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

Abstract

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.

Keywords: Coracoid bone-block; Fixation system; Glenohumeral instability; Glenohumeral stabilization; Graft healing; Latarjet procedure.