Biomechanical Evaluation of Primary Stability in Revision Latarjet Surgery Using Malleolar Screws Following Failure of All-Suture Cerclage Fixation.

Abstract

Metal-free fixation methods, such as the all-suture cerclage technique, for the Latarjet procedure aim to minimize implant-related complications. Clinical studies suggest equivalent clinical results while reducing implant related complications. However, recent studies have shown increased rates of graft migration and failure due to cortical cut-through. Revision strategies following such failures remain poorly described. The aim of this study is to evaluate the primary stability of revision Latarjet surgery using two conventional malleolar screws after failure of all-suture cerclage fixation compared to primary screw fixation. It is hypothesized that fixation of the coracoid graft using two malleolar screws in revision cases is equal or higher than primary screw fixation. Twelve fresh-frozen cadaveric shoulder specimens (six matched pairs) were previously tested in a study comparing suture cerclage and malleolar screw fixation. Following failure due to cortical bone cut-through, revision surgery was performed on the cerclage specimens using two malleolar screws. Bone graft displacement under cyclic loading in six load levels (up to 300 N) and static conjoint tendon tension (10 N) was measured using a three dimensional optical marker system. Outcomes were compared to those from primary screw fixations. No statistically significant differences in graft displacement under cyclic loading between the revision and primary groups at any load level (p > 0.05) could be found. The revision group showed slightly higher displacement at low load levels but demonstrated superior stability at higher loads compared to primary screw fixation. One intraoperative graft fracture was observed during revision but did not affect the primary stability of the tested specimen. Revision Latarjet surgery using malleolar screw fixation after failed all-suture cerclage provides non-inferior biomechanical primary stability compared to primary screw fixation. This technique appears to be a viable salvage option for addressing instability following failure of metal-free Latarjet constructs. Clinical studies need to be conducted in order to confirm the results of this biomechanical study.