Understanding the causes behind coracoid graft osteolysıs in latarjet procedure (finite element analysis and comparison of three fixation methods).
BACKGROUND
Latarjet is one of the most common surgical procedure performed on patients with shoulder instability with osseous defects, some complications include coracoid bone graft osteolysis, osteoarthritis, graft detachment, and malpositioning were previously reported. Several studies investigated potential causes of graft osteolysis but still, it remains a crucial area of investigation. We aim to use finite element analysis to examine the potential correlations between three modes of fixation methods used in the Latarjet procedure (screw, wedge plate, and endobutton), and the coracoid graft osteolysis.


HYPOTHESIS
Finite element analysis tested the hypothesis that there is a linear relationship between the compression stress on graft which was generated by fixation methods used in the latarjet and the coracoid graft osteolysis.


MATERIAL AND METHODS
Boundary conditions and inhomogeneous material properties were carefully assigned within the material of the scapula and coracoid interface. For the screw and wedge plate fixations, an applied torque in the range of 1-1.5Nm was used to characterize the surgeon's insertion torque during the surgical operation, while a 100N compressive force was selected for the endobutton fixation.


RESULTS
Relatively lesser stress magnitudes were observed with endobutton fixation method rather than screw and the wedge plate fixation. Statistical analyses revealed significant differences between the groups (p<0.05).


DISCUSSION
Excessive compressive stresses within the coracoid graft regions may be responsible for osteolysis due to negative effects over biological factors such as blood flow. Our study emphasizes the importance of taking into account the fixation method while performing the Latarjet procedure. We concluded that the mode of fixation used within the Latarjet procedure has a correlation on the coracoid graft osteolysis.


LEVEL OF EVIDENCE
I.
['Alp|Nazmi Bülent|NB|', 'Doğan|Oğuz|O|', 'Yılmaz|Tufan Gürkan|TG|', 'Kalay|Onur Can|OC|', 'Moussa|Abdellah Ait|AA|', 'Karpat|Fatih|F|', 'Khandaker|Morshed|M|', 'Akdag|Gokhan|G|']
D016025:Bone Transplantation D000070597:Coracoid Process D020342:Finite Element Analysis D006801:Humans D007593:Joint Instability D010014:Osteolysis D012540:Scapula D012785:Shoulder Joint
Latarjet Finite element analysis Osteolysis Wedge plate Endobutton