Original Research
Modes of Failure of Knotted and Knotless Suture Anchors in an Arthroscopic Bankart Repair Model With the Capsulolabral Tissues Intact
Am J Orthop. 2011 March;40(3):134-138
Author and Disclosure Information
Anil S. Ranawat, MD, S. Raymond Golish, MD, PhD, Mark D. Miller, MD, Paul E. Caldwell III, MD, Naveen Singanamala, MBBS, MS, Gehron Treme, MD, Ryan Costic, MS, Joseph M. Hart, PhD, ATC, and Jon K. Sekiya, MD
Dr. Ranawat is Assistant Attending, Hospital for Special Surgery, New York, New York, and Instructor, Weill Cornell Medical College, New York, New York.
Dr. Golish is Clinical Instructor, Department of Orthopaedic Surgery, Stanford University, Palo Alto, California.
Dr. Miller is Ward S. Casscells Professor and Head of the Division of Sports Medicine, Department of Orthopaedic Surgery, University of Virginia, Charlottesville, Virginia.
Dr. Caldwell is Orthopaedic Surgeon, and Dr. Singanamala is Research Fellow, Orthopaedic Research of Virginia, Richmond, Virginia.
Dr. Treme is Assistant Professor of Orthopaedic Surgery, University of New Mexico, Albuquerque, New Mexico.
Mr. Costic is Biomechanical Engineer, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.
Dr. Hart is Assistant Professor, Department of Orthopaedic Surgery, University of Virginia, Charlottesville, Virginia.
Dr. Sekiya is Associate Professor, MedSport-Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan.
The purpose of this study was to assess failure modes of knotless and knotted anchors in a Bankart repair model with the capsulolabral soft tissues intact. Previous reports used a model stripped of soft tissues.
In 8 matched pairs of cadaver shoulders, a Bankart lesion was repaired arthroscopically using either 2 Bio-SutureTak anchors (Arthrex, Naples, Florida) or 2 Bioknotless anchors (Mitek, Westwood, Massachusetts).
The shoulders were mounted with the repaired capsulolabral tissues attached to a custom sinusoidal clamp, and were tested in cyclic loading (20-80 N, 100 cycles, 0.5 mm/s) and then load to failure (1.25 mm/s).
Cut-through at the suture–tissue interface (23/32 anchors) was more common than pullout at the anchor– bone interface (9/32) as a mode of failure (P = .02). Failure at the suture–tissue interface occurred in 10/16 knotted and 13/16 knotless anchors. Mean (SD) ultimate load of knotted vs knotless anchors was 125.3 (67.4) N and 96.9 (95.1) N, respectively. Mean (SD) stiffness of knotted vs knotless anchors was 20.9 (6.4) N/mm and 19.8 (8.6)N/mm, respectively.
We concluded that both knotted and knotless anchors fail most often at the suture–tissue interface. The tested model with the capsulolabral tissues intact is distinct from previous models, which tested the anchor–bone interface only.