The effect of haemorrhagic shock and resuscitation on fracture healing in a rabbit model.

Aims Little is known about the effect of haemorrhagic shock and resuscitation on fracture healing. This study used a rabbit model with a femoral osteotomy and fixation to examine this relationship. Materials and Methods A total of 18 male New Zealand white rabbits underwent femoral osteotomy with intramedullary fixation with 'shock' (n = 9) and control (n = 9) groups. Shock was induced in the study group by removal of 35% of the total blood volume 45 minutes before resuscitation with blood and crystalloid. Fracture healing was monitored for eight weeks using serum markers of healing and radiographs. Results Four animals were excluded due to postoperative complications. The serum concentration of osteocalcin was significantly elevated in the shock group postoperatively (p < 0.0001). There were otherwise no differences with regard to serum markers of bone healing. The callus index was consistently increased in the shock group on anteroposterior (p = 0.0069) and lateral (p = 0.0165) radiographs from three weeks postoperatively. The control group showed an earlier decrease of callus index. Radiographic scores were significantly greater in the control group (p = 0.0025). Conclusion In a rabbit femoral osteotomy model with intramedullary fixation, haemorrhagic shock and resuscitation produced larger callus but with evidence of delayed remodelling.