An injectable porous poly(propylene glycol-co-fumaric acid) bone repair material as an adjunct for intramedullary fixation

A bioresorbable bone repair material made from the unsaturated polyester poly(propylene glycol-co-fumaric acid), PPF, was investigated for its potential to act as an adjunct to alleviate the disadvantages associated with wire fixation. The PPF bone repair material is an injectable system that can be delivered to the intramedullary site and crosslinked in the presence of a hydroxylapatite filler and effervescent agents. To test the feasibility of using a bioabsorbable material as an adjunct in fracture fixation, femoral osteotomies were created in two groups of 10 Sprague-Dawley rats. Osteotomies were fixed with a threaded Kirschner wire or stabilized with a Kirshner wire augmented with the PPF bone repair material. The quantity of new bone across the osteotomy site was assessed at 4 weeks postoperatively. Histologic analysis of the healing process revealed enhanced osteoconduction across the osteotomy with the PPF bone repair material. These findings were corroborated by histomorphometric analysis of new bone formation. These findings imply suitability of the PPF bone repair material to act as an adjunct to wire fixation, such as techniques used in hand surgery.