Metal-Free Cerclage Method of Arthroscopic Latarjet Using a Printed Poly Lactic Acid Coracoid Protector to Prevent Coracoid Stress Riser While Tensioning.

Abstract

Although the arthroscopic Latarjet procedure has evolved as the most reliable bony sling procedure for shoulder instability with bone loss, the soft cancellous nature of the coracoid makes the FiberTape option for metal-free fixation difficult because of cheese wiring and cutting into the coracoid when the tape is tensioned. Hence, long titanium screws or titanium buttons are used to fix the coracoid in all existing methods for the Latarjet procedure. Rigid and metal-based methods can cause abrasion of the bony moving surfaces coated with cartilage and can cause wear to contact areas, especially when osteolysis occurs during remodeling of the coracoid bone. We describe an absorbable poly lactic acid 3-dimensional printed coracoid protector (which we call the SJ Buckler) to protect the coracoid process resting on its anterior surface and prevent cut through, with laboratory-verified strength to withstand greater than 120 N. This allows us to perform metal-free fixation of the coracoid in the Latarjet procedure, which can be performed arthroscopically or open, where the coracoid tensioning can be done without fear of cut-through. The poly lactic acid material is absorbable and will integrate to bone or disintegrate after the purpose of bony union to glenoid has been achieved.