Comparative biomechanical study of five systems for fixation of the coracoid transfer during the Latarjet procedure for treatment of anterior recurrent shoulder instability

• Massin Valentin
• Lami Damien
• Ollivier Matthieu
• Pithioux Martine
• Argenson Jean-Noël

• Latarjet procedure
• Coracoid bone-block
• Glenohumeral instability
• Glenohumeral stabilization
• Fixation system
• Graft healing

Purpose: This work compares the biomechanical resistance of five modes of fixation coracoid bone-block fixation during Latarjet open-air or arthroscopic procedures. The hypothesis is that these systems are equivalent. Methods: Latarjet procedures were performed on cadavers, then the samples were subjected to an increasing tension until the fixation failed. Five systems were tested: two malleolar screws, one screw with washer, two 3.5-mm self-compressive screws, one 4-mm self-compressive screw associated with one 3-mm self-compressive screw, and endobutton. The main judgment criterion was the strength necessary for the failure of the fixation. The secondary criterion was the stiffness of the assembly. Results: The single malleolar screw fixing has a lower breaking threshold than other fixings. There is no difference in strength concerning the other systems. The average strength is greater than the stresses of a shoulder during daily life activities. There is no difference regarding the secondary criterion. Conclusion: The use of a single screw is insufficient, but the other systems seems reliable. The use of small diameter self-compressive cannulated screws can provide a better result. This biomechanical work must be validated in clinical studies.