Survival of percutaneous implants under various mechanical loading to the bone

Objective The purpose of the study was to explore bone formation processes and survival of percutaneous implants under various external compression of the bone. Material and methods 30 chinchilla male rabbits were used in the study. Tibia of the species was amputated at the upper third and an implant was surgically implanted with the distal part extending through the skin. A compression device was attached to the implant and loading provided to the bone next day after surgery. Five magnitudes of compression loading were used for animals subdivided into 5 groups comprising 6 species in each of the groups. Compression device with constantly maintained loading was attached to the limb during 6 weeks. Results Animals of groups I and II showed no case of the implant falling out throughout the whole period of observation. An implant fell out of the bone in one species of Group III after 56-day implantation, two and four species of Groups IV and V, correspondingly, 3 to 4 days after removal of compression device. Osseointegration was shown to improve in species of Groups I and II due to active angiogenesis in peri-implantation area. Conclusion Therefore loads of greater than 105260 Н/m2 applied to the bone result in decreased implant osseointegration whereas less intensive loading tends to improve osseointegration.