Internal fixation of oblique metacarpal fractures: a biomechanical evaluation by impact loading

Sports related injuries often involve impact as a primary mode of loading. To compare the impact failure strength of five types of internal fixation of metacarpal fracture, one hundred twenty preserved human metacarpals were dynamically tested in compression and bending after oblique osteotomies of the metacarpal and internal fixation. The failure occurred within 2 to 6 msec in the compressive impact and was almost immediate in the bending impact. The dorsal plate and the intramedullary rods fixations were the strongest. The K-wire tension band was significantly weaker than the plate fixation. The 2-screws was the weakest fixation in this group. This fixation with high risk of failure against impact loads may be avoided in the patient population who may be subjected to such loadings specially those athletes with direct hand involvement.