Stabilization of osteochondral fractures: an experimental study comparing polyglycollic acid degradable pin with...

Conventional metal implants may be unsuitable for the stabilization of osteochondral fractures as they may interfere with joint function and eventually require implant removal. We therefore compared the use of biodegradable implants with conventional metal ones in an animal experimental study conducted in skeletally mature rabbits. Biodegradable polyglycollic acids pins (PGA) 1.5 mm in diameter were used to stabilize an osteochondral fragment surgically created in the distal femur of rabbits. In another group of 36 animals, conventional metal K-wire of the same diameter was used for stabilization. The animals were killed at intervals of 3 to 24 weeks. Satisfactory union of the fragments was noted in 92% of the PGA implants as compared with 50% with the metal implants group. No implant migration was seen in the PGA group, while migration was noted in all animals with the metal implants. Histological studies showed that in 80% of the cases fixed with PGA implants, the fragment was viable. In the metal group 33% of the fragments underwent fragmentation and necrosis.