Suitability of biodegradable polydioxanone materials for the internal fixation of fractures.

A distal femoral osteotomy in 46 rabbits was fixed either with biodegradable polydioxanone (PDS) thread and pins (group A, 31 animals) or with metallic Kirschner wire and pins (group B, 15 animals). Postoperatively, the distal part of each femur was removed and evaluated, and bone sections were evaluated by histology and histomorphometry. Macroscopic studies showed complete PDS absorption in all cases 24 weeks postoperatively. The histologic studies revealed new bone surrounding the area of the implant 3 weeks postoperatively, and at 24 weeks postoperatively, there was thinning or disappearance of the new bone around the implant. On the basis of the present study, PDS thread and pins show promise for the fixation of osteotomies or fractures of cancellous metaphyses of small long bones, such as metacarpals and phalanges.