification of postoperative events following ACLR. By clearly distinguishing no complication, minor complication, major complication, and failure, this framework provides a shared language that may improve consistency in outcome reporting, facilitate comparison across studies, and enhance the interpretability of clinical research and registry data. LEVEL OF EVIDENCE: V, expert consensus.
Authors: Riccardo D'Ambrosi, Jakob Ackermann, Adrian Deichsel, Larissa Eckl, Lena Eggeling, Christoph Kittl, Brenda Laky, Dominic Mathis, Gergo B. Merkely, Lukas Nawid Muench, Maiti Muenchgesang, Anton Ferdinand Schmidt, Karl-Friederich Schuettler, Arasch Wafaisade, Elisabeth Abermann, Andrea Achtnich, Ralph Akoto, Peter Angele, Roland Becker, Georg Brandl, David Dejour, Florian Dirisamer, Björn H. Drews, Christian Egloff, Matthias J. Feucht, Christian Fink, Elmar Herbst, Erik Hohmann, Andreas B. Imhoff, Tobias Jung, Peter Philipp Koch, Matthias Krause, Christian Lattermann, James H. Lubowitz, Julian Mehl, Natalie Mengis, Volker Mushal, Stefan Nehrer, Thomas Pfeiffer, Sven Scheffler, Christian Schoepp, Rainer Siebold, Martin Volz, Andy Williams, Lukas Willinger, Thore Zantop, Johannes Zellner, Daniel Guenther
Institutions: IRCCS Ospedale Galeazzi - Sant'Ambrogio, Link Campus University, Rush University Medical Center, University of Zurich, Universitätsklinik Balgrist, University Hospital Münster, TUM Klinikum, Technical University of Munich, BG Klinikum Hamburg, Sigmund Freud Privatuniversität Wien, Austrian Research Group for Regenerative and Orthopedic Medicine, Medical University of Vienna, University of Basel, Semmelweis University, Harvard University, Massachusetts General Hospital, Witten/Herdecke University, Gelenkpunkt, Universitätsklinikum Brandenburg an der Havel, St. Vinzenz Kliniken Pfronten im Allgäu, Schulthess-Klinik, University of Freiburg, UMIT TIROL - Private University for Health Sciences and Health Technology, University of Pretoria, Charité - Universitätsmedizin Berlin, University Medical Center Hamburg-Eppendorf, Mass General Brigham, Kantonsspital Baselland, Kantonsspital Baselland Standort Bruderholz, UPMC Health System, University of Pittsburgh Medical Center, Universität für Weiterbildung Krems, Medizinische Hochschule Brandenburg Theodor Fontane, Essen University Hospital, BG Klinikum Duisburg, Stiftung Universitätsmedizin Essen, Fortius Clinic
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,000
Funder: Ministero della Salute
OpenAlex ID: W7143704020