Metacarpal fracture fixation with absorbable polyglycolide rods and stainless steel K wires: a biomechanical comparison.

Self-reinforced polyglycolide (SR-PGA) rods have been used widely for fracture fixation as an alternative to metallic implants. However, because of its insufficient strength and strength retention, the use of SR-PGA has been restricted to fractures or osteotomies of low stress bearing cancellous bone. To investigate its usefulness in fixing the fractures of cortical bone, the mechanical strength of a human metacarpal fracture fixed with SR-PGA rods was evaluated. The surgical constructs were immersed in buffered saline solution and maintained at body temperature (37 degrees C). The mean initial bending stiffness of the specimens fixed with the SR-PGA rods was 61% of that of the specimens fixed with Kirschner wires. The bending stiffness of the specimens fixed with the SR-PGA rods decreased gradually, and most of the specimens lost their mechanical stability when immersed for 4 weeks. When SR-PGA rods are used to fix the fracture of human cortical bone, such as diaphyseal fracture of the metacarpal bone, it should be protected by additional means.