Biomechanical Evaluation of the Effect of Intramedullary Fibular Graft in Proximal Humeral Fractures

Abstract

Aim: The aim of this study is to investigate the biomechanical effect of intramedullary fibular grafts in two-part proximal humeral fracture models. We also investigated two different positions of an intramedullary fibular graft in terms of fracture stability. Material and Method: A total of 21 two-part humeral neck fracture models were randomly separated into 3 groups. All fracture models were fixed with anatomic locking plates and 3.5mm locking screws. An intramedullary fibular graft was placed parallel to the long axis of the humerus in group I and at an approximately 135 degree angle, so as to support the calcar and medial column of the humeral neck, in group II. No fibular graft was used in the control group. All models were tested with a uniaxial electromechanic device at 20 degrees abduction that mimics the primary axial loads and shear forces with early active abduction. Values of loading and stiffness were measured. Results: No statistically significant difference was found for loading and stiffness values between groups. Discussion: These results were interpreted to mean that the presence or positioning of a fibular graft makes no additional contribution to the stability of twopart proximal humeral neck fractures with an anatomically reduced medial column fixed by a locking plate and screws. In conclusion, it is not necessary to utilize an intramedullary fibular graft in proximal humerus fractures when anatomic reduction is obtained. An unaccompanied locking plate and screws are adequate for these cases. Although using a fibular graft in proximal humerus fractures is a popular technique, it should be reserved for unstable osteoporotic fractures in which the medial column cannot be reduced.