Mechanical failures of osteosynthesis in Cotonou

Abstract

Introduction: Mechanical failures of osteosynthesis encompass permanent deformations, breakage of the osteosynthesis implant, and/or loosening of the fixation. The aim of this study was to analyze cases of mechanical failure of osteosynthesis in our practice to identify the causes and thus prevent them. Material and Method: This retrospective study included all patients treated surgically for a fracture between January 2007 and December 2014, who experienced a mechanical failure of their osteosynthesis. Patients had to have complete clinical and radiological records. Septic complications, arthroplasties, external fixators, isolated screw/pins fixation were excluded. Results: 28 cases of mechanical failure of osteosynthesis were identified, representing an annual incidence of 3.5. The average age was 46.18 years (25-73 years). There was a male predominance with a sex ratio of 2.11. Failures occurred in the osteosynthesis of 4 simple fractures (14.3%) and 24 complex or comminuted fractures (85.7%). They primarily affected the lower limb (17 cases, 60.71%), and most commonly the femur (15 cases, 53.57%), followed by the humerus (5 cases, 17.86%). There were 13 plate breakage, 3 plate bending, 6 plate removal, 4 nail breakage, and 2 isolated screw loosening. Plate breakage primarily occurred in younger patients (under 40years), and plate removal due to screw loosening occurred in older patients (over 55years). The identified causes included nonunion (17cases), technical error (5cases), and premature weight-bearing (6cases). Bone healing was achieved in 5 cases after simple immobilization, and in 4 cases after additional immobilization and restricted weight-bearing. Re-operation was performed in 19 cases. Conclusion: The causes of mechanical failure of osteosynthesis are multifactorial, involving the patient, the fracture, the quality of the implant, and the quality of the osteosynthesis procedure itself, which is directly attributable to the surgeon. Taking these factors into account would help reduce this complication.