Biomechanical Study And Clinic Research Of Double Reconstruction Plates Osteosynthesis For The Fracture In The Distal Part Of Humerus

Background:It is difficult to treat the fractures in the distal part of humerus with DCP and intramedullary nail as the special anatomy of the distal part of humerus. Seeking a new effective economical osteosynthesis.Objectives:To examine the biomechanical behavior of 2 configurationsof double reconstruction plate osteosynthesis for fractures of the adult distal humerus and review the clinical matetials of distal humerus fractures treated with double reconstruction plate. To deepen the knowledge of double reconstruction plate osteosynthesis for fractures of the adult distal humerus.Methods:Two matched groups with 6 fresh-frozen humeri each. A fracture model with a supracondylar osteotomy gap simulating metaphyseal comm- inution (AO type13-A3.3) was used.Two standard configurations of double reconstruction plate osteosynthesis were studied for biomechanical pro- perties of the constructs :the ulnar plate on the dorsal ulnar column and the radial plate on the lateral radial column in experimental group, the ulnar plate on the medial ulnar column and the radial plate on the dosal radial column in control group. Making the stiffness testing of the con-structsin anterior/posterior bending, inversion, torsion, and axial compression loading. 14 case of using double reconstruction plate were reviewed according to complication ,bone healing, shoulder and elbow function, followed up from 6 months to 21 months.Results: In the biomechanical test ,The displacement of anterior and posterior bending, inversion ,torsion, and axial compression loading is linear regression both in the experimental group and the control group. Study demonstrates that primary stiffness in anterior/posterior bending is decreased in the experimental group (P< 0.05) as compared control group, primary stiffness in torsion and axial compression loading is similar in the experimental group and the control group(P> 0.05). The differences between the different plate configuration are insignificant. In the cli- nical research 14 cases were followed up from 6 months to 21 months The complications of infection, neurologic deficit, nonunion and implant failure are not found. Clinical unions of all the cases are in the 3 months and the fracture lines are vague and disappeared. 12 cases had excellent elbow and should functions,2 cases had good function.Conclution:Under clinical and biomechanical evaluations, double reconstruction plate osteosynthesis has become the most feasible method of osteosynthesis.The stiffness of the double reconstruction plates configurations about the ulnar plate on the dorsal ulnar column and the radial plate on the lateral radial column is similar with the other configurations except in the anterior and posterior bending position.