A parametric analysis of bone fixation plates on fractured equine third metacarpal

A series of tests of the relative strengths of conventional bone fixation plate designs as compared to the strength of unfractured equine third metacarpal bones of the same age was performed. The tests involved a full factorial experimental design on three variables: plate length, lateral hole pitch, and fastener size. All tests were conducted in flexure, a concentrated load being applied on the posterior surface of the bone at mid-span, with the fixation plate in each case attached to the anterior bone surface. The most significant parameter was found to be plate length since an increase in length from 3 to 6 in, approximately doubled the capacity of the reconstructed bone specimen. Fastener size and lateral hole pitch produced no significant change in overall capacity for the structure. It was concluded that, in general, the use of a single fixation plate for fracture fixation of equine third metacarpal would not provide adequate support for weight bearing during osteogenesis.