RESUMO
PURPOSE: There are two widely used distal humerus fracture (DHF) fixation methods with either orthogonal or parallel double-plate osteosynthesis. However, biomechanical studies have shown inconsistent results on which technique is more effective. We performed a meta-analysis to compare these two fixation methods for adult DHF fixation. METHODS: We searched the literature for entries discussing the biomechanical testing of orthogonal and parallel fixation techniques for DHFs. We then performed a meta-analysis of the following biomechanical outcome measures: axial/sagittal/coronal/torsional stiffness, load to failure, and torque to failure. RESULTS: Seventeen studies comparing both constructs were included. The parallel configuration exhibited greater mechanical strength with respect to axial stiffness/load to failure, torsional stiffness, and posterior bending load to failure than the orthogonal constructs. Subgroup analysis revealed that parallel constructs also had higher torsional stiffness in supracondylar fractures. CONCLUSIONS: This meta-analysis shows that parallel constructs provide greater axial stiffness, axial strength, and torsional stiffness than orthogonal plate for DHF fixation. A subgroup analysis revealed that parallel constructs had better torsional stiffness in supracondylar fracture fixation. LEVEL OF EVIDENCE: IA.
