Hydroxyapatite stem cell repair of radial fracture gap in rabbits

摘要

Nanosized hydroxyapatite is used to replace bone gaps due to its similarity with the mineral constituents of bone. The effect of hydroxyapatite with or without stem cells implants on repair of radial bone gap fracture in groups of 5 New Zealand whiterabbits is described. Under anaesthesia, a 2cm section of right forelimb radial bone was removed by osteoma. Bone gaps were filled with a 1ml solution of ~2M adipose tissue derived stem cells, or a cylinder shaped hydroxyapatite pellet, or a 1ml solution of ~2M adipose tissue derived stem cells injected around the hydroxyapatite pellet implant. Controls were operated, but not treated or normal. Limbs were evaluated radiographically every 21 days for 3 months. At 3 months, rabbits were euthanized and bones subjected to biomechanical tests. Bone formation Lane and Sandhu radiological scores at 21 days were 1.4 ± 0.4 for stem cell 2.5 ± 1.00 pellet, 2.00 ± 0.1 pellet with stem cell implants and 2.00 ± 0.2 for controls. By day 42, scores were 2.2 ±0.84, 3.5 ± 0.75, 4.00 ± 0.3 and 4.00 ± 0.25 for the same measurements, respectively. By day 63 there were no significant differences in scores between stem cell, pellet or normal bone, but with controls there was (P < 0.005). Results suggest that stem cells may accelerate bone healing alone or with hydroxyapatite.